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Added support for .bmp images

This commit is contained in:
Seednode 2022-10-29 10:32:01 -05:00
parent 297c561fab
commit f6924ba7b5
15 changed files with 4111 additions and 2 deletions
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3
cmd/files.go
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@ -23,6 +23,7 @@ import (
"sync/atomic"
"time"
_ "golang.org/x/image/bmp"
_ "golang.org/x/image/webp"
"github.com/h2non/filetype"
@ -30,7 +31,7 @@ import (
var (
ErrNoImagesFound = fmt.Errorf("no supported image formats found")
extensions = [5]string{".jpg", ".jpeg", ".png", ".gif", ".webp"}
extensions = [7]string{".jpg", ".jpeg", ".png", ".gif", ".webp", ".bmp"}
)
type Files struct {

2
cmd/version.go
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@ -10,7 +10,7 @@ import (
"github.com/spf13/cobra"
)
var Version = "0.20.7"
var Version = "0.20.8"
func init() {
rootCmd.AddCommand(versionCmd)

245
vendor/golang.org/x/image/bmp/reader.go generated vendored Normal file
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@ -0,0 +1,245 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package bmp implements a BMP image decoder and encoder.
//
// The BMP specification is at http://www.digicamsoft.com/bmp/bmp.html.
package bmp // import "golang.org/x/image/bmp"
import (
"errors"
"image"
"image/color"
"io"
)
// ErrUnsupported means that the input BMP image uses a valid but unsupported
// feature.
var ErrUnsupported = errors.New("bmp: unsupported BMP image")
func readUint16(b []byte) uint16 {
return uint16(b[0]) | uint16(b[1])<<8
}
func readUint32(b []byte) uint32 {
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
// decodePaletted reads an 8 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodePaletted(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
paletted := image.NewPaletted(image.Rect(0, 0, c.Width, c.Height), c.ColorModel.(color.Palette))
if c.Width == 0 || c.Height == 0 {
return paletted, nil
}
var tmp [4]byte
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
p := paletted.Pix[y*paletted.Stride : y*paletted.Stride+c.Width]
if _, err := io.ReadFull(r, p); err != nil {
return nil, err
}
// Each row is 4-byte aligned.
if c.Width%4 != 0 {
_, err := io.ReadFull(r, tmp[:4-c.Width%4])
if err != nil {
return nil, err
}
}
}
return paletted, nil
}
// decodeRGB reads a 24 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodeRGB(r io.Reader, c image.Config, topDown bool) (image.Image, error) {
rgba := image.NewRGBA(image.Rect(0, 0, c.Width, c.Height))
if c.Width == 0 || c.Height == 0 {
return rgba, nil
}
// There are 3 bytes per pixel, and each row is 4-byte aligned.
b := make([]byte, (3*c.Width+3)&^3)
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
if _, err := io.ReadFull(r, b); err != nil {
return nil, err
}
p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
for i, j := 0, 0; i < len(p); i, j = i+4, j+3 {
// BMP images are stored in BGR order rather than RGB order.
p[i+0] = b[j+2]
p[i+1] = b[j+1]
p[i+2] = b[j+0]
p[i+3] = 0xFF
}
}
return rgba, nil
}
// decodeNRGBA reads a 32 bit-per-pixel BMP image from r.
// If topDown is false, the image rows will be read bottom-up.
func decodeNRGBA(r io.Reader, c image.Config, topDown, allowAlpha bool) (image.Image, error) {
rgba := image.NewNRGBA(image.Rect(0, 0, c.Width, c.Height))
if c.Width == 0 || c.Height == 0 {
return rgba, nil
}
y0, y1, yDelta := c.Height-1, -1, -1
if topDown {
y0, y1, yDelta = 0, c.Height, +1
}
for y := y0; y != y1; y += yDelta {
p := rgba.Pix[y*rgba.Stride : y*rgba.Stride+c.Width*4]
if _, err := io.ReadFull(r, p); err != nil {
return nil, err
}
for i := 0; i < len(p); i += 4 {
// BMP images are stored in BGRA order rather than RGBA order.
p[i+0], p[i+2] = p[i+2], p[i+0]
if !allowAlpha {
p[i+3] = 0xFF
}
}
}
return rgba, nil
}
// Decode reads a BMP image from r and returns it as an image.Image.
// Limitation: The file must be 8, 24 or 32 bits per pixel.
func Decode(r io.Reader) (image.Image, error) {
c, bpp, topDown, allowAlpha, err := decodeConfig(r)
if err != nil {
return nil, err
}
switch bpp {
case 8:
return decodePaletted(r, c, topDown)
case 24:
return decodeRGB(r, c, topDown)
case 32:
return decodeNRGBA(r, c, topDown, allowAlpha)
}
panic("unreachable")
}
// DecodeConfig returns the color model and dimensions of a BMP image without
// decoding the entire image.
// Limitation: The file must be 8, 24 or 32 bits per pixel.
func DecodeConfig(r io.Reader) (image.Config, error) {
config, _, _, _, err := decodeConfig(r)
return config, err
}
func decodeConfig(r io.Reader) (config image.Config, bitsPerPixel int, topDown bool, allowAlpha bool, err error) {
// We only support those BMP images with one of the following DIB headers:
// - BITMAPINFOHEADER (40 bytes)
// - BITMAPV4HEADER (108 bytes)
// - BITMAPV5HEADER (124 bytes)
const (
fileHeaderLen = 14
infoHeaderLen = 40
v4InfoHeaderLen = 108
v5InfoHeaderLen = 124
)
var b [1024]byte
if _, err := io.ReadFull(r, b[:fileHeaderLen+4]); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return image.Config{}, 0, false, false, err
}
if string(b[:2]) != "BM" {
return image.Config{}, 0, false, false, errors.New("bmp: invalid format")
}
offset := readUint32(b[10:14])
infoLen := readUint32(b[14:18])
if infoLen != infoHeaderLen && infoLen != v4InfoHeaderLen && infoLen != v5InfoHeaderLen {
return image.Config{}, 0, false, false, ErrUnsupported
}
if _, err := io.ReadFull(r, b[fileHeaderLen+4:fileHeaderLen+infoLen]); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return image.Config{}, 0, false, false, err
}
width := int(int32(readUint32(b[18:22])))
height := int(int32(readUint32(b[22:26])))
if height < 0 {
height, topDown = -height, true
}
if width < 0 || height < 0 {
return image.Config{}, 0, false, false, ErrUnsupported
}
// We only support 1 plane and 8, 24 or 32 bits per pixel and no
// compression.
planes, bpp, compression := readUint16(b[26:28]), readUint16(b[28:30]), readUint32(b[30:34])
// if compression is set to BI_BITFIELDS, but the bitmask is set to the default bitmask
// that would be used if compression was set to 0, we can continue as if compression was 0
if compression == 3 && infoLen > infoHeaderLen &&
readUint32(b[54:58]) == 0xff0000 && readUint32(b[58:62]) == 0xff00 &&
readUint32(b[62:66]) == 0xff && readUint32(b[66:70]) == 0xff000000 {
compression = 0
}
if planes != 1 || compression != 0 {
return image.Config{}, 0, false, false, ErrUnsupported
}
switch bpp {
case 8:
if offset != fileHeaderLen+infoLen+256*4 {
return image.Config{}, 0, false, false, ErrUnsupported
}
_, err = io.ReadFull(r, b[:256*4])
if err != nil {
return image.Config{}, 0, false, false, err
}
pcm := make(color.Palette, 256)
for i := range pcm {
// BMP images are stored in BGR order rather than RGB order.
// Every 4th byte is padding.
pcm[i] = color.RGBA{b[4*i+2], b[4*i+1], b[4*i+0], 0xFF}
}
return image.Config{ColorModel: pcm, Width: width, Height: height}, 8, topDown, false, nil
case 24:
if offset != fileHeaderLen+infoLen {
return image.Config{}, 0, false, false, ErrUnsupported
}
return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 24, topDown, false, nil
case 32:
if offset != fileHeaderLen+infoLen {
return image.Config{}, 0, false, false, ErrUnsupported
}
// 32 bits per pixel is possibly RGBX (X is padding) or RGBA (A is
// alpha transparency). However, for BMP images, "Alpha is a
// poorly-documented and inconsistently-used feature" says
// https://source.chromium.org/chromium/chromium/src/+/bc0a792d7ebc587190d1a62ccddba10abeea274b:third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_reader.cc;l=621
//
// That goes on to say "BITMAPV3HEADER+ have an alpha bitmask in the
// info header... so we respect it at all times... [For earlier
// (smaller) headers we] ignore alpha in Windows V3 BMPs except inside
// ICO files".
//
// "Ignore" means to always set alpha to 0xFF (fully opaque):
// https://source.chromium.org/chromium/chromium/src/+/bc0a792d7ebc587190d1a62ccddba10abeea274b:third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_reader.h;l=272
//
// Confusingly, "Windows V3" does not correspond to BITMAPV3HEADER, but
// instead corresponds to the earlier (smaller) BITMAPINFOHEADER:
// https://source.chromium.org/chromium/chromium/src/+/bc0a792d7ebc587190d1a62ccddba10abeea274b:third_party/blink/renderer/platform/image-decoders/bmp/bmp_image_reader.cc;l=258
//
// This Go package does not support ICO files and the (infoLen >
// infoHeaderLen) condition distinguishes BITMAPINFOHEADER (40 bytes)
// vs later (larger) headers.
allowAlpha = infoLen > infoHeaderLen
return image.Config{ColorModel: color.RGBAModel, Width: width, Height: height}, 32, topDown, allowAlpha, nil
}
return image.Config{}, 0, false, false, ErrUnsupported
}
func init() {
image.RegisterFormat("bmp", "BM????\x00\x00\x00\x00", Decode, DecodeConfig)
}

262
vendor/golang.org/x/image/bmp/writer.go generated vendored Normal file
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@ -0,0 +1,262 @@
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bmp
import (
"encoding/binary"
"errors"
"image"
"io"
)
type header struct {
sigBM [2]byte
fileSize uint32
resverved [2]uint16
pixOffset uint32
dibHeaderSize uint32
width uint32
height uint32
colorPlane uint16
bpp uint16
compression uint32
imageSize uint32
xPixelsPerMeter uint32
yPixelsPerMeter uint32
colorUse uint32
colorImportant uint32
}
func encodePaletted(w io.Writer, pix []uint8, dx, dy, stride, step int) error {
var padding []byte
if dx < step {
padding = make([]byte, step-dx)
}
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx
if _, err := w.Write(pix[min:max]); err != nil {
return err
}
if padding != nil {
if _, err := w.Write(padding); err != nil {
return err
}
}
}
return nil
}
func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int, opaque bool) error {
buf := make([]byte, step)
if opaque {
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx*4
off := 0
for i := min; i < max; i += 4 {
buf[off+2] = pix[i+0]
buf[off+1] = pix[i+1]
buf[off+0] = pix[i+2]
off += 3
}
if _, err := w.Write(buf); err != nil {
return err
}
}
} else {
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx*4
off := 0
for i := min; i < max; i += 4 {
a := uint32(pix[i+3])
if a == 0 {
buf[off+2] = 0
buf[off+1] = 0
buf[off+0] = 0
buf[off+3] = 0
off += 4
continue
} else if a == 0xff {
buf[off+2] = pix[i+0]
buf[off+1] = pix[i+1]
buf[off+0] = pix[i+2]
buf[off+3] = 0xff
off += 4
continue
}
buf[off+2] = uint8(((uint32(pix[i+0]) * 0xffff) / a) >> 8)
buf[off+1] = uint8(((uint32(pix[i+1]) * 0xffff) / a) >> 8)
buf[off+0] = uint8(((uint32(pix[i+2]) * 0xffff) / a) >> 8)
buf[off+3] = uint8(a)
off += 4
}
if _, err := w.Write(buf); err != nil {
return err
}
}
}
return nil
}
func encodeNRGBA(w io.Writer, pix []uint8, dx, dy, stride, step int, opaque bool) error {
buf := make([]byte, step)
if opaque {
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx*4
off := 0
for i := min; i < max; i += 4 {
buf[off+2] = pix[i+0]
buf[off+1] = pix[i+1]
buf[off+0] = pix[i+2]
off += 3
}
if _, err := w.Write(buf); err != nil {
return err
}
}
} else {
for y := dy - 1; y >= 0; y-- {
min := y*stride + 0
max := y*stride + dx*4
off := 0
for i := min; i < max; i += 4 {
buf[off+2] = pix[i+0]
buf[off+1] = pix[i+1]
buf[off+0] = pix[i+2]
buf[off+3] = pix[i+3]
off += 4
}
if _, err := w.Write(buf); err != nil {
return err
}
}
}
return nil
}
func encode(w io.Writer, m image.Image, step int) error {
b := m.Bounds()
buf := make([]byte, step)
for y := b.Max.Y - 1; y >= b.Min.Y; y-- {
off := 0
for x := b.Min.X; x < b.Max.X; x++ {
r, g, b, _ := m.At(x, y).RGBA()
buf[off+2] = byte(r >> 8)
buf[off+1] = byte(g >> 8)
buf[off+0] = byte(b >> 8)
off += 3
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
// Encode writes the image m to w in BMP format.
func Encode(w io.Writer, m image.Image) error {
d := m.Bounds().Size()
if d.X < 0 || d.Y < 0 {
return errors.New("bmp: negative bounds")
}
h := &header{
sigBM: [2]byte{'B', 'M'},
fileSize: 14 + 40,
pixOffset: 14 + 40,
dibHeaderSize: 40,
width: uint32(d.X),
height: uint32(d.Y),
colorPlane: 1,
}
var step int
var palette []byte
var opaque bool
switch m := m.(type) {
case *image.Gray:
step = (d.X + 3) &^ 3
palette = make([]byte, 1024)
for i := 0; i < 256; i++ {
palette[i*4+0] = uint8(i)
palette[i*4+1] = uint8(i)
palette[i*4+2] = uint8(i)
palette[i*4+3] = 0xFF
}
h.imageSize = uint32(d.Y * step)
h.fileSize += uint32(len(palette)) + h.imageSize
h.pixOffset += uint32(len(palette))
h.bpp = 8
case *image.Paletted:
step = (d.X + 3) &^ 3
palette = make([]byte, 1024)
for i := 0; i < len(m.Palette) && i < 256; i++ {
r, g, b, _ := m.Palette[i].RGBA()
palette[i*4+0] = uint8(b >> 8)
palette[i*4+1] = uint8(g >> 8)
palette[i*4+2] = uint8(r >> 8)
palette[i*4+3] = 0xFF
}
h.imageSize = uint32(d.Y * step)
h.fileSize += uint32(len(palette)) + h.imageSize
h.pixOffset += uint32(len(palette))
h.bpp = 8
case *image.RGBA:
opaque = m.Opaque()
if opaque {
step = (3*d.X + 3) &^ 3
h.bpp = 24
} else {
step = 4 * d.X
h.bpp = 32
}
h.imageSize = uint32(d.Y * step)
h.fileSize += h.imageSize
case *image.NRGBA:
opaque = m.Opaque()
if opaque {
step = (3*d.X + 3) &^ 3
h.bpp = 24
} else {
step = 4 * d.X
h.bpp = 32
}
h.imageSize = uint32(d.Y * step)
h.fileSize += h.imageSize
default:
step = (3*d.X + 3) &^ 3
h.imageSize = uint32(d.Y * step)
h.fileSize += h.imageSize
h.bpp = 24
}
if err := binary.Write(w, binary.LittleEndian, h); err != nil {
return err
}
if palette != nil {
if err := binary.Write(w, binary.LittleEndian, palette); err != nil {
return err
}
}
if d.X == 0 || d.Y == 0 {
return nil
}
switch m := m.(type) {
case *image.Gray:
return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
case *image.Paletted:
return encodePaletted(w, m.Pix, d.X, d.Y, m.Stride, step)
case *image.RGBA:
return encodeRGBA(w, m.Pix, d.X, d.Y, m.Stride, step, opaque)
case *image.NRGBA:
return encodeNRGBA(w, m.Pix, d.X, d.Y, m.Stride, step, opaque)
}
return encode(w, m, step)
}

