| 1 | /* |
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| 2 | * livejournal.c: decode livejournal captchas |
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| 3 | * $Id: livejournal.c 477 2005-04-27 08:54:33Z sam $ |
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| 4 | * |
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| 5 | * Copyright: (c) 2005 Sam Hocevar <sam@zoy.org> |
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| 6 | * This program is free software; you can redistribute it and/or |
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| 7 | * modify it under the terms of the Do What The Fuck You Want To |
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| 8 | * Public License as published by Banlu Kemiyatorn. See |
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| 9 | * http://sam.zoy.org/projects/COPYING.WTFPL for more details. |
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| 10 | */ |
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| 11 | |
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| 12 | #include <stdio.h> |
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| 13 | #include <stdlib.h> |
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| 14 | #include <string.h> |
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| 15 | #include <limits.h> |
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| 16 | |
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| 17 | #include "config.h" |
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| 18 | #include "common.h" |
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| 19 | |
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| 20 | static void find_glyphs(struct image *img); |
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| 21 | |
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| 22 | /* Our macros */ |
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| 23 | char *result; |
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| 24 | |
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| 25 | /* Main function */ |
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| 26 | char *decode_livejournal(struct image *img) |
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| 27 | { |
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| 28 | struct image *tmp; |
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| 29 | |
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| 30 | /* livejournal captchas have 7 characters */ |
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| 31 | result = malloc(8 * sizeof(char)); |
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| 32 | strcpy(result, " "); |
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| 33 | |
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| 34 | tmp = image_dup(img); |
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| 35 | filter_detect_lines(tmp); |
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| 36 | filter_fill_holes(tmp); |
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| 37 | filter_median(tmp); |
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| 38 | // filter_smooth(tmp); |
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| 39 | // filter_contrast(tmp); |
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| 40 | filter_equalize(tmp, 128); |
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| 41 | image_save(tmp, "foo.bmp"); |
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| 42 | find_glyphs(tmp); |
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| 43 | |
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| 44 | image_free(tmp); |
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| 45 | |
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| 46 | return result; |
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| 47 | } |
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| 48 | |
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| 49 | static void find_glyphs(struct image *img) |
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| 50 | { |
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| 51 | static struct font *font = NULL; |
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| 52 | struct image *tmp; |
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| 53 | int x, y, i = 0; |
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| 54 | int r, g, b; |
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| 55 | int xmin, xmax, ymin, ymax, startx = 0, cur = 0; |
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| 56 | int distmin, distx, disty, distch; |
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| 57 | |
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| 58 | if(!font) |
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| 59 | { |
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| 60 | font = font_load_variable("x_font_freesansbold_32_09az.bmp", |
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| 61 | "0123456789abcdefghijklmnopqrstuvwxyz"); |
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| 62 | if(!font) |
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| 63 | exit(1); |
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| 64 | } |
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| 65 | |
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| 66 | tmp = image_new(img->width, img->height); |
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| 67 | |
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| 68 | for(y = 0; y < img->height; y++) |
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| 69 | for(x = 0; x < img->width; x++) |
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| 70 | { |
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| 71 | getpixel(img, x, y, &r, &g, &b); |
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| 72 | setpixel(tmp, x, y, 255, g, 255); |
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| 73 | } |
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| 74 | |
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| 75 | while(cur < 7) |
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| 76 | { |
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| 77 | /* Try to find 1st letter */ |
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| 78 | distmin = INT_MAX; |
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| 79 | for(i = 0; i < font->size; i++) |
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| 80 | { |
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| 81 | int sqr; |
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| 82 | int localmin = INT_MAX, localx, localy; |
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| 83 | xmin = font->glyphs[i].xmin; |
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| 84 | ymin = font->glyphs[i].ymin; |
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| 85 | xmax = font->glyphs[i].xmax; |
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| 86 | ymax = font->glyphs[i].ymax; |
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| 87 | sqr = sqrt(xmax - xmin); |
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| 88 | for(y = -16; y < 8; y++) |
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| 89 | for(x = 25 * cur; x < 25 * cur + 5; x++) |
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| 90 | { |
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| 91 | int z, t, dist; |
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| 92 | dist = 0; |
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| 93 | for(t = 0; t < ymax - ymin; t++) |
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| 94 | for(z = 0; z < xmax - xmin; z++) |
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| 95 | { |
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| 96 | int r2; |
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| 97 | getgray(font->img, xmin + z, ymin + t, &r); |
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| 98 | getgray(img, x + z, y + t, &r2); |
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| 99 | dist += abs(r - r2); |
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| 100 | } |
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| 101 | //dist = dist * 128 / font->glyphs[i].count; |
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| 102 | dist = dist / (xmax - xmin) / sqr; |
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| 103 | if(dist < localmin) |
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| 104 | { |
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| 105 | localmin = dist; |
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| 106 | localx = x; |
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| 107 | localy = y; |
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| 108 | } |
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| 109 | } |
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| 110 | if(localmin < distmin) |
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| 111 | { |
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| 112 | distmin = localmin; |
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| 113 | distx = localx; |
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| 114 | disty = localy; |
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| 115 | distch = i; |
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| 116 | } |
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| 117 | } |
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| 118 | |
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| 119 | /* Print min glyph */ |
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| 120 | xmin = font->glyphs[distch].xmin; |
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| 121 | ymin = font->glyphs[distch].ymin; |
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| 122 | xmax = font->glyphs[distch].xmax; |
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| 123 | ymax = font->glyphs[distch].ymax; |
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| 124 | for(y = 0; y < ymax - ymin; y++) |
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| 125 | for(x = 0; x < xmax - xmin; x++) |
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| 126 | { |
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| 127 | getpixel(font->img, xmin + x, ymin + y, &r, &g, &b); |
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| 128 | if(r > 128) |
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| 129 | continue; |
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| 130 | setpixel(tmp, distx + x, disty + y, r, g, b); |
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| 131 | } |
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| 132 | |
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| 133 | startx = distx + 20; |
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| 134 | result[cur++] = font->glyphs[distch].c; |
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| 135 | } |
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| 136 | |
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| 137 | image_save(tmp, "foo2.bmp"); |
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| 138 | image_free(tmp); |
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| 139 | } |
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| 140 | |
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