/* * jpegicc.c * * 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 (C) 1998-2006 Tom Lane and Marti Maria * * 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 * * * jpegicc.c * * 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. If you need to do that, * change all the "unsigned int" variables to "INT32". You'll also need * to find a malloc() replacement that can allocate more than 64K. */ #include #include #include "jpegicc.h" /* * Since an ICC profile can be larger than the maximum size of a JPEG marker * (64K), we need provisions to split it into multiple markers. The format * defined by the ICC specifies one or more APP2 markers containing the * following data: * Identifying string ASCII "ICC_PROFILE\0" (12 bytes) * Marker sequence number 1 for first APP2, 2 for next, etc (1 byte) * Number of markers Total number of APP2's used (1 byte) * Profile data (remainder of APP2 data) * Decoders should use the marker sequence numbers to reassemble the profile, * rather than assuming that the APP2 markers appear in the correct sequence. */ #define ICC_MARKER (JPEG_APP0 + 2) /* JPEG marker code for ICC */ #define ICC_OVERHEAD_LEN 14 /* size of non-profile data in APP2 */ #define MAX_BYTES_IN_MARKER 65533 /* maximum data len of a JPEG marker */ #define MAX_DATA_BYTES_IN_MARKER (MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN) /* * 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.) */ void jpegICCWriteProfile(j_compress_ptr cinfo, const JOCTET *icc_data_ptr, unsigned int icc_data_len) { unsigned int num_markers; /* total number of markers we'll write */ int cur_marker = 1; /* per spec, counting starts at 1 */ unsigned int length; /* number of bytes to write in this marker */ /* Calculate the number of markers we'll need, rounding up of course */ num_markers = icc_data_len / MAX_DATA_BYTES_IN_MARKER; if (num_markers * MAX_DATA_BYTES_IN_MARKER != icc_data_len) num_markers++; while (icc_data_len > 0) { /* length of profile to put in this marker */ length = icc_data_len; if (length > MAX_DATA_BYTES_IN_MARKER) length = MAX_DATA_BYTES_IN_MARKER; icc_data_len -= length; /* Write the JPEG marker header (APP2 code and marker length) */ jpeg_write_m_header(cinfo, ICC_MARKER, (unsigned int) (length + ICC_OVERHEAD_LEN)); /* Write the marker identifying string "ICC_PROFILE" (null-terminated). * We code it in this less-than-transparent way so that the code works * even if the local character set is not ASCII. */ jpeg_write_m_byte(cinfo, 0x49); jpeg_write_m_byte(cinfo, 0x43); jpeg_write_m_byte(cinfo, 0x43); jpeg_write_m_byte(cinfo, 0x5F); jpeg_write_m_byte(cinfo, 0x50); jpeg_write_m_byte(cinfo, 0x52); jpeg_write_m_byte(cinfo, 0x4F); jpeg_write_m_byte(cinfo, 0x46); jpeg_write_m_byte(cinfo, 0x49); jpeg_write_m_byte(cinfo, 0x4C); jpeg_write_m_byte(cinfo, 0x45); jpeg_write_m_byte(cinfo, 0x0); /* Add the sequencing info */ jpeg_write_m_byte(cinfo, cur_marker); jpeg_write_m_byte(cinfo, (int) num_markers); /* Add the profile data */ while (length--) { jpeg_write_m_byte(cinfo, *icc_data_ptr); icc_data_ptr++; } cur_marker++; } } /* * 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 */ void jpegICCSetupReadICCProfile(j_decompress_ptr cinfo) { /* Tell the library to keep any APP2 data it may find */ jpeg_save_markers(cinfo, ICC_MARKER, 0xFFFF); } /* * Handy subroutine to test whether a saved marker is an ICC profile marker. */ static boolean marker_is_icc (jpeg_saved_marker_ptr marker) { return marker->marker == ICC_MARKER && marker->data_length >= ICC_OVERHEAD_LEN && /* verify the identifying string */ GETJOCTET(marker->data[0]) == 0x49 && GETJOCTET(marker->data[1]) == 0x43 && GETJOCTET(marker->data[2]) == 0x43 && GETJOCTET(marker->data[3]) == 0x5F && GETJOCTET(marker->data[4]) == 0x50 && GETJOCTET(marker->data[5]) == 0x52 && GETJOCTET(marker->data[6]) == 0x4F && GETJOCTET(marker->data[7]) == 0x46 && GETJOCTET(marker->data[8]) == 0x49 && GETJOCTET(marker->data[9]) == 0x4C && GETJOCTET(marker->data[10]) == 0x45 && GETJOCTET(marker->data[11]) == 0x0; } /* * 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.) * * NOTE: if the file contains invalid ICC APP2 markers, we just silently * return FALSE. You might want to issue an error message instead. */ boolean jpegICCReadProfile(j_decompress_ptr cinfo, JOCTET **icc_data_ptr, unsigned int *icc_data_len) { jpeg_saved_marker_ptr marker; int num_markers = 0; int seq_no; JOCTET *icc_data; unsigned int total_length; #define MAX_SEQ_NO 255 /* sufficient since marker numbers are bytes */ char marker_present[MAX_SEQ_NO+1]; /* 1 if marker found */ unsigned int data_length[MAX_SEQ_NO+1]; /* size of profile data in marker */ unsigned int data_offset[MAX_SEQ_NO+1]; /* offset for data in marker */ *icc_data_ptr = NULL; /* avoid confusion if FALSE return */ *icc_data_len = 0; /* This first pass over the saved markers discovers whether there are * any ICC markers and verifies the consistency of the marker numbering. */ for (seq_no = 1; seq_no <= MAX_SEQ_NO; seq_no++) marker_present[seq_no] = 0; for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) { if (marker_is_icc(marker)) { if (num_markers == 0) num_markers = GETJOCTET(marker->data[13]); else if (num_markers != GETJOCTET(marker->data[13])) return FALSE; /* inconsistent num_markers fields */ seq_no = GETJOCTET(marker->data[12]); if (seq_no <= 0 || seq_no > num_markers) return FALSE; /* bogus sequence number */ if (marker_present[seq_no]) return FALSE; /* duplicate sequence numbers */ marker_present[seq_no] = 1; data_length[seq_no] = marker->data_length - ICC_OVERHEAD_LEN; } } if (num_markers == 0) return FALSE; /* Check for missing markers, count total space needed, * compute offset of each marker's part of the data. */ total_length = 0; for (seq_no = 1; seq_no <= num_markers; seq_no++) { if (marker_present[seq_no] == 0) return FALSE; /* missing sequence number */ data_offset[seq_no] = total_length; total_length += data_length[seq_no]; } if (total_length <= 0) return FALSE; /* found only empty markers? */ /* Allocate space for assembled data */ icc_data = (JOCTET *) malloc(total_length * sizeof(JOCTET)); if (icc_data == NULL) return FALSE; /* oops, out of memory */ /* and fill it in */ for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) { if (marker_is_icc(marker)) { JOCTET FAR *src_ptr; JOCTET *dst_ptr; unsigned int length; seq_no = GETJOCTET(marker->data[12]); dst_ptr = icc_data + data_offset[seq_no]; src_ptr = marker->data + ICC_OVERHEAD_LEN; length = data_length[seq_no]; while (length--) { *dst_ptr++ = *src_ptr++; } } } *icc_data_ptr = icc_data; *icc_data_len = total_length; return TRUE; }