Go to the source code of this file.
scale an image
This is really Sheelagh's code that I've hacked into a more usable form. You simply call scale_image() passing in source and target images. The target image should be empty, but created - in order to define the destination size.
NOW DO THE VERTICAL SCALING from image2 to target_image
Definition at line 39 of file scaleimg.cpp.
References IMAGE::create(), dummy, dyn_prog(), err_exit(), IMAGE::fast_get_line(), IMAGE::get_bpp(), IMAGE::get_column(), IMAGE::get_xsize(), IMAGE::get_ysize(), new_line, NULL, IMAGELINE::pixels, IMAGE::put_column(), IMAGE::put_line(), scale_image_cop_out(), and tprintf().
00042 { 00043 INT32 xsize, ysize, new_xsize, new_ysize; 00044 IMAGELINE line, new_line; 00045 int *hires, *lores, *oldhires, *oldlores; 00046 int i, j, n, oldn, row, col; 00047 int offset = 0; //not used here 00048 float factor; 00049 UINT8 curr_colour, new_colour; 00050 int dummy = -1; 00051 IMAGE image2; //horiz scaled image 00052 00053 xsize = image.get_xsize (); 00054 ysize = image.get_ysize (); 00055 new_xsize = target_image.get_xsize (); 00056 new_ysize = target_image.get_ysize (); 00057 if (new_ysize > new_xsize) 00058 new_line.init (new_ysize); 00059 else 00060 new_line.init (new_xsize); 00061 00062 factor = (float) xsize / (float) new_xsize; 00063 00064 hires = (int *) calloc (xsize, sizeof (int)); 00065 lores = (int *) calloc (new_xsize, sizeof (int)); 00066 oldhires = (int *) calloc (xsize, sizeof (int)); 00067 oldlores = (int *) calloc (new_xsize, sizeof (int)); 00068 if ((hires == NULL) || (lores == NULL) || (oldhires == NULL) 00069 || (oldlores == NULL)) { 00070 fprintf (stderr, "Calloc error in scale_image\n"); 00071 err_exit(); 00072 } 00073 00074 image2.create (new_xsize, ysize, image.get_bpp ()); 00075 00076 oldn = 0; 00077 /* do first row separately because hires[col-1] doesn't make sense here */ 00078 image.fast_get_line (0, 0, xsize, &line); 00079 /* each line nominally begins with white */ 00080 curr_colour = 1; 00081 n = 0; 00082 for (i = 0; i < xsize; i++) { 00083 new_colour = *(line.pixels + i); 00084 if (new_colour != curr_colour) { 00085 hires[n] = i; 00086 n++; 00087 curr_colour = new_colour; 00088 } 00089 } 00090 if (offset != 0) 00091 for (i = 0; i < n; i++) 00092 hires[i] += offset; 00093 00094 if (n > new_xsize) { 00095 tprintf ("Too many transitions (%d) on line 0\n", n); 00096 scale_image_cop_out(image, 00097 target_image, 00098 factor, 00099 hires, 00100 lores, 00101 oldhires, 00102 oldlores); 00103 return; 00104 } 00105 else if (n > 0) 00106 dyn_prog (n, hires, lores, new_xsize, &dummy, &dummy, 0, factor); 00107 else 00108 lores[0] = new_xsize; 00109 00110 curr_colour = 1; 00111 j = 0; 00112 for (i = 0; i < new_xsize; i++) { 00113 if (lores[j] == i) { 00114 curr_colour = 1 - curr_colour; 00115 j++; 00116 } 00117 *(new_line.pixels + i) = curr_colour; 00118 } 00119 image2.put_line (0, 0, new_xsize, &new_line, 0); 00120 00121 for (i = 0; i < n; i++) { 00122 oldhires[i] = hires[i]; 00123 oldlores[i] = lores[i]; 00124 } 00125 00126 for (i = n; i < oldn; i++) { 