795
vendor/golang.org/x/image/ccitt/reader.go generated vendored Normal file
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@ -0,0 +1,795 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go run gen.go
// Package ccitt implements a CCITT (fax) image decoder.
package ccitt
import (
"encoding/binary"
"errors"
"image"
"io"
"math/bits"
)
var (
errIncompleteCode = errors.New("ccitt: incomplete code")
errInvalidBounds = errors.New("ccitt: invalid bounds")
errInvalidCode = errors.New("ccitt: invalid code")
errInvalidMode = errors.New("ccitt: invalid mode")
errInvalidOffset = errors.New("ccitt: invalid offset")
errMissingEOL = errors.New("ccitt: missing End-of-Line")
errRunLengthOverflowsWidth = errors.New("ccitt: run length overflows width")
errRunLengthTooLong = errors.New("ccitt: run length too long")
errUnsupportedMode = errors.New("ccitt: unsupported mode")
errUnsupportedSubFormat = errors.New("ccitt: unsupported sub-format")
errUnsupportedWidth = errors.New("ccitt: unsupported width")
)
// Order specifies the bit ordering in a CCITT data stream.
type Order uint32
const (
// LSB means Least Significant Bits first.
LSB Order = iota
// MSB means Most Significant Bits first.
MSB
)
// SubFormat represents that the CCITT format consists of a number of
// sub-formats. Decoding or encoding a CCITT data stream requires knowing the
// sub-format context. It is not represented in the data stream per se.
type SubFormat uint32
const (
Group3 SubFormat = iota
Group4
)
// AutoDetectHeight is passed as the height argument to NewReader to indicate
// that the image height (the number of rows) is not known in advance.
const AutoDetectHeight = -1
// Options are optional parameters.
type Options struct {
// Align means that some variable-bit-width codes are byte-aligned.
Align bool
// Invert means that black is the 1 bit or 0xFF byte, and white is 0.
Invert bool
}
// maxWidth is the maximum (inclusive) supported width. This is a limitation of
// this implementation, to guard against integer overflow, and not anything
// inherent to the CCITT format.
const maxWidth = 1 << 20
func invertBytes(b []byte) {
for i, c := range b {
b[i] = ^c
}
}
func reverseBitsWithinBytes(b []byte) {
for i, c := range b {
b[i] = bits.Reverse8(c)
}
}
// highBits writes to dst (1 bit per pixel, most significant bit first) the
// high (0x80) bits from src (1 byte per pixel). It returns the number of bytes
// written and read such that dst[:d] is the packed form of src[:s].
//
// For example, if src starts with the 8 bytes [0x7D, 0x7E, 0x7F, 0x80, 0x81,
// 0x82, 0x00, 0xFF] then 0x1D will be written to dst[0].
//
// If src has (8 * len(dst)) or more bytes then only len(dst) bytes are
// written, (8 * len(dst)) bytes are read, and invert is ignored.
//
// Otherwise, if len(src) is not a multiple of 8 then the final byte written to
// dst is padded with 1 bits (if invert is true) or 0 bits. If inverted, the 1s
// are typically temporary, e.g. they will be flipped back to 0s by an
// invertBytes call in the highBits caller, reader.Read.
func highBits(dst []byte, src []byte, invert bool) (d int, s int) {
// Pack as many complete groups of 8 src bytes as we can.
n := len(src) / 8
if n > len(dst) {
n = len(dst)
}
dstN := dst[:n]
for i := range dstN {
src8 := src[i*8 : i*8+8]
dstN[i] = ((src8[0] & 0x80) >> 0) |
((src8[1] & 0x80) >> 1) |
((src8[2] & 0x80) >> 2) |
((src8[3] & 0x80) >> 3) |
((src8[4] & 0x80) >> 4) |
((src8[5] & 0x80) >> 5) |
((src8[6] & 0x80) >> 6) |
((src8[7] & 0x80) >> 7)
}
d, s = n, 8*n
dst, src = dst[d:], src[s:]
// Pack up to 7 remaining src bytes, if there's room in dst.
if (len(dst) > 0) && (len(src) > 0) {
dstByte := byte(0)
if invert {
dstByte = 0xFF >> uint(len(src))
}
for n, srcByte := range src {
dstByte |= (srcByte & 0x80) >> uint(n)
}
dst[0] = dstByte
d, s = d+1, s+len(src)
}
return d, s
}
type bitReader struct {
r io.Reader
// readErr is the error returned from the most recent r.Read call. As the
// io.Reader documentation says, when r.Read returns (n, err), "always
// process the n > 0 bytes returned before considering the error err".
readErr error
// order is whether to process r's bytes LSB first or MSB first.
order Order
// The high nBits bits of the bits field hold upcoming bits in MSB order.
bits uint64
nBits uint32
// bytes[br:bw] holds bytes read from r but not yet loaded into bits.
br uint32
bw uint32
bytes [1024]uint8
}
func (b *bitReader) alignToByteBoundary() {
n := b.nBits & 7
b.bits <<= n
b.nBits -= n
}
// nextBitMaxNBits is the maximum possible value of bitReader.nBits after a
// bitReader.nextBit call, provided that bitReader.nBits was not more than this
// value before that call.
//
// Note that the decode function can unread bits, which can temporarily set the
// bitReader.nBits value above nextBitMaxNBits.
const nextBitMaxNBits = 31
func (b *bitReader) nextBit() (uint64, error) {
for {
if b.nBits > 0 {
bit := b.bits >> 63
b.bits <<= 1
b.nBits--
return bit, nil
}
if available := b.bw - b.br; available >= 4 {
// Read 32 bits, even though b.bits is a uint64, since the decode
// function may need to unread up to maxCodeLength bits, putting
// them back in the remaining (64 - 32) bits. TestMaxCodeLength
// checks that the generated maxCodeLength constant fits.
//
// If changing the Uint32 call, also change nextBitMaxNBits.
b.bits = uint64(binary.BigEndian.Uint32(b.bytes[b.br:])) << 32
b.br += 4
b.nBits = 32
continue
} else if available > 0 {
b.bits = uint64(b.bytes[b.br]) << (7 * 8)
b.br++
b.nBits = 8
continue
}
if b.readErr != nil {
return 0, b.readErr
}
n, err := b.r.Read(b.bytes[:])
b.br = 0
b.bw = uint32(n)
b.readErr = err
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:b.bw])
}
}
}
func decode(b *bitReader, decodeTable [][2]int16) (uint32, error) {
nBitsRead, bitsRead, state := uint32(0), uint64(0), int32(1)
for {
bit, err := b.nextBit()
if err != nil {
if err == io.EOF {
err = errIncompleteCode
}
return 0, err
}
bitsRead |= bit << (63 - nBitsRead)
nBitsRead++
// The "&1" is redundant, but can eliminate a bounds check.
state = int32(decodeTable[state][bit&1])
if state < 0 {
return uint32(^state), nil
} else if state == 0 {
// Unread the bits we've read, then return errInvalidCode.
b.bits = (b.bits >> nBitsRead) | bitsRead
b.nBits += nBitsRead
return 0, errInvalidCode
}
}
}
// decodeEOL decodes the 12-bit EOL code 0000_0000_0001.
func decodeEOL(b *bitReader) error {
nBitsRead, bitsRead := uint32(0), uint64(0)
for {
bit, err := b.nextBit()
if err != nil {
if err == io.EOF {
err = errMissingEOL
}
return err
}
bitsRead |= bit << (63 - nBitsRead)
nBitsRead++
if nBitsRead < 12 {
if bit&1 == 0 {
continue
}
} else if bit&1 != 0 {
return nil
}
// Unread the bits we've read, then return errMissingEOL.
b.bits = (b.bits >> nBitsRead) | bitsRead
b.nBits += nBitsRead
return errMissingEOL
}
}
type reader struct {
br bitReader
subFormat SubFormat
// width is the image width in pixels.
width int
// rowsRemaining starts at the image height in pixels, when the reader is
// driven through the io.Reader interface, and decrements to zero as rows
// are decoded. Alternatively, it may be negative if the image height is
// not known in advance at the time of the NewReader call.
//
// When driven through DecodeIntoGray, this field is unused.
rowsRemaining int
// curr and prev hold the current and previous rows. Each element is either
// 0x00 (black) or 0xFF (white).
//
// prev may be nil, when processing the first row.
curr []byte
prev []byte
// ri is the read index. curr[:ri] are those bytes of curr that have been
// passed along via the Read method.
//
// When the reader is driven through DecodeIntoGray, instead of through the
// io.Reader interface, this field is unused.
ri int
// wi is the write index. curr[:wi] are those bytes of curr that have
// already been decoded via the decodeRow method.
//
// What this implementation calls wi is roughly equivalent to what the spec
// calls the a0 index.
wi int
// These fields are copied from the *Options (which may be nil).
align bool
invert bool
// atStartOfRow is whether we have just started the row. Some parts of the
// spec say to treat this situation as if "wi = -1".
atStartOfRow bool
// penColorIsWhite is whether the next run is black or white.
penColorIsWhite bool
// seenStartOfImage is whether we've called the startDecode method.
seenStartOfImage bool
// truncated is whether the input is missing the final 6 consecutive EOL's
// (for Group3) or 2 consecutive EOL's (for Group4). Omitting that trailer
// (but otherwise padding to a byte boundary, with either all 0 bits or all
// 1 bits) is invalid according to the spec, but happens in practice when
// exporting from Adobe Acrobat to TIFF + CCITT. This package silently
// ignores the format error for CCITT input that has been truncated in that
// fashion, returning the full decoded image.
//
// Detecting trailer truncation (just after the final row of pixels)
// requires knowing which row is the final row, and therefore does not
// trigger if the image height is not known in advance.
truncated bool
// readErr is a sticky error for the Read method.
readErr error
}
func (z *reader) Read(p []byte) (int, error) {
if z.readErr != nil {
return 0, z.readErr
}
originalP := p
for len(p) > 0 {
// Allocate buffers (and decode any start-of-image codes), if
// processing the first or second row.
if z.curr == nil {
if !z.seenStartOfImage {
if z.readErr = z.startDecode(); z.readErr != nil {
break
}
z.atStartOfRow = true
}
z.curr = make([]byte, z.width)
}
// Decode the next row, if necessary.
if z.atStartOfRow {
if z.rowsRemaining < 0 {
// We do not know the image height in advance. See if the next
// code is an EOL. If it is, it is consumed. If it isn't, the
// bitReader shouldn't advance along the bit stream, and we
// simply decode another row of pixel data.
//
// For the Group4 subFormat, we may need to align to a byte
// boundary. For the Group3 subFormat, the previous z.decodeRow
// call (or z.startDecode call) has already consumed one of the
// 6 consecutive EOL's. The next EOL is actually the second of
// 6, in the middle, and we shouldn't align at that point.
if z.align && (z.subFormat == Group4) {
z.br.alignToByteBoundary()
}
if err := z.decodeEOL(); err == errMissingEOL {
// No-op. It's another row of pixel data.
} else if err != nil {
z.readErr = err
break
} else {
if z.readErr = z.finishDecode(true); z.readErr != nil {
break
}
z.readErr = io.EOF
break
}
} else if z.rowsRemaining == 0 {
// We do know the image height in advance, and we have already
// decoded exactly that many rows.
if z.readErr = z.finishDecode(false); z.readErr != nil {
break
}
z.readErr = io.EOF
break
} else {
z.rowsRemaining--
}
if z.readErr = z.decodeRow(z.rowsRemaining == 0); z.readErr != nil {
break
}
}
// Pack from z.curr (1 byte per pixel) to p (1 bit per pixel).
packD, packS := highBits(p, z.curr[z.ri:], z.invert)
p = p[packD:]
z.ri += packS
// Prepare to decode the next row, if necessary.
if z.ri == len(z.curr) {
z.ri, z.curr, z.prev = 0, z.prev, z.curr
z.atStartOfRow = true
}
}
n := len(originalP) - len(p)
if z.invert {
invertBytes(originalP[:n])
}
return n, z.readErr
}
func (z *reader) penColor() byte {
if z.penColorIsWhite {
return 0xFF
}
return 0x00
}
func (z *reader) startDecode() error {
switch z.subFormat {
case Group3:
if err := z.decodeEOL(); err != nil {
return err
}
case Group4:
// No-op.
default:
return errUnsupportedSubFormat
}
z.seenStartOfImage = true
return nil
}
func (z *reader) finishDecode(alreadySeenEOL bool) error {
numberOfEOLs := 0
switch z.subFormat {
case Group3:
if z.truncated {
return nil
}
// The stream ends with a RTC (Return To Control) of 6 consecutive
// EOL's, but we should have already just seen an EOL, either in
// z.startDecode (for a zero-height image) or in z.decodeRow.
numberOfEOLs = 5
case Group4:
autoDetectHeight := z.rowsRemaining < 0
if autoDetectHeight {
// Aligning to a byte boundary was already handled by reader.Read.
} else if z.align {
z.br.alignToByteBoundary()
}
// The stream ends with two EOL's. If the first one is missing, and we
// had an explicit image height, we just assume that the trailing two
// EOL's were truncated and return a nil error.
if err := z.decodeEOL(); err != nil {
if (err == errMissingEOL) && !autoDetectHeight {
z.truncated = true
return nil
}
return err
}
numberOfEOLs = 1
default:
return errUnsupportedSubFormat
}
if alreadySeenEOL {
numberOfEOLs--
}
for ; numberOfEOLs > 0; numberOfEOLs-- {
if err := z.decodeEOL(); err != nil {
return err
}
}
return nil
}
func (z *reader) decodeEOL() error {
return decodeEOL(&z.br)
}
func (z *reader) decodeRow(finalRow bool) error {
z.wi = 0
z.atStartOfRow = true
z.penColorIsWhite = true
if z.align {
z.br.alignToByteBoundary()
}
switch z.subFormat {
case Group3:
for ; z.wi < len(z.curr); z.atStartOfRow = false {
if err := z.decodeRun(); err != nil {
return err
}
}
err := z.decodeEOL()
if finalRow && (err == errMissingEOL) {
z.truncated = true
return nil
}
return err
case Group4:
for ; z.wi < len(z.curr); z.atStartOfRow = false {
mode, err := decode(&z.br, modeDecodeTable[:])
if err != nil {
return err
}
rm := readerMode{}
if mode < uint32(len(readerModes)) {
rm = readerModes[mode]
}
if rm.function == nil {
return errInvalidMode
}
if err := rm.function(z, rm.arg); err != nil {
return err
}
}
return nil
}
return errUnsupportedSubFormat
}
func (z *reader) decodeRun() error {
table := blackDecodeTable[:]
if z.penColorIsWhite {
table = whiteDecodeTable[:]
}
total := 0
for {
n, err := decode(&z.br, table)
if err != nil {
return err
}
if n > maxWidth {
panic("unreachable")
}
total += int(n)
if total > maxWidth {
return errRunLengthTooLong
}
// Anything 0x3F or below is a terminal code.
if n <= 0x3F {
break
}
}
if total > (len(z.curr) - z.wi) {
return errRunLengthOverflowsWidth
}
dst := z.curr[z.wi : z.wi+total]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi += total
z.penColorIsWhite = !z.penColorIsWhite
return nil
}
// The various modes' semantics are based on determining a row of pixels'
// "changing elements": those pixels whose color differs from the one on its
// immediate left.
//
// The row above the first row is implicitly all white. Similarly, the column
// to the left of the first column is implicitly all white.
//
// For example, here's Figure 1 in "ITU-T Recommendation T.6", where the
// current and previous rows contain black (B) and white (w) pixels. The a?
// indexes point into curr, the b? indexes point into prev.
//
// b1 b2
// v v
// prev: BBBBBwwwwwBBBwwwww
// curr: BBBwwwwwBBBBBBwwww
// ^ ^ ^
// a0 a1 a2
//
// a0 is the "reference element" or current decoder position, roughly
// equivalent to what this implementation calls reader.wi.
//
// a1 is the next changing element to the right of a0, on the "coding line"
// (the current row).
//
// a2 is the next changing element to the right of a1, again on curr.
//
// b1 is the first changing element on the "reference line" (the previous row)
// to the right of a0 and of opposite color to a0.
//
// b2 is the next changing element to the right of b1, again on prev.
//
// The various modes calculate a1 (and a2, for modeH):
// - modePass calculates that a1 is at or to the right of b2.
// - modeH calculates a1 and a2 without considering b1 or b2.
// - modeV* calculates a1 to be b1 plus an adjustment (between -3 and +3).
const (
findB1 = false
findB2 = true
)
// findB finds either the b1 or b2 value.
func (z *reader) findB(whichB bool) int {
// The initial row is a special case. The previous row is implicitly all
// white, so that there are no changing pixel elements. We return b1 or b2
// to be at the end of the row.
if len(z.prev) != len(z.curr) {
return len(z.curr)
}
i := z.wi
if z.atStartOfRow {
// a0 is implicitly at -1, on a white pixel. b1 is the first black
// pixel in the previous row. b2 is the first white pixel after that.
for ; (i < len(z.prev)) && (z.prev[i] == 0xFF); i++ {
}
if whichB == findB2 {
for ; (i < len(z.prev)) && (z.prev[i] == 0x00); i++ {
}
}
return i
}
// As per figure 1 above, assume that the current pen color is white.
// First, walk past every contiguous black pixel in prev, starting at a0.
oppositeColor := ^z.penColor()
for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ {
}
// Then walk past every contiguous white pixel.
penColor := ^oppositeColor
for ; (i < len(z.prev)) && (z.prev[i] == penColor); i++ {
}
// We're now at a black pixel (or at the end of the row). That's b1.
if whichB == findB2 {
// If we're looking for b2, walk past every contiguous black pixel
// again.
oppositeColor := ^penColor
for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ {
}
}
return i
}
type readerMode struct {
function func(z *reader, arg int) error
arg int
}
var readerModes = [...]readerMode{
modePass: {function: readerModePass},
modeH: {function: readerModeH},
modeV0: {function: readerModeV, arg: +0},
modeVR1: {function: readerModeV, arg: +1},
modeVR2: {function: readerModeV, arg: +2},
modeVR3: {function: readerModeV, arg: +3},
modeVL1: {function: readerModeV, arg: -1},
modeVL2: {function: readerModeV, arg: -2},
modeVL3: {function: readerModeV, arg: -3},
modeExt: {function: readerModeExt},
}
func readerModePass(z *reader, arg int) error {
b2 := z.findB(findB2)
if (b2 < z.wi) || (len(z.curr) < b2) {
return errInvalidOffset
}
dst := z.curr[z.wi:b2]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi = b2
return nil
}
func readerModeH(z *reader, arg int) error {
// The first iteration finds a1. The second finds a2.
for i := 0; i < 2; i++ {
if err := z.decodeRun(); err != nil {
return err
}
}
return nil
}
func readerModeV(z *reader, arg int) error {
a1 := z.findB(findB1) + arg
if (a1 < z.wi) || (len(z.curr) < a1) {
return errInvalidOffset
}
dst := z.curr[z.wi:a1]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi = a1
z.penColorIsWhite = !z.penColorIsWhite
return nil
}
func readerModeExt(z *reader, arg int) error {
return errUnsupportedMode
}
// DecodeIntoGray decodes the CCITT-formatted data in r into dst.
//
// It returns an error if dst's width and height don't match the implied width
// and height of CCITT-formatted data.
func DecodeIntoGray(dst *image.Gray, r io.Reader, order Order, sf SubFormat, opts *Options) error {
bounds := dst.Bounds()
if (bounds.Dx() < 0) || (bounds.Dy() < 0) {
return errInvalidBounds
}
if bounds.Dx() > maxWidth {
return errUnsupportedWidth
}
z := reader{
br: bitReader{r: r, order: order},
subFormat: sf,
align: (opts != nil) && opts.Align,
invert: (opts != nil) && opts.Invert,
width: bounds.Dx(),
}
if err := z.startDecode(); err != nil {
return err
}
width := bounds.Dx()
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
p := (y - bounds.Min.Y) * dst.Stride
z.curr = dst.Pix[p : p+width]
if err := z.decodeRow(y+1 == bounds.Max.Y); err != nil {
return err
}
z.curr, z.prev = nil, z.curr
}
if err := z.finishDecode(false); err != nil {
return err
}
if z.invert {
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
p := (y - bounds.Min.Y) * dst.Stride
invertBytes(dst.Pix[p : p+width])
}
}
return nil
}
// NewReader returns an io.Reader that decodes the CCITT-formatted data in r.
// The resultant byte stream is one bit per pixel (MSB first), with 1 meaning
// white and 0 meaning black. Each row in the result is byte-aligned.
//
// A negative height, such as passing AutoDetectHeight, means that the image
// height is not known in advance. A negative width is invalid.
func NewReader(r io.Reader, order Order, sf SubFormat, width int, height int, opts *Options) io.Reader {
readErr := error(nil)
if width < 0 {
readErr = errInvalidBounds
} else if width > maxWidth {
readErr = errUnsupportedWidth
}
return &reader{
br: bitReader{r: r, order: order},
subFormat: sf,
align: (opts != nil) && opts.Align,
invert: (opts != nil) && opts.Invert,
width: width,
rowsRemaining: height,
readErr: readErr,
}
}

