/src/leptonica/src/enhance.c
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1 | | /*====================================================================* |
2 | | - Copyright (C) 2001 Leptonica. All rights reserved. |
3 | | - |
4 | | - Redistribution and use in source and binary forms, with or without |
5 | | - modification, are permitted provided that the following conditions |
6 | | - are met: |
7 | | - 1. Redistributions of source code must retain the above copyright |
8 | | - notice, this list of conditions and the following disclaimer. |
9 | | - 2. Redistributions in binary form must reproduce the above |
10 | | - copyright notice, this list of conditions and the following |
11 | | - disclaimer in the documentation and/or other materials |
12 | | - provided with the distribution. |
13 | | - |
14 | | - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
15 | | - ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
16 | | - LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
17 | | - A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANY |
18 | | - CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
19 | | - EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
20 | | - PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
21 | | - PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
22 | | - OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
23 | | - NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
24 | | - SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
25 | | *====================================================================*/ |
26 | | |
27 | | /*! |
28 | | * \file enhance.c |
29 | | * <pre> |
30 | | * |
31 | | * Gamma TRC (tone reproduction curve) mapping |
32 | | * PIX *pixGammaTRC() |
33 | | * PIX *pixGammaTRCMasked() |
34 | | * PIX *pixGammaTRCWithAlpha() |
35 | | * NUMA *numaGammaTRC() |
36 | | * |
37 | | * Contrast enhancement |
38 | | * PIX *pixContrastTRC() |
39 | | * PIX *pixContrastTRCMasked() |
40 | | * NUMA *numaContrastTRC() |
41 | | * |
42 | | * Histogram equalization |
43 | | * PIX *pixEqualizeTRC() |
44 | | * NUMA *numaEqualizeTRC() |
45 | | * |
46 | | * Generic TRC mapper |
47 | | * l_int32 pixTRCMap() |
48 | | * l_int32 pixTRCMapGeneral() |
49 | | * |
50 | | * Unsharp-masking |
51 | | * PIX *pixUnsharpMasking() |
52 | | * PIX *pixUnsharpMaskingGray() |
53 | | * PIX *pixUnsharpMaskingFast() |
54 | | * PIX *pixUnsharpMaskingGrayFast() |
55 | | * PIX *pixUnsharpMaskingGray1D() |
56 | | * PIX *pixUnsharpMaskingGray2D() |
57 | | * |
58 | | * Hue and saturation modification |
59 | | * PIX *pixModifyHue() |
60 | | * PIX *pixModifySaturation() |
61 | | * l_int32 pixMeasureSaturation() |
62 | | * PIX *pixModifyBrightness() |
63 | | * |
64 | | * Color shifting |
65 | | * PIX *pixMosaicColorShiftRGB() |
66 | | * PIX *pixColorShiftRGB() |
67 | | * |
68 | | * Darken gray (unsaturated) pixels |
69 | | * PIX *pixDarkenGray() |
70 | | * |
71 | | * General multiplicative constant color transform |
72 | | * PIX *pixMultConstantColor() |
73 | | * PIX *pixMultMatrixColor() |
74 | | * |
75 | | * Edge by bandpass |
76 | | * PIX *pixHalfEdgeByBandpass() |
77 | | * |
78 | | * Gamma correction, contrast enhancement and histogram equalization |
79 | | * apply a simple mapping function to each pixel (or, for color |
80 | | * images, to each sample (i.e., r,g,b) of the pixel). |
81 | | * |
82 | | * ~ Gamma correction either lightens the image or darkens |
83 | | * it, depending on whether the gamma factor is greater |
84 | | * or less than 1.0, respectively. |
85 | | * |
86 | | * ~ Contrast enhancement darkens the pixels that are already |
87 | | * darker than the middle of the dynamic range (128) |
88 | | * and lightens pixels that are lighter than 128. |
89 | | * |
90 | | * ~ Histogram equalization remaps to have the same number |
91 | | * of image pixels at each of 256 intensity values. This is |
92 | | * a quick and dirty method of adjusting contrast and brightness |
93 | | * to bring out details in both light and dark regions. |
94 | | * |
95 | | * Unsharp masking is a more complicated enhancement. |
96 | | * A "high frequency" image, generated by subtracting |
97 | | * the smoothed ("low frequency") part of the image from |
98 | | * itself, has all the energy at the edges. This "edge image" |
99 | | * has 0 average value. A fraction of the edge image is |
100 | | * then added to the original, enhancing the differences |
101 | | * between pixel values at edges. Because we represent |
102 | | * images as l_uint8 arrays, we preserve dynamic range and |
103 | | * handle negative values by doing all the arithmetic on |
104 | | * shifted l_uint16 arrays; the l_uint8 values are recovered |
105 | | * at the end. |
106 | | * |
107 | | * Hue and saturation modification work in HSV space. Because |
108 | | * this is too large for efficient table lookup, each pixel value |
109 | | * is transformed to HSV, modified, and transformed back. |
110 | | * It's not the fastest way to do this, but the method is |
111 | | * easily understood. |
112 | | * |
113 | | * Unsharp masking is never in-place, and returns a clone if no |
114 | | * operation is to be performed. |
115 | | * </pre> |
116 | | */ |
117 | | |
118 | | #ifdef HAVE_CONFIG_H |
119 | | #include <config_auto.h> |
120 | | #endif /* HAVE_CONFIG_H */ |
121 | | |
122 | | #include <math.h> |
123 | | #include "allheaders.h" |
124 | | |
125 | | /* Scales contrast enhancement factor to have a useful range |
126 | | * between 0.0 and 1.0 */ |
127 | | static const l_float32 EnhanceScaleFactor = 5.0; |
128 | | |
129 | | /*-------------------------------------------------------------* |
130 | | * Gamma TRC (tone reproduction curve) mapping * |
131 | | *-------------------------------------------------------------*/ |
132 | | /*! |
133 | | * \brief pixGammaTRC() |
134 | | * |
135 | | * \param[in] pixd [optional] null or equal to pixs |
136 | | * \param[in] pixs 8 or 32 bpp; or 2, 4 or 8 bpp with colormap |
137 | | * \param[in] gamma gamma correction; must be > 0.0 |
138 | | * \param[in] minval input value that gives 0 for output; can be < 0 |
139 | | * \param[in] maxval input value that gives 255 for output; can be > 255 |
140 | | * \return pixd always |
141 | | * |
142 | | * <pre> |
143 | | * Notes: |
144 | | * (1) pixd must either be null or equal to pixs. |
145 | | * For in-place operation, set pixd == pixs: |
146 | | * pixGammaTRC(pixs, pixs, ...); |
147 | | * To get a new image, set pixd == null: |
148 | | * pixd = pixGammaTRC(NULL, pixs, ...); |
149 | | * (2) If pixs is colormapped, the colormap is transformed, |
150 | | * either in-place or in a copy of pixs. |
151 | | * (3) We use a gamma mapping between minval and maxval. |
152 | | * (4) If gamma < 1.0, the image will appear darker; |
153 | | * if gamma > 1.0, the image will appear lighter; |
154 | | * (5) If gamma = 1.0 and minval = 0 and maxval = 255, no |
155 | | * enhancement is performed; return a copy unless in-place, |
156 | | * in which case this is a no-op. |
157 | | * (6) For color images that are not colormapped, the mapping |
158 | | * is applied to each component. |
159 | | * (7) minval and maxval are not restricted to the interval [0, 255]. |
160 | | * If minval < 0, an input value of 0 is mapped to a |
161 | | * nonzero output. This will turn black to gray. |
162 | | * If maxval > 255, an input value of 255 is mapped to |
163 | | * an output value less than 255. This will turn |
164 | | * white (e.g., in the background) to gray. |
165 | | * (8) Increasing minval darkens the image. |
166 | | * (9) Decreasing maxval bleaches the image. |
167 | | * (10) Simultaneously increasing minval and decreasing maxval |
168 | | * will darken the image and make the colors more intense; |
169 | | * e.g., minval = 50, maxval = 200. |
170 | | * (11) See numaGammaTRC() for further examples of use. |
171 | | * (12) Use pixTRCMapGeneral() if applying different mappings |
172 | | * to each channel in an RGB image. |
173 | | * </pre> |
174 | | */ |
175 | | PIX * |
176 | | pixGammaTRC(PIX *pixd, |
177 | | PIX *pixs, |
178 | | l_float32 gamma, |
179 | | l_int32 minval, |
180 | | l_int32 maxval) |
181 | 0 | { |
182 | 0 | l_int32 d; |
183 | 0 | NUMA *nag; |
184 | 0 | PIXCMAP *cmap; |
185 | |
|
186 | 0 | if (!pixs) |
187 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd); |
188 | 0 | if (pixd && (pixd != pixs)) |
189 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
190 | 0 | if (gamma <= 0.0) { |
191 | 0 | L_WARNING("gamma must be > 0.0; setting to 1.0\n", __func__); |
192 | 0 | gamma = 1.0; |
193 | 0 | } |
194 | 0 | if (minval >= maxval) |
195 | 0 | return (PIX *)ERROR_PTR("minval not < maxval", __func__, pixd); |
196 | 0 | cmap = pixGetColormap(pixs); |
197 | 0 | d = pixGetDepth(pixs); |
198 | 0 | if (!cmap && d != 8 && d != 32) |
199 | 0 | return (PIX *)ERROR_PTR("depth not 8 or 32 bpp", __func__, pixd); |
200 | | |
201 | 0 | if (gamma == 1.0 && minval == 0 && maxval == 255) /* no-op */ |
202 | 0 | return pixCopy(pixd, pixs); |
203 | | |
204 | 0 | if (!pixd) /* start with a copy if not in-place */ |
205 | 0 | pixd = pixCopy(NULL, pixs); |
206 | |
|
207 | 0 | if (cmap) { |
208 | 0 | pixcmapGammaTRC(pixGetColormap(pixd), gamma, minval, maxval); |
209 | 0 | return pixd; |
210 | 0 | } |
211 | | |
212 | | /* pixd is 8 or 32 bpp */ |
213 | 0 | if ((nag = numaGammaTRC(gamma, minval, maxval)) == NULL) |
214 | 0 | return (PIX *)ERROR_PTR("nag not made", __func__, pixd); |
215 | 0 | pixTRCMap(pixd, NULL, nag); |
216 | 0 | numaDestroy(&nag); |
217 | |
|
218 | 0 | return pixd; |
219 | 0 | } |
220 | | |
221 | | |
222 | | /*! |
223 | | * \brief pixGammaTRCMasked() |
224 | | * |
225 | | * \param[in] pixd [optional] null or equal to pixs |
226 | | * \param[in] pixs 8 or 32 bpp; not colormapped |
227 | | * \param[in] pixm [optional] null or 1 bpp |
228 | | * \param[in] gamma gamma correction; must be > 0.0 |
229 | | * \param[in] minval input value that gives 0 for output; can be < 0 |
230 | | * \param[in] maxval input value that gives 255 for output; can be > 255 |
231 | | * \return pixd always |
232 | | * |
233 | | * <pre> |
234 | | * Notes: |
235 | | * (1) Same as pixGammaTRC() except mapping is optionally over |
236 | | * a subset of pixels described by pixm. |
237 | | * (2) Masking does not work for colormapped images. |
238 | | * (3) See pixGammaTRC() for details on how to use the parameters. |
239 | | * </pre> |
240 | | */ |
241 | | PIX * |
242 | | pixGammaTRCMasked(PIX *pixd, |
243 | | PIX *pixs, |
244 | | PIX *pixm, |
245 | | l_float32 gamma, |
246 | | l_int32 minval, |
247 | | l_int32 maxval) |
248 | 0 | { |
249 | 0 | l_int32 d; |
250 | 0 | NUMA *nag; |
251 | |
|
252 | 0 | if (!pixm) |
253 | 0 | return pixGammaTRC(pixd, pixs, gamma, minval, maxval); |
254 | | |
255 | 0 | if (!pixs) |
256 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd); |
257 | 0 | if (pixGetColormap(pixs)) |
258 | 0 | return (PIX *)ERROR_PTR("invalid: pixs has a colormap", __func__, pixd); |
259 | 0 | if (pixd && (pixd != pixs)) |
260 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
261 | 0 | d = pixGetDepth(pixs); |
262 | 0 | if (d != 8 && d != 32) |
263 | 0 | return (PIX *)ERROR_PTR("depth not 8 or 32 bpp", __func__, pixd); |
264 | 0 | if (minval >= maxval) |
265 | 0 | return (PIX *)ERROR_PTR("minval not < maxval", __func__, pixd); |
266 | 0 | if (gamma <= 0.0) { |
267 | 0 | L_WARNING("gamma must be > 0.0; setting to 1.0\n", __func__); |
268 | 0 | gamma = 1.0; |
269 | 0 | } |
270 | |
|
271 | 0 | if (gamma == 1.0 && minval == 0 && maxval == 255) |
272 | 0 | return pixCopy(pixd, pixs); |
273 | | |
274 | 0 | if (!pixd) /* start with a copy if not in-place */ |
275 | 0 | pixd = pixCopy(NULL, pixs); |
276 | |
|
