1 /* 2 * iccprofile.h 3 * 4 * This file provides code to read and write International Color Consortium 5 * (ICC) device profiles embedded in JFIF JPEG image files. The ICC has 6 * defined a standard format for including such data in JPEG "APP2" markers. 7 * The code given here does not know anything about the internal structure 8 * of the ICC profile data; it just knows how to put the profile data into 9 * a JPEG file being written, or get it back out when reading. 10 * 11 * This code depends on new features added to the IJG JPEG library as of 12 * IJG release 6b; it will not compile or work with older IJG versions. 13 * 14 * NOTE: this code would need surgery to work on 16-bit-int machines 15 * with ICC profiles exceeding 64K bytes in size. See iccprofile.c 16 * for details. 17 */ 18 19 #include <stdio.h> /* needed to define "FILE", "NULL" */ 20 21 #if defined(USE_SYSTEM_LIBJPEG) 22 #include <jpeglib.h> 23 #else 24 #include "jpeglib.h" 25 #endif 26 27 28 /* 29 * This routine writes the given ICC profile data into a JPEG file. 30 * It *must* be called AFTER calling jpeg_start_compress() and BEFORE 31 * the first call to jpeg_write_scanlines(). 32 * (This ordering ensures that the APP2 marker(s) will appear after the 33 * SOI and JFIF or Adobe markers, but before all else.) 34 */ 35 36 extern void write_icc_profile JPP((j_compress_ptr cinfo, 37 const JOCTET *icc_data_ptr, 38 unsigned int icc_data_len)); 39 40 41 /* 42 * Reading a JPEG file that may contain an ICC profile requires two steps: 43 * 44 * 1. After jpeg_create_decompress() but before jpeg_read_header(), 45 * call setup_read_icc_profile(). This routine tells the IJG library 46 * to save in memory any APP2 markers it may find in the file. 47 * 48 * 2. After jpeg_read_header(), call read_icc_profile() to find out 49 * whether there was a profile and obtain it if so. 50 */ 51 52 53 /* 54 * Prepare for reading an ICC profile 55 */ 56 57 extern void setup_read_icc_profile JPP((j_decompress_ptr cinfo)); 58 59 60 /* 61 * See if there was an ICC profile in the JPEG file being read; 62 * if so, reassemble and return the profile data. 63 * 64 * TRUE is returned if an ICC profile was found, FALSE if not. 65 * If TRUE is returned, *icc_data_ptr is set to point to the 66 * returned data, and *icc_data_len is set to its length. 67 * 68 * IMPORTANT: the data at **icc_data_ptr has been allocated with malloc() 69 * and must be freed by the caller with free() when the caller no longer 70 * needs it. (Alternatively, we could write this routine to use the 71 * IJG library's memory allocator, so that the data would be freed implicitly 72 * at jpeg_finish_decompress() time. But it seems likely that many apps 73 * will prefer to have the data stick around after decompression finishes.) 74 */ 75 76 extern boolean read_icc_profile JPP((j_decompress_ptr cinfo, 77 JOCTET **icc_data_ptr, 78 unsigned int *icc_data_len)); 79