1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/image/decoders/iccjpeg.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,187 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +/*
1.9 + * iccprofile.c
1.10 + *
1.11 + * This file provides code to read and write International Color Consortium
1.12 + * (ICC) device profiles embedded in JFIF JPEG image files. The ICC has
1.13 + * defined a standard format for including such data in JPEG "APP2" markers.
1.14 + * The code given here does not know anything about the internal structure
1.15 + * of the ICC profile data; it just knows how to put the profile data into
1.16 + * a JPEG file being written, or get it back out when reading.
1.17 + *
1.18 + * This code depends on new features added to the IJG JPEG library as of
1.19 + * IJG release 6b; it will not compile or work with older IJG versions.
1.20 + *
1.21 + * NOTE: this code would need surgery to work on 16-bit-int machines
1.22 + * with ICC profiles exceeding 64K bytes in size. If you need to do that,
1.23 + * change all the "unsigned int" variables to "INT32". You'll also need
1.24 + * to find a malloc() replacement that can allocate more than 64K.
1.25 + */
1.26 +
1.27 +#include "iccjpeg.h"
1.28 +#include <stdlib.h> /* define malloc() */
1.29 +
1.30 +
1.31 +/*
1.32 + * Since an ICC profile can be larger than the maximum size of a JPEG marker
1.33 + * (64K), we need provisions to split it into multiple markers. The format
1.34 + * defined by the ICC specifies one or more APP2 markers containing the
1.35 + * following data:
1.36 + * Identifying string ASCII "ICC_PROFILE\0" (12 bytes)
1.37 + * Marker sequence number 1 for first APP2, 2 for next, etc (1 byte)
1.38 + * Number of markers Total number of APP2's used (1 byte)
1.39 + * Profile data (remainder of APP2 data)
1.40 + * Decoders should use the marker sequence numbers to reassemble the profile,
1.41 + * rather than assuming that the APP2 markers appear in the correct sequence.
1.42 + */
1.43 +
1.44 +#define ICC_MARKER (JPEG_APP0 + 2) /* JPEG marker code for ICC */
1.45 +#define ICC_OVERHEAD_LEN 14 /* size of non-profile data in APP2 */
1.46 +#define MAX_BYTES_IN_MARKER 65533 /* maximum data len of a JPEG marker */
1.47 +#define MAX_DATA_BYTES_IN_MARKER (MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN)
1.48 +
1.49 +/*
1.50 + * Prepare for reading an ICC profile
1.51 + */
1.52 +
1.53 +void
1.54 +setup_read_icc_profile (j_decompress_ptr cinfo)
1.55 +{
1.56 + /* Tell the library to keep any APP2 data it may find */
1.57 + jpeg_save_markers(cinfo, ICC_MARKER, 0xFFFF);
1.58 +}
1.59 +
1.60 +
1.61 +/*
1.62 + * Handy subroutine to test whether a saved marker is an ICC profile marker.
1.63 + */
1.64 +
1.65 +static boolean
1.66 +marker_is_icc (jpeg_saved_marker_ptr marker)
1.67 +{
1.68 + return
1.69 + marker->marker == ICC_MARKER &&
1.70 + marker->data_length >= ICC_OVERHEAD_LEN &&
1.71 + /* verify the identifying string */
1.72 + GETJOCTET(marker->data[0]) == 0x49 &&
1.73 + GETJOCTET(marker->data[1]) == 0x43 &&
1.74 + GETJOCTET(marker->data[2]) == 0x43 &&
1.75 + GETJOCTET(marker->data[3]) == 0x5F &&
1.76 + GETJOCTET(marker->data[4]) == 0x50 &&
1.77 + GETJOCTET(marker->data[5]) == 0x52 &&
1.78 + GETJOCTET(marker->data[6]) == 0x4F &&
1.79 + GETJOCTET(marker->data[7]) == 0x46 &&
1.80 + GETJOCTET(marker->data[8]) == 0x49 &&
1.81 + GETJOCTET(marker->data[9]) == 0x4C &&
1.82 + GETJOCTET(marker->data[10]) == 0x45 &&
1.83 + GETJOCTET(marker->data[11]) == 0x0;
1.84 +}
1.85 +
1.86 +
1.87 +/*
1.88 + * See if there was an ICC profile in the JPEG file being read;
1.89 + * if so, reassemble and return the profile data.
1.90 + *
1.91 + * TRUE is returned if an ICC profile was found, FALSE if not.
1.92 + * If TRUE is returned, *icc_data_ptr is set to point to the
1.93 + * returned data, and *icc_data_len is set to its length.