277 | 0 | if ((nag = numaGammaTRC(gamma, minval, maxval)) == NULL) |
278 | 0 | return (PIX *)ERROR_PTR("nag not made", __func__, pixd); |
279 | 0 | pixTRCMap(pixd, pixm, nag); |
280 | 0 | numaDestroy(&nag); |
281 | |
|
282 | 0 | return pixd; |
283 | 0 | } |
284 | | |
285 | | |
286 | | /*! |
287 | | * \brief pixGammaTRCWithAlpha() |
288 | | * |
289 | | * \param[in] pixd [optional] null or equal to pixs |
290 | | * \param[in] pixs 32 bpp |
291 | | * \param[in] gamma gamma correction; must be > 0.0 |
292 | | * \param[in] minval input value that gives 0 for output; can be < 0 |
293 | | * \param[in] maxval input value that gives 255 for output; can be > 255 |
294 | | * \return pixd always |
295 | | * |
296 | | * <pre> |
297 | | * Notes: |
298 | | * (1) See usage notes in pixGammaTRC(). |
299 | | * (2) This version saves the alpha channel. It is only valid |
300 | | * for 32 bpp (no colormap), and is a bit slower. |
301 | | * </pre> |
302 | | */ |
303 | | PIX * |
304 | | pixGammaTRCWithAlpha(PIX *pixd, |
305 | | PIX *pixs, |
306 | | l_float32 gamma, |
307 | | l_int32 minval, |
308 | | l_int32 maxval) |
309 | 0 | { |
310 | 0 | NUMA *nag; |
311 | 0 | PIX *pixalpha; |
312 | |
|
313 | 0 | if (!pixs || pixGetDepth(pixs) != 32) |
314 | 0 | return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, pixd); |
315 | 0 | if (pixd && (pixd != pixs)) |
316 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
317 | 0 | if (gamma <= 0.0) { |
318 | 0 | L_WARNING("gamma must be > 0.0; setting to 1.0\n", __func__); |
319 | 0 | gamma = 1.0; |
320 | 0 | } |
321 | 0 | if (minval >= maxval) |
322 | 0 | return (PIX *)ERROR_PTR("minval not < maxval", __func__, pixd); |
323 | | |
324 | 0 | if (gamma == 1.0 && minval == 0 && maxval == 255) |
325 | 0 | return pixCopy(pixd, pixs); |
326 | 0 | if (!pixd) /* start with a copy if not in-place */ |
327 | 0 | pixd = pixCopy(NULL, pixs); |
328 | |
|
329 | 0 | pixalpha = pixGetRGBComponent(pixs, L_ALPHA_CHANNEL); /* save */ |
330 | 0 | if ((nag = numaGammaTRC(gamma, minval, maxval)) == NULL) |
331 | 0 | return (PIX *)ERROR_PTR("nag not made", __func__, pixd); |
332 | 0 | pixTRCMap(pixd, NULL, nag); |
333 | 0 | pixSetRGBComponent(pixd, pixalpha, L_ALPHA_CHANNEL); /* restore */ |
334 | 0 | pixSetSpp(pixd, 4); |
335 | |
|
336 | 0 | numaDestroy(&nag); |
337 | 0 | pixDestroy(&pixalpha); |
338 | 0 | return pixd; |
339 | 0 | } |
340 | | |
341 | | |
342 | | /*! |
343 | | * \brief numaGammaTRC() |
344 | | * |
345 | | * \param[in] gamma gamma factor; must be > 0.0 |
346 | | * \param[in] minval input value that gives 0 for output |
347 | | * \param[in] maxval input value that gives 255 for output |
348 | | * \return na, or NULL on error |
349 | | * |
350 | | * <pre> |
351 | | * Notes: |
352 | | * (1) The map is returned as a numa; values are clipped to [0, 255]. |
353 | | * (2) For a linear mapping, set gamma = 1.0. |
354 | | * (3) To force all intensities into a range within fraction delta |
355 | | * of white, use: minval = -256 * (1 - delta) / delta |
356 | | * maxval = 255 |
357 | | * (4) To force all intensities into a range within fraction delta |
358 | | * of black, use: minval = 0 |
359 | | * maxval = 256 * (1 - delta) / delta |
360 | | * </pre> |
361 | | */ |
362 | | NUMA * |
363 | | numaGammaTRC(l_float32 gamma, |
364 | | l_int32 minval, |
365 | | l_int32 maxval) |
366 | 0 | { |
367 | 0 | l_int32 i, val; |
368 | 0 | l_float32 x, invgamma; |
369 | 0 | NUMA *na; |
370 | |
|
371 | 0 | if (minval >= maxval) |
372 | 0 | return (NUMA *)ERROR_PTR("minval not < maxval", __func__, NULL); |
373 | 0 | if (gamma <= 0.0) { |
374 | 0 | L_WARNING("gamma must be > 0.0; setting to 1.0\n", __func__); |
375 | 0 | gamma = 1.0; |
376 | 0 | } |
377 | |
|
378 | 0 | invgamma = 1. / gamma; |
379 | 0 | na = numaCreate(256); |
380 | 0 | for (i = 0; i < minval; i++) |
381 | 0 | numaAddNumber(na, 0); |
382 | 0 | for (i = minval; i <= maxval; i++) { |
383 | 0 | if (i < 0) continue; |
384 | 0 | if (i > 255) continue; |
385 | 0 | x = (l_float32)(i - minval) / (l_float32)(maxval - minval); |
386 | 0 | val = (l_int32)(255. * powf(x, invgamma) + 0.5); |
387 | 0 | val = L_MAX(val, 0); |
388 | 0 | val = L_MIN(val, 255); |
389 | 0 | numaAddNumber(na, val); |
390 | 0 | } |
391 | 0 | for (i = maxval + 1; i < 256; i++) |
392 | 0 | numaAddNumber(na, 255); |
393 | |
|
394 | 0 | return na; |
395 | 0 | } |
396 | | |
397 | | |
398 | | /*-------------------------------------------------------------* |
399 | | * Contrast enhancement * |
400 | | *-------------------------------------------------------------*/ |
401 | | /*! |
402 | | * \brief pixContrastTRC() |
403 | | * |
404 | | * \param[in] pixd [optional] null or equal to pixs |
405 | | * \param[in] pixs 8 or 32 bpp; or 2, 4 or 8 bpp with colormap |
406 | | * \param[in] factor 0.0 is no enhancement |
407 | | * \return pixd always |
408 | | * |
409 | | * <pre> |
410 | | * Notes: |
411 | | * (1) pixd must either be null or equal to pixs. |
412 | | * For in-place operation, set pixd == pixs: |
413 | | * pixContrastTRC(pixs, pixs, ...); |
414 | | * To get a new image, set pixd == null: |
415 | | * pixd = pixContrastTRC(NULL, pixs, ...); |
416 | | * (2) If pixs is colormapped, the colormap is transformed, |
417 | | * either in-place or in a copy of pixs. |
418 | | * (3) Contrast is enhanced by mapping each color component |
419 | | * using an atan function with maximum slope at 127. |
420 | | * Pixels below 127 are lowered in intensity and pixels |
421 | | * above 127 are increased. |
422 | | * (4) The useful range for the contrast factor is scaled to |
423 | | * be in (0.0 to 1.0), but larger values can also be used. |
424 | | * (5) If factor == 0.0, no enhancement is performed; return a copy |
425 | | * unless in-place, in which case this is a no-op. |
426 | | * (6) For color images that are not colormapped, the mapping |
427 | | * is applied to each component. |
428 | | * </pre> |
429 | | */ |
430 | | PIX * |
431 | | pixContrastTRC(PIX *pixd, |
432 | | PIX *pixs, |
433 | | l_float32 factor) |
434 | 0 | { |
435 | 0 | l_int32 d; |
436 | 0 | NUMA *nac; |
437 | 0 | PIXCMAP *cmap; |
438 | |
|
439 | 0 | if (!pixs) |
440 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd); |
441 | 0 | if (pixd && (pixd != pixs)) |
442 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
443 | 0 | if (factor < 0.0) { |
444 | 0 | L_WARNING("factor must be >= 0.0; using 0.0\n", __func__); |
445 | 0 | factor = 0.0; |
446 | 0 | } |
447 | 0 | if (factor == 0.0) |
448 | 0 | return pixCopy(pixd, pixs); |
449 | | |
450 | 0 | cmap = pixGetColormap(pixs); |
451 | 0 | d = pixGetDepth(pixs); |
452 | 0 | if (!cmap && d != 8 && d != 32) |
453 | 0 | return (PIX *)ERROR_PTR("depth not 8 or 32 bpp", __func__, pixd); |
454 | | |
455 | 0 | if (!pixd) /* start with a copy if not in-place */ |
456 | 0 | pixd = pixCopy(NULL, pixs); |
457 | |
|
458 | 0 | if (cmap) { |
459 | 0 | pixcmapContrastTRC(pixGetColormap(pixd), factor); |
460 | 0 | return pixd; |
461 | 0 | } |
462 | | |
463 | | /* pixd is 8 or 32 bpp */ |
464 | 0 | if ((nac = numaContrastTRC(factor)) == NULL) |
465 | 0 | return (PIX *)ERROR_PTR("nac not made", __func__, pixd); |
466 | 0 | pixTRCMap(pixd, NULL, nac); |
467 | 0 | numaDestroy(&nac); |
468 | |
|
469 | 0 | return pixd; |
470 | 0 | } |
471 | | |
472 | | |
473 | | /*! |
474 | | * \brief pixContrastTRCMasked() |
475 | | * |
476 | | * \param[in] pixd [optional] null or equal to pixs |
477 | | * \param[in] pixs 8 or 32 bpp; or 2, 4 or 8 bpp with colormap |
478 | | * \param[in] pixm [optional] null or 1 bpp |
479 | | * \param[in] factor 0.0 is no enhancement |
480 | | * \return pixd always |
481 | | * |
482 | | * <pre> |
483 | | * Notes: |
484 | | * (1) Same as pixContrastTRC() except mapping is optionally over |
485 | | * a subset of pixels described by pixm. |
486 | | * (2) Masking does not work for colormapped images. |
487 | | * (3) See pixContrastTRC() for details on how to use the parameters. |
488 | | * </pre> |
489 | | */ |
490 | | PIX * |
491 | | pixContrastTRCMasked(PIX *pixd, |
492 | | PIX *pixs, |
493 | | PIX *pixm, |
494 | | l_float32 factor) |
495 | 0 | { |
496 | 0 | l_int32 d; |
497 | 0 | NUMA *nac; |
498 | |
|
499 | 0 | if (!pixm) |
500 | 0 | return pixContrastTRC(pixd, pixs, factor); |
501 | | |
502 | 0 | if (!pixs) |
503 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, pixd); |
504 | 0 | if (pixGetColormap(pixs)) |
505 | 0 | return (PIX *)ERROR_PTR("invalid: pixs has a colormap", __func__, pixd); |
506 | 0 | if (pixd && (pixd != pixs)) |
507 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
508 | 0 | d = pixGetDepth(pixs); |
509 | 0 | if (d != 8 && d != 32) |
510 | 0 | return (PIX *)ERROR_PTR("depth not 8 or 32 bpp", __func__, pixd); |
511 | | |
512 | 0 | if (factor < 0.0) { |
513 | 0 | L_WARNING("factor must be >= 0.0; using 0.0\n", __func__); |
514 | 0 | factor = 0.0; |
515 | 0 | } |
516 | 0 | if (factor == 0.0) |
517 | 0 | return pixCopy(pixd, pixs); |
518 | | |
519 | 0 | if (!pixd) /* start with a copy if not in-place */ |
520 | 0 | pixd = pixCopy(NULL, pixs); |
521 | |
|
522 | 0 | if ((nac = numaContrastTRC(factor)) == NULL) |
523 | 0 | return (PIX *)ERROR_PTR("nac not made", __func__, pixd); |
524 | 0 | pixTRCMap(pixd, pixm, nac); |
525 | 0 | numaDestroy(&nac); |
526 | |
|
527 | 0 | return pixd; |
528 | 0 | } |
529 | | |
530 | | |
531 | | /*! |
532 | | * \brief numaContrastTRC() |
533 | | * |
534 | | * \param[in] factor generally between 0.0 [no enhancement] |
535 | | * and 1.0, but can be larger than 1.0 |
536 | | * \return na, or NULL on error |
537 | | * |
538 | | * <pre> |
539 | | * Notes: |
540 | | * (1) The mapping is monotonic increasing, where 0 is mapped |
541 | | * to 0 and 255 is mapped to 255. |
542 | | * (2) As 'factor' is increased from 0.0 (where the mapping is linear), |
543 | | * the map gets closer to its limit as a step function that |
544 | | * jumps from 0 to 255 at the center (input value = 127). |
545 | | * </pre> |
546 | | */ |
547 | | NUMA * |
548 | | numaContrastTRC(l_float32 factor) |
549 | 0 | { |
550 | 0 | l_int32 i, val; |
551 | 0 | l_float64 x, ymax, ymin, dely, scale; |
552 | 0 | NUMA *na; |
553 | |
|
554 | 0 | if (factor < 0.0) { |
555 | 0 | L_WARNING("factor must be >= 0.0; using 0.0; no enhancement\n", |
556 | 0 | __func__); |
557 | 0 | factor = 0.0; |
558 | 0 | } |
559 | 0 | if (factor == 0.0) |
560 | 0 | return numaMakeSequence(0, 1, 256); /* linear map */ |
561 | | |
562 | 0 | scale = EnhanceScaleFactor; |
563 | 0 | ymax = atan((l_float64)(1.0 * factor * scale)); |
564 | 0 | ymin = atan((l_float64)(-127. * factor * scale / 128.)); |
565 | 0 | dely = ymax - ymin; |
566 | 0 | na = numaCreate(256); |
567 | 0 | for (i = 0; i < 256; i++) { |
568 | 0 | x = (l_float64)i; |
569 | 0 | val = (l_int32)((255. / dely) * |
570 | 0 | (-ymin + atan((l_float64)(factor * scale * (x - 127.) / 128.))) + |
571 | 0 | 0.5); |
572 | 0 | numaAddNumber(na, val); |
573 | 0 | } |
574 | |
|
575 | 0 | return na; |
576 | 0 | } |
577 | | |
578 | | |
579 | | /*-------------------------------------------------------------* |
580 | | * Histogram equalization * |
581 | | *-------------------------------------------------------------*/ |
582 | | /*! |
583 | | * \brief pixEqualizeTRC() |
584 | | * |
585 | | * \param[in] pixd [optional] null or equal to pixs |
586 | | * \param[in] pixs 8 bpp gray, 32 bpp rgb, or colormapped |
587 | | * \param[in] fract fraction of equalization movement of pixel values |
588 | | * \param[in] factor subsampling factor; integer >= 1 |
589 | | * \return pixd, or NULL on error |
590 | | * |
591 | | * <pre> |
592 | | * Notes: |
593 | | * (1) pixd must either be null or equal to pixs. |
594 | | * For in-place operation, set pixd == pixs: |
595 | | * pixEqualizeTRC(pixs, pixs, ...); |
596 | | * To get a new image, set pixd == null: |