00127 oldhires[i] = 0; 00128 oldlores[i] = 0; 00129 } 00130 oldn = n; 00131 00132 for (row = 1; row < ysize; row++) { 00133 image.fast_get_line (0, row, xsize, &line); 00134 /* each line nominally begins with white */ 00135 curr_colour = 1; 00136 n = 0; 00137 for (i = 0; i < xsize; i++) { 00138 new_colour = *(line.pixels + i); 00139 if (new_colour != curr_colour) { 00140 hires[n] = i; 00141 n++; 00142 curr_colour = new_colour; 00143 } 00144 } 00145 for (i = n; i < oldn; i++) { 00146 hires[i] = 0; 00147 lores[i] = 0; 00148 } 00149 if (offset != 0) 00150 for (i = 0; i < n; i++) 00151 hires[i] += offset; 00152 00153 if (n > new_xsize) { 00154 tprintf ("Too many transitions (%d) on line %d\n", n, row); 00155 scale_image_cop_out(image, 00156 target_image, 00157 factor, 00158 hires, 00159 lores, 00160 oldhires, 00161 oldlores); 00162 return; 00163 } 00164 else if (n > 0) 00165 dyn_prog(n, hires, lores, new_xsize, oldhires, oldlores, oldn, factor); 00166 else 00167 lores[0] = new_xsize; 00168 00169 curr_colour = 1; 00170 j = 0; 00171 for (i = 0; i < new_xsize; i++) { 00172 if (lores[j] == i) { 00173 curr_colour = 1 - curr_colour; 00174 j++; 00175 } 00176 *(new_line.pixels + i) = curr_colour; 00177 } 00178 image2.put_line (0, row, new_xsize, &new_line, 0); 00179 00180 for (i = 0; i < n; i++) { 00181 oldhires[i] = hires[i]; 00182 oldlores[i] = lores[i]; 00183 } 00184 for (i = n; i < oldn; i++) { 00185 oldhires[i] = 0; 00186 oldlores[i] = 0; 00187 } 00188 oldn = n; 00189 } 00190 00191 free(hires); 00192 free(lores); 00193 free(oldhires); 00194 free(oldlores); 00195 00199 xsize = new_xsize; 00200 factor = (float) ysize / (float) new_ysize; 00201 offset = 0; 00202 00203 hires = (int *) calloc (ysize, sizeof (int)); 00204 lores = (int *) calloc (new_ysize, sizeof (int)); 00205 oldhires = (int *) calloc (ysize, sizeof (int)); 00206 oldlores = (int *) calloc (new_ysize, sizeof (int)); 00207 if ((hires == NULL) || (lores == NULL) || (oldhires == NULL) 00208 || (oldlores == NULL)) { 00209 fprintf (stderr, "Calloc error in scale_image (vert)\n"); 00210 err_exit(); 00211 } 00212 00213 oldn = 0; 00214 /* do first col separately because hires[col-1] doesn't make sense here */ 00215 image2.get_column (0, 0, ysize, &line, 0); 00216 /* each line nominally begins with white */ 00217 curr_colour = 1; 00218 n = 0; 00219 for (i = 0; i < ysize; i++) { 00220 new_colour = *(line.pixels + i); 00221 if (new_colour != curr_colour) { 00222 hires[n] = i; 00223 n++; 00224 curr_colour = new_colour; 00225 } 00226 } 00227 00228 if (offset != 0) 00229 for (i = 0; i < n; i++) 00230 hires[i] += offset; 00231 00232 if (n > new_ysize) { 00233 tprintf ("Too many transitions (%d) on column 0\n", n); 00234 scale_image_cop_out(image, 00235 target_image, 00236 factor, 00237 hires, 00238 lores, 00239 oldhires, 00240 oldlores); 00241 return; 00242 } 00243 else if (n > 0) 00244 dyn_prog (n, hires, lores, new_ysize, &dummy, &dummy, 0, factor); 00245 else 00246 lores[0] = new_ysize; 00247 00248 curr_colour = 1; 00249 j = 0; 00250 for (i = 0; i < new_ysize; i++) { 00251 if (lores[j] == i) { 00252 curr_colour = 1 - curr_colour; 00253 j++; 00254 } 00255 *(new_line.pixels + i) = curr_colour; 00256 } 00257 target_image.put_column (0, 0, new_ysize, &new_line, 0); 00258 00259 for (i = 0; i < n; i++) { 00260 oldhires[i] = hires[i]; 00261 oldlores[i] = lores[i]; 00262 } 00263 for (i = n; i < oldn; i++) { 00264 oldhires[i] = 0; 00265 oldlores[i] = 0; 00266 } 00267 oldn = n; 00268 00269 for (col = 1; col < xsize; col++) { 00270 image2.get_column (col, 0, ysize, &line, 0); 00271 /* each line nominally begins with white */ 00272 curr_colour = 1; 00273 n = 0; 00274 for (i = 0; i < ysize; i++) { 00275 new_colour = *(line.pixels + i); 00276 if (new_colour != curr_colour) { 00277 hires[n] = i; 00278 n++; 00279 curr_colour = new_colour; 00280 } 00281 } 00282 for (i = n; i < oldn; i++) { 00283 hires[i] = 0; 00284 lores[i] = 0; 00285 } 00286 00287 if (offset != 0) 00288 for (i = 0; i < n; i++) 00289 hires[i] += offset; 00290 00291 if (n > new_ysize) { 00292 tprintf ("Too many transitions (%d) on column %d\n", n, col); 00293 scale_image_cop_out(image, 00294 target_image, 00295 factor, 00296 hires, 00297 lores, 00298 oldhires, 00299 oldlores); 00300 return; 00301 } 00302 else if (n > 0) 00303 dyn_prog(n, hires, lores, new_ysize, oldhires, oldlores, oldn, factor); 00304 else 00305 lores[0] = new_ysize; 00306 00307 curr_colour = 1; 00308 j = 0; 00309 for (i = 0; i < new_ysize; i++) { 00310 if (lores[j] == i) { 00311 curr_colour = 1 - curr_colour; 00312 j++; 00313 } 00314 *(new_line.pixels + i) = curr_colour; 00315 } 00316 target_image.put_column (col, 0, new_ysize, &new_line, 0); 00317 00318 for (i = 0; i < n; i++) { 00319 oldhires[i] = hires[i]; 00320 oldlores[i] = lores[i]; 00321 } 00322 for (i = n; i < oldn; i++) { 00323 oldhires[i] = 0; 00324 oldlores[i] = 0; 00325 } 00326 oldn = n; 00327 } 00328 free(hires); 00329 free(lores); 00330 free(oldhires); 00331 free(oldlores); 00332 }
| void scale_image_cop_out | ( | IMAGE & | image, | |
| IMAGE & | target_image, | |||
| float | factor, | |||
| int * | hires, | |||
| int * | lores, | |||
| int * | oldhires, | |||
| int * | oldlores | |||
| ) |
Cop-out of scale_image by doing it the easy way and free the data.
Definition at line 338 of file scaleimg.cpp.
References copy_sub_image(), enlarge_sub_image(), FALSE, IMAGE::get_xsize(), IMAGE::get_ysize(), and reduce_sub_image().
Referenced by scale_image().
00345 { 00346 INT32 xsize, ysize, new_xsize, new_ysize; 00347 00348 xsize = image.get_xsize (); 00349 ysize = image.get_ysize (); 00350 new_xsize = target_image.get_xsize (); 00351 new_ysize = target_image.get_ysize (); 00352 00353 if (factor <= 0.5) 00354 reduce_sub_image (&image, 0, 0, xsize, ysize, 00355 &target_image, 0, 0, (INT32) (1.0 / factor), FALSE); 00356 else if (factor >= 2) 00357 enlarge_sub_image (&image, 0, 0, &target_image, 00358 0, 0, new_xsize, new_ysize, (INT32) factor, FALSE); 00359 else 00360 copy_sub_image (&image, 0, 0, xsize, ysize, &target_image, 0, 0, FALSE); 00361 free(hires); 00362 free(lores); 00363 free(oldhires); 00364 free(oldlores); 00365 }
1.5.1