File indexing completed on 2025-01-19 03:55:55

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 1998-01-25
  * Description : helper methods to handle ICC color profile with JPEG file.
  *
  * SPDX-FileCopyrightText: 1998-2004 by Marti Maria <info at littlecms dot com>
  * SPDX-FileCopyrightText: 2005-2024 by Gilles Caulier <caulier dot gilles at gmail dot com>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 /**
  * Notes from Little CMS project (www.littlecms.com)
  *
  * 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.
  *
  * This code would need surgery to work on 16-bit-int machines
  * with ICC profiles exceeding 64K bytes in size. See iccjpeg.c
  * for details.
  */
 
 #ifndef DIGIKAM_ICC_JPEG_H
 #define DIGIKAM_ICC_JPEG_H
 
 #include <stdio.h>    /* needed to define "FILE", "NULL" */
 #include <jpeglib.h>
 
 #include "digikam_export.h"
 
 /**
  * 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.)
  */
 DIGIKAM_EXPORT extern void write_icc_profile JPP((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
  */
 DIGIKAM_EXPORT extern void setup_read_icc_profile JPP((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.)
  */
 DIGIKAM_EXPORT extern boolean read_icc_profile JPP((j_decompress_ptr cinfo,
                                                    JOCTET** icc_data_ptr,
                                                    unsigned int* icc_data_len));
 
 #endif /* DIGIKAM_ICC_JPEG_H */