597 | | * pixd = pixEqualizeTRC(NULL, pixs, ...); |
598 | | * (2) In histogram equalization, a tone reproduction curve |
599 | | * mapping is used to make the number of pixels at each |
600 | | * intensity equal. |
601 | | * (3) If fract == 0.0, no equalization is performed; return a copy |
602 | | * unless in-place, in which case this is a no-op. |
603 | | * If fract == 1.0, equalization is complete. |
604 | | * (4) Set the subsampling factor > 1 to reduce the amount of computation. |
605 | | * (5) If pixs is colormapped, the colormap is removed and |
606 | | * converted to rgb or grayscale. |
607 | | * (6) If pixs has color, equalization is done in each channel |
608 | | * separately. |
609 | | * (7) Note that even if there is a colormap, we can get an |
610 | | * in-place operation because the intermediate image pixt |
611 | | * is copied back to pixs (which for in-place is the same |
612 | | * as pixd). |
613 | | * </pre> |
614 | | */ |
615 | | PIX * |
616 | | pixEqualizeTRC(PIX *pixd, |
617 | | PIX *pixs, |
618 | | l_float32 fract, |
619 | | l_int32 factor) |
620 | 0 | { |
621 | 0 | l_int32 d; |
622 | 0 | NUMA *na; |
623 | 0 | PIX *pixt, *pix8; |
624 | 0 | PIXCMAP *cmap; |
625 | |
|
626 | 0 | if (!pixs) |
627 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
628 | 0 | if (pixd && (pixd != pixs)) |
629 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
630 | 0 | cmap = pixGetColormap(pixs); |
631 | 0 | d = pixGetDepth(pixs); |
632 | 0 | if (d != 8 && d != 32 && !cmap) |
633 | 0 | return (PIX *)ERROR_PTR("pixs not 8/32 bpp or cmapped", __func__, NULL); |
634 | 0 | if (fract < 0.0 || fract > 1.0) |
635 | 0 | return (PIX *)ERROR_PTR("fract not in [0.0 ... 1.0]", __func__, NULL); |
636 | 0 | if (factor < 1) |
637 | 0 | return (PIX *)ERROR_PTR("sampling factor < 1", __func__, NULL); |
638 | | |
639 | 0 | if (fract == 0.0) |
640 | 0 | return pixCopy(pixd, pixs); |
641 | | |
642 | | /* If there is a colormap, remove it. */ |
643 | 0 | if (cmap) |
644 | 0 | pixt = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC); |
645 | 0 | else |
646 | 0 | pixt = pixClone(pixs); |
647 | | |
648 | | /* Make a copy if necessary */ |
649 | 0 | pixd = pixCopy(pixd, pixt); |
650 | 0 | pixDestroy(&pixt); |
651 | |
|
652 | 0 | d = pixGetDepth(pixd); |
653 | 0 | if (d == 8) { |
654 | 0 | na = numaEqualizeTRC(pixd, fract, factor); |
655 | 0 | pixTRCMap(pixd, NULL, na); |
656 | 0 | numaDestroy(&na); |
657 | 0 | } else { /* 32 bpp */ |
658 | 0 | pix8 = pixGetRGBComponent(pixd, COLOR_RED); |
659 | 0 | na = numaEqualizeTRC(pix8, fract, factor); |
660 | 0 | pixTRCMap(pix8, NULL, na); |
661 | 0 | pixSetRGBComponent(pixd, pix8, COLOR_RED); |
662 | 0 | numaDestroy(&na); |
663 | 0 | pixDestroy(&pix8); |
664 | 0 | pix8 = pixGetRGBComponent(pixd, COLOR_GREEN); |
665 | 0 | na = numaEqualizeTRC(pix8, fract, factor); |
666 | 0 | pixTRCMap(pix8, NULL, na); |
667 | 0 | pixSetRGBComponent(pixd, pix8, COLOR_GREEN); |
668 | 0 | numaDestroy(&na); |
669 | 0 | pixDestroy(&pix8); |
670 | 0 | pix8 = pixGetRGBComponent(pixd, COLOR_BLUE); |
671 | 0 | na = numaEqualizeTRC(pix8, fract, factor); |
672 | 0 | pixTRCMap(pix8, NULL, na); |
673 | 0 | pixSetRGBComponent(pixd, pix8, COLOR_BLUE); |
674 | 0 | numaDestroy(&na); |
675 | 0 | pixDestroy(&pix8); |
676 | 0 | } |
677 | |
|
678 | 0 | return pixd; |
679 | 0 | } |
680 | | |
681 | | |
682 | | /*! |
683 | | * \brief numaEqualizeTRC() |
684 | | * |
685 | | * \param[in] pix 8 bpp, no colormap |
686 | | * \param[in] fract fraction of equalization movement of pixel values |
687 | | * \param[in] factor subsampling factor; integer >= 1 |
688 | | * \return nad, or NULL on error |
689 | | * |
690 | | * <pre> |
691 | | * Notes: |
692 | | * (1) If fract == 0.0, no equalization will be performed. |
693 | | * If fract == 1.0, equalization is complete. |
694 | | * (2) Set the subsampling factor > 1 to reduce the amount of computation. |
695 | | * (3) The map is returned as a numa with 256 values, specifying |
696 | | * the equalized value (array value) for every input value |
697 | | * (the array index). |
698 | | * </pre> |
699 | | */ |
700 | | NUMA * |
701 | | numaEqualizeTRC(PIX *pix, |
702 | | l_float32 fract, |
703 | | l_int32 factor) |
704 | 0 | { |
705 | 0 | l_int32 iin, iout, itarg; |
706 | 0 | l_float32 val, sum; |
707 | 0 | NUMA *nah, *nasum, *nad; |
708 | |
|
709 | 0 | if (!pix) |
710 | 0 | return (NUMA *)ERROR_PTR("pix not defined", __func__, NULL); |
711 | 0 | if (pixGetDepth(pix) != 8) |
712 | 0 | return (NUMA *)ERROR_PTR("pix not 8 bpp", __func__, NULL); |
713 | 0 | if (fract < 0.0 || fract > 1.0) |
714 | 0 | return (NUMA *)ERROR_PTR("fract not in [0.0 ... 1.0]", __func__, NULL); |
715 | 0 | if (factor < 1) |
716 | 0 | return (NUMA *)ERROR_PTR("sampling factor < 1", __func__, NULL); |
717 | | |
718 | 0 | if (fract == 0.0) |
719 | 0 | L_WARNING("fract = 0.0; no equalization requested\n", __func__); |
720 | |
|
721 | 0 | if ((nah = pixGetGrayHistogram(pix, factor)) == NULL) |
722 | 0 | return (NUMA *)ERROR_PTR("histogram not made", __func__, NULL); |
723 | 0 | numaGetSum(nah, &sum); |
724 | 0 | nasum = numaGetPartialSums(nah); |
725 | |
|
726 | 0 | nad = numaCreate(256); |
727 | 0 | for (iin = 0; iin < 256; iin++) { |
728 | 0 | numaGetFValue(nasum, iin, &val); |
729 | 0 | itarg = (l_int32)(255. * val / sum + 0.5); |
730 | 0 | iout = iin + (l_int32)(fract * (itarg - iin)); |
731 | 0 | iout = L_MIN(iout, 255); /* to be safe */ |
732 | 0 | numaAddNumber(nad, iout); |
733 | 0 | } |
734 | |
|
735 | 0 | numaDestroy(&nah); |
736 | 0 | numaDestroy(&nasum); |
737 | 0 | return nad; |
738 | 0 | } |
739 | | |
740 | | |
741 | | /*-------------------------------------------------------------* |
742 | | * Generic TRC mapping * |
743 | | *-------------------------------------------------------------*/ |
744 | | /*! |
745 | | * \brief pixTRCMap() |
746 | | * |
747 | | * \param[in] pixs 8 grayscale or 32 bpp rgb; not colormapped |
748 | | * \param[in] pixm [optional] 1 bpp mask |
749 | | * \param[in] na mapping array |
750 | | * \return 0 if OK, 1 on error |
751 | | * |
752 | | * <pre> |
753 | | * Notes: |
754 | | * (1) This operation is in-place on pixs. |
755 | | * (2) For 32 bpp, this applies the same map to each of the r,g,b |
756 | | * components. |
757 | | * (3) The mapping array is of size 256, and it maps the input |
758 | | * index into values in the range [0, 255]. |
759 | | * (4) If defined, the optional 1 bpp mask pixm has its origin |
760 | | * aligned with pixs, and the map function is applied only |
761 | | * to pixels in pixs under the fg of pixm. |
762 | | * (5) For 32 bpp, this does not save the alpha channel. |
763 | | * </pre> |
764 | | */ |
765 | | l_int32 |
766 | | pixTRCMap(PIX *pixs, |
767 | | PIX *pixm, |
768 | | NUMA *na) |
769 | 0 | { |
770 | 0 | l_int32 w, h, d, wm, hm, wpl, wplm, i, j, sval8, dval8; |
771 | 0 | l_uint32 sval32, dval32; |
772 | 0 | l_uint32 *data, *datam, *line, *linem, *tab; |
773 | |
|
774 | 0 | if (!pixs) |
775 | 0 | return ERROR_INT("pixs not defined", __func__, 1); |
776 | 0 | if (pixGetColormap(pixs)) |
777 | 0 | return ERROR_INT("pixs is colormapped", __func__, 1); |
778 | 0 | if (!na) |
779 | 0 | return ERROR_INT("na not defined", __func__, 1); |
780 | 0 | if (numaGetCount(na) != 256) |
781 | 0 | return ERROR_INT("na not of size 256", __func__, 1); |
782 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
783 | 0 | if (d != 8 && d != 32) |
784 | 0 | return ERROR_INT("pixs not 8 or 32 bpp", __func__, 1); |
785 | 0 | if (pixm) { |
786 | 0 | if (pixGetDepth(pixm) != 1) |
787 | 0 | return ERROR_INT("pixm not 1 bpp", __func__, 1); |
788 | 0 | } |
789 | | |
790 | 0 | tab = (l_uint32 *)numaGetIArray(na); /* get the array for efficiency */ |
791 | 0 | wpl = pixGetWpl(pixs); |
792 | 0 | data = pixGetData(pixs); |
793 | 0 | if (!pixm) { |
794 | 0 | if (d == 8) { |
795 | 0 | for (i = 0; i < h; i++) { |
796 | 0 | line = data + i * wpl; |
797 | 0 | for (j = 0; j < w; j++) { |
798 | 0 | sval8 = GET_DATA_BYTE(line, j); |
799 | 0 | dval8 = tab[sval8]; |
800 | 0 | SET_DATA_BYTE(line, j, dval8); |
801 | 0 | } |
802 | 0 | } |
803 | 0 | } else { /* d == 32 */ |
804 | 0 | for (i = 0; i < h; i++) { |
805 | 0 | line = data + i * wpl; |
806 | 0 | for (j = 0; j < w; j++) { |
807 | 0 | sval32 = *(line + j); |
808 | 0 | dval32 = |
809 | 0 | tab[(sval32 >> L_RED_SHIFT) & 0xff] << L_RED_SHIFT | |
810 | 0 | tab[(sval32 >> L_GREEN_SHIFT) & 0xff] << L_GREEN_SHIFT | |
811 | 0 | tab[(sval32 >> L_BLUE_SHIFT) & 0xff] << L_BLUE_SHIFT; |
812 | 0 | *(line + j) = dval32; |
813 | 0 | } |
814 | 0 | } |
815 | 0 | } |
816 | 0 | } else { |
817 | 0 | datam = pixGetData(pixm); |
818 | 0 | wplm = pixGetWpl(pixm); |
819 | 0 | pixGetDimensions(pixm, &wm, &hm, NULL); |
820 | 0 | if (d == 8) { |
821 | 0 | for (i = 0; i < h; i++) { |
822 | 0 | if (i >= hm) |
823 | 0 | break; |
824 | 0 | line = data + i * wpl; |
825 | 0 | linem = datam + i * wplm; |
826 | 0 | for (j = 0; j < w; j++) { |
827 | 0 | if (j >= wm) |
828 | 0 | break; |
829 | 0 | if (GET_DATA_BIT(linem, j) == 0) |
830 | 0 | continue; |
831 | 0 | sval8 = GET_DATA_BYTE(line, j); |
832 | 0 | dval8 = tab[sval8]; |
833 | 0 | SET_DATA_BYTE(line, j, dval8); |
834 | 0 | } |
835 | 0 | } |
836 | 0 | } else { /* d == 32 */ |
837 | 0 | for (i = 0; i < h; i++) { |
838 | 0 | if (i >= hm) |
839 | 0 | break; |
840 | 0 | line = data + i * wpl; |
841 | 0 | linem = datam + i * wplm; |
842 | 0 | for (j = 0; j < w; j++) { |
843 | 0 | if (j >= wm) |
844 | 0 | break; |
845 | 0 | if (GET_DATA_BIT(linem, j) == 0) |
846 | 0 | continue; |
847 | 0 | sval32 = *(line + j); |
848 | 0 | dval32 = |
849 | 0 | tab[(sval32 >> L_RED_SHIFT) & 0xff] << L_RED_SHIFT | |
850 | 0 | tab[(sval32 >> L_GREEN_SHIFT) & 0xff] << L_GREEN_SHIFT | |
851 | 0 | tab[(sval32 >> L_BLUE_SHIFT) & 0xff] << L_BLUE_SHIFT; |
852 | 0 | *(line + j) = dval32; |
853 | 0 | } |
854 | 0 | } |
855 | 0 | } |
856 | 0 | } |
857 | |
|
858 | 0 | LEPT_FREE(tab); |
859 | 0 | return 0; |
860 | 0 | } |
861 | | |
862 | | |
863 | | /*! |
864 | | * \brief pixTRCMapGeneral() |
865 | | * |
866 | | * \param[in] pixs 32 bpp rgb; not colormapped |
867 | | * \param[in] pixm [optional] 1 bpp mask |
868 | | * \param[in] nar, nag, nab mapping arrays |
869 | | * \return 0 if OK, 1 on error |
870 | | * |
871 | | * <pre> |
872 | | * Notes: |
873 | | * (1) This operation is in-place on %pixs. |
874 | | * (2) Each of the r,g,b mapping arrays is of size 256. They map the |
875 | | * input value for that color component into values in the |
876 | | * range [0, 255]. |
877 | | * (3) In the special case where the r, g and b mapping arrays are |
878 | | * all the same, call pixTRCMap() instead. |
879 | | * (4) If defined, the optional 1 bpp mask %pixm has its origin |
880 | | * aligned with %pixs, and the map function is applied only |
881 | | * to pixels in %pixs under the fg of pixm. |
882 | | * (5) The alpha channel is not saved. |
883 | | * </pre> |
884 | | */ |
885 | | l_int32 |
886 | | pixTRCMapGeneral(PIX *pixs, |
887 | | PIX *pixm, |
888 | | NUMA *nar, |
889 | | NUMA *nag, |
890 | | NUMA *nab) |
891 | 0 | { |
892 | 0 | l_int32 w, h, wm, hm, wpl, wplm, i, j; |
893 | 0 | l_uint32 sval32, dval32; |
894 | 0 | l_uint32 *data, *datam, *line, *linem, *tabr, *tabg, *tabb; |
895 | |
|
896 | 0 | if (!pixs || pixGetDepth(pixs) != 32) |
897 | 0 | return ERROR_INT("pixs not defined or not 32 bpp", __func__, 1); |
898 | 0 | if (pixm && pixGetDepth(pixm) != 1) |
899 | 0 | return ERROR_INT("pixm defined and not 1 bpp", __func__, 1); |
900 | 0 | if (!nar || !nag || !nab) |
901 | 0 | return ERROR_INT("na{r,g,b} not all defined", __func__, 1); |
902 | 0 | if (numaGetCount(nar) != 256 || numaGetCount(nag) != 256 || |
903 | 0 | numaGetCount(nab) != 256) |
