src/common/tonemap.h

/* Copyright (c) 1997 Regents of the University of California */

/* SCCSid "$SunId$ LBL" */

/*
 * Header file for tone mapping functions.
 */
                                /* required non-system header files */
#include        "color.h"

/****    Argument Macros    ****/
                                /* Flags of what to do */
#define TM_F_HCONTR     01              /* human contrast sensitivity */
#define TM_F_MESOPIC    02              /* mesopic color sensitivity */
#define TM_F_LINEAR     04              /* linear brightness mapping */
#define TM_F_ACUITY     010             /* acuity adjustment */
#define TM_F_VEIL       020             /* veiling glare */
#define TM_F_CWEIGHT    040             /* center weighting */
#define TM_F_FOVEAL     0100            /* use foveal sample size */
#define TM_F_BW         0200            /* luminance only */
#define TM_F_NOSTDERR   0400            /* don't report errors to stderr */
                                /* combined modes */
#define TM_F_CAMERA     0
#define TM_F_HUMAN      (TM_F_HCONTR|TM_F_MESOPIC|TM_F_VEIL|\
                                TM_F_ACUITY|TM_F_FOVEAL)
#define TM_F_UNIMPL     (TM_F_CWEIGHT|TM_F_VEIL|TM_F_ACUITY|TM_F_FOVEAL)

                                /* special pointer values */
#define TM_XYZPRIM      (RGBPRIMP)NULL  /* indicate XYZ primaries (Note 1) */
#define TM_NOCHROM      (BYTE *)NULL    /* indicate no chrominance */
#define TM_NOCHROMP     (BYTE **)NULL   /* indicate no chrominances */
#define TM_GETFILE      (FILE *)NULL    /* indicate file must be opened */

/****    Error Return Values    ****/

#define TM_E_OK         0               /* normal return status */
#define TM_E_NOMEM      1               /* out of memory */
#define TM_E_ILLEGAL    2               /* illegal argument value */
#define TM_E_TMINVAL    3               /* no valid tone mapping */
#define TM_E_TMFAIL     4               /* cannot compute tone mapping */
#define TM_E_BADFILE    5               /* cannot open or understand file */

/****    Conversion Constants and Table Sizes    ****/

#define TM_BRTSCALE     128             /* brightness scale factor (integer) */

#define TM_GAMTSZ       1024            /* gamma lookup table size */

/****    Global Data Structures    ****/

extern char     *tmErrorMessage[];      /* error messages */

typedef short   TMbright;               /* encoded luminance type */

                                /* basic tone mapping data structure */
extern struct tmStruct {
        int             flags;          /* flags of what to do */
        RGBPRIMP        monpri;         /* monitor RGB primaries */
        double          mongam;         /* monitor gamma value (approx.) */
        BYTE            gamb[TM_GAMTSZ];/* gamma lookup table from mongam */
        COLOR           clf;            /* computed luminance coefficients */
        COLR            clfb;           /* normalized version of clf */
        RGBPRIMP        inppri;         /* current input primaries */
        double          inpsf;          /* current input scalefactor */
        TMbright        inpsfb;         /* encoded version of inpsf */
        COLORMAT        cmat;           /* color conversion matrix */
        TMbright        brmin, brmax;   /* input brightness limits */   
        int             *histo;         /* input histogram */
        unsigned short  *lumap;         /* computed luminance map */
        struct tmStruct *tmprev;        /* previous tone mapping */
}       *tmTop;                 /* current tone mapping stack */

/****    Useful Macros    ****/

#define tmLuminance(li) exp((li)/(double)TM_BRTSCALE)

/****    Library Function Calls    ****/

#ifdef NOPROTO

extern struct tmStruct  *tmInit(), *tmPop();
extern void     tmClearHisto(), tmDone();
extern int      tmSetSpace(), tmCvColors(), tmCvColrs();
extern int      tmAddHisto(), tmComputeMapping(), tmMapPixels();
extern int      tmLoadPicture(), tmMapPicture(), tmPull(), tmPush();

#else

extern struct tmStruct *
tmInit(int flags, RGBPRIMP monpri, double gamval);
/*
        Initialize new tone mapping and push it onto stack.

        flags   -       TM_F_* flags indicating what is to be done.
        monpri  -       display monitor primaries (Note 1).
        gamval  -       display gamma response (can be approximate).

        returns -       new tmTop, or NULL if insufficient memory.
*/

extern int
tmSetSpace(RGBPRIMP pri, double sf);
/*
        Set color primaries and scale factor for incoming scanlines.

