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root/radiance/ray/src/common/tonemap.h
Revision: 3.14
Committed: Fri Jun 27 06:53:22 2003 UTC (20 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 3.13: +1 -4 lines
Log Message:
Broke standard.h into rtio.h, rterror.h, rtmath.h, and rtmisc.h

File Contents

# Content
1 /* RCSid $Id: tonemap.h,v 3.13 2003/06/06 16:38:47 schorsch Exp $ */
2 /*
3 * Header file for tone mapping functions.
4 *
5 * Include after "color.h"
6 */
7 #ifndef _RAD_TONEMAP_H_
8 #define _RAD_TONEMAP_H_
9 #ifdef __cplusplus
10 extern "C" {
11 #endif
12
13 /**** Argument Macros ****/
14 /* Flags of what to do */
15 #define TM_F_HCONTR 01 /* human contrast sensitivity */
16 #define TM_F_MESOPIC 02 /* mesopic color sensitivity */
17 #define TM_F_LINEAR 04 /* linear brightness mapping */
18 #define TM_F_ACUITY 010 /* acuity adjustment */
19 #define TM_F_VEIL 020 /* veiling glare */
20 #define TM_F_CWEIGHT 040 /* center weighting */
21 #define TM_F_FOVEAL 0100 /* use foveal sample size */
22 #define TM_F_BW 0200 /* luminance only */
23 #define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
24 /* combined modes */
25 #define TM_F_CAMERA 0
26 #define TM_F_HUMAN (TM_F_HCONTR|TM_F_MESOPIC|TM_F_VEIL|\
27 TM_F_ACUITY|TM_F_FOVEAL)
28 #define TM_F_UNIMPL (TM_F_CWEIGHT|TM_F_VEIL|TM_F_ACUITY|TM_F_FOVEAL)
29
30 /* special pointer values */
31 #define TM_XYZPRIM (RGBPRIMP)NULL /* indicate XYZ primaries (Note 1) */
32 #define TM_NOCHROM (BYTE *)NULL /* indicate no chrominance */
33 #define TM_NOCHROMP (BYTE **)NULL /* indicate no chrominances */
34 #define TM_GETFILE (FILE *)NULL /* indicate file must be opened */
35
36
37 /**** Error Return Values ****/
38
39 #define TM_E_OK 0 /* normal return status */
40 #define TM_E_NOMEM 1 /* out of memory */
41 #define TM_E_ILLEGAL 2 /* illegal argument value */
42 #define TM_E_TMINVAL 3 /* no valid tone mapping */
43 #define TM_E_TMFAIL 4 /* cannot compute tone mapping */
44 #define TM_E_BADFILE 5 /* cannot open or understand file */
45 #define TM_E_CODERR1 6 /* code consistency error 1 */
46 #define TM_E_CODERR2 7 /* code consistency error 2 */
47
48
49 /**** Conversion Constants and Table Sizes ****/
50
51 #define TM_BRTSCALE 128 /* brightness scale factor (integer) */
52
53 #define TM_NOBRT (-1<<15) /* bogus brightness value */
54 #define TM_NOLUM (1e-17) /* ridiculously small luminance */
55
56 #define TM_MAXPKG 8 /* maximum number of color formats */
57
58
59 /**** Global Data Types and Structures ****/
60
61 #ifndef MEM_PTR
62 #define MEM_PTR void *
63 #endif
64
65 extern char *tmErrorMessage[]; /* error messages */
66 extern int tmLastError; /* last error incurred by library */
67 extern char *tmLastFunction; /* error-generating function name */
68
69 typedef short TMbright; /* encoded luminance type */
70
71 /* basic tone mapping data structure */
72 extern struct tmStruct {
73 int flags; /* flags of what to do */
74 RGBPRIMP monpri; /* monitor RGB primaries */
75 double mongam; /* monitor gamma value (approx.) */
76 COLOR clf; /* computed luminance coefficients */
77 int cdiv[3]; /* computed color divisors */
78 RGBPRIMP inppri; /* current input primaries */
79 double inpsf; /* current input scalefactor */
80 COLORMAT cmat; /* color conversion matrix */
81 TMbright hbrmin, hbrmax; /* histogram brightness limits */
82 int *histo; /* input histogram */
83 TMbright mbrmin, mbrmax; /* mapped brightness limits */
84 unsigned short *lumap; /* computed luminance map */
85 struct tmStruct *tmprev; /* previous tone mapping */
86 MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
87 } *tmTop; /* current tone mapping stack */
88
89 /* conversion package functions */
90 struct tmPackage {
91 MEM_PTR (*Init)(struct tmStruct *tms);
92 void (*NewSpace)(struct tmStruct *tms);
93 void (*Free)(MEM_PTR pp);
94 };
95 /* our list of conversion packages */
96 extern struct tmPackage *tmPkg[TM_MAXPKG];
97 extern int tmNumPkgs; /* number of registered packages */
98
99
100 /**** Useful Macros ****/
101
102 /* compute luminance from encoded value */
103 #define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
104
105 /* does tone mapping need color matrix? */
106 #define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
107
108 /* register a conversion package */
109 #define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
110 (tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
111
112 /* get the specific package's data */
113 #define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
114
115
116 /**** Library Function Calls ****/
117
118
119 extern struct tmStruct *
120 tmInit(int flags, RGBPRIMP monpri, double gamval);
121 /*
122 Initialize new tone mapping and push it onto stack.
123
124 flags - TM_F_* flags indicating what is to be done.