904 | 0 | return ERROR_INT("na{r,g,b} not all of size 256", __func__, 1); |
905 | | |
906 | | /* Get the arrays for efficiency */ |
907 | 0 | tabr = (l_uint32 *)numaGetIArray(nar); |
908 | 0 | tabg = (l_uint32 *)numaGetIArray(nag); |
909 | 0 | tabb = (l_uint32 *)numaGetIArray(nab); |
910 | 0 | pixGetDimensions(pixs, &w, &h, NULL); |
911 | 0 | wpl = pixGetWpl(pixs); |
912 | 0 | data = pixGetData(pixs); |
913 | 0 | if (!pixm) { |
914 | 0 | for (i = 0; i < h; i++) { |
915 | 0 | line = data + i * wpl; |
916 | 0 | for (j = 0; j < w; j++) { |
917 | 0 | sval32 = *(line + j); |
918 | 0 | dval32 = |
919 | 0 | tabr[(sval32 >> L_RED_SHIFT) & 0xff] << L_RED_SHIFT | |
920 | 0 | tabg[(sval32 >> L_GREEN_SHIFT) & 0xff] << L_GREEN_SHIFT | |
921 | 0 | tabb[(sval32 >> L_BLUE_SHIFT) & 0xff] << L_BLUE_SHIFT; |
922 | 0 | *(line + j) = dval32; |
923 | 0 | } |
924 | 0 | } |
925 | 0 | } else { |
926 | 0 | datam = pixGetData(pixm); |
927 | 0 | wplm = pixGetWpl(pixm); |
928 | 0 | pixGetDimensions(pixm, &wm, &hm, NULL); |
929 | 0 | for (i = 0; i < h; i++) { |
930 | 0 | if (i >= hm) |
931 | 0 | break; |
932 | 0 | line = data + i * wpl; |
933 | 0 | linem = datam + i * wplm; |
934 | 0 | for (j = 0; j < w; j++) { |
935 | 0 | if (j >= wm) |
936 | 0 | break; |
937 | 0 | if (GET_DATA_BIT(linem, j) == 0) |
938 | 0 | continue; |
939 | 0 | sval32 = *(line + j); |
940 | 0 | dval32 = |
941 | 0 | tabr[(sval32 >> L_RED_SHIFT) & 0xff] << L_RED_SHIFT | |
942 | 0 | tabg[(sval32 >> L_GREEN_SHIFT) & 0xff] << L_GREEN_SHIFT | |
943 | 0 | tabb[(sval32 >> L_BLUE_SHIFT) & 0xff] << L_BLUE_SHIFT; |
944 | 0 | *(line + j) = dval32; |
945 | 0 | } |
946 | 0 | } |
947 | 0 | } |
948 | |
|
949 | 0 | LEPT_FREE(tabr); |
950 | 0 | LEPT_FREE(tabg); |
951 | 0 | LEPT_FREE(tabb); |
952 | 0 | return 0; |
953 | 0 | } |
954 | | |
955 | | |
956 | | |
957 | | /*-----------------------------------------------------------------------* |
958 | | * Unsharp masking * |
959 | | *-----------------------------------------------------------------------*/ |
960 | | /*! |
961 | | * \brief pixUnsharpMasking() |
962 | | * |
963 | | * \param[in] pixs all depths except 1 bpp; with or without colormaps |
964 | | * \param[in] halfwidth "half-width" of smoothing filter |
965 | | * \param[in] fract fraction of edge added back into image |
966 | | * \return pixd, or NULL on error |
967 | | * |
968 | | * <pre> |
969 | | * Notes: |
970 | | * (1) We use symmetric smoothing filters of odd dimension, |
971 | | * typically use sizes of 3, 5, 7, etc. The %halfwidth parameter |
972 | | * for these is (size - 1)/2; i.e., 1, 2, 3, etc. |
973 | | * (2) The fract parameter is typically taken in the |
974 | | * range: 0.2 < fract < 0.7 |
975 | | * (3) Returns a clone if no sharpening is requested. |
976 | | * </pre> |
977 | | */ |
978 | | PIX * |
979 | | pixUnsharpMasking(PIX *pixs, |
980 | | l_int32 halfwidth, |
981 | | l_float32 fract) |
982 | 0 | { |
983 | 0 | l_int32 d; |
984 | 0 | PIX *pix1, *pixd, *pixr, *pixrs, *pixg, *pixgs, *pixb, *pixbs; |
985 | |
|
986 | 0 | if (!pixs || (pixGetDepth(pixs) == 1)) |
987 | 0 | return (PIX *)ERROR_PTR("pixs not defined or 1 bpp", __func__, NULL); |
988 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
989 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
990 | 0 | return pixClone(pixs); |
991 | 0 | } |
992 | | |
993 | 0 | if (halfwidth == 1 || halfwidth == 2) |
994 | 0 | return pixUnsharpMaskingFast(pixs, halfwidth, fract, L_BOTH_DIRECTIONS); |
995 | | |
996 | | /* Remove colormap; clone if possible; result is either 8 or 32 bpp */ |
997 | 0 | if ((pix1 = pixConvertTo8Or32(pixs, L_CLONE, 0)) == NULL) |
998 | 0 | return (PIX *)ERROR_PTR("pix1 not made", __func__, NULL); |
999 | | |
1000 | | /* Sharpen */ |
1001 | 0 | d = pixGetDepth(pix1); |
1002 | 0 | if (d == 8) { |
1003 | 0 | pixd = pixUnsharpMaskingGray(pix1, halfwidth, fract); |
1004 | 0 | } else { /* d == 32 */ |
1005 | 0 | pixr = pixGetRGBComponent(pix1, COLOR_RED); |
1006 | 0 | pixrs = pixUnsharpMaskingGray(pixr, halfwidth, fract); |
1007 | 0 | pixDestroy(&pixr); |
1008 | 0 | pixg = pixGetRGBComponent(pix1, COLOR_GREEN); |
1009 | 0 | pixgs = pixUnsharpMaskingGray(pixg, halfwidth, fract); |
1010 | 0 | pixDestroy(&pixg); |
1011 | 0 | pixb = pixGetRGBComponent(pix1, COLOR_BLUE); |
1012 | 0 | pixbs = pixUnsharpMaskingGray(pixb, halfwidth, fract); |
1013 | 0 | pixDestroy(&pixb); |
1014 | 0 | pixd = pixCreateRGBImage(pixrs, pixgs, pixbs); |
1015 | 0 | pixDestroy(&pixrs); |
1016 | 0 | pixDestroy(&pixgs); |
1017 | 0 | pixDestroy(&pixbs); |
1018 | 0 | if (pixGetSpp(pixs) == 4) |
1019 | 0 | pixCopyRGBComponent(pixd, pixs, L_ALPHA_CHANNEL); |
1020 | 0 | } |
1021 | |
|
1022 | 0 | pixDestroy(&pix1); |
1023 | 0 | return pixd; |
1024 | 0 | } |
1025 | | |
1026 | | |
1027 | | /*! |
1028 | | * \brief pixUnsharpMaskingGray() |
1029 | | * |
1030 | | * \param[in] pixs 8 bpp; no colormap |
1031 | | * \param[in] halfwidth "half-width" of smoothing filter |
1032 | | * \param[in] fract fraction of edge added back into image |
1033 | | * \return pixd, or NULL on error |
1034 | | * |
1035 | | * <pre> |
1036 | | * Notes: |
1037 | | * (1) We use symmetric smoothing filters of odd dimension, |
1038 | | * typically use sizes of 3, 5, 7, etc. The %halfwidth parameter |
1039 | | * for these is (size - 1)/2; i.e., 1, 2, 3, etc. |
1040 | | * (2) The fract parameter is typically taken in the range: |
1041 | | * 0.2 < fract < 0.7 |
1042 | | * (3) Returns a clone if no sharpening is requested. |
1043 | | * </pre> |
1044 | | */ |
1045 | | PIX * |
1046 | | pixUnsharpMaskingGray(PIX *pixs, |
1047 | | l_int32 halfwidth, |
1048 | | l_float32 fract) |
1049 | 0 | { |
1050 | 0 | l_int32 w, h, d; |
1051 | 0 | PIX *pixc, *pixd; |
1052 | 0 | PIXACC *pixacc; |
1053 | |
|
1054 | 0 | if (!pixs) |
1055 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1056 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1057 | 0 | if (d != 8 || pixGetColormap(pixs) != NULL) |
1058 | 0 | return (PIX *)ERROR_PTR("pixs not 8 bpp or has cmap", __func__, NULL); |
1059 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
1060 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
1061 | 0 | return pixClone(pixs); |
1062 | 0 | } |
1063 | 0 | if (halfwidth == 1 || halfwidth == 2) |
1064 | 0 | return pixUnsharpMaskingGrayFast(pixs, halfwidth, fract, |
1065 | 0 | L_BOTH_DIRECTIONS); |
1066 | | |
1067 | 0 | if ((pixc = pixBlockconvGray(pixs, NULL, halfwidth, halfwidth)) == NULL) |
1068 | 0 | return (PIX *)ERROR_PTR("pixc not made", __func__, NULL); |
1069 | | |
1070 | | /* Steps: |
1071 | | * (1) edge image is pixs - pixc (this is highpass part) |
1072 | | * (2) multiply edge image by fract |
1073 | | * (3) add fraction of edge to pixs |
1074 | | * |
1075 | | * To show how this is done with both interfaces to arithmetic |
1076 | | * on integer Pix, here is the implementation in the lower-level |
1077 | | * function calls: |
1078 | | * pixt = pixInitAccumulate(w, h, 0x10000000)) == NULL) |
1079 | | * pixAccumulate(pixt, pixs, L_ARITH_ADD); |
1080 | | * pixAccumulate(pixt, pixc, L_ARITH_SUBTRACT); |
1081 | | * pixMultConstAccumulate(pixt, fract, 0x10000000); |
1082 | | * pixAccumulate(pixt, pixs, L_ARITH_ADD); |
1083 | | * pixd = pixFinalAccumulate(pixt, 0x10000000, 8)) == NULL) |
1084 | | * pixDestroy(&pixt); |
1085 | | * |
1086 | | * The code below does the same thing using the Pixacc accumulator, |
1087 | | * hiding the details of the offset that is needed for subtraction. |
1088 | | */ |
1089 | 0 | pixacc = pixaccCreate(w, h, 1); |
1090 | 0 | pixaccAdd(pixacc, pixs); |
1091 | 0 | pixaccSubtract(pixacc, pixc); |
1092 | 0 | pixaccMultConst(pixacc, fract); |
1093 | 0 | pixaccAdd(pixacc, pixs); |
1094 | 0 | pixd = pixaccFinal(pixacc, 8); |
1095 | 0 | pixaccDestroy(&pixacc); |
1096 | |
|
1097 | 0 | pixDestroy(&pixc); |
1098 | 0 | return pixd; |
1099 | 0 | } |
1100 | | |
1101 | | |
1102 | | /*! |
1103 | | * \brief pixUnsharpMaskingFast() |
1104 | | * |
1105 | | * \param[in] pixs all depths except 1 bpp; with or without colormaps |
1106 | | * \param[in] halfwidth "half-width" of smoothing filter; 1 and 2 only |
1107 | | * \param[in] fract fraction of high frequency added to image |
1108 | | * \param[in] direction L_HORIZ, L_VERT, L_BOTH_DIRECTIONS |
1109 | | * \return pixd, or NULL on error |
1110 | | * |
1111 | | * <pre> |
1112 | | * Notes: |
1113 | | * (1) The fast version uses separable 1-D filters directly on |
1114 | | * the input image. The halfwidth is either 1 (full width = 3) |
1115 | | * or 2 (full width = 5). |
1116 | | * (2) The fract parameter is typically taken in the |
1117 | | * range: 0.2 < fract < 0.7 |
1118 | | * (3) To skip horizontal sharpening, use %fracth = 0.0; ditto for %fractv |
1119 | | * (4) For one dimensional filtering (as an example): |
1120 | | * For %halfwidth = 1, the low-pass filter is |
1121 | | * L: 1/3 1/3 1/3 |
1122 | | * and the high-pass filter is |
1123 | | * H = I - L: -1/3 2/3 -1/3 |
1124 | | * For %halfwidth = 2, the low-pass filter is |
1125 | | * L: 1/5 1/5 1/5 1/5 1/5 |
1126 | | * and the high-pass filter is |
1127 | | * H = I - L: -1/5 -1/5 4/5 -1/5 -1/5 |
1128 | | * The new sharpened pixel value is found by adding some fraction |
1129 | | * of the high-pass filter value (which sums to 0) to the |
1130 | | * initial pixel value: |
1131 | | * N = I + fract * H |
1132 | | * (5) For 2D, the sharpening filter is not separable, because the |
1133 | | * vertical filter depends on the horizontal location relative |
1134 | | * to the filter origin, and v.v. So we either do the full |
1135 | | * 2D filter (for %halfwidth == 1) or do the low-pass |
1136 | | * convolution separably and then compose with the original pix. |
1137 | | * (6) Returns a clone if no sharpening is requested. |
1138 | | * </pre> |
1139 | | */ |
1140 | | PIX * |
1141 | | pixUnsharpMaskingFast(PIX *pixs, |
1142 | | l_int32 halfwidth, |
1143 | | l_float32 fract, |
1144 | | l_int32 direction) |
1145 | 0 | { |
1146 | 0 | l_int32 d; |
1147 | 0 | PIX *pixt, *pixd, *pixr, *pixrs, *pixg, *pixgs, *pixb, *pixbs; |
1148 | |
|
1149 | 0 | if (!pixs || (pixGetDepth(pixs) == 1)) |
1150 | 0 | return (PIX *)ERROR_PTR("pixs not defined or 1 bpp", __func__, NULL); |
1151 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
1152 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
1153 | 0 | return pixClone(pixs); |
1154 | 0 | } |
1155 | 0 | if (halfwidth != 1 && halfwidth != 2) |
1156 | 0 | return (PIX *)ERROR_PTR("halfwidth must be 1 or 2", __func__, NULL); |
1157 | 0 | if (direction != L_HORIZ && direction != L_VERT && |
1158 | 0 | direction != L_BOTH_DIRECTIONS) |
1159 | 0 | return (PIX *)ERROR_PTR("invalid direction", __func__, NULL); |
1160 | | |
1161 | | /* Remove colormap; clone if possible; result is either 8 or 32 bpp */ |
1162 | 0 | if ((pixt = pixConvertTo8Or32(pixs, L_CLONE, 0)) == NULL) |
1163 | 0 | return (PIX *)ERROR_PTR("pixt not made", __func__, NULL); |
1164 | | |
1165 | | /* Sharpen */ |
1166 | 0 | d = pixGetDepth(pixt); |
1167 | 0 | if (d == 8) { |
1168 | 0 | pixd = pixUnsharpMaskingGrayFast(pixt, halfwidth, fract, direction); |
1169 | 0 | } else { /* d == 32 */ |
1170 | 0 | pixr = pixGetRGBComponent(pixs, COLOR_RED); |
1171 | 0 | pixrs = pixUnsharpMaskingGrayFast(pixr, halfwidth, fract, direction); |
1172 | 0 | pixDestroy(&pixr); |
1173 | 0 | pixg = pixGetRGBComponent(pixs, COLOR_GREEN); |
1174 | 0 | pixgs = pixUnsharpMaskingGrayFast(pixg, halfwidth, fract, direction); |
1175 | 0 | pixDestroy(&pixg); |
1176 | 0 | pixb = pixGetRGBComponent(pixs, COLOR_BLUE); |
1177 | 0 | pixbs = pixUnsharpMaskingGrayFast(pixb, halfwidth, fract, direction); |
1178 | 0 | pixDestroy(&pixb); |
1179 | 0 | pixd = pixCreateRGBImage(pixrs, pixgs, pixbs); |
1180 | 0 | if (pixGetSpp(pixs) == 4) |
1181 | 0 | pixCopyRGBComponent(pixd, pixs, L_ALPHA_CHANNEL); |