972
vendor/golang.org/x/image/ccitt/table.go generated vendored Normal file
View File

@ -0,0 +1,972 @@
// generated by "go run gen.go". DO NOT EDIT.
package ccitt
// Each decodeTable is represented by an array of [2]int16's: a binary tree.
// Each array element (other than element 0, which means invalid) is a branch
// node in that tree. The root node is always element 1 (the second element).
//
// To walk the tree, look at the next bit in the bit stream, using it to select
// the first or second element of the [2]int16. If that int16 is 0, we have an
// invalid code. If it is positive, go to that branch node. If it is negative,
// then we have a leaf node, whose value is the bitwise complement (the ^
// operator) of that int16.
//
// Comments above each decodeTable also show the same structure visually. The
// "b123" lines show the 123'rd branch node. The "=XXXXX" lines show an invalid
// code. The "=v1234" lines show a leaf node with value 1234. When reading the
// bit stream, a 0 or 1 bit means to go up or down, as you move left to right.
//
// For example, in modeDecodeTable, branch node b005 is three steps up from the
// root node, meaning that we have already seen "000". If the next bit is "0"
// then we move to branch node b006. Otherwise, the next bit is "1", and we
// move to the leaf node v0000 (also known as the modePass constant). Indeed,
// the bits that encode modePass are "0001".
//
// Tables 1, 2 and 3 come from the "ITU-T Recommendation T.6: FACSIMILE CODING
// SCHEMES AND CODING CONTROL FUNCTIONS FOR GROUP 4 FACSIMILE APPARATUS"
// specification:
//
// https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-T.6-198811-I!!PDF-E&type=items
// modeDecodeTable represents Table 1 and the End-of-Line code.
//
// +=XXXXX
// b009 +-+
// | +=v0009
// b007 +-+
// | | +=v0008
// b010 | +-+
// | +=v0005
// b006 +-+
// | | +=v0007
// b008 | +-+
// | +=v0004
// b005 +-+
// | +=v0000
// b003 +-+
// | +=v0001
// b002 +-+
// | | +=v0006
// b004 | +-+
// | +=v0003
// b001 +-+
// +=v0002
var modeDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, ^2},
2: {3, 4},
3: {5, ^1},
4: {^6, ^3},
5: {6, ^0},
6: {7, 8},
7: {9, 10},
8: {^7, ^4},
9: {0, ^9},
10: {^8, ^5},
}
// whiteDecodeTable represents Tables 2 and 3 for a white run.
//
// +=XXXXX
// b059 +-+
// | | +=v1792
// b096 | | +-+
// | | | | +=v1984
// b100 | | | +-+
// | | | +=v2048
// b094 | | +-+
// | | | | +=v2112
// b101 | | | | +-+
// | | | | | +=v2176
// b097 | | | +-+
// | | | | +=v2240
// b102 | | | +-+
// | | | +=v2304
// b085 | +-+
// | | +=v1856
// b098 | | +-+
// | | | +=v1920
// b095 | +-+
// | | +=v2368
// b103 | | +-+
// | | | +=v2432
// b099 | +-+
// | | +=v2496
// b104 | +-+
// | +=v2560
// b040 +-+
// | | +=v0029
// b060 | +-+
// | +=v0030
// b026 +-+
// | | +=v0045
// b061 | | +-+
// | | | +=v0046
// b041 | +-+
// | +=v0022
// b016 +-+
// | | +=v0023
// b042 | | +-+
// | | | | +=v0047
// b062 | | | +-+
// | | | +=v0048
// b027 | +-+
// | +=v0013
// b008 +-+
// | | +=v0020
// b043 | | +-+
// | | | | +=v0033
// b063 | | | +-+
// | | | +=v0034
// b028 | | +-+
// | | | | +=v0035
// b064 | | | | +-+
// | | | | | +=v0036
// b044 | | | +-+
// | | | | +=v0037
// b065 | | | +-+
// | | | +=v0038
// b017 | +-+
// | | +=v0019
// b045 | | +-+
// | | | | +=v0031
// b066 | | | +-+
// | | | +=v0032
// b029 | +-+
// | +=v0001
// b004 +-+
// | | +=v0012
// b030 | | +-+
// | | | | +=v0053
// b067 | | | | +-+
// | | | | | +=v0054
// b046 | | | +-+
// | | | +=v0026
// b018 | | +-+
// | | | | +=v0039
// b068 | | | | +-+
// | | | | | +=v0040
// b047 | | | | +-+
// | | | | | | +=v0041
// b069 | | | | | +-+
// | | | | | +=v0042
// b031 | | | +-+
// | | | | +=v0043
// b070 | | | | +-+
// | | | | | +=v0044
// b048 | | | +-+
// | | | +=v0021
// b009 | +-+
// | | +=v0028
// b049 | | +-+
// | | | | +=v0061
// b071 | | | +-+
// | | | +=v0062
// b032 | | +-+
// | | | | +=v0063
// b072 | | | | +-+
// | | | | | +=v0000
// b050 | | | +-+
// | | | | +=v0320
// b073 | | | +-+
// | | | +=v0384
// b019 | +-+
// | +=v0010
// b002 +-+
// | | +=v0011
// b020 | | +-+
// | | | | +=v0027
// b051 | | | | +-+
// | | | | | | +=v0059
// b074 | | | | | +-+
// | | | | | +=v0060
// b033 | | | +-+
// | | | | +=v1472
// b086 | | | | +-+
// | | | | | +=v1536
// b075 | | | | +-+
// | | | | | | +=v1600
// b087 | | | | | +-+
// | | | | | +=v1728
// b052 | | | +-+
// | | | +=v0018
// b010 | | +-+
// | | | | +=v0024
// b053 | | | | +-+
// | | | | | | +=v0049
// b076 | | | | | +-+
// | | | | | +=v0050
// b034 | | | | +-+
// | | | | | | +=v0051
// b077 | | | | | | +-+
// | | | | | | | +=v0052
// b054 | | | | | +-+
// | | | | | +=v0025
// b021 | | | +-+
// | | | | +=v0055
// b078 | | | | +-+
// | | | | | +=v0056
// b055 | | | | +-+
// | | | | | | +=v0057
// b079 | | | | | +-+
// | | | | | +=v0058
// b035 | | | +-+
// | | | +=v0192
// b005 | +-+
// | | +=v1664
// b036 | | +-+
// | | | | +=v0448
// b080 | | | | +-+
// | | | | | +=v0512
// b056 | | | +-+
// | | | | +=v0704
// b088 | | | | +-+
// | | | | | +=v0768
// b081 | | | +-+
// | | | +=v0640
// b022 | | +-+
// | | | | +=v0576
// b082 | | | | +-+
// | | | | | | +=v0832
// b089 | | | | | +-+
// | | | | | +=v0896
// b057 | | | | +-+
// | | | | | | +=v0960
// b090 | | | | | | +-+
// | | | | | | | +=v1024
// b083 | | | | | +-+
// | | | | | | +=v1088
// b091 | | | | | +-+
// | | | | | +=v1152
// b037 | | | +-+
// | | | | +=v1216
// b092 | | | | +-+
// | | | | | +=v1280
// b084 | | | | +-+
// | | | | | | +=v1344
// b093 | | | | | +-+
// | | | | | +=v1408
// b058 | | | +-+
// | | | +=v0256
// b011 | +-+
// | +=v0002
// b001 +-+
// | +=v0003
// b012 | +-+
// | | | +=v0128
// b023 | | +-+
// | | +=v0008
// b006 | +-+
// | | | +=v0009
// b024 | | | +-+
// | | | | | +=v0016
// b038 | | | | +-+
// | | | | +=v0017
// b013 | | +-+
// | | +=v0004
// b003 +-+
// | +=v0005
// b014 | +-+
// | | | +=v0014
// b039 | | | +-+
// | | | | +=v0015
// b025 | | +-+
// | | +=v0064
// b007 +-+
// | +=v0006
// b015 +-+
// +=v0007
var whiteDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, 3},
2: {4, 5},
3: {6, 7},
4: {8, 9},
5: {10, 11},
6: {12, 13},
7: {14, 15},
8: {16, 17},
9: {18, 19},
10: {20, 21},
11: {22, ^2},
12: {^3, 23},
13: {24, ^4},
14: {^5, 25},
15: {^6, ^7},
16: {26, 27},
17: {28, 29},
18: {30, 31},
19: {32, ^10},
20: {^11, 33},
21: {34, 35},
22: {36, 37},
23: {^128, ^8},
24: {^9, 38},
25: {39, ^64},
26: {40, 41},
27: {42, ^13},
28: {43, 44},
29: {45, ^1},
30: {^12, 46},
31: {47, 48},
32: {49, 50},
33: {51, 52},
34: {53, 54},
35: {55, ^192},
36: {^1664, 56},
37: {57, 58},
38: {^16, ^17},
39: {^14, ^15},
40: {59, 60},
41: {61, ^22},
42: {^23, 62},
43: {^20, 63},
44: {64, 65},
45: {^19, 66},
46: {67, ^26},
47: {68, 69},
48: {70, ^21},
49: {^28, 71},
50: {72, 73},
51: {^27, 74},
52: {75, ^18},
53: {^24, 76},
54: {77, ^25},
55: {78, 79},
56: {80, 81},
57: {82, 83},
58: {84, ^256},
59: {0, 85},
60: {^29, ^30},
61: {^45, ^46},
62: {^47, ^48},
63: {^33, ^34},
64: {^35, ^36},
65: {^37, ^38},
66: {^31, ^32},
67: {^53, ^54},
68: {^39, ^40},
69: {^41, ^42},
70: {^43, ^44},
71: {^61, ^62},
72: {^63, ^0},
73: {^320, ^384},
74: {^59, ^60},
75: {86, 87},
76: {^49, ^50},
77: {^51, ^52},
78: {^55, ^56},
79: {^57, ^58},
80: {^448, ^512},
81: {88, ^640},
82: {^576, 89},
83: {90, 91},
84: {92, 93},
85: {94, 95},
86: {^1472, ^1536},
87: {^1600, ^1728},
88: {^704, ^768},
89: {^832, ^896},
90: {^960, ^1024},
91: {^1088, ^1152},
92: {^1216, ^1280},
93: {^1344, ^1408},
94: {96, 97},
95: {98, 99},
96: {^1792, 100},
97: {101, 102},
98: {^1856, ^1920},
99: {103, 104},
100: {^1984, ^2048},
101: {^2112, ^2176},
102: {^2240, ^2304},
103: {^2368, ^2432},
104: {^2496, ^2560},
}
// blackDecodeTable represents Tables 2 and 3 for a black run.
//
// +=XXXXX
// b017 +-+
// | | +=v1792
// b042 | | +-+
// | | | | +=v1984
// b063 | | | +-+
// | | | +=v2048
// b029 | | +-+
// | | | | +=v2112
// b064 | | | | +-+
// | | | | | +=v2176
// b043 | | | +-+
// | | | | +=v2240
// b065 | | | +-+
// | | | +=v2304
// b022 | +-+
// | | +=v1856
// b044 | | +-+
// | | | +=v1920
// b030 | +-+
// | | +=v2368
// b066 | | +-+
// | | | +=v2432
// b045 | +-+
// | | +=v2496
// b067 | +-+
// | +=v2560
// b013 +-+
// | | +=v0018
// b031 | | +-+
// | | | | +=v0052
// b068 | | | | +-+
// | | | | | | +=v0640
// b095 | | | | | +-+
// | | | | | +=v0704
// b046 | | | +-+
// | | | | +=v0768
// b096 | | | | +-+
// | | | | | +=v0832
// b069 | | | +-+
// | | | +=v0055
// b023 | | +-+
// | | | | +=v0056
// b070 | | | | +-+
// | | | | | | +=v1280
// b097 | | | | | +-+
// | | | | | +=v1344
// b047 | | | | +-+
// | | | | | | +=v1408
// b098 | | | | | | +-+
// | | | | | | | +=v1472
// b071 | | | | | +-+
// | | | | | +=v0059
// b032 | | | +-+
// | | | | +=v0060
// b072 | | | | +-+
// | | | | | | +=v1536
// b099 | | | | | +-+
// | | | | | +=v1600
// b048 | | | +-+
// | | | +=v0024
// b018 | +-+
// | | +=v0025
// b049 | | +-+
// | | | | +=v1664
// b100 | | | | +-+
// | | | | | +=v1728
// b073 | | | +-+
// | | | +=v0320
// b033 | | +-+
// | | | | +=v0384
// b074 | | | | +-+
// | | | | | +=v0448
// b050 | | | +-+
// | | | | +=v0512
// b101 | | | | +-+
// | | | | | +=v0576
// b075 | | | +-+
// | | | +=v0053
// b024 | +-+
// | | +=v0054
// b076 | | +-+
// | | | | +=v0896
// b102 | | | +-+
// | | | +=v0960
// b051 | | +-+
// | | | | +=v1024
// b103 | | | | +-+
// | | | | | +=v1088
// b077 | | | +-+
// | | | | +=v1152
// b104 | | | +-+
// | | | +=v1216
// b034 | +-+
// | +=v0064
// b010 +-+
// | | +=v0013
// b019 | | +-+
// | | | | +=v0023
// b052 | | | | +-+
// | | | | | | +=v0050
// b078 | | | | | +-+
// | | | | | +=v0051
// b035 | | | | +-+
// | | | | | | +=v0044
// b079 | | | | | | +-+
// | | | | | | | +=v0045
// b053 | | | | | +-+
// | | | | | | +=v0046
// b080 | | | | | +-+
// | | | | | +=v0047
// b025 | | | +-+
// | | | | +=v0057
// b081 | | | | +-+
// | | | | | +=v0058
// b054 | | | | +-+
// | | | | | | +=v0061
// b082 | | | | | +-+
// | | | | | +=v0256
// b036 | | | +-+
// | | | +=v0016
// b014 | +-+
// | | +=v0017
// b037 | | +-+
// | | | | +=v0048
// b083 | | | | +-+
// | | | | | +=v0049
// b055 | | | +-+
// | | | | +=v0062
// b084 | | | +-+
// | | | +=v0063
// b026 | | +-+
// | | | | +=v0030
// b085 | | | | +-+
// | | | | | +=v0031
// b056 | | | | +-+
// | | | | | | +=v0032
// b086 | | | | | +-+
// | | | | | +=v0033
// b038 | | | +-+
// | | | | +=v0040
// b087 | | | | +-+
// | | | | | +=v0041
// b057 | | | +-+
// | | | +=v0022
// b020 | +-+
// | +=v0014
// b008 +-+
// | | +=v0010
// b015 | | +-+
// | | | +=v0011
// b011 | +-+
// | | +=v0015
// b027 | | +-+
// | | | | +=v0128
// b088 | | | | +-+
// | | | | | +=v0192
// b058 | | | | +-+
// | | | | | | +=v0026
// b089 | | | | | +-+
// | | | | | +=v0027
// b039 | | | +-+
// | | | | +=v0028
