* This source file was originally part of the LCMS package. I asked
* Marti for permission to change its license from MIT to GPL (Aug 4,
* 2006). Daniel German
* Copyright Tom Lane and Marti Maria
* Dec 2006
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
* You should have received a copy of the GNU General Public
* License along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* Author: Tom Lane and Marti Maria
* This file provides code to read and write International Color Consortium
* (ICC) device profiles embedded in JFIF JPEG image files. The ICC has
* defined a standard format for including such data in JPEG "APP2" markers.
* The code given here does not know anything about the internal structure
* of the ICC profile data; it just knows how to put the profile data into
* a JPEG file being written, or get it back out when reading.
* This code depends on new features added to the IJG JPEG library as of
* IJG release 6b; it will not compile or work with older IJG versions.
* NOTE: this code would need surgery to work on 16-bit-int machines
* with ICC profiles exceeding 64K bytes in size. See iccprofile.c
* for details.
* This routine writes the given ICC profile data into a JPEG file.
* It *must* be called AFTER calling jpeg_start_compress() and BEFORE
* the first call to jpeg_write_scanlines().
* (This ordering ensures that the APP2 marker(s) will appear after the
* SOI and JFIF or Adobe markers, but before all else.)
extern void jpegICCWriteProfile(j_compress_ptr cinfo,
const JOCTET *icc_data_ptr,
unsigned int icc_data_len);
* Reading a JPEG file that may contain an ICC profile requires two steps:
* 1. After jpeg_create_decompress() but before jpeg_read_header(),
* call setup_read_icc_profile(). This routine tells the IJG library
* to save in memory any APP2 markers it may find in the file.
* 2. After jpeg_read_header(), call read_icc_profile() to find out
* whether there was a profile and obtain it if so.
* Prepare for reading an ICC profile
extern void jpegICCSetupReadICCProfile(j_decompress_ptr cinfo);
* See if there was an ICC profile in the JPEG file being read;
* if so, reassemble and return the profile data.
* TRUE is returned if an ICC profile was found, FALSE if not.
* If TRUE is returned, *icc_data_ptr is set to point to the
* returned data, and *icc_data_len is set to its length.
* IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
* and must be freed by the caller with free() when the caller no longer
* needs it. (Alternatively, we could write this routine to use the
* IJG library's memory allocator, so that the data would be freed implicitly
* at jpeg_finish_decompress() time. But it seems likely that many apps
* will prefer to have the data stick around after decompression finishes.)
extern boolean jpegICCReadProfile(j_decompress_ptr cinfo,
unsigned int *icc_data_len);