        pri     -       RGB color input primaries (Note 1).
        sf      -       scale factor to get to luminance in cd/m^2.

        returns -       0 on success, TM_E_* code on failure.
*/

extern void
tmClearHisto(void);
/*
        Clear histogram for current tone mapping.
*/

extern int
tmCvColors(TMbright *ls, BYTE *cs, COLOR *scan, int len);
/*
        Convert RGB/XYZ float scanline to encoded luminance and chrominance.

        ls      -       returned encoded luminance values.
        cs      -       returned encoded chrominance values (Note 2).
        scan    -       input scanline.
        len     -       scanline length.

        returns -       0 on success, TM_E_* on error.
*/

extern int
tmCvColrs(TMbright *ls, BYTE *cs, COLR *scan, int len);
/*
        Convert RGBE/XYZE scanline to encoded luminance and chrominance.

        ls      -       returned encoded luminance values.
        cs      -       returned encoded chrominance values (Note 2).
        scan    -       input scanline.
        len     -       scanline length.

        returns -       0 on success, TM_E_* on error.
*/

extern int
tmAddHisto(TMbright *ls, int len, int wt);
/*
        Add brightness values to current histogram.

        ls      -       encoded luminance values.
        len     -       number of luminance values.
        wt      -       integer weight to use for each value (usually 1 or -1).

        returns -       0 on success, TM_E_* on error.
*/

extern int
tmComputeMapping(double gamval, double Lddyn, double Ldmax);
/*
        Compute tone mapping function.

        gamval  -       display gamma response (0. for default).
        Lddyn   -       the display's dynamic range (0. for default).
        Ldmax   -       maximum display luminance in cd/m^2 (0. for default).

        returns -       0 on success, TM_E_* on failure.
*/

extern int
tmMapPixels(BYTE *ps, TMbright *ls, BYTE *cs, int len);
/*
        Apply tone mapping function to pixel values.

        ps      -       returned pixel values (Note 2).
        ls      -       encoded luminance values.
        cs      -       encoded chrominance values (Note 2).
        len     -       number of pixels.

        returns -       0 on success, TM_E_* on failure.
*/

extern int
tmLoadPicture(TMbright **lpp, BYTE **cpp, int *xp, int *yp,
                char *fname, FILE *fp);
/*
        Load Radiance picture and convert to tone mapping representation.

        lpp     -       returned array of encoded luminances, English ordering.
        cpp     -       returned array of encoded chrominances (Note 2).
        xp, yp  -       returned picture dimensions.
        fname   -       picture file name.
        fp      -       pointer to open file (Note 3).

        returns -       0 on success, TM_E_* on failure.
*/

extern int
tmMapPicture(BYTE **psp, int *xp, int *yp, int flags,
                RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
                char *fname, FILE *fp);
/*
        Load and apply tone mapping to Radiance picture.
        Stack is restored to its original state upon return.
        If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
        calls pcond to perform the actual conversion, which takes
        longer but gives access to all the TM_F_* features.

        psp     -       returned array of tone mapped pixels, English ordering.
        xp, yp  -       returned picture dimensions.
        flags   -       TM_F_* flags indicating what is to be done.
        monpri  -       display monitor primaries (Note 1).
        gamval  -       display gamma response.
        Lddyn   -       the display's dynamic range (0. for default).
        Ldmax   -       maximum display luminance in cd/m^2 (0. for default).
        fname   -       picture file name.
        fp      -       pointer to open file (Note 3).

        returns -       0 on success, TM_E_* on failure.
*/

extern struct tmStruct *
tmPop(void);
/*
        Pops current tone mapping from stack.

        returns -       pointer to tone mapping structure, or NULL if none.
*/

extern int
tmPull(struct tmStruct *tms);
/*
        Pull tone mapping from anywhere in stack.

        tms     -       tone mapping structure to find.

        returns -       1 if found in stack, 0 otherwise.
*/

extern int
tmPush(struct tmStruct *tms);
/*
        Make tone mapping active by (pulling it and) pushing it to the top.

        tms     -       initialized tone mapping structure.

        returns -       0 on success, TM_E_* if tms is invalid.
*/

extern void
tmDone(struct tmStruct *tms);
/*
        Free data associated with the given tone mapping structure.
        Calls tmPull() first to remove it from the stack if present.
        The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
        all have the same effect, which is to remove and free
        the current tone mapping.

        tms     -       tone mapping structure to free.
*/

#endif

/****    Notes    ****/
/*
        General:

        The usual sequence after calling tmInit() is to convert some
        pixel values to chroma and luminance encodings, which can
        be passed to tmAddHisto() to put into the tone mapping histogram.
        This histogram is then used along with the display parameters
        by tmComputMapping() to compute the luminance mapping function.
        (Colors are tone-mapped as they are converted if TM_F_MESOPIC
        is set.)  The encoded chroma and luminance values may then be
        passed to tmMapPixels() to apply the computed tone mapping in
        a second pass.