// b090 | | | | +-+
// | | | | | +=v0029
// b059 | | | +-+
// | | | +=v0019
// b021 | | +-+
// | | | | +=v0020
// b060 | | | | +-+
// | | | | | | +=v0034
// b091 | | | | | +-+
// | | | | | +=v0035
// b040 | | | | +-+
// | | | | | | +=v0036
// b092 | | | | | | +-+
// | | | | | | | +=v0037
// b061 | | | | | +-+
// | | | | | | +=v0038
// b093 | | | | | +-+
// | | | | | +=v0039
// b028 | | | +-+
// | | | | +=v0021
// b062 | | | | +-+
// | | | | | | +=v0042
// b094 | | | | | +-+
// | | | | | +=v0043
// b041 | | | +-+
// | | | +=v0000
// b016 | +-+
// | +=v0012
// b006 +-+
// | | +=v0009
// b012 | | +-+
// | | | +=v0008
// b009 | +-+
// | +=v0007
// b004 +-+
// | | +=v0006
// b007 | +-+
// | +=v0005
// b002 +-+
// | | +=v0001
// b005 | +-+
// | +=v0004
// b001 +-+
// | +=v0003
// b003 +-+
// +=v0002
var blackDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, 3},
2: {4, 5},
3: {^3, ^2},
4: {6, 7},
5: {^1, ^4},
6: {8, 9},
7: {^6, ^5},
8: {10, 11},
9: {12, ^7},
10: {13, 14},
11: {15, 16},
12: {^9, ^8},
13: {17, 18},
14: {19, 20},
15: {^10, ^11},
16: {21, ^12},
17: {0, 22},
18: {23, 24},
19: {^13, 25},
20: {26, ^14},
21: {27, 28},
22: {29, 30},
23: {31, 32},
24: {33, 34},
25: {35, 36},
26: {37, 38},
27: {^15, 39},
28: {40, 41},
29: {42, 43},
30: {44, 45},
31: {^18, 46},
32: {47, 48},
33: {49, 50},
34: {51, ^64},
35: {52, 53},
36: {54, ^16},
37: {^17, 55},
38: {56, 57},
39: {58, 59},
40: {60, 61},
41: {62, ^0},
42: {^1792, 63},
43: {64, 65},
44: {^1856, ^1920},
45: {66, 67},
46: {68, 69},
47: {70, 71},
48: {72, ^24},
49: {^25, 73},
50: {74, 75},
51: {76, 77},
52: {^23, 78},
53: {79, 80},
54: {81, 82},
55: {83, 84},
56: {85, 86},
57: {87, ^22},
58: {88, 89},
59: {90, ^19},
60: {^20, 91},
61: {92, 93},
62: {^21, 94},
63: {^1984, ^2048},
64: {^2112, ^2176},
65: {^2240, ^2304},
66: {^2368, ^2432},
67: {^2496, ^2560},
68: {^52, 95},
69: {96, ^55},
70: {^56, 97},
71: {98, ^59},
72: {^60, 99},
73: {100, ^320},
74: {^384, ^448},
75: {101, ^53},
76: {^54, 102},
77: {103, 104},
78: {^50, ^51},
79: {^44, ^45},
80: {^46, ^47},
81: {^57, ^58},
82: {^61, ^256},
83: {^48, ^49},
84: {^62, ^63},
85: {^30, ^31},
86: {^32, ^33},
87: {^40, ^41},
88: {^128, ^192},
89: {^26, ^27},
90: {^28, ^29},
91: {^34, ^35},
92: {^36, ^37},
93: {^38, ^39},
94: {^42, ^43},
95: {^640, ^704},
96: {^768, ^832},
97: {^1280, ^1344},
98: {^1408, ^1472},
99: {^1536, ^1600},
100: {^1664, ^1728},
101: {^512, ^576},
102: {^896, ^960},
103: {^1024, ^1088},
104: {^1152, ^1216},
}
const maxCodeLength = 13
// Each encodeTable is represented by an array of bitStrings.
// bitString is a pair of uint32 values representing a bit code.
// The nBits low bits of bits make up the actual bit code.
// Eg. bitString{0x0004, 8} represents the bitcode "00000100".
type bitString struct {
bits uint32
nBits uint32
}
// modeEncodeTable represents Table 1 and the End-of-Line code.
var modeEncodeTable = [...]bitString{
0: {0x0001, 4}, // "0001"
1: {0x0001, 3}, // "001"
2: {0x0001, 1}, // "1"
3: {0x0003, 3}, // "011"
4: {0x0003, 6}, // "000011"
5: {0x0003, 7}, // "0000011"
6: {0x0002, 3}, // "010"
7: {0x0002, 6}, // "000010"
8: {0x0002, 7}, // "0000010"
9: {0x0001, 7}, // "0000001"
}
// whiteEncodeTable2 represents Table 2 for a white run.
var whiteEncodeTable2 = [...]bitString{
0: {0x0035, 8}, // "00110101"
1: {0x0007, 6}, // "000111"
2: {0x0007, 4}, // "0111"
3: {0x0008, 4}, // "1000"
4: {0x000b, 4}, // "1011"
5: {0x000c, 4}, // "1100"
6: {0x000e, 4}, // "1110"
7: {0x000f, 4}, // "1111"
8: {0x0013, 5}, // "10011"
9: {0x0014, 5}, // "10100"
10: {0x0007, 5}, // "00111"
11: {0x0008, 5}, // "01000"
12: {0x0008, 6}, // "001000"
13: {0x0003, 6}, // "000011"
14: {0x0034, 6}, // "110100"
15: {0x0035, 6}, // "110101"
16: {0x002a, 6}, // "101010"
17: {0x002b, 6}, // "101011"
18: {0x0027, 7}, // "0100111"
19: {0x000c, 7}, // "0001100"
20: {0x0008, 7}, // "0001000"
21: {0x0017, 7}, // "0010111"
22: {0x0003, 7}, // "0000011"
23: {0x0004, 7}, // "0000100"
24: {0x0028, 7}, // "0101000"
25: {0x002b, 7}, // "0101011"
26: {0x0013, 7}, // "0010011"
27: {0x0024, 7}, // "0100100"
28: {0x0018, 7}, // "0011000"
29: {0x0002, 8}, // "00000010"
30: {0x0003, 8}, // "00000011"
31: {0x001a, 8}, // "00011010"
32: {0x001b, 8}, // "00011011"
33: {0x0012, 8}, // "00010010"
34: {0x0013, 8}, // "00010011"
35: {0x0014, 8}, // "00010100"
36: {0x0015, 8}, // "00010101"
37: {0x0016, 8}, // "00010110"
38: {0x0017, 8}, // "00010111"
39: {0x0028, 8}, // "00101000"
40: {0x0029, 8}, // "00101001"
41: {0x002a, 8}, // "00101010"
42: {0x002b, 8}, // "00101011"
43: {0x002c, 8}, // "00101100"
44: {0x002d, 8}, // "00101101"
45: {0x0004, 8}, // "00000100"
46: {0x0005, 8}, // "00000101"
47: {0x000a, 8}, // "00001010"
48: {0x000b, 8}, // "00001011"
49: {0x0052, 8}, // "01010010"
50: {0x0053, 8}, // "01010011"
51: {0x0054, 8}, // "01010100"
52: {0x0055, 8}, // "01010101"
53: {0x0024, 8}, // "00100100"
54: {0x0025, 8}, // "00100101"
55: {0x0058, 8}, // "01011000"
56: {0x0059, 8}, // "01011001"
57: {0x005a, 8}, // "01011010"
58: {0x005b, 8}, // "01011011"
59: {0x004a, 8}, // "01001010"
60: {0x004b, 8}, // "01001011"
61: {0x0032, 8}, // "00110010"
62: {0x0033, 8}, // "00110011"
63: {0x0034, 8}, // "00110100"
}
// whiteEncodeTable3 represents Table 3 for a white run.
var whiteEncodeTable3 = [...]bitString{
0: {0x001b, 5}, // "11011"
1: {0x0012, 5}, // "10010"
2: {0x0017, 6}, // "010111"
3: {0x0037, 7}, // "0110111"
4: {0x0036, 8}, // "00110110"
5: {0x0037, 8}, // "00110111"
6: {0x0064, 8}, // "01100100"
7: {0x0065, 8}, // "01100101"
8: {0x0068, 8}, // "01101000"
9: {0x0067, 8}, // "01100111"
10: {0x00cc, 9}, // "011001100"
11: {0x00cd, 9}, // "011001101"
12: {0x00d2, 9}, // "011010010"
13: {0x00d3, 9}, // "011010011"
14: {0x00d4, 9}, // "011010100"
15: {0x00d5, 9}, // "011010101"
16: {0x00d6, 9}, // "011010110"
17: {0x00d7, 9}, // "011010111"
18: {0x00d8, 9}, // "011011000"
19: {0x00d9, 9}, // "011011001"
20: {0x00da, 9}, // "011011010"
21: {0x00db, 9}, // "011011011"
22: {0x0098, 9}, // "010011000"
23: {0x0099, 9}, // "010011001"
24: {0x009a, 9}, // "010011010"
25: {0x0018, 6}, // "011000"
26: {0x009b, 9}, // "010011011"
27: {0x0008, 11}, // "00000001000"
28: {0x000c, 11}, // "00000001100"
29: {0x000d, 11}, // "00000001101"
30: {0x0012, 12}, // "000000010010"
31: {0x0013, 12}, // "000000010011"
32: {0x0014, 12}, // "000000010100"
33: {0x0015, 12}, // "000000010101"
34: {0x0016, 12}, // "000000010110"
35: {0x0017, 12}, // "000000010111"
36: {0x001c, 12}, // "000000011100"
37: {0x001d, 12}, // "000000011101"
38: {0x001e, 12}, // "000000011110"
39: {0x001f, 12}, // "000000011111"
}
// blackEncodeTable2 represents Table 2 for a black run.
var blackEncodeTable2 = [...]bitString{
0: {0x0037, 10}, // "0000110111"
1: {0x0002, 3}, // "010"
2: {0x0003, 2}, // "11"
3: {0x0002, 2}, // "10"
4: {0x0003, 3}, // "011"
5: {0x0003, 4}, // "0011"
6: {0x0002, 4}, // "0010"
7: {0x0003, 5}, // "00011"
8: {0x0005, 6}, // "000101"
9: {0x0004, 6}, // "000100"
10: {0x0004, 7}, // "0000100"
11: {0x0005, 7}, // "0000101"
12: {0x0007, 7}, // "0000111"
13: {0x0004, 8}, // "00000100"
14: {0x0007, 8}, // "00000111"
15: {0x0018, 9}, // "000011000"
16: {0x0017, 10}, // "0000010111"
17: {0x0018, 10}, // "0000011000"
18: {0x0008, 10}, // "0000001000"
19: {0x0067, 11}, // "00001100111"
20: {0x0068, 11}, // "00001101000"
21: {0x006c, 11}, // "00001101100"
22: {0x0037, 11}, // "00000110111"
23: {0x0028, 11}, // "00000101000"
24: {0x0017, 11}, // "00000010111"
25: {0x0018, 11}, // "00000011000"
26: {0x00ca, 12}, // "000011001010"
27: {0x00cb, 12}, // "000011001011"
28: {0x00cc, 12}, // "000011001100"
29: {0x00cd, 12}, // "000011001101"
30: {0x0068, 12}, // "000001101000"
31: {0x0069, 12}, // "000001101001"
32: {0x006a, 12}, // "000001101010"
33: {0x006b, 12}, // "000001101011"
34: {0x00d2, 12}, // "000011010010"
35: {0x00d3, 12}, // "000011010011"
36: {0x00d4, 12}, // "000011010100"
37: {0x00d5, 12}, // "000011010101"
38: {0x00d6, 12}, // "000011010110"
39: {0x00d7, 12}, // "000011010111"
40: {0x006c, 12}, // "000001101100"
41: {0x006d, 12}, // "000001101101"
42: {0x00da, 12}, // "000011011010"
43: {0x00db, 12}, // "000011011011"
44: {0x0054, 12}, // "000001010100"
45: {0x0055, 12}, // "000001010101"
46: {0x0056, 12}, // "000001010110"
47: {0x0057, 12}, // "000001010111"
48: {0x0064, 12}, // "000001100100"
49: {0x0065, 12}, // "000001100101"
50: {0x0052, 12}, // "000001010010"
51: {0x0053, 12}, // "000001010011"
52: {0x0024, 12}, // "000000100100"
53: {0x0037, 12}, // "000000110111"
54: {0x0038, 12}, // "000000111000"
55: {0x0027, 12}, // "000000100111"
56: {0x0028, 12}, // "000000101000"
57: {0x0058, 12}, // "000001011000"
58: {0x0059, 12}, // "000001011001"
59: {0x002b, 12}, // "000000101011"
60: {0x002c, 12}, // "000000101100"
61: {0x005a, 12}, // "000001011010"
62: {0x0066, 12}, // "000001100110"
63: {0x0067, 12}, // "000001100111"
}
// blackEncodeTable3 represents Table 3 for a black run.
var blackEncodeTable3 = [...]bitString{
0: {0x000f, 10}, // "0000001111"
1: {0x00c8, 12}, // "000011001000"
2: {0x00c9, 12}, // "000011001001"
3: {0x005b, 12}, // "000001011011"
4: {0x0033, 12}, // "000000110011"
5: {0x0034, 12}, // "000000110100"
6: {0x0035, 12}, // "000000110101"
7: {0x006c, 13}, // "0000001101100"
8: {0x006d, 13}, // "0000001101101"
9: {0x004a, 13}, // "0000001001010"
10: {0x004b, 13}, // "0000001001011"
11: {0x004c, 13}, // "0000001001100"
12: {0x004d, 13}, // "0000001001101"
13: {0x0072, 13}, // "0000001110010"
14: {0x0073, 13}, // "0000001110011"
15: {0x0074, 13}, // "0000001110100"
16: {0x0075, 13}, // "0000001110101"
17: {0x0076, 13}, // "0000001110110"
18: {0x0077, 13}, // "0000001110111"
19: {0x0052, 13}, // "0000001010010"
20: {0x0053, 13}, // "0000001010011"
21: {0x0054, 13}, // "0000001010100"
22: {0x0055, 13}, // "0000001010101"
23: {0x005a, 13}, // "0000001011010"
24: {0x005b, 13}, // "0000001011011"
25: {0x0064, 13}, // "0000001100100"
26: {0x0065, 13}, // "0000001100101"
27: {0x0008, 11}, // "00000001000"
28: {0x000c, 11}, // "00000001100"
29: {0x000d, 11}, // "00000001101"
30: {0x0012, 12}, // "000000010010"
31: {0x0013, 12}, // "000000010011"
32: {0x0014, 12}, // "000000010100"
33: {0x0015, 12}, // "000000010101"
34: {0x0016, 12}, // "000000010110"
35: {0x0017, 12}, // "000000010111"
36: {0x001c, 12}, // "000000011100"
37: {0x001d, 12}, // "000000011101"
38: {0x001e, 12}, // "000000011110"
39: {0x001f, 12}, // "000000011111"
}
// COPY PASTE table.go BEGIN
const (
modePass = iota // Pass
modeH // Horizontal
modeV0 // Vertical-0
modeVR1 // Vertical-Right-1
modeVR2 // Vertical-Right-2
modeVR3 // Vertical-Right-3
modeVL1 // Vertical-Left-1
modeVL2 // Vertical-Left-2
modeVL3 // Vertical-Left-3
modeExt // Extension
)
// COPY PASTE table.go END

