4
* Borrowed from the LittleCMS "jpegicc" utility
6
* This file provides code to read and write International Color Consortium
7
* (ICC) device profiles embedded in JFIF JPEG image files. The ICC has
8
* defined a standard format for including such data in JPEG "APP2" markers.
9
* The code given here does not know anything about the internal structure
10
* of the ICC profile data; it just knows how to put the profile data into
11
* a JPEG file being written, or get it back out when reading.
13
* This code depends on new features added to the IJG JPEG library as of
14
* IJG release 6b; it will not compile or work with older IJG versions.
16
* NOTE: this code would need surgery to work on 16-bit-int machines
17
* with ICC profiles exceeding 64K bytes in size. See iccprofile.c
21
#include <stdio.h> /* needed to define "FILE", "NULL" */
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.)
36
extern void write_icc_profile JPP((j_compress_ptr cinfo,
37
const JOCTET *icc_data_ptr,
38
unsigned int icc_data_len));
42
* Reading a JPEG file that may contain an ICC profile requires two steps:
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.
48
* 2. After jpeg_read_header(), call read_icc_profile() to find out
49
* whether there was a profile and obtain it if so.
54
* Prepare for reading an ICC profile
57
extern void setup_read_icc_profile JPP((j_decompress_ptr cinfo));
61
* See if there was an ICC profile in the JPEG file being read;
62
* if so, reassemble and return the profile data.
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.
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.)
76
extern boolean read_icc_profile JPP((j_decompress_ptr cinfo,
77
JOCTET **icc_data_ptr,
78
unsigned int *icc_data_len));
added
removed
imagesource/iccjpeg.h