1.94 + *
1.95 + * IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
1.96 + * and must be freed by the caller with free() when the caller no longer
1.97 + * needs it. (Alternatively, we could write this routine to use the
1.98 + * IJG library's memory allocator, so that the data would be freed implicitly
1.99 + * at jpeg_finish_decompress() time. But it seems likely that many apps
1.100 + * will prefer to have the data stick around after decompression finishes.)
1.101 + *
1.102 + * NOTE: if the file contains invalid ICC APP2 markers, we just silently
1.103 + * return FALSE. You might want to issue an error message instead.
1.104 + */
1.105 +
1.106 +boolean
1.107 +read_icc_profile (j_decompress_ptr cinfo,
1.108 + JOCTET **icc_data_ptr,
1.109 + unsigned int *icc_data_len)
1.110 +{
1.111 + jpeg_saved_marker_ptr marker;
1.112 + int num_markers = 0;
1.113 + int seq_no;
1.114 + JOCTET *icc_data;
1.115 + unsigned int total_length;
1.116 +#define MAX_SEQ_NO 255 /* sufficient since marker numbers are bytes */
1.117 + char marker_present[MAX_SEQ_NO+1]; /* 1 if marker found */
1.118 + unsigned int data_length[MAX_SEQ_NO+1]; /* size of profile data in marker */
1.119 + unsigned int data_offset[MAX_SEQ_NO+1]; /* offset for data in marker */
1.120 +
1.121 + *icc_data_ptr = NULL; /* avoid confusion if FALSE return */
1.122 + *icc_data_len = 0;
1.123 +
1.124 + /* This first pass over the saved markers discovers whether there are
1.125 + * any ICC markers and verifies the consistency of the marker numbering.
1.126 + */
1.127 +
1.128 + for (seq_no = 1; seq_no <= MAX_SEQ_NO; seq_no++)
1.129 + marker_present[seq_no] = 0;
1.130 +
1.131 + for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
1.132 + if (marker_is_icc(marker)) {
1.133 + if (num_markers == 0)
1.134 + num_markers = GETJOCTET(marker->data[13]);
1.135 + else if (num_markers != GETJOCTET(marker->data[13]))
1.136 + return FALSE; /* inconsistent num_markers fields */
1.137 + seq_no = GETJOCTET(marker->data[12]);
1.138 + if (seq_no <= 0 || seq_no > num_markers)
1.139 + return FALSE; /* bogus sequence number */
1.140 + if (marker_present[seq_no])
1.141 + return FALSE; /* duplicate sequence numbers */
1.142 + marker_present[seq_no] = 1;
1.143 + data_length[seq_no] = marker->data_length - ICC_OVERHEAD_LEN;
1.144 + }
1.145 + }
1.146 +
1.147 + if (num_markers == 0)
1.148 + return FALSE;
1.149 +
1.150 + /* Check for missing markers, count total space needed,
1.151 + * compute offset of each marker's part of the data.
1.152 + */
1.153 +
1.154 + total_length = 0;
1.155 + for (seq_no = 1; seq_no <= num_markers; seq_no++) {
1.156 + if (marker_present[seq_no] == 0)
1.157 + return FALSE; /* missing sequence number */
1.158 + data_offset[seq_no] = total_length;
1.159 + total_length += data_length[seq_no];
1.160 + }
1.161 +
1.162 + if (total_length <= 0)
1.163 + return FALSE; /* found only empty markers? */
1.164 +
1.165 + /* Allocate space for assembled data */
1.166 + icc_data = (JOCTET *) malloc(total_length * sizeof(JOCTET));
1.167 + if (icc_data == NULL)
1.168 + return FALSE; /* oops, out of memory */
1.169 +
1.170 + /* and fill it in */
1.171 + for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
1.172 + if (marker_is_icc(marker)) {
1.173 + JOCTET FAR *src_ptr;
1.174 + JOCTET *dst_ptr;
1.175 + unsigned int length;
1.176 + seq_no = GETJOCTET(marker->data[12]);
1.177 + dst_ptr = icc_data + data_offset[seq_no];
1.178 + src_ptr = marker->data + ICC_OVERHEAD_LEN;
1.179 + length = data_length[seq_no];
1.180 + while (length--) {
1.181 + *dst_ptr++ = *src_ptr++;
1.182 + }
1.183 + }
1.184 + }
1.185 +
1.186 + *icc_data_ptr = icc_data;
1.187 + *icc_data_len = total_length;
1.188 +
1.189 + return TRUE;
1.190 +}