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vendor/golang.org/x/image/ccitt/writer.go generated vendored Normal file
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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ccitt
import (
"encoding/binary"
"io"
)
type bitWriter struct {
w io.Writer
// order is whether to process w's bytes LSB first or MSB first.
order Order
// The high nBits bits of the bits field hold encoded bits to be written to w.
bits uint64
nBits uint32
// bytes[:bw] holds encoded bytes not yet written to w.
// Overflow protection is ensured by using a multiple of 8 as bytes length.
bw uint32
bytes [1024]uint8
}
// flushBits copies 64 bits from b.bits to b.bytes. If b.bytes is then full, it
// is written to b.w.
func (b *bitWriter) flushBits() error {
binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits)
b.bits = 0
b.nBits = 0
b.bw += 8
if b.bw < uint32(len(b.bytes)) {
return nil
}
b.bw = 0
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:])
}
_, err := b.w.Write(b.bytes[:])
return err
}
// close finalizes a bitcode stream by writing any
// pending bits to bitWriter's underlying io.Writer.
func (b *bitWriter) close() error {
// Write any encoded bits to bytes.
if b.nBits > 0 {
binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits)
b.bw += (b.nBits + 7) >> 3
}
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:b.bw])
}
// Write b.bw bytes to b.w.
_, err := b.w.Write(b.bytes[:b.bw])
return err
}
// alignToByteBoundary rounds b.nBits up to a multiple of 8.
// If all 64 bits are used, flush them to bitWriter's bytes.
func (b *bitWriter) alignToByteBoundary() error {
if b.nBits = (b.nBits + 7) &^ 7; b.nBits == 64 {
return b.flushBits()
}
return nil
}
// writeCode writes a variable length bitcode to b's underlying io.Writer.
func (b *bitWriter) writeCode(bs bitString) error {
bits := bs.bits
nBits := bs.nBits
if 64-b.nBits >= nBits {
// b.bits has sufficient room for storing nBits bits.
b.bits |= uint64(bits) << (64 - nBits - b.nBits)
b.nBits += nBits
if b.nBits == 64 {
return b.flushBits()
}
return nil
}
// Number of leading bits that fill b.bits.
i := 64 - b.nBits
// Fill b.bits then flush and write remaining bits.
b.bits |= uint64(bits) >> (nBits - i)
b.nBits = 64
if err := b.flushBits(); err != nil {
return err
}
nBits -= i
b.bits = uint64(bits) << (64 - nBits)
b.nBits = nBits
return nil
}

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vendor/golang.org/x/image/tiff/buffer.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import "io"
// buffer buffers an io.Reader to satisfy io.ReaderAt.
type buffer struct {
r io.Reader
buf []byte
}
// fill reads data from b.r until the buffer contains at least end bytes.
func (b *buffer) fill(end int) error {
m := len(b.buf)
if end > m {
if end > cap(b.buf) {
newcap := 1024
for newcap < end {
newcap *= 2
}
newbuf := make([]byte, end, newcap)
copy(newbuf, b.buf)
b.buf = newbuf
} else {
b.buf = b.buf[:end]
}
if n, err := io.ReadFull(b.r, b.buf[m:end]); err != nil {
end = m + n
b.buf = b.buf[:end]
return err
}
}
return nil
}
func (b *buffer) ReadAt(p []byte, off int64) (int, error) {
o := int(off)
end := o + len(p)
if int64(end) != off+int64(len(p)) {
return 0, io.ErrUnexpectedEOF
}
err := b.fill(end)
return copy(p, b.buf[o:end]), err
}
// Slice returns a slice of the underlying buffer. The slice contains
// n bytes starting at offset off.
func (b *buffer) Slice(off, n int) ([]byte, error) {
end := off + n
if err := b.fill(end); err != nil {
return nil, err
}
return b.buf[off:end], nil
}
// newReaderAt converts an io.Reader into an io.ReaderAt.
func newReaderAt(r io.Reader) io.ReaderAt {
if ra, ok := r.(io.ReaderAt); ok {
return ra
}
return &buffer{
r: r,
buf: make([]byte, 0, 1024),
}
}