1182 | 0 | pixDestroy(&pixrs); |
1183 | 0 | pixDestroy(&pixgs); |
1184 | 0 | pixDestroy(&pixbs); |
1185 | 0 | } |
1186 | |
|
1187 | 0 | pixDestroy(&pixt); |
1188 | 0 | return pixd; |
1189 | 0 | } |
1190 | | |
1191 | | |
1192 | | |
1193 | | /*! |
1194 | | * \brief pixUnsharpMaskingGrayFast() |
1195 | | * |
1196 | | * \param[in] pixs 8 bpp; no colormap |
1197 | | * \param[in] halfwidth "half-width" of smoothing filter: 1 or 2 |
1198 | | * \param[in] fract fraction of high frequency added to image |
1199 | | * \param[in] direction L_HORIZ, L_VERT, L_BOTH_DIRECTIONS |
1200 | | * \return pixd, or NULL on error |
1201 | | * |
1202 | | * <pre> |
1203 | | * Notes: |
1204 | | * (1) For usage and explanation of the algorithm, see notes |
1205 | | * in pixUnsharpMaskingFast(). |
1206 | | * (2) Returns a clone if no sharpening is requested. |
1207 | | * </pre> |
1208 | | */ |
1209 | | PIX * |
1210 | | pixUnsharpMaskingGrayFast(PIX *pixs, |
1211 | | l_int32 halfwidth, |
1212 | | l_float32 fract, |
1213 | | l_int32 direction) |
1214 | 0 | { |
1215 | 0 | PIX *pixd; |
1216 | |
|
1217 | 0 | if (!pixs) |
1218 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1219 | 0 | if (pixGetDepth(pixs) != 8 || pixGetColormap(pixs) != NULL) |
1220 | 0 | return (PIX *)ERROR_PTR("pixs not 8 bpp or has cmap", __func__, NULL); |
1221 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
1222 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
1223 | 0 | return pixClone(pixs); |
1224 | 0 | } |
1225 | 0 | if (halfwidth != 1 && halfwidth != 2) |
1226 | 0 | return (PIX *)ERROR_PTR("halfwidth must be 1 or 2", __func__, NULL); |
1227 | 0 | if (direction != L_HORIZ && direction != L_VERT && |
1228 | 0 | direction != L_BOTH_DIRECTIONS) |
1229 | 0 | return (PIX *)ERROR_PTR("invalid direction", __func__, NULL); |
1230 | | |
1231 | 0 | if (direction != L_BOTH_DIRECTIONS) |
1232 | 0 | pixd = pixUnsharpMaskingGray1D(pixs, halfwidth, fract, direction); |
1233 | 0 | else /* 2D sharpening */ |
1234 | 0 | pixd = pixUnsharpMaskingGray2D(pixs, halfwidth, fract); |
1235 | |
|
1236 | 0 | return pixd; |
1237 | 0 | } |
1238 | | |
1239 | | |
1240 | | /*! |
1241 | | * \brief pixUnsharpMaskingGray1D() |
1242 | | * |
1243 | | * \param[in] pixs 8 bpp; no colormap |
1244 | | * \param[in] halfwidth "half-width" of smoothing filter: 1 or 2 |
1245 | | * \param[in] fract fraction of high frequency added to image |
1246 | | * \param[in] direction filtering direction; use L_HORIZ or L_VERT |
1247 | | * \return pixd, or NULL on error |
1248 | | * |
1249 | | * <pre> |
1250 | | * Notes: |
1251 | | * (1) For usage and explanation of the algorithm, see notes |
1252 | | * in pixUnsharpMaskingFast(). |
1253 | | * (2) Returns a clone if no sharpening is requested. |
1254 | | * </pre> |
1255 | | */ |
1256 | | PIX * |
1257 | | pixUnsharpMaskingGray1D(PIX *pixs, |
1258 | | l_int32 halfwidth, |
1259 | | l_float32 fract, |
1260 | | l_int32 direction) |
1261 | 0 | { |
1262 | 0 | l_int32 w, h, d, wpls, wpld, i, j, ival; |
1263 | 0 | l_uint32 *datas, *datad; |
1264 | 0 | l_uint32 *lines, *lines0, *lines1, *lines2, *lines3, *lines4, *lined; |
1265 | 0 | l_float32 val, a[5]; |
1266 | 0 | PIX *pixd; |
1267 | |
|
1268 | 0 | if (!pixs) |
1269 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1270 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1271 | 0 | if (d != 8 || pixGetColormap(pixs) != NULL) |
1272 | 0 | return (PIX *)ERROR_PTR("pixs not 8 bpp or has cmap", __func__, NULL); |
1273 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
1274 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
1275 | 0 | return pixClone(pixs); |
1276 | 0 | } |
1277 | 0 | if (halfwidth != 1 && halfwidth != 2) |
1278 | 0 | return (PIX *)ERROR_PTR("halfwidth must be 1 or 2", __func__, NULL); |
1279 | | |
1280 | | /* Initialize pixd with pixels from pixs that will not be |
1281 | | * set when computing the sharpened values. */ |
1282 | 0 | pixd = pixCopyBorder(NULL, pixs, halfwidth, halfwidth, |
1283 | 0 | halfwidth, halfwidth); |
1284 | 0 | datas = pixGetData(pixs); |
1285 | 0 | datad = pixGetData(pixd); |
1286 | 0 | wpls = pixGetWpl(pixs); |
1287 | 0 | wpld = pixGetWpl(pixd); |
1288 | |
|
1289 | 0 | if (halfwidth == 1) { |
1290 | 0 | a[0] = -fract / 3.0; |
1291 | 0 | a[1] = 1.0 + fract * 2.0 / 3.0; |
1292 | 0 | a[2] = a[0]; |
1293 | 0 | } else { /* halfwidth == 2 */ |
1294 | 0 | a[0] = -fract / 5.0; |
1295 | 0 | a[1] = a[0]; |
1296 | 0 | a[2] = 1.0 + fract * 4.0 / 5.0; |
1297 | 0 | a[3] = a[0]; |
1298 | 0 | a[4] = a[0]; |
1299 | 0 | } |
1300 | |
|
1301 | 0 | if (direction == L_HORIZ) { |
1302 | 0 | for (i = 0; i < h; i++) { |
1303 | 0 | lines = datas + i * wpls; |
1304 | 0 | lined = datad + i * wpld; |
1305 | 0 | if (halfwidth == 1) { |
1306 | 0 | for (j = 1; j < w - 1; j++) { |
1307 | 0 | val = a[0] * GET_DATA_BYTE(lines, j - 1) + |
1308 | 0 | a[1] * GET_DATA_BYTE(lines, j) + |
1309 | 0 | a[2] * GET_DATA_BYTE(lines, j + 1); |
1310 | 0 | ival = (l_int32)val; |
1311 | 0 | ival = L_MAX(0, ival); |
1312 | 0 | ival = L_MIN(255, ival); |
1313 | 0 | SET_DATA_BYTE(lined, j, ival); |
1314 | 0 | } |
1315 | 0 | } else { /* halfwidth == 2 */ |
1316 | 0 | for (j = 2; j < w - 2; j++) { |
1317 | 0 | val = a[0] * GET_DATA_BYTE(lines, j - 2) + |
1318 | 0 | a[1] * GET_DATA_BYTE(lines, j - 1) + |
1319 | 0 | a[2] * GET_DATA_BYTE(lines, j) + |
1320 | 0 | a[3] * GET_DATA_BYTE(lines, j + 1) + |
1321 | 0 | a[4] * GET_DATA_BYTE(lines, j + 2); |
1322 | 0 | ival = (l_int32)val; |
1323 | 0 | ival = L_MAX(0, ival); |
1324 | 0 | ival = L_MIN(255, ival); |
1325 | 0 | SET_DATA_BYTE(lined, j, ival); |
1326 | 0 | } |
1327 | 0 | } |
1328 | 0 | } |
1329 | 0 | } else { /* direction == L_VERT */ |
1330 | 0 | if (halfwidth == 1) { |
1331 | 0 | for (i = 1; i < h - 1; i++) { |
1332 | 0 | lines0 = datas + (i - 1) * wpls; |
1333 | 0 | lines1 = datas + i * wpls; |
1334 | 0 | lines2 = datas + (i + 1) * wpls; |
1335 | 0 | lined = datad + i * wpld; |
1336 | 0 | for (j = 0; j < w; j++) { |
1337 | 0 | val = a[0] * GET_DATA_BYTE(lines0, j) + |
1338 | 0 | a[1] * GET_DATA_BYTE(lines1, j) + |
1339 | 0 | a[2] * GET_DATA_BYTE(lines2, j); |
1340 | 0 | ival = (l_int32)val; |
1341 | 0 | ival = L_MAX(0, ival); |
1342 | 0 | ival = L_MIN(255, ival); |
1343 | 0 | SET_DATA_BYTE(lined, j, ival); |
1344 | 0 | } |
1345 | 0 | } |
1346 | 0 | } else { /* halfwidth == 2 */ |
1347 | 0 | for (i = 2; i < h - 2; i++) { |
1348 | 0 | lines0 = datas + (i - 2) * wpls; |
1349 | 0 | lines1 = datas + (i - 1) * wpls; |
1350 | 0 | lines2 = datas + i * wpls; |
1351 | 0 | lines3 = datas + (i + 1) * wpls; |
1352 | 0 | lines4 = datas + (i + 2) * wpls; |
1353 | 0 | lined = datad + i * wpld; |
1354 | 0 | for (j = 0; j < w; j++) { |
1355 | 0 | val = a[0] * GET_DATA_BYTE(lines0, j) + |
1356 | 0 | a[1] * GET_DATA_BYTE(lines1, j) + |
1357 | 0 | a[2] * GET_DATA_BYTE(lines2, j) + |
1358 | 0 | a[3] * GET_DATA_BYTE(lines3, j) + |
1359 | 0 | a[4] * GET_DATA_BYTE(lines4, j); |
1360 | 0 | ival = (l_int32)val; |
1361 | 0 | ival = L_MAX(0, ival); |
1362 | 0 | ival = L_MIN(255, ival); |
1363 | 0 | SET_DATA_BYTE(lined, j, ival); |
1364 | 0 | } |
1365 | 0 | } |
1366 | 0 | } |
1367 | 0 | } |
1368 | |
|
1369 | 0 | return pixd; |
1370 | 0 | } |
1371 | | |
1372 | | |
1373 | | /*! |
1374 | | * \brief pixUnsharpMaskingGray2D() |
1375 | | * |
1376 | | * \param[in] pixs 8 bpp; no colormap |
1377 | | * \param[in] halfwidth "half-width" of smoothing filter: 1 or 2 |
1378 | | * \param[in] fract fraction of high frequency added to image |
1379 | | * \return pixd, or NULL on error |
1380 | | * |
1381 | | * <pre> |
1382 | | * Notes: |
1383 | | * (1) This is for %halfwidth == 1, 2. |
1384 | | * (2) The lowpass filter is implemented separably. |
1385 | | * (3) Returns a clone if no sharpening is requested. |
1386 | | * </pre> |
1387 | | */ |
1388 | | PIX * |
1389 | | pixUnsharpMaskingGray2D(PIX *pixs, |
1390 | | l_int32 halfwidth, |
1391 | | l_float32 fract) |
1392 | 0 | { |
1393 | 0 | l_int32 w, h, d, wpls, wpld, wplf, i, j, ival, sval; |
1394 | 0 | l_uint32 *datas, *datad, *lines, *lined; |
1395 | 0 | l_float32 val, norm; |
1396 | 0 | l_float32 *dataf, *linef, *linef0, *linef1, *linef2, *linef3, *linef4; |
1397 | 0 | PIX *pixd; |
1398 | 0 | FPIX *fpix; |
1399 | |
|
1400 | 0 | if (!pixs) |
1401 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1402 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1403 | 0 | if (d != 8 || pixGetColormap(pixs) != NULL) |
1404 | 0 | return (PIX *)ERROR_PTR("pixs not 8 bpp or has cmap", __func__, NULL); |
1405 | 0 | if (fract <= 0.0 || halfwidth <= 0) { |
1406 | 0 | L_WARNING("no sharpening requested; clone returned\n", __func__); |
1407 | 0 | return pixClone(pixs); |
1408 | 0 | } |
1409 | 0 | if (halfwidth != 1 && halfwidth != 2) |
1410 | 0 | return (PIX *)ERROR_PTR("halfwidth must be 1 or 2", __func__, NULL); |
1411 | | |
1412 | 0 | if ((pixd = pixCopyBorder(NULL, pixs, halfwidth, halfwidth, |
1413 | 0 | halfwidth, halfwidth)) == NULL) |
1414 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
1415 | 0 | datad = pixGetData(pixd); |
1416 | 0 | wpld = pixGetWpl(pixd); |
1417 | 0 | datas = pixGetData(pixs); |
1418 | 0 | wpls = pixGetWpl(pixs); |
1419 | | |
1420 | | /* Do the low pass separably. Store the result of horizontal |
1421 | | * smoothing in an intermediate fpix. */ |
1422 | 0 | if ((fpix = fpixCreate(w, h)) == NULL) { |
1423 | 0 | pixDestroy(&pixd); |
1424 | 0 | return (PIX *)ERROR_PTR("fpix not made", __func__, NULL); |
1425 | 0 | } |
1426 | 0 | dataf = fpixGetData(fpix); |
1427 | 0 | wplf = fpixGetWpl(fpix); |
1428 | 0 | if (halfwidth == 1) { |
1429 | 0 | for (i = 0; i < h; i++) { |
1430 | 0 | lines = datas + i * wpls; |
1431 | 0 | linef = dataf + i * wplf; |
1432 | 0 | for (j = 1; j < w - 1; j++) { |
1433 | 0 | val = GET_DATA_BYTE(lines, j - 1) + |
1434 | 0 | GET_DATA_BYTE(lines, j) + |
1435 | 0 | GET_DATA_BYTE(lines, j + 1); |
1436 | 0 | linef[j] = val; |
1437 | 0 | } |
1438 | 0 | } |
1439 | 0 | } else { |
1440 | 0 | for (i = 0; i < h; i++) { |
1441 | 0 | lines = datas + i * wpls; |
1442 | 0 | linef = dataf + i * wplf; |
1443 | 0 | for (j = 2; j < w - 2; j++) { |
1444 | 0 | val = GET_DATA_BYTE(lines, j - 2) + |
1445 | 0 | GET_DATA_BYTE(lines, j - 1) + |
1446 | 0 | GET_DATA_BYTE(lines, j) + |
1447 | 0 | GET_DATA_BYTE(lines, j + 1) + |
1448 | 0 | GET_DATA_BYTE(lines, j + 2); |
1449 | 0 | linef[j] = val; |
1450 | 0 | } |
1451 | 0 | } |
1452 | 0 | } |
1453 | | |
1454 | | /* Do vertical smoothing to finish the low-pass filter. |
1455 | | * At each pixel, if L is the lowpass value, I is the |
1456 | | * src pixel value and f is the fraction of highpass to |
1457 | | * be added to I, then the highpass filter value is |
1458 | | * H = I - L |
1459 | | * and the new sharpened value is |
1460 | | * N = I + f * H. */ |
1461 | 0 | if (halfwidth == 1) { |
1462 | 0 | for (i = 1; i < h - 1; i++) { |
1463 | 0 | linef0 = dataf + (i - 1) * wplf; |
1464 | 0 | linef1 = dataf + i * wplf; |
1465 | 0 | linef2 = dataf + (i + 1) * wplf; |
1466 | 0 | lined = datad + i * wpld; |
1467 | 0 | lines = datas + i * wpls; |
1468 | 0 | norm = 1.0f / 9.0f; |
1469 | 0 | for (j = 1; j < w - 1; j++) { |
1470 | 0 | val = norm * (linef0[j] + linef1[j] + |
1471 | 0 | linef2[j]); /* L: lowpass filter value */ |
1472 | 0 | sval = GET_DATA_BYTE(lines, j); /* I: source pixel */ |
1473 | 0 | ival = (l_int32)(sval + fract * (sval - val) + 0.5); |
1474 | 0 | ival = L_MAX(0, ival); |
1475 | 0 | ival = L_MIN(255, ival); |
1476 | 0 | SET_DATA_BYTE(lined, j, ival); |
1477 | 0 | } |
1478 | 0 | } |
1479 | 0 | } else { |
1480 | 0 | for (i = 2; i < h - 2; i++) { |
1481 | 0 | linef0 = dataf + (i - 2) * wplf; |
1482 | 0 | linef1 = dataf + (i - 1) * wplf; |
1483 | 0 | linef2 = dataf + i * wplf; |
1484 | 0 | linef3 = dataf + (i + 1) * wplf; |
