74 lines
2.7 KiB
C
74 lines
2.7 KiB
C
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/*
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* iccprofile.h
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*
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* This file provides code to read and write International Color Consortium
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* (ICC) device profiles embedded in JFIF JPEG image files. The ICC has
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* defined a standard format for including such data in JPEG "APP2" markers.
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* The code given here does not know anything about the internal structure
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* of the ICC profile data; it just knows how to put the profile data into
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* a JPEG file being written, or get it back out when reading.
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*
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* This code depends on new features added to the IJG JPEG library as of
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* IJG release 6b; it will not compile or work with older IJG versions.
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*
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* NOTE: this code would need surgery to work on 16-bit-int machines
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* with ICC profiles exceeding 64K bytes in size. See iccprofile.c
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* for details.
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*/
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#include <stdio.h> /* needed to define "FILE", "NULL" */
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#include "jpeglib.h"
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/*
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* This routine writes the given ICC profile data into a JPEG file.
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* It *must* be called AFTER calling jpeg_start_compress() and BEFORE
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* the first call to jpeg_write_scanlines().
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* (This ordering ensures that the APP2 marker(s) will appear after the
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* SOI and JFIF or Adobe markers, but before all else.)
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*/
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extern void write_icc_profile JPP((j_compress_ptr cinfo,
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const JOCTET *icc_data_ptr,
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unsigned int icc_data_len));
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/*
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* Reading a JPEG file that may contain an ICC profile requires two steps:
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*
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* 1. After jpeg_create_decompress() but before jpeg_read_header(),
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* call setup_read_icc_profile(). This routine tells the IJG library
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* to save in memory any APP2 markers it may find in the file.
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*
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* 2. After jpeg_read_header(), call read_icc_profile() to find out
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* whether there was a profile and obtain it if so.
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*/
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/*
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* Prepare for reading an ICC profile
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*/
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extern void setup_read_icc_profile JPP((j_decompress_ptr cinfo));
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/*
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* See if there was an ICC profile in the JPEG file being read;
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* if so, reassemble and return the profile data.
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*
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* TRUE is returned if an ICC profile was found, FALSE if not.
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* If TRUE is returned, *icc_data_ptr is set to point to the
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* returned data, and *icc_data_len is set to its length.
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*
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* IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
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* and must be freed by the caller with free() when the caller no longer
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* needs it. (Alternatively, we could write this routine to use the
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* IJG library's memory allocator, so that the data would be freed implicitly
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* at jpeg_finish_decompress() time. But it seems likely that many apps
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* will prefer to have the data stick around after decompression finishes.)
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*/
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extern boolean read_icc_profile JPP((j_decompress_ptr cinfo,
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JOCTET **icc_data_ptr,
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unsigned int *icc_data_len));
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