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vendor/golang.org/x/image/tiff/compress.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import (
"bufio"
"io"
)
type byteReader interface {
io.Reader
io.ByteReader
}
// unpackBits decodes the PackBits-compressed data in src and returns the
// uncompressed data.
//
// The PackBits compression format is described in section 9 (p. 42)
// of the TIFF spec.
func unpackBits(r io.Reader) ([]byte, error) {
buf := make([]byte, 128)
dst := make([]byte, 0, 1024)
br, ok := r.(byteReader)
if !ok {
br = bufio.NewReader(r)
}
for {
b, err := br.ReadByte()
if err != nil {
if err == io.EOF {
return dst, nil
}
return nil, err
}
code := int(int8(b))
switch {
case code >= 0:
n, err := io.ReadFull(br, buf[:code+1])
if err != nil {
return nil, err
}
dst = append(dst, buf[:n]...)
case code == -128:
// No-op.
default:
if b, err = br.ReadByte(); err != nil {
return nil, err
}
for j := 0; j < 1-code; j++ {
buf[j] = b
}
dst = append(dst, buf[:1-code]...)
}
}
}

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vendor/golang.org/x/image/tiff/consts.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
// A tiff image file contains one or more images. The metadata
// of each image is contained in an Image File Directory (IFD),
// which contains entries of 12 bytes each and is described
// on page 14-16 of the specification. An IFD entry consists of
//
// - a tag, which describes the signification of the entry,
// - the data type and length of the entry,
// - the data itself or a pointer to it if it is more than 4 bytes.
//
// The presence of a length means that each IFD is effectively an array.
const (
leHeader = "II\x2A\x00" // Header for little-endian files.
beHeader = "MM\x00\x2A" // Header for big-endian files.
ifdLen = 12 // Length of an IFD entry in bytes.
)
// Data types (p. 14-16 of the spec).
const (
dtByte = 1
dtASCII = 2
dtShort = 3
dtLong = 4
dtRational = 5
)
// The length of one instance of each data type in bytes.
var lengths = [...]uint32{0, 1, 1, 2, 4, 8}
// Tags (see p. 28-41 of the spec).
const (
tImageWidth = 256
tImageLength = 257
tBitsPerSample = 258
tCompression = 259
tPhotometricInterpretation = 262
tFillOrder = 266
tStripOffsets = 273
tSamplesPerPixel = 277
tRowsPerStrip = 278
tStripByteCounts = 279
tT4Options = 292 // CCITT Group 3 options, a set of 32 flag bits.
tT6Options = 293 // CCITT Group 4 options, a set of 32 flag bits.
tTileWidth = 322
tTileLength = 323
tTileOffsets = 324
tTileByteCounts = 325
tXResolution = 282
tYResolution = 283
tResolutionUnit = 296
tPredictor = 317
tColorMap = 320
tExtraSamples = 338
tSampleFormat = 339
)
// Compression types (defined in various places in the spec and supplements).
const (
cNone = 1
cCCITT = 2
cG3 = 3 // Group 3 Fax.
cG4 = 4 // Group 4 Fax.
cLZW = 5
cJPEGOld = 6 // Superseded by cJPEG.
cJPEG = 7
cDeflate = 8 // zlib compression.
cPackBits = 32773
cDeflateOld = 32946 // Superseded by cDeflate.
)
// Photometric interpretation values (see p. 37 of the spec).
const (
pWhiteIsZero = 0
pBlackIsZero = 1
pRGB = 2
pPaletted = 3
pTransMask = 4 // transparency mask
pCMYK = 5
pYCbCr = 6
pCIELab = 8
)
// Values for the tPredictor tag (page 64-65 of the spec).
const (
prNone = 1
prHorizontal = 2
)
// Values for the tResolutionUnit tag (page 18).
const (
resNone = 1
resPerInch = 2 // Dots per inch.
resPerCM = 3 // Dots per centimeter.
)
// imageMode represents the mode of the image.
type imageMode int
const (
mBilevel imageMode = iota
mPaletted
mGray
mGrayInvert
mRGB
mRGBA
mNRGBA
mCMYK
)
// CompressionType describes the type of compression used in Options.
type CompressionType int
// Constants for supported compression types.
const (
Uncompressed CompressionType = iota
Deflate
LZW
CCITTGroup3
CCITTGroup4
)
// specValue returns the compression type constant from the TIFF spec that
// is equivalent to c.
func (c CompressionType) specValue() uint32 {
switch c {
case LZW:
return cLZW
case Deflate:
return cDeflate
case CCITTGroup3:
return cG3
case CCITTGroup4:
return cG4
}
return cNone
}

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vendor/golang.org/x/image/tiff/fuzz.go generated vendored Normal file
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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build gofuzz
// +build gofuzz
package tiff
import "bytes"
func Fuzz(data []byte) int {
cfg, err := DecodeConfig(bytes.NewReader(data))
if err != nil {
return 0
}
if cfg.Width*cfg.Height > 1e6 {
return 0
}
img, err := Decode(bytes.NewReader(data))
if err != nil {
return 0
}
var w bytes.Buffer
err = Encode(&w, img, nil)
if err != nil {
panic(err)
}
return 1
}

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vendor/golang.org/x/image/tiff/lzw/reader.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package lzw implements the Lempel-Ziv-Welch compressed data format,
// described in T. A. Welch, “A Technique for High-Performance Data
// Compression”, Computer, 17(6) (June 1984), pp 8-19.
//
// In particular, it implements LZW as used by the TIFF file format, including
// an "off by one" algorithmic difference when compared to standard LZW.
package lzw // import "golang.org/x/image/tiff/lzw"
/*
This file was branched from src/pkg/compress/lzw/reader.go in the
standard library. Differences from the original are marked with "NOTE".
The tif_lzw.c file in the libtiff C library has this comment:
----
The 5.0 spec describes a different algorithm than Aldus
implements. Specifically, Aldus does code length transitions
one code earlier than should be done (for real LZW).
Earlier versions of this library implemented the correct
LZW algorithm, but emitted codes in a bit order opposite
to the TIFF spec. Thus, to maintain compatibility w/ Aldus
we interpret MSB-LSB ordered codes to be images written w/
old versions of this library, but otherwise adhere to the
Aldus "off by one" algorithm.
----
The Go code doesn't read (invalid) TIFF files written by old versions of
libtiff, but the LZW algorithm in this package still differs from the one in
Go's standard package library to accommodate this "off by one" in valid TIFFs.
*/
import (
"bufio"
"errors"
"fmt"
"io"
)
// Order specifies the bit ordering in an LZW data stream.
type Order int
const (
// LSB means Least Significant Bits first, as used in the GIF file format.
LSB Order = iota
// MSB means Most Significant Bits first, as used in the TIFF and PDF
// file formats.
MSB
)
const (
maxWidth = 12
decoderInvalidCode = 0xffff
flushBuffer = 1 << maxWidth
)
// decoder is the state from which the readXxx method converts a byte
// stream into a code stream.
type decoder struct {
r io.ByteReader
bits uint32
nBits uint
width uint
read func(*decoder) (uint16, error) // readLSB or readMSB
litWidth int // width in bits of literal codes
err error
// The first 1<<litWidth codes are literal codes.
// The next two codes mean clear and EOF.
// Other valid codes are in the range [lo, hi] where lo := clear + 2,
// with the upper bound incrementing on each code seen.
// overflow is the code at which hi overflows the code width. NOTE: TIFF's LZW is "off by one".
// last is the most recently seen code, or decoderInvalidCode.
clear, eof, hi, overflow, last uint16
// Each code c in [lo, hi] expands to two or more bytes. For c != hi:
// suffix[c] is the last of these bytes.
// prefix[c] is the code for all but the last byte.
// This code can either be a literal code or another code in [lo, c).
// The c == hi case is a special case.
suffix [1 << maxWidth]uint8
prefix [1 << maxWidth]uint16
// output is the temporary output buffer.
// Literal codes are accumulated from the start of the buffer.
// Non-literal codes decode to a sequence of suffixes that are first
// written right-to-left from the end of the buffer before being copied
// to the start of the buffer.
// It is flushed when it contains >= 1<<maxWidth bytes,
// so that there is always room to decode an entire code.
output [2 * 1 << maxWidth]byte
o int // write index into output
toRead []byte // bytes to return from Read
}
// readLSB returns the next code for "Least Significant Bits first" data.
func (d *decoder) readLSB() (uint16, error) {
for d.nBits < d.width {
x, err := d.r.ReadByte()
if err != nil {
return 0, err
}
d.bits |= uint32(x) << d.nBits
d.nBits += 8
}
code := uint16(d.bits & (1<<d.width - 1))
d.bits >>= d.width
d.nBits -= d.width
return code, nil
}
// readMSB returns the next code for "Most Significant Bits first" data.
func (d *decoder) readMSB() (uint16, error) {
for d.nBits < d.width {
x, err := d.r.ReadByte()
if err != nil {
return 0, err
}
d.bits |= uint32(x) << (24 - d.nBits)
d.nBits += 8
}
code := uint16(d.bits >> (32 - d.width))
d.bits <<= d.width
d.nBits -= d.width
return code, nil
}
func (d *decoder) Read(b []byte) (int, error) {
for {
if len(d.toRead) > 0 {
n := copy(b, d.toRead)
d.toRead = d.toRead[n:]
return n, nil
}
if d.err != nil {
return 0, d.err
}
d.decode()
}
}
// decode decompresses bytes from r and leaves them in d.toRead.
// read specifies how to decode bytes into codes.
// litWidth is the width in bits of literal codes.
func (d *decoder) decode() {
// Loop over the code stream, converting codes into decompressed bytes.
loop:
for {
code, err := d.read(d)
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
d.err = err
break
}
switch {
case code < d.clear:
// We have a literal code.
d.output[d.o] = uint8(code)
d.o++
if d.last != decoderInvalidCode {
// Save what the hi code expands to.
d.suffix[d.hi] = uint8(code)
d.prefix[d.hi] = d.last
}
case code == d.clear:
d.width = 1 + uint(d.litWidth)
d.hi = d.eof
d.overflow = 1 << d.width
d.last = decoderInvalidCode
continue
case code == d.eof:
d.err = io.EOF
break loop
case code <= d.hi:
c, i := code, len(d.output)-1
if code == d.hi && d.last != decoderInvalidCode {
// code == hi is a special case which expands to the last expansion
// followed by the head of the last expansion. To find the head, we walk
// the prefix chain until we find a literal code.
c = d.last
for c >= d.clear {
c = d.prefix[c]
}
d.output[i] = uint8(c)
i--
c = d.last
}
// Copy the suffix chain into output and then write that to w.
for c >= d.clear {
d.output[i] = d.suffix[c]
i--
c = d.prefix[c]
}
d.output[i] = uint8(c)
d.o += copy(d.output[d.o:], d.output[i:])
if d.last != decoderInvalidCode {
// Save what the hi code expands to.
d.suffix[d.hi] = uint8(c)
d.prefix[d.hi] = d.last
}
default:
d.err = errors.New("lzw: invalid code")
break loop
}
d.last, d.hi = code, d.hi+1
if d.hi+1 >= d.overflow { // NOTE: the "+1" is where TIFF's LZW differs from the standard algorithm.
if d.width == maxWidth {
d.last = decoderInvalidCode
} else {
d.width++
d.overflow <<= 1
}
}
if d.o >= flushBuffer {
break
}
}
// Flush pending output.
d.toRead = d.output[:d.o]
d.o = 0
}
var errClosed = errors.New("lzw: reader/writer is closed")
func (d *decoder) Close() error {
d.err = errClosed // in case any Reads come along
return nil
}
// NewReader creates a new io.ReadCloser.
// Reads from the returned io.ReadCloser read and decompress data from r.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
// It is the caller's responsibility to call Close on the ReadCloser when
// finished reading.
// The number of bits to use for literal codes, litWidth, must be in the
// range [2,8] and is typically 8. It must equal the litWidth
// used during compression.
func NewReader(r io.Reader, order Order, litWidth int) io.ReadCloser {
d := new(decoder)
switch order {
case LSB:
d.read = (*decoder).readLSB
case MSB:
d.read = (*decoder).readMSB
default:
d.err = errors.New("lzw: unknown order")
return d
}
if litWidth < 2 || 8 < litWidth {
d.err = fmt.Errorf("lzw: litWidth %d out of range", litWidth)
return d
}
if br, ok := r.(io.ByteReader); ok {
d.r = br
} else {
d.r = bufio.NewReader(r)
}
d.litWidth = litWidth
d.width = 1 + uint(litWidth)
d.clear = uint16(1) << uint(litWidth)
d.eof, d.hi = d.clear+1, d.clear+1
d.overflow = uint16(1) << d.width
d.last = decoderInvalidCode
return d
}