1485 | 0 | linef4 = dataf + (i + 2) * wplf; |
1486 | 0 | lined = datad + i * wpld; |
1487 | 0 | lines = datas + i * wpls; |
1488 | 0 | norm = 1.0f / 25.0f; |
1489 | 0 | for (j = 2; j < w - 2; j++) { |
1490 | 0 | val = norm * (linef0[j] + linef1[j] + linef2[j] + linef3[j] + |
1491 | 0 | linef4[j]); /* L: lowpass filter value */ |
1492 | 0 | sval = GET_DATA_BYTE(lines, j); /* I: source pixel */ |
1493 | 0 | ival = (l_int32)(sval + fract * (sval - val) + 0.5); |
1494 | 0 | ival = L_MAX(0, ival); |
1495 | 0 | ival = L_MIN(255, ival); |
1496 | 0 | SET_DATA_BYTE(lined, j, ival); |
1497 | 0 | } |
1498 | 0 | } |
1499 | 0 | } |
1500 | |
|
1501 | 0 | fpixDestroy(&fpix); |
1502 | 0 | return pixd; |
1503 | 0 | } |
1504 | | |
1505 | | |
1506 | | /*-----------------------------------------------------------------------* |
1507 | | * Hue and saturation modification * |
1508 | | *-----------------------------------------------------------------------*/ |
1509 | | /*! |
1510 | | * \brief pixModifyHue() |
1511 | | * |
1512 | | * \param[in] pixd [optional] can be null or equal to pixs |
1513 | | * \param[in] pixs 32 bpp rgb |
1514 | | * \param[in] fract between -1.0 and 1.0 |
1515 | | * \return pixd, or NULL on error |
1516 | | * |
1517 | | * <pre> |
1518 | | * Notes: |
1519 | | * (1) pixd must either be null or equal to pixs. |
1520 | | * For in-place operation, set pixd == pixs: |
1521 | | * pixEqualizeTRC(pixs, pixs, ...); |
1522 | | * To get a new image, set pixd == null: |
1523 | | * pixd = pixEqualizeTRC(NULL, pixs, ...); |
1524 | | * (2) Use fract > 0.0 to increase hue value; < 0.0 to decrease it. |
1525 | | * 1.0 (or -1.0) represents a 360 degree rotation; i.e., no change. |
1526 | | * (3) If no modification is requested (fract = -1.0 or 0 or 1.0), |
1527 | | * return a copy unless in-place, in which case this is a no-op. |
1528 | | * (4) This leaves saturation and intensity invariant. |
1529 | | * (5) See discussion of color-modification methods, in coloring.c. |
1530 | | * </pre> |
1531 | | */ |
1532 | | PIX * |
1533 | | pixModifyHue(PIX *pixd, |
1534 | | PIX *pixs, |
1535 | | l_float32 fract) |
1536 | 0 | { |
1537 | 0 | l_int32 w, h, d, i, j, wpl, delhue; |
1538 | 0 | l_int32 rval, gval, bval, hval, sval, vval; |
1539 | 0 | l_uint32 *data, *line; |
1540 | |
|
1541 | 0 | if (!pixs) |
1542 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1543 | 0 | if (pixGetColormap(pixs) != NULL) |
1544 | 0 | return (PIX *)ERROR_PTR("pixs colormapped", __func__, NULL); |
1545 | 0 | if (pixd && (pixd != pixs)) |
1546 | 0 | return (PIX *)ERROR_PTR("pixd not null or pixs", __func__, pixd); |
1547 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1548 | 0 | if (d != 32) |
1549 | 0 | return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL); |
1550 | 0 | if (L_ABS(fract) > 1.0) |
1551 | 0 | return (PIX *)ERROR_PTR("fract not in [-1.0 ... 1.0]", __func__, NULL); |
1552 | | |
1553 | 0 | pixd = pixCopy(pixd, pixs); |
1554 | |
|
1555 | 0 | delhue = (l_int32)(240 * fract); |
1556 | 0 | if (delhue == 0 || delhue == 240 || delhue == -240) { |
1557 | 0 | L_WARNING("no change requested in hue\n", __func__); |
1558 | 0 | return pixd; |
1559 | 0 | } |
1560 | 0 | if (delhue < 0) |
1561 | 0 | delhue += 240; |
1562 | |
|
1563 | 0 | data = pixGetData(pixd); |
1564 | 0 | wpl = pixGetWpl(pixd); |
1565 | 0 | for (i = 0; i < h; i++) { |
1566 | 0 | line = data + i * wpl; |
1567 | 0 | for (j = 0; j < w; j++) { |
1568 | 0 | extractRGBValues(line[j], &rval, &gval, &bval); |
1569 | 0 | convertRGBToHSV(rval, gval, bval, &hval, &sval, &vval); |
1570 | 0 | hval = (hval + delhue) % 240; |
1571 | 0 | convertHSVToRGB(hval, sval, vval, &rval, &gval, &bval); |
1572 | 0 | composeRGBPixel(rval, gval, bval, line + j); |
1573 | 0 | } |
1574 | 0 | } |
1575 | 0 | if (pixGetSpp(pixs) == 4) |
1576 | 0 | pixCopyRGBComponent(pixd, pixs, L_ALPHA_CHANNEL); |
1577 | |
|
1578 | 0 | return pixd; |
1579 | 0 | } |
1580 | | |
1581 | | |
1582 | | /*! |
1583 | | * \brief pixModifySaturation() |
1584 | | * |
1585 | | * \param[in] pixd [optional] can be null, existing or equal to pixs |
1586 | | * \param[in] pixs 32 bpp rgb |
1587 | | * \param[in] fract between -1.0 and 1.0 |
1588 | | * \return pixd, or NULL on error |
1589 | | * |
1590 | | * <pre> |
1591 | | * Notes: |
1592 | | * (1) If fract > 0.0, it gives the fraction that the pixel |
1593 | | * saturation is moved from its initial value toward 255. |
1594 | | * If fract < 0.0, it gives the fraction that the pixel |
1595 | | * saturation is moved from its initial value toward 0. |
1596 | | * The limiting values for fract = -1.0 (1.0) thus set the |
1597 | | * saturation to 0 (255). |
1598 | | * (2) If fract = 0, no modification is requested; return a copy |
1599 | | * unless in-place, in which case this is a no-op. |
1600 | | * (3) This leaves hue and intensity invariant. |
1601 | | * (4) See discussion of color-modification methods, in coloring.c. |
1602 | | * </pre> |
1603 | | */ |
1604 | | PIX * |
1605 | | pixModifySaturation(PIX *pixd, |
1606 | | PIX *pixs, |
1607 | | l_float32 fract) |
1608 | 0 | { |
1609 | 0 | l_int32 w, h, d, i, j, wpl; |
1610 | 0 | l_int32 rval, gval, bval, hval, sval, vval; |
1611 | 0 | l_uint32 *data, *line; |
1612 | |
|
1613 | 0 | if (!pixs) |
1614 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1615 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1616 | 0 | if (d != 32) |
1617 | 0 | return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL); |
1618 | 0 | if (L_ABS(fract) > 1.0) |
1619 | 0 | return (PIX *)ERROR_PTR("fract not in [-1.0 ... 1.0]", __func__, NULL); |
1620 | | |
1621 | 0 | pixd = pixCopy(pixd, pixs); |
1622 | 0 | if (fract == 0.0) { |
1623 | 0 | L_WARNING("no change requested in saturation\n", __func__); |
1624 | 0 | return pixd; |
1625 | 0 | } |
1626 | | |
1627 | 0 | data = pixGetData(pixd); |
1628 | 0 | wpl = pixGetWpl(pixd); |
1629 | 0 | for (i = 0; i < h; i++) { |
1630 | 0 | line = data + i * wpl; |
1631 | 0 | for (j = 0; j < w; j++) { |
1632 | 0 | extractRGBValues(line[j], &rval, &gval, &bval); |
1633 | 0 | convertRGBToHSV(rval, gval, bval, &hval, &sval, &vval); |
1634 | 0 | if (fract < 0.0) |
1635 | 0 | sval = (l_int32)(sval * (1.0 + fract)); |
1636 | 0 | else |
1637 | 0 | sval = (l_int32)(sval + fract * (255 - sval)); |
1638 | 0 | convertHSVToRGB(hval, sval, vval, &rval, &gval, &bval); |
1639 | 0 | composeRGBPixel(rval, gval, bval, line + j); |
1640 | 0 | } |
1641 | 0 | } |
1642 | 0 | if (pixGetSpp(pixs) == 4) |
1643 | 0 | pixCopyRGBComponent(pixd, pixs, L_ALPHA_CHANNEL); |
1644 | |
|
1645 | 0 | return pixd; |
1646 | 0 | } |
1647 | | |
1648 | | |
1649 | | /*! |
1650 | | * \brief pixMeasureSaturation() |
1651 | | * |
1652 | | * \param[in] pixs 32 bpp rgb |
1653 | | * \param[in] factor subsampling factor; integer >= 1 |
1654 | | * \param[out] psat average saturation |
1655 | | * \return 0 if OK, 1 on error |
1656 | | */ |
1657 | | l_int32 |
1658 | | pixMeasureSaturation(PIX *pixs, |
1659 | | l_int32 factor, |
1660 | | l_float32 *psat) |
1661 | 0 | { |
1662 | 0 | l_int32 w, h, d, i, j, wpl, sum, count; |
1663 | 0 | l_int32 rval, gval, bval, hval, sval, vval; |
1664 | 0 | l_uint32 *data, *line; |
1665 | |
|
1666 | 0 | if (!psat) |
1667 | 0 | return ERROR_INT("pixs not defined", __func__, 1); |
1668 | 0 | *psat = 0.0; |
1669 | 0 | if (!pixs) |
1670 | 0 | return ERROR_INT("pixs not defined", __func__, 1); |
1671 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1672 | 0 | if (d != 32) |
1673 | 0 | return ERROR_INT("pixs not 32 bpp", __func__, 1); |
1674 | 0 | if (factor < 1) |
1675 | 0 | return ERROR_INT("subsampling factor < 1", __func__, 1); |
1676 | | |
1677 | 0 | data = pixGetData(pixs); |
1678 | 0 | wpl = pixGetWpl(pixs); |
1679 | 0 | for (i = 0, sum = 0, count = 0; i < h; i += factor) { |
1680 | 0 | line = data + i * wpl; |
1681 | 0 | for (j = 0; j < w; j += factor) { |
1682 | 0 | extractRGBValues(line[j], &rval, &gval, &bval); |
1683 | 0 | convertRGBToHSV(rval, gval, bval, &hval, &sval, &vval); |
1684 | 0 | sum += sval; |
1685 | 0 | count++; |
1686 | 0 | } |
1687 | 0 | } |
1688 | |
|
1689 | 0 | if (count > 0) |
1690 | 0 | *psat = (l_float32)sum / (l_float32)count; |
1691 | 0 | return 0; |
1692 | 0 | } |
1693 | | |
1694 | | |
1695 | | /*! |
1696 | | * \brief pixModifyBrightness() |
1697 | | * |
1698 | | * \param[in] pixd [optional] can be null, existing or equal to pixs |
1699 | | * \param[in] pixs 32 bpp rgb |
1700 | | * \param[in] fract between -1.0 and 1.0 |
1701 | | * \return pixd, or NULL on error |
1702 | | * |
1703 | | * <pre> |
1704 | | * Notes: |
1705 | | * (1) If fract > 0.0, it gives the fraction that the v-parameter, |
1706 | | * which is max(r,g,b), is moved from its initial value toward 255. |
1707 | | * If fract < 0.0, it gives the fraction that the v-parameter |
1708 | | * is moved from its initial value toward 0. |
1709 | | * The limiting values for fract = -1.0 (1.0) thus set the |
1710 | | * v-parameter to 0 (255). |
1711 | | * (2) If fract = 0, no modification is requested; return a copy |
1712 | | * unless in-place, in which case this is a no-op. |
1713 | | * (3) This leaves hue and saturation invariant. |
1714 | | * (4) See discussion of color-modification methods, in coloring.c. |
1715 | | * </pre> |
1716 | | */ |
1717 | | PIX * |
1718 | | pixModifyBrightness(PIX *pixd, |
1719 | | PIX *pixs, |
1720 | | l_float32 fract) |
1721 | 0 | { |
1722 | 0 | l_int32 w, h, d, i, j, wpl; |
1723 | 0 | l_int32 rval, gval, bval, hval, sval, vval; |
1724 | 0 | l_uint32 *data, *line; |
1725 | |
|
1726 | 0 | if (!pixs) |
1727 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1728 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
1729 | 0 | if (d != 32) |
1730 | 0 | return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL); |
1731 | 0 | if (L_ABS(fract) > 1.0) |
1732 | 0 | return (PIX *)ERROR_PTR("fract not in [-1.0 ... 1.0]", __func__, NULL); |
1733 | | |
1734 | 0 | pixd = pixCopy(pixd, pixs); |
1735 | 0 | if (fract == 0.0) { |
1736 | 0 | L_WARNING("no change requested in brightness\n", __func__); |
1737 | 0 | return pixd; |
1738 | 0 | } |
1739 | | |
1740 | 0 | data = pixGetData(pixd); |
1741 | 0 | wpl = pixGetWpl(pixd); |
1742 | 0 | for (i = 0; i < h; i++) { |
1743 | 0 | line = data + i * wpl; |
1744 | 0 | for (j = 0; j < w; j++) { |
1745 | 0 | extractRGBValues(line[j], &rval, &gval, &bval); |
1746 | 0 | convertRGBToHSV(rval, gval, bval, &hval, &sval, &vval); |
1747 | 0 | if (fract > 0.0) |
1748 | 0 | vval = (l_int32)(vval + fract * (255.0 - vval)); |
1749 | 0 | else |
1750 | 0 | vval = (l_int32)(vval * (1.0 + fract)); |
1751 | 0 | convertHSVToRGB(hval, sval, vval, &rval, &gval, &bval); |
1752 | 0 | composeRGBPixel(rval, gval, bval, line + j); |
1753 | 0 | } |
1754 | 0 | } |
1755 | 0 | if (pixGetSpp(pixs) == 4) |
1756 | 0 | pixCopyRGBComponent(pixd, pixs, L_ALPHA_CHANNEL); |
1757 | |
|
1758 | 0 | return pixd; |
1759 | 0 | } |
1760 | | |
1761 | | |
1762 | | /*-----------------------------------------------------------------------* |
1763 | | * Color shifting * |
1764 | | *-----------------------------------------------------------------------*/ |
1765 | | /*! |
1766 | | * \brief pixMosaicColorShiftRGB() |
1767 | | * |
1768 | | * \param[in] pixs 32 bpp rgb |
1769 | | * \param[in] roff center offset of red component |
1770 | | * \param[in] goff center offset of green component |
1771 | | * \param[in] boff center offset of blue component |
1772 | | * \param[in] delta increments from center offsets [0.0 - 0.1]; |
1773 | | * use 0.0 to get the default (0.04) |
1774 | | * \param[in] nincr number of increments in each (positive and negative) |
1775 | | * direction; use 0 to get the default (2). |
1776 | | * \return pix, or NULL on error |
1777 | | * |