125 monpri - display monitor primaries (Note 1).
126 gamval - display gamma response (can be approximate).
127
128 returns - new tmTop, or NULL if insufficient memory.
129 */
130
131 extern int
132 tmSetSpace(RGBPRIMP pri, double sf);
133 /*
134 Set color primaries and scale factor for incoming scanlines.
135
136 pri - RGB color input primaries (Note 1).
137 sf - scale factor to get to luminance in cd/m^2.
138
139 returns - 0 on success, TM_E_* code on failure.
140 */
141
142 extern void
143 tmClearHisto(void);
144 /*
145 Clear histogram for current tone mapping.
146 */
147
148 extern int
149 tmAddHisto(TMbright *ls, int len, int wt);
150 /*
151 Add brightness values to current histogram.
152
153 ls - encoded luminance values.
154 len - number of luminance values.
155 wt - integer weight to use for each value (usually 1 or -1).
156
157 returns - 0 on success, TM_E_* on error.
158 */
159
160 extern int
161 tmFixedMapping(double expmult, double gamval);
162 /*
163 Assign a fixed, linear tone-mapping using the given multiplier,
164 which is the ratio of maximum output to uncalibrated input.
165 This mapping will be used in subsequent calls to tmMapPixels()
166 until a new tone mapping is computed.
167 Only the min. and max. values are used from the histogram.
168
169 expmult - the fixed exposure multiplier to use.
170 gamval - display gamma response (0. for default).
171 returns - 0 on success, TM_E_* on error.
172 */
173
174 extern int
175 tmComputeMapping(double gamval, double Lddyn, double Ldmax);
176 /*
177 Compute tone mapping function from the current histogram.
178 This mapping will be used in subsequent calls to tmMapPixels()
179 until a new tone mapping is computed.
180 I.e., calls to tmAddHisto() have no immediate effect.
181
182 gamval - display gamma response (0. for default).
183 Lddyn - the display's dynamic range (0. for default).
184 Ldmax - maximum display luminance in cd/m^2 (0. for default).
185
186 returns - 0 on success, TM_E_* on failure.
187 */
188
189 extern int
190 tmMapPixels(BYTE *ps, TMbright *ls, BYTE *cs, int len);
191 /*
192 Apply tone mapping function to pixel values.
193
194 ps - returned pixel values (Note 2).
195 ls - encoded luminance values.
196 cs - encoded chrominance values (Note 2).
197 len - number of pixels.
198
199 returns - 0 on success, TM_E_* on failure.
200 */
201
202 extern struct tmStruct *
203 tmPop(void);
204 /*
205 Pops current tone mapping from stack.
206
207 returns - pointer to tone mapping structure, or NULL if none.
208 */
209
210 extern int
211 tmPull(struct tmStruct *tms);
212 /*
213 Pull tone mapping from anywhere in stack.
214
215 tms - tone mapping structure to find.
216
217 returns - 1 if found in stack, 0 otherwise.
218 */
219
220 extern int
221 tmPush(struct tmStruct *tms);
222 /*
223 Make tone mapping active by (pulling it and) pushing it to the top.
224
225 tms - initialized tone mapping structure.
226
227 returns - 0 on success, TM_E_* if tms is invalid.
228 */
229
230 extern struct tmStruct *
231 tmDup(void);
232 /*
233 Duplicate the current tone mapping into a new structure on the stack.
234
235 returns - pointer to new top, or NULL on error.
236 */
237
238 extern void
239 tmDone(struct tmStruct *tms);
240 /*
241 Free data associated with the given tone mapping structure.
242 Calls tmPull() first to remove it from the stack if present.
243 The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
244 all have the same effect, which is to remove and free
245 the current tone mapping.
246
247 tms - tone mapping structure to free.
248 */
249
250 extern int
251 tmCvColors(TMbright *ls, BYTE *cs, COLOR *scan, int len);
252 /*
253 Convert RGB/XYZ float scanline to encoded luminance and chrominance.
254
255 ls - returned encoded luminance values.
256 cs - returned encoded chrominance values (Note 2).
257 scan - input scanline.
258 len - scanline length.
259
260 returns - 0 on success, TM_E_* on error.
261 */
262
263 extern int
264 tmCvGrays(TMbright *ls, float *scan, int len);
265 /*
266 Convert gray float scanline to encoded luminance.
267
268 ls - returned encoded luminance values.
269 scan - input scanline.
270 len - scanline length.
271
272 returns - 0 on success, TM_E_* on error.