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vendor/golang.org/x/image/tiff/reader.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package tiff implements a TIFF image decoder and encoder.
//
// The TIFF specification is at http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
package tiff // import "golang.org/x/image/tiff"
import (
"compress/zlib"
"encoding/binary"
"fmt"
"image"
"image/color"
"io"
"io/ioutil"
"math"
"golang.org/x/image/ccitt"
"golang.org/x/image/tiff/lzw"
)
// A FormatError reports that the input is not a valid TIFF image.
type FormatError string
func (e FormatError) Error() string {
return "tiff: invalid format: " + string(e)
}
// An UnsupportedError reports that the input uses a valid but
// unimplemented feature.
type UnsupportedError string
func (e UnsupportedError) Error() string {
return "tiff: unsupported feature: " + string(e)
}
var errNoPixels = FormatError("not enough pixel data")
type decoder struct {
r io.ReaderAt
byteOrder binary.ByteOrder
config image.Config
mode imageMode
bpp uint
features map[int][]uint
palette []color.Color
buf []byte
off int // Current offset in buf.
v uint32 // Buffer value for reading with arbitrary bit depths.
nbits uint // Remaining number of bits in v.
}
// firstVal returns the first uint of the features entry with the given tag,
// or 0 if the tag does not exist.
func (d *decoder) firstVal(tag int) uint {
f := d.features[tag]
if len(f) == 0 {
return 0
}
return f[0]
}
// ifdUint decodes the IFD entry in p, which must be of the Byte, Short
// or Long type, and returns the decoded uint values.
func (d *decoder) ifdUint(p []byte) (u []uint, err error) {
var raw []byte
if len(p) < ifdLen {
return nil, FormatError("bad IFD entry")
}
datatype := d.byteOrder.Uint16(p[2:4])
if dt := int(datatype); dt <= 0 || dt >= len(lengths) {
return nil, UnsupportedError("IFD entry datatype")
}
count := d.byteOrder.Uint32(p[4:8])
if count > math.MaxInt32/lengths[datatype] {
return nil, FormatError("IFD data too large")
}
if datalen := lengths[datatype] * count; datalen > 4 {
// The IFD contains a pointer to the real value.
raw = make([]byte, datalen)
_, err = d.r.ReadAt(raw, int64(d.byteOrder.Uint32(p[8:12])))
} else {
raw = p[8 : 8+datalen]
}
if err != nil {
return nil, err
}
u = make([]uint, count)
switch datatype {
case dtByte:
for i := uint32(0); i < count; i++ {
u[i] = uint(raw[i])
}
case dtShort:
for i := uint32(0); i < count; i++ {
u[i] = uint(d.byteOrder.Uint16(raw[2*i : 2*(i+1)]))
}
case dtLong:
for i := uint32(0); i < count; i++ {
u[i] = uint(d.byteOrder.Uint32(raw[4*i : 4*(i+1)]))
}
default:
return nil, UnsupportedError("data type")
}
return u, nil
}
// parseIFD decides whether the IFD entry in p is "interesting" and
// stows away the data in the decoder. It returns the tag number of the
// entry and an error, if any.
func (d *decoder) parseIFD(p []byte) (int, error) {
tag := d.byteOrder.Uint16(p[0:2])
switch tag {
case tBitsPerSample,
tExtraSamples,
tPhotometricInterpretation,
tCompression,
tPredictor,
tStripOffsets,
tStripByteCounts,
tRowsPerStrip,
tTileWidth,
tTileLength,
tTileOffsets,
tTileByteCounts,
tImageLength,
tImageWidth,
tFillOrder,
tT4Options,
tT6Options:
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
d.features[int(tag)] = val
case tColorMap:
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
numcolors := len(val) / 3
if len(val)%3 != 0 || numcolors <= 0 || numcolors > 256 {
return 0, FormatError("bad ColorMap length")
}
d.palette = make([]color.Color, numcolors)
for i := 0; i < numcolors; i++ {
d.palette[i] = color.RGBA64{
uint16(val[i]),
uint16(val[i+numcolors]),
uint16(val[i+2*numcolors]),
0xffff,
}
}
case tSampleFormat:
// Page 27 of the spec: If the SampleFormat is present and
// the value is not 1 [= unsigned integer data], a Baseline
// TIFF reader that cannot handle the SampleFormat value
// must terminate the import process gracefully.
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
for _, v := range val {
if v != 1 {
return 0, UnsupportedError("sample format")
}
}
}
return int(tag), nil
}
// readBits reads n bits from the internal buffer starting at the current offset.
func (d *decoder) readBits(n uint) (v uint32, ok bool) {
for d.nbits < n {
d.v <<= 8
if d.off >= len(d.buf) {
return 0, false
}
d.v |= uint32(d.buf[d.off])
d.off++
d.nbits += 8
}
d.nbits -= n
rv := d.v >> d.nbits
d.v &^= rv << d.nbits
return rv, true
}
// flushBits discards the unread bits in the buffer used by readBits.
// It is used at the end of a line.
func (d *decoder) flushBits() {
d.v = 0
d.nbits = 0
}
// minInt returns the smaller of x or y.
func minInt(a, b int) int {
if a <= b {
return a
}
return b
}
// decode decodes the raw data of an image.
// It reads from d.buf and writes the strip or tile into dst.
func (d *decoder) decode(dst image.Image, xmin, ymin, xmax, ymax int) error {
d.off = 0
// Apply horizontal predictor if necessary.
// In this case, p contains the color difference to the preceding pixel.
// See page 64-65 of the spec.
if d.firstVal(tPredictor) == prHorizontal {
switch d.bpp {
case 16:
var off int
n := 2 * len(d.features[tBitsPerSample]) // bytes per sample times samples per pixel
for y := ymin; y < ymax; y++ {
off += n
for x := 0; x < (xmax-xmin-1)*n; x += 2 {
if off+2 > len(d.buf) {
return errNoPixels
}
v0 := d.byteOrder.Uint16(d.buf[off-n : off-n+2])
v1 := d.byteOrder.Uint16(d.buf[off : off+2])
d.byteOrder.PutUint16(d.buf[off:off+2], v1+v0)
off += 2
}
}
case 8:
var off int
n := 1 * len(d.features[tBitsPerSample]) // bytes per sample times samples per pixel
for y := ymin; y < ymax; y++ {
off += n
for x := 0; x < (xmax-xmin-1)*n; x++ {
if off >= len(d.buf) {
return errNoPixels
}
d.buf[off] += d.buf[off-n]
off++
}
}
case 1:
return UnsupportedError("horizontal predictor with 1 BitsPerSample")
}
}
rMaxX := minInt(xmax, dst.Bounds().Max.X)
rMaxY := minInt(ymax, dst.Bounds().Max.Y)
switch d.mode {
case mGray, mGrayInvert:
if d.bpp == 16 {
img := dst.(*image.Gray16)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+2 > len(d.buf) {
return errNoPixels
}
v := d.byteOrder.Uint16(d.buf[d.off : d.off+2])
d.off += 2
if d.mode == mGrayInvert {
v = 0xffff - v
}
img.SetGray16(x, y, color.Gray16{v})
}
if rMaxX == img.Bounds().Max.X {
d.off += 2 * (xmax - img.Bounds().Max.X)
}
}
} else {
img := dst.(*image.Gray)
max := uint32((1 << d.bpp) - 1)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
v, ok := d.readBits(d.bpp)
if !ok {
return errNoPixels
}
v = v * 0xff / max
if d.mode == mGrayInvert {
v = 0xff - v
}
img.SetGray(x, y, color.Gray{uint8(v)})
}
d.flushBits()
}
}
case mPaletted:
img := dst.(*image.Paletted)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
v, ok := d.readBits(d.bpp)
if !ok {
return errNoPixels
}
img.SetColorIndex(x, y, uint8(v))
}
d.flushBits()
}
case mRGB:
if d.bpp == 16 {
img := dst.(*image.RGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+6 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
d.off += 6
img.SetRGBA64(x, y, color.RGBA64{r, g, b, 0xffff})
}
}
} else {
img := dst.(*image.RGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
off := (y - ymin) * (xmax - xmin) * 3
for i := min; i < max; i += 4 {
if off+3 > len(d.buf) {
return errNoPixels
}
img.Pix[i+0] = d.buf[off+0]
img.Pix[i+1] = d.buf[off+1]
img.Pix[i+2] = d.buf[off+2]
img.Pix[i+3] = 0xff
off += 3
}
}
}
case mNRGBA:
if d.bpp == 16 {
img := dst.(*image.NRGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+8 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
a := d.byteOrder.Uint16(d.buf[d.off+6 : d.off+8])
d.off += 8
img.SetNRGBA64(x, y, color.NRGBA64{r, g, b, a})
}
}
} else {
img := dst.(*image.NRGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
i0, i1 := (y-ymin)*(xmax-xmin)*4, (y-ymin+1)*(xmax-xmin)*4
if i1 > len(d.buf) {
return errNoPixels
}
copy(img.Pix[min:max], d.buf[i0:i1])
}
}
case mRGBA:
if d.bpp == 16 {
img := dst.(*image.RGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+8 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
a := d.byteOrder.Uint16(d.buf[d.off+6 : d.off+8])
d.off += 8
img.SetRGBA64(x, y, color.RGBA64{r, g, b, a})
}
}
} else {
img := dst.(*image.RGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
i0, i1 := (y-ymin)*(xmax-xmin)*4, (y-ymin+1)*(xmax-xmin)*4
if i1 > len(d.buf) {
return errNoPixels
}
copy(img.Pix[min:max], d.buf[i0:i1])
}
}
}
return nil
}
func newDecoder(r io.Reader) (*decoder, error) {
d := &decoder{
r: newReaderAt(r),
features: make(map[int][]uint),
}
p := make([]byte, 8)
if _, err := d.r.ReadAt(p, 0); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return nil, err
}
switch string(p[0:4]) {
case leHeader:
d.byteOrder = binary.LittleEndian
case beHeader:
d.byteOrder = binary.BigEndian
default:
return nil, FormatError("malformed header")
}
ifdOffset := int64(d.byteOrder.Uint32(p[4:8]))
// The first two bytes contain the number of entries (12 bytes each).
if _, err := d.r.ReadAt(p[0:2], ifdOffset); err != nil {
return nil, err
}
numItems := int(d.byteOrder.Uint16(p[0:2]))
// All IFD entries are read in one chunk.
p = make([]byte, ifdLen*numItems)
if _, err := d.r.ReadAt(p, ifdOffset+2); err != nil {
return nil, err
}
prevTag := -1
for i := 0; i < len(p); i += ifdLen {
tag, err := d.parseIFD(p[i : i+ifdLen])
if err != nil {
return nil, err
}
if tag <= prevTag {
return nil, FormatError("tags are not sorted in ascending order")
}
prevTag = tag
}
d.config.Width = int(d.firstVal(tImageWidth))
d.config.Height = int(d.firstVal(tImageLength))
if _, ok := d.features[tBitsPerSample]; !ok {
// Default is 1 per specification.
d.features[tBitsPerSample] = []uint{1}
}
d.bpp = d.firstVal(tBitsPerSample)
switch d.bpp {
case 0:
return nil, FormatError("BitsPerSample must not be 0")
case 1, 8, 16:
// Nothing to do, these are accepted by this implementation.
default:
return nil, UnsupportedError(fmt.Sprintf("BitsPerSample of %v", d.bpp))
}
// Determine the image mode.
switch d.firstVal(tPhotometricInterpretation) {
case pRGB:
if d.bpp == 16 {
for _, b := range d.features[tBitsPerSample] {
if b != 16 {
return nil, FormatError("wrong number of samples for 16bit RGB")
}
}
} else {
for _, b := range d.features[tBitsPerSample] {
if b != 8 {
return nil, FormatError("wrong number of samples for 8bit RGB")
}
}
}
// RGB images normally have 3 samples per pixel.
// If there are more, ExtraSamples (p. 31-32 of the spec)
// gives their meaning (usually an alpha channel).
//
// This implementation does not support extra samples
// of an unspecified type.
switch len(d.features[tBitsPerSample]) {
case 3:
d.mode = mRGB
if d.bpp == 16 {
d.config.ColorModel = color.RGBA64Model
} else {
d.config.ColorModel = color.RGBAModel
}
case 4:
switch d.firstVal(tExtraSamples) {
case 1:
d.mode = mRGBA
if d.bpp == 16 {
d.config.ColorModel = color.RGBA64Model
} else {
d.config.ColorModel = color.RGBAModel
}
case 2:
d.mode = mNRGBA
if d.bpp == 16 {
d.config.ColorModel = color.NRGBA64Model
} else {
d.config.ColorModel = color.NRGBAModel
}
default:
return nil, FormatError("wrong number of samples for RGB")
}
default:
return nil, FormatError("wrong number of samples for RGB")
}
case pPaletted:
d.mode = mPaletted
d.config.ColorModel = color.Palette(d.palette)
case pWhiteIsZero:
d.mode = mGrayInvert
if d.bpp == 16 {
d.config.ColorModel = color.Gray16Model
} else {
d.config.ColorModel = color.GrayModel
}
case pBlackIsZero:
d.mode = mGray
if d.bpp == 16 {
d.config.ColorModel = color.Gray16Model
} else {
d.config.ColorModel = color.GrayModel
}
default:
return nil, UnsupportedError("color model")
}
return d, nil
}
// DecodeConfig returns the color model and dimensions of a TIFF image without
// decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
d, err := newDecoder(r)
if err != nil {
return image.Config{}, err
}
return d.config, nil
}
func ccittFillOrder(tiffFillOrder uint) ccitt.Order {
if tiffFillOrder == 2 {
return ccitt.LSB
}
return ccitt.MSB
}
// Decode reads a TIFF image from r and returns it as an image.Image.
// The type of Image returned depends on the contents of the TIFF.
func Decode(r io.Reader) (img image.Image, err error) {
d, err := newDecoder(r)
if err != nil {
return
}
blockPadding := false
blockWidth := d.config.Width
blockHeight := d.config.Height
blocksAcross := 1
blocksDown := 1
if d.config.Width == 0 {
blocksAcross = 0
}
if d.config.Height == 0 {
blocksDown = 0
}
var blockOffsets, blockCounts []uint
if int(d.firstVal(tTileWidth)) != 0 {
blockPadding = true
blockWidth = int(d.firstVal(tTileWidth))
blockHeight = int(d.firstVal(tTileLength))
if blockWidth != 0 {
blocksAcross = (d.config.Width + blockWidth - 1) / blockWidth
}
if blockHeight != 0 {
blocksDown = (d.config.Height + blockHeight - 1) / blockHeight
}
blockCounts = d.features[tTileByteCounts]
blockOffsets = d.features[tTileOffsets]
} else {
if int(d.firstVal(tRowsPerStrip)) != 0 {
blockHeight = int(d.firstVal(tRowsPerStrip))
}
if blockHeight != 0 {
blocksDown = (d.config.Height + blockHeight - 1) / blockHeight
}
blockOffsets = d.features[tStripOffsets]
blockCounts = d.features[tStripByteCounts]
}
// Check if we have the right number of strips/tiles, offsets and counts.
if n := blocksAcross * blocksDown; len(blockOffsets) < n || len(blockCounts) < n {
return nil, FormatError("inconsistent header")
}
imgRect := image.Rect(0, 0, d.config.Width, d.config.Height)
switch d.mode {
case mGray, mGrayInvert:
if d.bpp == 16 {
img = image.NewGray16(imgRect)
} else {
img = image.NewGray(imgRect)
}
case mPaletted:
img = image.NewPaletted(imgRect, d.palette)
case mNRGBA:
if d.bpp == 16 {
img = image.NewNRGBA64(imgRect)
} else {
img = image.NewNRGBA(imgRect)
}
case mRGB, mRGBA:
if d.bpp == 16 {
img = image.NewRGBA64(imgRect)
} else {
img = image.NewRGBA(imgRect)
}
}
for i := 0; i < blocksAcross; i++ {
blkW := blockWidth
if !blockPadding && i == blocksAcross-1 && d.config.Width%blockWidth != 0 {
blkW = d.config.Width % blockWidth
}
for j := 0; j < blocksDown; j++ {
blkH := blockHeight
if !blockPadding && j == blocksDown-1 && d.config.Height%blockHeight != 0 {
blkH = d.config.Height % blockHeight
}
offset := int64(blockOffsets[j*blocksAcross+i])
n := int64(blockCounts[j*blocksAcross+i])
switch d.firstVal(tCompression) {
// According to the spec, Compression does not have a default value,
// but some tools interpret a missing Compression value as none so we do
// the same.
case cNone, 0:
if b, ok := d.r.(*buffer); ok {
d.buf, err = b.Slice(int(offset), int(n))
} else {
d.buf = make([]byte, n)
_, err = d.r.ReadAt(d.buf, offset)
}
case cG3:
inv := d.firstVal(tPhotometricInterpretation) == pWhiteIsZero
order := ccittFillOrder(d.firstVal(tFillOrder))
r := ccitt.NewReader(io.NewSectionReader(d.r, offset, n), order, ccitt.Group3, blkW, blkH, &ccitt.Options{Invert: inv, Align: false})
d.buf, err = ioutil.ReadAll(r)
case cG4:
inv := d.firstVal(tPhotometricInterpretation) == pWhiteIsZero
order := ccittFillOrder(d.firstVal(tFillOrder))
r := ccitt.NewReader(io.NewSectionReader(d.r, offset, n), order, ccitt.Group4, blkW, blkH, &ccitt.Options{Invert: inv, Align: false})
d.buf, err = ioutil.ReadAll(r)
case cLZW:
r := lzw.NewReader(io.NewSectionReader(d.r, offset, n), lzw.MSB, 8)
d.buf, err = ioutil.ReadAll(r)
r.Close()
case cDeflate, cDeflateOld:
var r io.ReadCloser
r, err = zlib.NewReader(io.NewSectionReader(d.r, offset, n))
if err != nil {
return nil, err
}
d.buf, err = ioutil.ReadAll(r)
r.Close()
case cPackBits:
d.buf, err = unpackBits(io.NewSectionReader(d.r, offset, n))
default:
err = UnsupportedError(fmt.Sprintf("compression value %d", d.firstVal(tCompression)))
}
if err != nil {
return nil, err
}
xmin := i * blockWidth
ymin := j * blockHeight
xmax := xmin + blkW
ymax := ymin + blkH
err = d.decode(img, xmin, ymin, xmax, ymax)
if err != nil {
return nil, err
}
}
}
return
}
func init() {
image.RegisterFormat("tiff", leHeader, Decode, DecodeConfig)
image.RegisterFormat("tiff", beHeader, Decode, DecodeConfig)
}

