1 | /* |
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2 | * clubic.c: decode clubic captchas |
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3 | * $Id: clubic.c 445 2005-01-10 11:23:38Z 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 | #define FONTNAME "font_clubic.png" |
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24 | static struct image *font = NULL; |
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25 | char *result; |
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26 | |
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27 | /* Main function */ |
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28 | char *decode_clubic(struct image *img) |
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29 | { |
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30 | struct image *tmp; |
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31 | |
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32 | if(!font) |
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33 | { |
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34 | char fontname[BUFSIZ]; |
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35 | sprintf(fontname, "%s/%s", share, FONTNAME); |
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36 | font = image_load(fontname); |
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37 | if(!font) |
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38 | { |
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39 | fprintf(stderr, "cannot load font %s\n", fontname); |
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40 | exit(-1); |
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41 | } |
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42 | } |
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43 | |
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44 | /* clubic captchas have 6 characters */ |
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45 | result = malloc(7 * sizeof(char)); |
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46 | strcpy(result, " "); |
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47 | |
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48 | tmp = image_dup(img); |
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49 | filter_equalize(tmp, 200); |
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50 | find_glyphs(tmp); |
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51 | |
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52 | image_free(tmp); |
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53 | |
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54 | return result; |
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55 | } |
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56 | |
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57 | static void find_glyphs(struct image *img) |
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58 | { |
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59 | char all[] = "0123456789"; |
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60 | struct |
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61 | { |
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62 | int xmin, xmax, ymin, ymax; |
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63 | int count; |
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64 | } |
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65 | glyphs[10]; |
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66 | struct image *tmp; |
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67 | int x, y, i = 0; |
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68 | int r, g, b; |
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69 | int xmin, xmax, ymin, ymax, incell = 0, count = 0, startx = 0, cur = 0; |
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70 | int distmin, distx, disty, distch; |
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71 | |
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72 | tmp = image_new(img->width, img->height); |
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73 | |
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74 | for(y = 0; y < img->height; y++) |
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75 | for(x = 0; x < img->width; x++) |
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76 | { |
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77 | getpixel(img, x, y, &r, &g, &b); |
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78 | setpixel(tmp, x, y, 255, g, 255); |
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79 | } |
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80 | |
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81 | for(x = 0; x < font->width; x++) |
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82 | { |
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83 | int found = 0; |
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84 | for(y = 0; y < font->height; y++) |
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85 | { |
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86 | getpixel(font, x, y, &r, &g, &b); |
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87 | if(r < 128) |
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88 | { |
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89 | found = 1; |
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90 | count += (255 - r); |
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91 | } |
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92 | } |
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93 | if(found && !incell) |
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94 | { |
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95 | incell = 1; |
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96 | xmin = x; |
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97 | } |
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98 | else if(!found && incell) |
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99 | { |
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100 | incell = 0; |
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101 | xmax = x; |
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102 | ymin = 0; |
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103 | ymax = font->height; |
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104 | glyphs[i].xmin = xmin; |
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105 | glyphs[i].xmax = xmax; |
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106 | glyphs[i].ymin = ymin; |
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107 | glyphs[i].ymax = ymax; |
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108 | glyphs[i].count = count; |
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109 | count = 0; |
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110 | i++; |
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111 | } |
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112 | } |
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113 | |
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114 | if(i != 10) |
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115 | { |
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116 | printf("error: could not find 10 glyphs in font\n"); |
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117 | exit(-1); |
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118 | } |
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119 | |
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120 | while(cur < 6) |
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121 | { |
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122 | /* Try to find 1st letter */ |
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123 | distmin = INT_MAX; |
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124 | for(i = 0; i < 10; i++) |
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125 | { |
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126 | int localmin = INT_MAX, localx, localy; |
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127 | xmin = glyphs[i].xmin; |
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128 | ymin = glyphs[i].ymin; |
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129 | xmax = glyphs[i].xmax; |
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130 | ymax = glyphs[i].ymax; |
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131 | for(y = -4; y < 4; y++) |
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132 | for(x = startx; x < startx + 4; x++) |
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133 | { |
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134 | int z, t, dist; |
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135 | dist = 0; |
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136 | for(t = 0; t < ymax - ymin; t++) |
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137 | for(z = 0; z < xmax - xmin; z++) |
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138 | { |
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139 | int r2; |
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140 | getgray(font, xmin + z, ymin + t, &r); |
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141 | getgray(img, x + z, y + t, &r2); |
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142 | dist += abs(r - r2); |
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143 | } |
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144 | dist = dist * 128 / glyphs[i].count; |
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145 | if(dist < localmin) |
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146 | { |
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147 | localmin = dist; |
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148 | localx = x; |
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149 | localy = y; |
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150 | } |
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151 | } |
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152 | if(localmin < distmin) |
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153 | { |
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154 | distmin = localmin; |
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155 | distx = localx; |
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156 | disty = localy; |
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157 | distch = i; |
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158 | } |
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159 | } |
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160 | |
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161 | /* Print min glyph */ |
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162 | xmin = glyphs[distch].xmin; |
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163 | ymin = glyphs[distch].ymin; |
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164 | xmax = glyphs[distch].xmax; |
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165 | ymax = glyphs[distch].ymax; |
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166 | for(y = 0; y < ymax - ymin; y++) |
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167 | for(x = 0; x < xmax - xmin; x++) |
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168 | { |
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169 | getpixel(font, xmin + x, ymin + y, &r, &g, &b); |
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170 | if(r > 128) continue; |
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171 | setpixel(tmp, distx + x, disty + y, r, g, b); |
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172 | } |
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173 | |
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174 | startx = distx + xmax - xmin; |
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175 | result[cur++] = all[distch]; |
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176 | } |
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177 | |
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178 | image_free(tmp); |
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179 | } |
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180 | |
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