273 */
274
275 extern int
276 tmCvColrs(TMbright *ls, BYTE *cs, COLR *scan, int len);
277 /*
278 Convert RGBE/XYZE scanline to encoded luminance and chrominance.
279
280 ls - returned encoded luminance values.
281 cs - returned encoded chrominance values (Note 2).
282 scan - input scanline.
283 len - scanline length.
284
285 returns - 0 on success, TM_E_* on error.
286 */
287
288 extern int
289 tmLoadPicture(TMbright **lpp, BYTE **cpp, int *xp, int *yp,
290 char *fname, FILE *fp);
291 /*
292 Load Radiance picture and convert to tone mapping representation.
293 Memory for the luminance and chroma arrays is allocated using
294 malloc(3), and should be freed with free(3) when no longer needed.
295 Calls tmSetSpace() to calibrate input color space.
296
297 lpp - returned array of encoded luminances, picture ordering.
298 cpp - returned array of encoded chrominances (Note 2).
299 xp, yp - returned picture dimensions.
300 fname - picture file name.
301 fp - pointer to open file (Note 3).
302
303 returns - 0 on success, TM_E_* on failure.
304 */
305
306 extern int
307 tmMapPicture(BYTE **psp, int *xp, int *yp, int flags,
308 RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
309 char *fname, FILE *fp);
310 /*
311 Load and apply tone mapping to Radiance picture.
312 Stack is restored to its original state upon return.
313 If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
314 calls pcond to perform the actual conversion, which takes
315 longer but gives access to all the TM_F_* features.
316 Memory for the final pixel array is allocated using malloc(3),
317 and should be freed with free(3) when it is no longer needed.
318
319 psp - returned array of tone mapped pixels, picture ordering.
320 xp, yp - returned picture dimensions.
321 flags - TM_F_* flags indicating what is to be done.
322 monpri - display monitor primaries (Note 1).
323 gamval - display gamma response.
324 Lddyn - the display's dynamic range (0. for default).
325 Ldmax - maximum display luminance in cd/m^2 (0. for default).
326 fname - picture file name.
327 fp - pointer to open file (Note 3).
328
329 returns - 0 on success, TM_E_* on failure.
330 */
331
332
333
334 /**** Notes ****/
335 /*
336 General:
337
338 The usual sequence after calling tmInit() is to convert some
339 pixel values to chroma and luminance encodings, which can
340 be passed to tmAddHisto() to put into the tone mapping histogram.
341 This histogram is then used along with the display parameters
342 by tmComputeMapping() to compute the luminance mapping function.
343 (Colors are tone-mapped as they are converted if TM_F_MESOPIC
344 is set.) The encoded chroma and luminance values may then be
345 passed to tmMapPixels() to apply the computed tone mapping in
346 a second pass.
347
348 Especially for RGBE colors in the same color space as the
349 target display, the conversion to chroma and luminance values
350 is fast enough that it may be recomputed on the second pass
351 if memory is at a premium. (Since the chroma values are only
352 used during final mapping, setting the cs parameter to TM_NOCHROM
353 on the first pass will save time.) Another memory saving option
354 if third and subsequent passes are not needed is to use the
355 same array to store the mapped pixels as used to store
356 the encoded chroma values. This way, only two extra bytes
357 for storing encoded luminances are required per pixel. This
358 is the method employed by tmMapPicture(), for example.
359 */
360 /*
361 Note 1:
362
363 All RGBPRIMP values should be pointers to static structures.
364 I.e., the same pointer should be used for the same primaries,
365 and those primaries should not change from one call to the next.
366 This is because the routines use the pointer value to identify
367 computed conversion matrices, so the matrices do not have to be
368 rebuilt each time. If you are using the standard primaries,
369 use the standard primary pointer, stdprims.
370
371 To indicate a set of input primaries are actually CIE XYZ,
372 the TM_XYZPRIM macro may be passed. If the input primaries
373 are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
374 By default, the input primaries equal the monitor primaries
375 and the scalefactor is set to WHTEFFICACY in tmInit().
376 */
377 /*
378 Note 2:
379
380 Chrominance is optional in most of these routines, whether
381 TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
382 TM_NOCHROMP for picture reading) indicates that returned
383 color values are not desired.
384
385 If TM_NOCHROM is passed to a mapping routine expecting chroma
386 input, it will do without it and return luminance channel
387 rather than RGB pixel values. Otherwise, the array for
388 returned pixel values may be the same array used to pass
389 encoded chrominances if no other mappings are desired.
390 */
391 /*
392 Note 3:
393
394 Picture files may either be opened by the calling routine or by
395 the library function. If opened by the calling routine, the
396 pointer to the stream is passed, which may be a pipe or other
397 non-seekable input as it is only read once. It must be
398 positioned at the beginning when the function is called, and it
399 will be positioned at the end on return. It will not be closed.
400 If the passed stream pointer is TM_GETFILE, then the library
401 function will open the file, read its contents and close it
402 before returning, whether or not an error was encountered.
403 */
404
405 #ifdef __cplusplus
406 }
407 #endif
408 #endif /* _RAD_TONEMAP_H_ */
409