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vendor/golang.org/x/image/tiff/writer.go generated vendored Normal file
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@ -0,0 +1,441 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import (
"bytes"
"compress/zlib"
"encoding/binary"
"errors"
"image"
"io"
"sort"
)
// The TIFF format allows to choose the order of the different elements freely.
// The basic structure of a TIFF file written by this package is:
//
// 1. Header (8 bytes).
// 2. Image data.
// 3. Image File Directory (IFD).
// 4. "Pointer area" for larger entries in the IFD.
// We only write little-endian TIFF files.
var enc = binary.LittleEndian
// An ifdEntry is a single entry in an Image File Directory.
// A value of type dtRational is composed of two 32-bit values,
// thus data contains two uints (numerator and denominator) for a single number.
type ifdEntry struct {
tag int
datatype int
data []uint32
}
func (e ifdEntry) putData(p []byte) {
for _, d := range e.data {
switch e.datatype {
case dtByte, dtASCII:
p[0] = byte(d)
p = p[1:]
case dtShort:
enc.PutUint16(p, uint16(d))
p = p[2:]
case dtLong, dtRational:
enc.PutUint32(p, uint32(d))
p = p[4:]
}
}
}
type byTag []ifdEntry
func (d byTag) Len() int { return len(d) }
func (d byTag) Less(i, j int) bool { return d[i].tag < d[j].tag }
func (d byTag) Swap(i, j int) { d[i], d[j] = d[j], d[i] }
func encodeGray(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
if !predictor {
return writePix(w, pix, dy, dx, stride)
}
buf := make([]byte, dx)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx
off := 0
var v0 uint8
for i := min; i < max; i++ {
v1 := pix[i]
buf[off] = v1 - v0
v0 = v1
off++
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeGray16(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
buf := make([]byte, dx*2)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*2
off := 0
var v0 uint16
for i := min; i < max; i += 2 {
// An image.Gray16's Pix is in big-endian order.
v1 := uint16(pix[i])<<8 | uint16(pix[i+1])
if predictor {
v0, v1 = v1, v1-v0
}
// We only write little-endian TIFF files.
buf[off+0] = byte(v1)
buf[off+1] = byte(v1 >> 8)
off += 2
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
if !predictor {
return writePix(w, pix, dy, dx*4, stride)
}
buf := make([]byte, dx*4)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*4
off := 0
var r0, g0, b0, a0 uint8
for i := min; i < max; i += 4 {
r1, g1, b1, a1 := pix[i+0], pix[i+1], pix[i+2], pix[i+3]
buf[off+0] = r1 - r0
buf[off+1] = g1 - g0
buf[off+2] = b1 - b0
buf[off+3] = a1 - a0
off += 4
r0, g0, b0, a0 = r1, g1, b1, a1
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeRGBA64(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
buf := make([]byte, dx*8)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*8
off := 0
var r0, g0, b0, a0 uint16
for i := min; i < max; i += 8 {
// An image.RGBA64's Pix is in big-endian order.
r1 := uint16(pix[i+0])<<8 | uint16(pix[i+1])
g1 := uint16(pix[i+2])<<8 | uint16(pix[i+3])
b1 := uint16(pix[i+4])<<8 | uint16(pix[i+5])
a1 := uint16(pix[i+6])<<8 | uint16(pix[i+7])
if predictor {
r0, r1 = r1, r1-r0
g0, g1 = g1, g1-g0
b0, b1 = b1, b1-b0
a0, a1 = a1, a1-a0
}
// We only write little-endian TIFF files.
buf[off+0] = byte(r1)
buf[off+1] = byte(r1 >> 8)
buf[off+2] = byte(g1)
buf[off+3] = byte(g1 >> 8)
buf[off+4] = byte(b1)
buf[off+5] = byte(b1 >> 8)
buf[off+6] = byte(a1)
buf[off+7] = byte(a1 >> 8)
off += 8
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encode(w io.Writer, m image.Image, predictor bool) error {
bounds := m.Bounds()
buf := make([]byte, 4*bounds.Dx())
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
off := 0
if predictor {
var r0, g0, b0, a0 uint8
for x := bounds.Min.X; x < bounds.Max.X; x++ {
r, g, b, a := m.At(x, y).RGBA()
r1 := uint8(r >> 8)
g1 := uint8(g >> 8)
b1 := uint8(b >> 8)
a1 := uint8(a >> 8)
buf[off+0] = r1 - r0
buf[off+1] = g1 - g0
buf[off+2] = b1 - b0
buf[off+3] = a1 - a0
off += 4
r0, g0, b0, a0 = r1, g1, b1, a1
}
} else {
for x := bounds.Min.X; x < bounds.Max.X; x++ {
r, g, b, a := m.At(x, y).RGBA()
buf[off+0] = uint8(r >> 8)
buf[off+1] = uint8(g >> 8)
buf[off+2] = uint8(b >> 8)
buf[off+3] = uint8(a >> 8)
off += 4
}
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
// writePix writes the internal byte array of an image to w. It is less general
// but much faster then encode. writePix is used when pix directly
// corresponds to one of the TIFF image types.
func writePix(w io.Writer, pix []byte, nrows, length, stride int) error {
if length == stride {
_, err := w.Write(pix[:nrows*length])
return err
}
for ; nrows > 0; nrows-- {
if _, err := w.Write(pix[:length]); err != nil {
return err
}
pix = pix[stride:]
}
return nil
}
func writeIFD(w io.Writer, ifdOffset int, d []ifdEntry) error {
var buf [ifdLen]byte
// Make space for "pointer area" containing IFD entry data
// longer than 4 bytes.
parea := make([]byte, 1024)
pstart := ifdOffset + ifdLen*len(d) + 6
var o int // Current offset in parea.
// The IFD has to be written with the tags in ascending order.
sort.Sort(byTag(d))
// Write the number of entries in this IFD.
if err := binary.Write(w, enc, uint16(len(d))); err != nil {
return err
}
for _, ent := range d {
enc.PutUint16(buf[0:2], uint16(ent.tag))
enc.PutUint16(buf[2:4], uint16(ent.datatype))
count := uint32(len(ent.data))
if ent.datatype == dtRational {
count /= 2
}
enc.PutUint32(buf[4:8], count)
datalen := int(count * lengths[ent.datatype])
if datalen <= 4 {
ent.putData(buf[8:12])
} else {
if (o + datalen) > len(parea) {
newlen := len(parea) + 1024
for (o + datalen) > newlen {
newlen += 1024
}
newarea := make([]byte, newlen)
copy(newarea, parea)
parea = newarea
}
ent.putData(parea[o : o+datalen])
enc.PutUint32(buf[8:12], uint32(pstart+o))
o += datalen
}
if _, err := w.Write(buf[:]); err != nil {
return err
}
}
// The IFD ends with the offset of the next IFD in the file,
// or zero if it is the last one (page 14).
if err := binary.Write(w, enc, uint32(0)); err != nil {
return err
}
_, err := w.Write(parea[:o])
return err
}
// Options are the encoding parameters.
type Options struct {
// Compression is the type of compression used.
Compression CompressionType
// Predictor determines whether a differencing predictor is used;
// if true, instead of each pixel's color, the color difference to the
// preceding one is saved. This improves the compression for certain
// types of images and compressors. For example, it works well for
// photos with Deflate compression.
Predictor bool
}
// Encode writes the image m to w. opt determines the options used for
// encoding, such as the compression type. If opt is nil, an uncompressed
// image is written.
func Encode(w io.Writer, m image.Image, opt *Options) error {
d := m.Bounds().Size()
compression := uint32(cNone)
predictor := false
if opt != nil {
compression = opt.Compression.specValue()
// The predictor field is only used with LZW. See page 64 of the spec.
predictor = opt.Predictor && compression == cLZW
}
_, err := io.WriteString(w, leHeader)
if err != nil {
return err
}
// Compressed data is written into a buffer first, so that we
// know the compressed size.
var buf bytes.Buffer
// dst holds the destination for the pixel data of the image --
// either w or a writer to buf.
var dst io.Writer
// imageLen is the length of the pixel data in bytes.
// The offset of the IFD is imageLen + 8 header bytes.
var imageLen int
switch compression {
case cNone:
dst = w
// Write IFD offset before outputting pixel data.
switch m.(type) {
case *image.Paletted:
imageLen = d.X * d.Y * 1
case *image.Gray:
imageLen = d.X * d.Y * 1
case *image.Gray16:
imageLen = d.X * d.Y * 2
case *image.RGBA64:
imageLen = d.X * d.Y * 8
case *image.NRGBA64:
imageLen = d.X * d.Y * 8
default:
imageLen = d.X * d.Y * 4
}
err = binary.Write(w, enc, uint32(imageLen+8))
if err != nil {
return err
}
case cDeflate:
dst = zlib.NewWriter(&buf)
default:
return errors.New("tiff: unsupported compression")
}
pr := uint32(prNone)
photometricInterpretation := uint32(pRGB)
samplesPerPixel := uint32(4)
bitsPerSample := []uint32{8, 8, 8, 8}
extraSamples := uint32(0)
colorMap := []uint32{}
if predictor {
pr = prHorizontal
}
switch m := m.(type) {
case *image.Paletted:
photometricInterpretation = pPaletted
samplesPerPixel = 1
bitsPerSample = []uint32{8}
colorMap = make([]uint32, 256*3)
for i := 0; i < 256 && i < len(m.Palette); i++ {
r, g, b, _ := m.Palette[i].RGBA()
colorMap[i+0*256] = uint32(r)
colorMap[i+1*256] = uint32(g)
colorMap[i+2*256] = uint32(b)
}
err = encodeGray(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.Gray:
photometricInterpretation = pBlackIsZero
samplesPerPixel = 1
bitsPerSample = []uint32{8}
err = encodeGray(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.Gray16:
photometricInterpretation = pBlackIsZero
samplesPerPixel = 1
bitsPerSample = []uint32{16}
err = encodeGray16(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.NRGBA:
extraSamples = 2 // Unassociated alpha.
err = encodeRGBA(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.NRGBA64:
extraSamples = 2 // Unassociated alpha.
bitsPerSample = []uint32{16, 16, 16, 16}
err = encodeRGBA64(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.RGBA:
extraSamples = 1 // Associated alpha.
err = encodeRGBA(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.RGBA64:
extraSamples = 1 // Associated alpha.
bitsPerSample = []uint32{16, 16, 16, 16}
err = encodeRGBA64(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
default:
extraSamples = 1 // Associated alpha.
err = encode(dst, m, predictor)
}
if err != nil {
return err
}
if compression != cNone {
if err = dst.(io.Closer).Close(); err != nil {
return err
}
imageLen = buf.Len()
if err = binary.Write(w, enc, uint32(imageLen+8)); err != nil {
return err
}
if _, err = buf.WriteTo(w); err != nil {
return err
}
}
ifd := []ifdEntry{
{tImageWidth, dtShort, []uint32{uint32(d.X)}},
{tImageLength, dtShort, []uint32{uint32(d.Y)}},
{tBitsPerSample, dtShort, bitsPerSample},
{tCompression, dtShort, []uint32{compression}},
{tPhotometricInterpretation, dtShort, []uint32{photometricInterpretation}},
{tStripOffsets, dtLong, []uint32{8}},
{tSamplesPerPixel, dtShort, []uint32{samplesPerPixel}},
{tRowsPerStrip, dtShort, []uint32{uint32(d.Y)}},
{tStripByteCounts, dtLong, []uint32{uint32(imageLen)}},
// There is currently no support for storing the image
// resolution, so give a bogus value of 72x72 dpi.
{tXResolution, dtRational, []uint32{72, 1}},
{tYResolution, dtRational, []uint32{72, 1}},
{tResolutionUnit, dtShort, []uint32{resPerInch}},
}
if pr != prNone {
ifd = append(ifd, ifdEntry{tPredictor, dtShort, []uint32{pr}})
}
if len(colorMap) != 0 {
ifd = append(ifd, ifdEntry{tColorMap, dtShort, colorMap})
}
if extraSamples > 0 {
ifd = append(ifd, ifdEntry{tExtraSamples, dtShort, []uint32{extraSamples}})
}
return writeIFD(w, imageLen+8, ifd)
}

4
vendor/modules.txt vendored
View File

@ -15,7 +15,11 @@ github.com/spf13/cobra
github.com/spf13/pflag
# golang.org/x/image v0.1.0
## explicit; go 1.12
golang.org/x/image/bmp
golang.org/x/image/ccitt
golang.org/x/image/riff
golang.org/x/image/tiff
golang.org/x/image/tiff/lzw
golang.org/x/image/vp8
golang.org/x/image/vp8l
golang.org/x/image/webp