jdicc.c
/*
* jdicc.c
*
* Copyright (C) 1997-1998, Thomas G. Lane, Todd Newman.
* Copyright (C) 2017, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
* This file provides code to read International Color Consortium (ICC) device
* profiles embedded in JFIF JPEG image files. The ICC has defined a standard
* 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 get the profile data from a JPEG file while reading it.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jerror.h"
#define ICC_MARKER (JPEG_APP0 + 2) /* JPEG marker code for ICC */
#define ICC_OVERHEAD_LEN 14 /* size of non-profile data in APP2 */
/*
* Handy subroutine to test whether a saved marker is an ICC profile marker.
*/
LOCAL(boolean)
marker_is_icc(jpeg_saved_marker_ptr marker)
{
return
marker->marker == ICC_MARKER &&
marker->data_length >= ICC_OVERHEAD_LEN &&
/* verify the identifying string */
marker->data[0] == 0x49 &&
marker->data[1] == 0x43 &&
marker->data[2] == 0x43 &&
marker->data[3] == 0x5F &&
marker->data[4] == 0x50 &&
marker->data[5] == 0x52 &&
marker->data[6] == 0x4F &&
marker->data[7] == 0x46 &&
marker->data[8] == 0x49 &&
marker->data[9] == 0x4C &&
marker->data[10] == 0x45 &&
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 is 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 when
* jpeg_finish_decompress() is called. But it seems likely that many
* applications will prefer to have the data stick around after decompression
* finishes.)
*/
GLOBAL(boolean)
jpeg_read_icc_profile(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 */
if (icc_data_ptr == NULL || icc_data_len == NULL)
ERREXIT(cinfo, JERR_BUFFER_SIZE);
if (cinfo->global_state < DSTATE_READY)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
*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 = marker->data[13];
else if (num_markers != marker->data[13]) {
WARNMS(cinfo, JWRN_BOGUS_ICC); /* inconsistent num_markers fields */
return FALSE;
}
seq_no = marker->data[12];
if (seq_no <= 0 || seq_no > num_markers) {
WARNMS(cinfo, JWRN_BOGUS_ICC); /* bogus sequence number */
return FALSE;
}
if (marker_present[seq_no]) {
WARNMS(cinfo, JWRN_BOGUS_ICC); /* duplicate sequence numbers */
return FALSE;
}
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) {
WARNMS(cinfo, JWRN_BOGUS_ICC); /* missing sequence number */
return FALSE;
}
data_offset[seq_no] = total_length;
total_length += data_length[seq_no];
}
if (total_length == 0) {
WARNMS(cinfo, JWRN_BOGUS_ICC); /* found only empty markers? */
return FALSE;
}
/* Allocate space for assembled data */
icc_data = (JOCTET *)malloc(total_length * sizeof(JOCTET));
if (icc_data == NULL)
ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 11); /* 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 = 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;
}