Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 1 | /*- iccfrompng |
| 2 | * |
| 3 | * COPYRIGHT: Written by John Cunningham Bowler, 2011. |
| 4 | * To the extent possible under law, the author has waived all copyright and |
| 5 | * related or neighboring rights to this work. This work is published from: |
| 6 | * United States. |
| 7 | * |
| 8 | * Extract any icc profiles found in the given PNG files. This is a simple |
| 9 | * example of a program which extracts information from the header of a PNG file |
| 10 | * without processing the image. Notice that some header information may occur |
| 11 | * after the image data, textual data and comments are an example; the approach |
| 12 | * in this file won't work reliably for such data because it only looks for the |
| 13 | * information in the section of the file that preceeds the image data. |
| 14 | * |
| 15 | * Compile and link against libpng and zlib, plus anything else required on the |
| 16 | * system you use. |
| 17 | * |
| 18 | * To use supply a list of PNG files containing iCCP chunks, the chunks will be |
| 19 | * extracted to a similarly named file with the extension replaced by 'icc', |
| 20 | * which will be overwritten without warning. |
| 21 | */ |
| 22 | #include <stdlib.h> |
| 23 | #include <setjmp.h> |
| 24 | #include <string.h> |
| 25 | #include <stdio.h> |
| 26 | |
| 27 | #include <png.h> |
| 28 | |
| 29 | static int verbose = 1; |
| 30 | static png_byte no_profile[] = "no profile"; |
| 31 | |
| 32 | static png_bytep |
| 33 | extract(FILE *fp, png_uint_32 *proflen) |
| 34 | { |
| 35 | png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0); |
| 36 | png_infop info_ptr = NULL; |
| 37 | png_bytep result = NULL; |
| 38 | |
| 39 | /* Initialize for error or no profile: */ |
| 40 | *proflen = 0; |
| 41 | |
| 42 | if (png_ptr == NULL) |
| 43 | { |
| 44 | fprintf(stderr, "iccfrompng: version library mismatch?\n"); |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | if (setjmp(png_jmpbuf(png_ptr))) |
| 49 | { |
| 50 | png_destroy_read_struct(&png_ptr, &info_ptr, NULL); |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | png_init_io(png_ptr, fp); |
| 55 | |
| 56 | info_ptr = png_create_info_struct(png_ptr); |
| 57 | if (info_ptr == NULL) |
| 58 | png_error(png_ptr, "OOM allocating info structure"); |
| 59 | |
| 60 | png_read_info(png_ptr, info_ptr); |
| 61 | |
| 62 | { |
| 63 | png_charp name; |
| 64 | int compression_type; |
| 65 | png_bytep profile; |
| 66 | |
| 67 | if (png_get_iCCP(png_ptr, info_ptr, &name, &compression_type, &profile, |
| 68 | proflen) & PNG_INFO_iCCP) |
| 69 | { |
| 70 | result = malloc(*proflen); |
| 71 | if (result != NULL) |
| 72 | memcpy(result, profile, *proflen); |
| 73 | |
| 74 | else |
| 75 | png_error(png_ptr, "OOM allocating profile buffer"); |
| 76 | } |
| 77 | |
| 78 | else |
| 79 | result = no_profile; |
| 80 | } |
| 81 | |
| 82 | png_destroy_read_struct(&png_ptr, &info_ptr, NULL); |
| 83 | return result; |
| 84 | } |
| 85 | |
| 86 | static int |
| 87 | extract_one_file(const char *filename) |
| 88 | { |
| 89 | int result = 0; |
| 90 | FILE *fp = fopen(filename, "rb"); |
| 91 | |
| 92 | if (fp != NULL) |
| 93 | { |
| 94 | png_uint_32 proflen = 0; |
| 95 | png_bytep profile = extract(fp, &proflen); |
| 96 | |
| 97 | if (profile != NULL && profile != no_profile) |
| 98 | { |
| 99 | size_t len; |
| 100 | char *output; |
| 101 | |
| 102 | { |
| 103 | const char *ep = strrchr(filename, '.'); |
| 104 | |
| 105 | if (ep != NULL) |
| 106 | len = ep-filename; |
| 107 | |
| 108 | else |
| 109 | len = strlen(filename); |
| 110 | } |
| 111 | |
| 112 | output = malloc(len + 5); |
| 113 | if (output != NULL) |
| 114 | { |
| 115 | FILE *of; |
| 116 | |
| 117 | memcpy(output, filename, len); |
| 118 | strcpy(output+len, ".icc"); |
| 119 | |
| 120 | of = fopen(output, "wb"); |
| 121 | if (of != NULL) |
| 122 | { |
| 123 | if (fwrite(profile, proflen, 1, of) == 1 && |
| 124 | fflush(of) == 0 && |
| 125 | fclose(of) == 0) |
| 126 | { |
| 127 | if (verbose) |
| 128 | printf("%s -> %s\n", filename, output); |
| 129 | /* Success return */ |
| 130 | result = 1; |
| 131 | } |
| 132 | |
| 133 | else |
| 134 | { |
| 135 | fprintf(stderr, "%s: error writing profile\n", output); |
| 136 | if (remove(output)) |
| 137 | fprintf(stderr, "%s: could not remove file\n", output); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | else |
| 142 | fprintf(stderr, "%s: failed to open output file\n", output); |
| 143 | |
| 144 | free(output); |
| 145 | } |
| 146 | |
| 147 | else |
| 148 | fprintf(stderr, "%s: OOM allocating string!\n", filename); |
| 149 | |
| 150 | free(profile); |
| 151 | } |
| 152 | |
| 153 | else if (verbose && profile == no_profile) |
| 154 | printf("%s has no profile\n", filename); |
| 155 | } |
| 156 | |
| 157 | else |
| 158 | fprintf(stderr, "%s: could not open file\n", filename); |
| 159 | |
| 160 | return result; |
| 161 | } |
| 162 | |
| 163 | int |
| 164 | main(int argc, char **argv) |
| 165 | { |
| 166 | int i; |
| 167 | int extracted = 0; |
| 168 | |
| 169 | for (i=1; i<argc; ++i) |
| 170 | { |
| 171 | if (strcmp(argv[i], "-q") == 0) |
| 172 | verbose = 0; |
| 173 | |
| 174 | else if (extract_one_file(argv[i])) |
| 175 | extracted = 1; |
| 176 | } |
| 177 | |
| 178 | /* Exit code is true if any extract succeeds */ |
| 179 | return extracted == 0; |
| 180 | } |