1778 | | * <pre> |
1779 | | * Notes: |
1780 | | * (1) This generates a mosaic view of the effect of shifting the RGB |
1781 | | * components. See pixColorShiftRGB() for details on the shifting. |
1782 | | * (2) The offsets (%roff, %goff, %boff) set the color center point, |
1783 | | * and the deviations from this are shown separately for deltas |
1784 | | * in r, g and b. For each component, we show 2 * %nincr + 1 |
1785 | | * images. |
1786 | | * (3) The pix must have minimum dimensions of 100 and an aspect |
1787 | | * ratio not exceeding 5.0. |
1788 | | * (4) Usage: color prints differ from the original due to three factors: |
1789 | | * illumination, calibration of the camera in acquisition, |
1790 | | * and calibration of the printer. This function can be used |
1791 | | * to iteratively match a color print to the original. On each |
1792 | | * iteration, the center offsets are set to the best match so |
1793 | | * far, and the %delta increments are typically reduced. |
1794 | | * </pre> |
1795 | | */ |
1796 | | PIX * |
1797 | | pixMosaicColorShiftRGB(PIX *pixs, |
1798 | | l_float32 roff, |
1799 | | l_float32 goff, |
1800 | | l_float32 boff, |
1801 | | l_float32 delta, |
1802 | | l_int32 nincr) |
1803 | 0 | { |
1804 | 0 | char buf[64]; |
1805 | 0 | l_int32 i, w, h; |
1806 | 0 | l_float32 del, ratio; |
1807 | 0 | L_BMF *bmf; |
1808 | 0 | PIX *pix1, *pix2, *pix3; |
1809 | 0 | PIXA *pixa; |
1810 | |
|
1811 | 0 | if (!pixs || pixGetDepth(pixs) != 32) |
1812 | 0 | return (PIX *)ERROR_PTR("pixs undefined or not rgb", __func__, NULL); |
1813 | 0 | if (roff < -1.0 || roff > 1.0) |
1814 | 0 | return (PIX *)ERROR_PTR("roff not in [-1.0, 1.0]", __func__, NULL); |
1815 | 0 | if (goff < -1.0 || goff > 1.0) |
1816 | 0 | return (PIX *)ERROR_PTR("goff not in [-1.0, 1.0]", __func__, NULL); |
1817 | 0 | if (boff < -1.0 || boff > 1.0) |
1818 | 0 | return (PIX *)ERROR_PTR("boff not in [-1.0, 1.0]", __func__, NULL); |
1819 | 0 | if (delta < 0.0 || delta > 0.1) |
1820 | 0 | return (PIX *)ERROR_PTR("delta not in [0.0, 0.1]", __func__, NULL); |
1821 | 0 | if (delta == 0.0) delta = 0.04f; |
1822 | 0 | if (nincr < 0 || nincr > 6) |
1823 | 0 | return (PIX *)ERROR_PTR("nincr not in [0, 6]", __func__, NULL); |
1824 | 0 | if (nincr == 0) nincr = 2; |
1825 | | |
1826 | | /* Require width and height to be >= 100, and the aspect ratio <= 5.0 */ |
1827 | 0 | pixGetDimensions(pixs, &w, &h, NULL); |
1828 | 0 | if (w < 100 || h < 100) |
1829 | 0 | return (PIX *)ERROR_PTR("w and h not both >= 100", __func__, NULL); |
1830 | 0 | pixMaxAspectRatio(pixs, &ratio); |
1831 | 0 | if (ratio < 1.0 || ratio > 5.0) { |
1832 | 0 | L_ERROR("invalid aspect ratio %5.1f\n", __func__, ratio); |
1833 | 0 | return NULL; |
1834 | 0 | } |
1835 | | |
1836 | 0 | pixa = pixaCreate(3 * (2 * nincr + 1)); |
1837 | 0 | bmf = bmfCreate(NULL, 8); |
1838 | 0 | pix1 = pixScaleToSize(pixs, 400, 0); |
1839 | 0 | for (i = 0, del = - nincr * delta; i < 2 * nincr + 1; i++, del += delta) { |
1840 | 0 | pix2 = pixColorShiftRGB(pix1, roff + del, goff, boff); |
1841 | 0 | snprintf(buf, sizeof(buf), "%4.2f, %4.2f, %4.2f", |
1842 | 0 | roff + del, goff, boff); |
1843 | 0 | pix3 = pixAddSingleTextblock(pix2, bmf, buf, 0xff000000, |
1844 | 0 | L_ADD_BELOW, 0); |
1845 | 0 | pixaAddPix(pixa, pix3, L_INSERT); |
1846 | 0 | pixDestroy(&pix2); |
1847 | 0 | } |
1848 | 0 | for (i = 0, del = - nincr * delta; i < 2 * nincr + 1; i++, del += delta) { |
1849 | 0 | pix2 = pixColorShiftRGB(pix1, roff, goff + del, boff); |
1850 | 0 | snprintf(buf, sizeof(buf), "%4.2f, %4.2f, %4.2f", |
1851 | 0 | roff, goff + del, boff); |
1852 | 0 | pix3 = pixAddSingleTextblock(pix2, bmf, buf, 0xff000000, |
1853 | 0 | L_ADD_BELOW, 0); |
1854 | 0 | pixaAddPix(pixa, pix3, L_INSERT); |
1855 | 0 | pixDestroy(&pix2); |
1856 | 0 | } |
1857 | 0 | for (i = 0, del = - nincr * delta; i < 2 * nincr + 1; i++, del += delta) { |
1858 | 0 | pix2 = pixColorShiftRGB(pix1, roff, goff, boff + del); |
1859 | 0 | snprintf(buf, sizeof(buf), "%4.2f, %4.2f, %4.2f", |
1860 | 0 | roff, goff, boff + del); |
1861 | 0 | pix3 = pixAddSingleTextblock(pix2, bmf, buf, 0xff000000, |
1862 | 0 | L_ADD_BELOW, 0); |
1863 | 0 | pixaAddPix(pixa, pix3, L_INSERT); |
1864 | 0 | pixDestroy(&pix2); |
1865 | 0 | } |
1866 | 0 | pixDestroy(&pix1); |
1867 | |
|
1868 | 0 | pix1 = pixaDisplayTiledAndScaled(pixa, 32, 300, 2 * nincr + 1, 0, 30, 2); |
1869 | 0 | pixaDestroy(&pixa); |
1870 | 0 | bmfDestroy(&bmf); |
1871 | 0 | return pix1; |
1872 | 0 | } |
1873 | | |
1874 | | |
1875 | | /*! |
1876 | | * \brief pixColorShiftRGB() |
1877 | | * |
1878 | | * \param[in] pixs 32 bpp rgb |
1879 | | * \param[in] rfract fractional shift in red component |
1880 | | * \param[in] gfract fractional shift in green component |
1881 | | * \param[in] bfract fractional shift in blue component |
1882 | | * \return pixd, or NULL on error |
1883 | | * |
1884 | | * <pre> |
1885 | | * Notes: |
1886 | | * (1) This allows independent fractional shifts of the r,g and b |
1887 | | * components. A positive shift pushes to saturation (255); |
1888 | | * a negative shift pushes toward 0 (black). |
1889 | | * (2) The effect can be imagined using a color wheel that consists |
1890 | | * (for our purposes) of these 6 colors, separated by 60 degrees: |
1891 | | * red, magenta, blue, cyan, green, yellow |
1892 | | * (3) So, for example, a negative shift of the blue component |
1893 | | * (bfract < 0) could be accompanied by positive shifts |
1894 | | * of red and green to make an image more yellow. |
1895 | | * (4) Examples of limiting cases: |
1896 | | * rfract = 1 ==> r = 255 |
1897 | | * rfract = -1 ==> r = 0 |
1898 | | * </pre> |
1899 | | */ |
1900 | | PIX * |
1901 | | pixColorShiftRGB(PIX *pixs, |
1902 | | l_float32 rfract, |
1903 | | l_float32 gfract, |
1904 | | l_float32 bfract) |
1905 | 0 | { |
1906 | 0 | l_int32 w, h, i, j, wpls, wpld, rval, gval, bval; |
1907 | 0 | l_int32 *rlut, *glut, *blut; |
1908 | 0 | l_uint32 *datas, *datad, *lines, *lined; |
1909 | 0 | l_float32 fi; |
1910 | 0 | PIX *pixd; |
1911 | |
|
1912 | 0 | if (!pixs) |
1913 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
1914 | 0 | if (pixGetDepth(pixs) != 32) |
1915 | 0 | return (PIX *)ERROR_PTR("pixs not 32 bpp", __func__, NULL); |
1916 | 0 | if (rfract < -1.0 || rfract > 1.0) |
1917 | 0 | return (PIX *)ERROR_PTR("rfract not in [-1.0, 1.0]", __func__, NULL); |
1918 | 0 | if (gfract < -1.0 || gfract > 1.0) |
1919 | 0 | return (PIX *)ERROR_PTR("gfract not in [-1.0, 1.0]", __func__, NULL); |
1920 | 0 | if (bfract < -1.0 || bfract > 1.0) |
1921 | 0 | return (PIX *)ERROR_PTR("bfract not in [-1.0, 1.0]", __func__, NULL); |
1922 | 0 | if (rfract == 0.0 && gfract == 0.0 && bfract == 0.0) |
1923 | 0 | return pixCopy(NULL, pixs); |
1924 | | |
1925 | 0 | rlut = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32)); |
1926 | 0 | glut = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32)); |
1927 | 0 | blut = (l_int32 *)LEPT_CALLOC(256, sizeof(l_int32)); |
1928 | 0 | for (i = 0; i < 256; i++) { |
1929 | 0 | fi = i; |
1930 | 0 | if (rfract >= 0) { |
1931 | 0 | rlut[i] = (l_int32)(fi + (255.0 - fi) * rfract); |
1932 | 0 | } else { |
1933 | 0 | rlut[i] = (l_int32)(fi * (1.0 + rfract)); |
1934 | 0 | } |
1935 | 0 | if (gfract >= 0) { |
1936 | 0 | glut[i] = (l_int32)(fi + (255.0 - fi) * gfract); |
1937 | 0 | } else { |
1938 | 0 | glut[i] = (l_int32)(fi * (1.0 + gfract)); |
1939 | 0 | } |
1940 | 0 | if (bfract >= 0) { |
1941 | 0 | blut[i] = (l_int32)(fi + (255.0 - fi) * bfract); |
1942 | 0 | } else { |
1943 | 0 | blut[i] = (l_int32)(fi * (1.0 + bfract)); |
1944 | 0 | } |
1945 | 0 | } |
1946 | |
|
1947 | 0 | pixGetDimensions(pixs, &w, &h, NULL); |
1948 | 0 | datas = pixGetData(pixs); |
1949 | 0 | wpls = pixGetWpl(pixs); |
1950 | 0 | pixd = pixCreate(w, h, 32); |
1951 | 0 | datad = pixGetData(pixd); |
1952 | 0 | wpld = pixGetWpl(pixd); |
1953 | 0 | for (i = 0; i < h; i++) { |
1954 | 0 | lines = datas + i * wpls; |
1955 | 0 | lined = datad + i * wpld; |
1956 | 0 | for (j = 0; j < w; j++) { |
1957 | 0 | extractRGBValues(lines[j], &rval, &gval, &bval); |
1958 | 0 | composeRGBPixel(rlut[rval], glut[gval], blut[bval], lined + j); |
1959 | 0 | } |
1960 | 0 | } |
1961 | |
|
1962 | 0 | LEPT_FREE(rlut); |
1963 | 0 | LEPT_FREE(glut); |
1964 | 0 | LEPT_FREE(blut); |
1965 | 0 | return pixd; |
1966 | 0 | } |
1967 | | |
1968 | | /*-----------------------------------------------------------------------* |
1969 | | * Darken gray (unsaturated) pixels |
1970 | | *-----------------------------------------------------------------------*/ |
1971 | | /*! |
1972 | | * \brief pixDarkenGray() |
1973 | | * |
1974 | | * \param[in] pixd [optional] can be null or equal to pixs |
1975 | | * \param[in] pixs 32 bpp rgb |
1976 | | * \param[in] thresh pixels with max component >= %thresh are unchanged |
1977 | | * \param[in] satlimit pixels with saturation >= %satlimit are unchanged |
1978 | | * \return pixd, or NULL on error |
1979 | | * |
1980 | | * <pre> |
1981 | | * Notes: |
1982 | | * (1) This darkens gray pixels, by a fraction (sat/%satlimit), where |
1983 | | * the saturation, sat, is the component difference (max - min). |
1984 | | * The pixel value is unchanged if sat >= %satlimit. A typical |
1985 | | * value of %satlimit might be 40; the larger the value, the |
1986 | | * more that pixels with a smaller saturation will be darkened. |
1987 | | * (2) Pixels with max component >= %thresh are unchanged. This can be |
1988 | | * used to prevent bright pixels with low saturation from being |
1989 | | * darkened. Setting thresh == 0 is a no-op; setting %thresh == 255 |
1990 | | * causes the darkening to be applied to all pixels. |
1991 | | * (3) This function is useful to enhance pixels relative to a |
1992 | | * gray background. |
1993 | | * (4) A related function that builds a 1 bpp mask over the gray |
1994 | | * pixels is pixMaskOverGrayPixels(). |
1995 | | * </pre> |
1996 | | */ |
1997 | | PIX * |
1998 | | pixDarkenGray(PIX *pixd, |
1999 | | PIX *pixs, |
2000 | | l_int32 thresh, |
2001 | | l_int32 satlimit) |
2002 | 0 | { |
2003 | 0 | l_int32 w, h, i, j, wpls, wpld; |
2004 | 0 | l_int32 rval, gval, bval, minrg, min, maxrg, max, sat; |
2005 | 0 | l_uint32 *datas, *datad, *lines, *lined; |
2006 | 0 | l_float32 ratio; |
2007 | |
|
2008 | 0 | if (!pixs || pixGetDepth(pixs) != 32) |
2009 | 0 | return (PIX *)ERROR_PTR("pixs undefined or not 32 bpp", __func__, NULL); |
2010 | 0 | if (thresh < 0 || thresh > 255) |
2011 | 0 | return (PIX *)ERROR_PTR("invalid thresh", __func__, NULL); |
2012 | 0 | if (satlimit < 1) |
2013 | 0 | return (PIX *)ERROR_PTR("invalid satlimit", __func__, NULL); |
2014 | 0 | if (pixd && (pixs != pixd)) |
2015 | 0 | return (PIX *)ERROR_PTR("not new or in-place", __func__, NULL); |
2016 | | |
2017 | 0 | pixGetDimensions(pixs, &w, &h, NULL); |
2018 | 0 | datas = pixGetData(pixs); |
2019 | 0 | wpls = pixGetWpl(pixs); |
2020 | 0 | if ((pixd = pixCopy(pixd, pixs)) == NULL) |
2021 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
2022 | 0 | datad = pixGetData(pixd); |
2023 | 0 | wpld = pixGetWpl(pixd); |
2024 | |
|
2025 | 0 | for (i = 0; i < h; i++) { |
2026 | 0 | lines = datas + i * wpls; |
2027 | 0 | lined = datad + i * wpld; |
2028 | 0 | for (j = 0; j < w; j++) { |
2029 | 0 | extractRGBValues(lines[j], &rval, &gval, &bval); |
2030 | 0 | minrg = L_MIN(rval, gval); |
2031 | 0 | min = L_MIN(minrg, bval); |
2032 | 0 | maxrg = L_MAX(rval, gval); |
2033 | 0 | max = L_MAX(maxrg, bval); |
2034 | 0 | sat = max - min; |
2035 | 0 | if (max >= thresh || sat >= satlimit) |
2036 | 0 | continue; |
2037 | 0 | ratio = (l_float32)sat / (l_float32)satlimit; |
2038 | 0 | composeRGBPixel((l_int32)(ratio * rval), (l_int32)(ratio * gval), |
2039 | 0 | (l_int32)(ratio * bval), &lined[j]); |
2040 | 0 | } |
2041 | 0 | } |
2042 | 0 | return pixd; |
2043 | 0 | } |
2044 | | |
2045 | | |
2046 | | /*-----------------------------------------------------------------------* |
2047 | | * General multiplicative constant color transform * |
2048 | | *-----------------------------------------------------------------------*/ |
2049 | | /*! |
2050 | | * \brief pixMultConstantColor() |
2051 | | * |
2052 | | * \param[in] pixs colormapped or rgb |
2053 | | * \param[in] rfact red multiplicative factor |
2054 | | * \param[in] gfact green multiplicative factor |
2055 | | * \param[in] bfact blue multiplicative factor |
2056 | | * \return pixd colormapped or rgb, with colors scaled, or NULL on error |
2057 | | * |
2058 | | * <pre> |
2059 | | * Notes: |
2060 | | * (1) rfact, gfact and bfact can only have non-negative values. |
2061 | | * They can be greater than 1.0. All transformed component |
2062 | | * values are clipped to the interval [0, 255]. |
2063 | | * (2) For multiplication with a general 3x3 matrix of constants, |
2064 | | * use pixMultMatrixColor(). |
2065 | | * </pre> |
2066 | | */ |
2067 | | PIX * |
2068 | | pixMultConstantColor(PIX *pixs, |
2069 | | l_float32 rfact, |
2070 | | l_float32 gfact, |
2071 | | l_float32 bfact) |
2072 | 0 | { |
2073 | 0 | l_int32 i, j, w, h, d, wpls, wpld; |
2074 | 0 | l_int32 ncolors, rval, gval, bval, nrval, ngval, nbval; |
2075 | 0 | l_uint32 nval; |
2076 | 0 | l_uint32 *datas, *datad, *lines, *lined; |
2077 | 0 | PIX *pixd; |
2078 | 0 | PIXCMAP *cmap; |
2079 | |
|
2080 | 0 | if (!pixs) |
2081 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
2082 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
2083 | 0 | cmap = pixGetColormap(pixs); |
2084 | 0 | if (!cmap && d != 32) |
2085 | 0 | return (PIX *)ERROR_PTR("pixs not cmapped or 32 bpp", __func__, NULL); |
2086 | 0 | rfact = L_MAX(0.0, rfact); |
2087 | 0 | gfact = L_MAX(0.0, gfact); |
2088 | 0 | bfact = L_MAX(0.0, bfact); |
2089 | |
|
2090 | 0 | if (cmap) { |
2091 | 0 | if ((pixd = pixCopy(NULL, pixs)) == NULL) |
2092 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
2093 | 0 | cmap = pixGetColormap(pixd); |
2094 | 0 | ncolors = pixcmapGetCount(cmap); |
2095 | 0 | for (i = 0; i < ncolors; i++) { |
2096 | 0 | pixcmapGetColor(cmap, i, &rval, &gval, &bval); |
2097 | 0 | nrval = (l_int32)(rfact * rval); |
2098 | 0 | ngval = (l_int32)(gfact * gval); |
2099 | 0 | nbval = (l_int32)(bfact * bval); |
2100 | 0 | nrval = L_MIN(255, nrval); |
2101 | 0 | ngval = L_MIN(255, ngval); |
2102 | 0 | nbval = L_MIN(255, nbval); |
2103 | 0 | pixcmapResetColor(cmap, i, nrval, ngval, nbval); |
2104 | 0 | } |
2105 | 0 | return pixd; |
2106 | 0 | } |
2107 | | |
2108 | 0 | if ((pixd = pixCreateTemplate(pixs)) == NULL) |
2109 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
2110 | 0 | datas = pixGetData(pixs); |
2111 | 0 | datad = pixGetData(pixd); |
2112 | 0 | wpls = pixGetWpl(pixs); |
2113 | 0 | wpld = pixGetWpl(pixd); |
2114 | 0 | for (i = 0; i < h; i++) { |
2115 | 0 | lines = datas + i * wpls; |
2116 | 0 | lined = datad + i * wpld; |
2117 | 0 | for (j = 0; j < w; j++) { |
2118 | 0 | extractRGBValues(lines[j], &rval, &gval, &bval); |
2119 | 0 | nrval = (l_int32)(rfact * rval); |
2120 | 0 | ngval = (l_int32)(gfact * gval); |
2121 | 0 | nbval = (l_int32)(bfact * bval); |
2122 | 0 | nrval = L_MIN(255, nrval); |
2123 | 0 | ngval = L_MIN(255, ngval); |
2124 | 0 | nbval = L_MIN(255, nbval); |
2125 | 0 | composeRGBPixel(nrval, ngval, nbval, &nval); |
2126 | 0 | *(lined + j) = nval; |
2127 | 0 | } |
2128 | 0 | } |
2129 | |
|
2130 | 0 | return pixd; |
2131 | 0 | } |
2132 | | |
2133 | | |
2134 | | /*! |
2135 | | * \brief pixMultMatrixColor() |
2136 | | * |
2137 | | * \param[in] pixs colormapped or rgb |
2138 | | * \param[in] kel kernel 3x3 matrix of floats |
2139 | | * \return pixd colormapped or rgb, or NULL on error |
2140 | | * |
2141 | | * <pre> |
2142 | | * Notes: |
2143 | | * (1) The kernel is a data structure used mostly for floating point |
2144 | | * convolution. Here it is a 3x3 matrix of floats that are used |
2145 | | * to transform the pixel values by matrix multiplication: |
2146 | | * nrval = a[0,0] * rval + a[0,1] * gval + a[0,2] * bval |
2147 | | * ngval = a[1,0] * rval + a[1,1] * gval + a[1,2] * bval |
2148 | | * nbval = a[2,0] * rval + a[2,1] * gval + a[2,2] * bval |
2149 | | * (2) The matrix can be generated in several ways. |
2150 | | * See kernel.c for details. Here are two of them: |
2151 | | * (a) kel = kernelCreate(3, 3); |
2152 | | * kernelSetElement(kel, 0, 0, val00); |
2153 | | * kernelSetElement(kel, 0, 1, val01); |
2154 | | * ... |
2155 | | * (b) from a static string; e.g.,: |
2156 | | * const char *kdata = " 0.6 0.3 -0.2 " |
2157 | | * " 0.1 1.2 0.4 " |
2158 | | * " -0.4 0.2 0.9 "; |
2159 | | * kel = kernelCreateFromString(3, 3, 0, 0, kdata); |
2160 | | * (3) For the special case where the matrix is diagonal, it is easier |
2161 | | * to use pixMultConstantColor(). |
2162 | | * (4) Matrix entries can have positive and negative values, and can |
2163 | | * be larger than 1.0. All transformed component values |
2164 | | * are clipped to [0, 255]. |
2165 | | * </pre> |
2166 | | */ |
2167 | | PIX * |
2168 | | pixMultMatrixColor(PIX *pixs, |
2169 | | L_KERNEL *kel) |
2170 | 0 | { |
2171 | 0 | l_int32 i, j, index, kw, kh, w, h, d, wpls, wpld; |
2172 | 0 | l_int32 ncolors, rval, gval, bval, nrval, ngval, nbval; |
2173 | 0 | l_uint32 nval; |
2174 | 0 | l_uint32 *datas, *datad, *lines, *lined; |
2175 | 0 | l_float32 v[9]; /* use linear array for convenience */ |
2176 | 0 | PIX *pixd; |
2177 | 0 | PIXCMAP *cmap; |
2178 | |
|
2179 | 0 | if (!pixs) |
2180 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
2181 | 0 | if (!kel) |
2182 | 0 | return (PIX *)ERROR_PTR("kel not defined", __func__, NULL); |
2183 | 0 | kernelGetParameters(kel, &kw, &kh, NULL, NULL); |
2184 | 0 | if (kw != 3 || kh != 3) |
2185 | 0 | return (PIX *)ERROR_PTR("matrix not 3x3", __func__, NULL); |
2186 | 0 | pixGetDimensions(pixs, &w, &h, &d); |
2187 | 0 | cmap = pixGetColormap(pixs); |
2188 | 0 | if (!cmap && d != 32) |
2189 | 0 | return (PIX *)ERROR_PTR("pixs not cmapped or 32 bpp", __func__, NULL); |
2190 | | |
2191 | 0 | for (i = 0, index = 0; i < 3; i++) |
2192 | 0 | for (j = 0; j < 3; j++, index++) |
2193 | 0 | kernelGetElement(kel, i, j, v + index); |
2194 | |
|
2195 | 0 | if (cmap) { |
2196 | 0 | if ((pixd = pixCopy(NULL, pixs)) == NULL) |
2197 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
2198 | 0 | cmap = pixGetColormap(pixd); |
2199 | 0 | ncolors = pixcmapGetCount(cmap); |
2200 | 0 | for (i = 0; i < ncolors; i++) { |
2201 | 0 | pixcmapGetColor(cmap, i, &rval, &gval, &bval); |
2202 | 0 | nrval = (l_int32)(v[0] * rval + v[1] * gval + v[2] * bval); |
2203 | 0 | ngval = (l_int32)(v[3] * rval + v[4] * gval + v[5] * bval); |
2204 | 0 | nbval = (l_int32)(v[6] * rval + v[7] * gval + v[8] * bval); |
2205 | 0 | nrval = L_MAX(0, L_MIN(255, nrval)); |
2206 | 0 | ngval = L_MAX(0, L_MIN(255, ngval)); |
2207 | 0 | nbval = L_MAX(0, L_MIN(255, nbval)); |
2208 | 0 | pixcmapResetColor(cmap, i, nrval, ngval, nbval); |
2209 | 0 | } |
2210 | 0 | return pixd; |
2211 | 0 | } |
2212 | | |
2213 | 0 | if ((pixd = pixCreateTemplate(pixs)) == NULL) |
2214 | 0 | return (PIX *)ERROR_PTR("pixd not made", __func__, NULL); |
2215 | 0 | datas = pixGetData(pixs); |
2216 | 0 | datad = pixGetData(pixd); |
2217 | 0 | wpls = pixGetWpl(pixs); |
2218 | 0 | wpld = pixGetWpl(pixd); |
2219 | 0 | for (i = 0; i < h; i++) { |
2220 | 0 | lines = datas + i * wpls; |
2221 | 0 | lined = datad + i * wpld; |
2222 | 0 | for (j = 0; j < w; j++) { |
2223 | 0 | extractRGBValues(lines[j], &rval, &gval, &bval); |
2224 | 0 | nrval = (l_int32)(v[0] * rval + v[1] * gval + v[2] * bval); |
2225 | 0 | ngval = (l_int32)(v[3] * rval + v[4] * gval + v[5] * bval); |
2226 | 0 | nbval = (l_int32)(v[6] * rval + v[7] * gval + v[8] * bval); |
2227 | 0 | nrval = L_MAX(0, L_MIN(255, nrval)); |
2228 | 0 | ngval = L_MAX(0, L_MIN(255, ngval)); |
2229 | 0 | nbval = L_MAX(0, L_MIN(255, nbval)); |
2230 | 0 | composeRGBPixel(nrval, ngval, nbval, &nval); |
2231 | 0 | *(lined + j) = nval; |
2232 | 0 | } |
2233 | 0 | } |
2234 | |
|
2235 | 0 | return pixd; |
2236 | 0 | } |
2237 | | |
2238 | | |
2239 | | /*-------------------------------------------------------------* |
2240 | | * Half-edge by bandpass * |
2241 | | *-------------------------------------------------------------*/ |
2242 | | /*! |
2243 | | * \brief pixHalfEdgeByBandpass() |
2244 | | * |
2245 | | * \param[in] pixs 8 bpp gray or 32 bpp rgb |
2246 | | * \param[in] sm1h, sm1v "half-widths" of smoothing filter sm1 |
2247 | | * \param[in] sm2h, sm2v "half-widths" of smoothing filter sm2; |
2248 | | * require sm2 != sm1 |
2249 | | * \return pixd, or NULL on error |
2250 | | * |
2251 | | * <pre> |
2252 | | * Notes: |
2253 | | * (1) We use symmetric smoothing filters of odd dimension, |
2254 | | * typically use 3, 5, 7, etc. The smoothing parameters |
2255 | | * for these are 1, 2, 3, etc. The filter size is related |
2256 | | * to the smoothing parameter by |
2257 | | * size = 2 * smoothing + 1 |
2258 | | * (2) Because we take the difference of two lowpass filters, |
2259 | | * this is actually a bandpass filter. |
2260 | | * (3) We allow both filters to be anisotropic. |
2261 | | * (4) Consider either the h or v component of the 2 filters. |
2262 | | * Depending on whether sm1 > sm2 or sm2 > sm1, we get |
2263 | | * different halves of the smoothed gradients (or "edges"). |
2264 | | * This difference of smoothed signals looks more like |
2265 | | * a second derivative of a transition, which we rectify |
2266 | | * by not allowing the signal to go below zero. If sm1 < sm2, |
2267 | | * the sm2 transition is broader, so the difference between |
2268 | | * sm1 and sm2 signals is positive on the upper half of |
2269 | | * the transition. Likewise, if sm1 > sm2, the sm1 - sm2 |
2270 | | * signal difference is positive on the lower half of |
2271 | | * the transition. |
2272 | | * </pre> |
2273 | | */ |
2274 | | PIX * |
2275 | | pixHalfEdgeByBandpass(PIX *pixs, |
2276 | | l_int32 sm1h, |
2277 | | l_int32 sm1v, |
2278 | | l_int32 sm2h, |
2279 | | l_int32 sm2v) |
2280 | 0 | { |
2281 | 0 | l_int32 d; |
2282 | 0 | PIX *pixg, *pixacc, *pixc1, *pixc2; |
2283 | |
|
2284 | 0 | if (!pixs) |
2285 | 0 | return (PIX *)ERROR_PTR("pixs not defined", __func__, NULL); |
2286 | 0 | if (sm1h == sm2h && sm1v == sm2v) |
2287 | 0 | return (PIX *)ERROR_PTR("sm2 = sm1", __func__, NULL); |
2288 | 0 | d = pixGetDepth(pixs); |
2289 | 0 | if (d != 8 && d != 32) |
2290 | 0 | return (PIX *)ERROR_PTR("pixs not 8 or 32 bpp", __func__, NULL); |
2291 | 0 | if (d == 32) |
2292 | 0 | pixg = pixConvertRGBToLuminance(pixs); |
2293 | 0 | else /* d == 8 */ |
2294 | 0 | pixg = pixClone(pixs); |
2295 | | |
2296 | | /* Make a convolution accumulator and use it twice */ |
2297 | 0 | if ((pixacc = pixBlockconvAccum(pixg)) == NULL) { |
2298 | 0 | pixDestroy(&pixg); |
2299 | 0 | return (PIX *)ERROR_PTR("pixacc not made", __func__, NULL); |
2300 | 0 | } |
2301 | 0 | if ((pixc1 = pixBlockconvGray(pixg, pixacc, sm1h, sm1v)) == NULL) { |
2302 | 0 | pixDestroy(&pixg); |
2303 | 0 | pixDestroy(&pixacc); |
2304 | 0 | return (PIX *)ERROR_PTR("pixc1 not made", __func__, NULL); |
2305 | 0 | } |
2306 | 0 | pixc2 = pixBlockconvGray(pixg, pixacc, sm2h, sm2v); |
2307 | 0 | pixDestroy(&pixg); |
2308 | 0 | pixDestroy(&pixacc); |
2309 | 0 | if (!pixc2) { |
2310 | 0 | pixDestroy(&pixc1); |
2311 | 0 | return (PIX *)ERROR_PTR("pixc2 not made", __func__, NULL); |
2312 | 0 | } |
2313 | | |
2314 | | /* Compute the half-edge using pixc1 - pixc2. */ |
2315 | 0 | pixSubtractGray(pixc1, pixc1, pixc2); |
2316 | 0 | pixDestroy(&pixc2); |
2317 | 0 | return pixc1; |
2318 | 0 | } |