        Especially for RGBE colors in the same color space as the
        target display, the conversion to chroma and luminance values
        is fast enough that it may be recomputed on the second pass
        if memory is at a premium.  (Since the chroma values are only
        used during final mapping, setting the cs parameter to TM_NOCHROM
        on the first pass will save time.)  Another memory saving option
        if third and subsequent passes are not needed is to use the
        same array to store the mapped pixels as is used to store
        the encoded chroma values.  This way, only two extra bytes
        for storing encoded luminances are required per pixel.  This
        is the method employed by tmMapPicture(), for example.
*/
/*
        Note 1:

        All RGBPRIMP values should be pointers to static structures.
        I.e., the same pointer should be used for the same primaries,
        and those primaries should not change from one call to the next.
        This is because the routines use the pointer value to identify
        computed conversion matrices, so the matrices do not have to be
        rebuilt each time.  If you are using the standard primaries,
        use the standard primary pointer, stdprims.

        To indicate a set of input primaries are actually CIE XYZ,
        the TM_XYZPRIM macro may be passed.  If the input primaries
        are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
        By default, the input primaries equal the monitor primaries
        and the scalefactor is set to WHTEFFICACY in tmInit().
*/
/*
        Note 2:

        Chrominance is optional in most of these routines, whether
        TM_F_BW is set or not.  Passing a value of TM_NOCHROM (or
        TM_NOCHROMP for picture reading) indicates that returned
        color values are not desired.
        
        If TM_NOCHROM is passed to a mapping routine expecting chroma
        input, it will do without it and return luminance channel
        rather than RGB pixel values.  Otherwise, the array for
        returned pixel values may be the same array used to pass
        encoded chrominances if no other mappings are desired.
*/
/*
        Note 3:

        Picture files may either be opened by the calling routine or by
        the library function.  If opened by the calling routine, the
        pointer to the stream is passed, which may be a pipe or other
        non-seekable input as it is only read once.  It must be
        positioned at the beginning when the function is called, and it
        will be positioned at the end on return.  It will not be closed.
        If the passed stream pointer is TM_GETFILE, then the library
        function will open the file, read its contents and close it
        before returning, whether or not an error was encountered.
*/
Revision:	3.2
Committed:	Tue Apr 15 20:04:41 1997 UTC (27 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.1:	+1 -1 lines
Log Message:	changed TM_F_NOERRS to TM_F_NOSTDERR skipped histogram clipping for TM_F_LINEAR in tmComputeMapping()
#	Content
1	/* Copyright (c) 1997 Regents of the University of California */
2
3	/* SCCSid "$SunId$ LBL" */
4
5	/*
6	* Header file for tone mapping functions.
7	*/
8	/* required non-system header files */
9	#include "color.h"
10
11	/** Argument Macros **/
12	/* Flags of what to do */
13	#define TM_F_HCONTR 01 /* human contrast sensitivity */
14	#define TM_F_MESOPIC 02 /* mesopic color sensitivity */
15	#define TM_F_LINEAR 04 /* linear brightness mapping */
16	#define TM_F_ACUITY 010 /* acuity adjustment */
17	#define TM_F_VEIL 020 /* veiling glare */
18	#define TM_F_CWEIGHT 040 /* center weighting */
19	#define TM_F_FOVEAL 0100 /* use foveal sample size */
20	#define TM_F_BW 0200 /* luminance only */
21	#define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
22	/* combined modes */
23	#define TM_F_CAMERA 0
24	#define TM_F_HUMAN (TM_F_HCONTR\|TM_F_MESOPIC\|TM_F_VEIL\|\
25	TM_F_ACUITY\|TM_F_FOVEAL)
26	#define TM_F_UNIMPL (TM_F_CWEIGHT\|TM_F_VEIL\|TM_F_ACUITY\|TM_F_FOVEAL)
27
28	/* special pointer values */
29	#define TM_XYZPRIM (RGBPRIMP)NULL /* indicate XYZ primaries (Note 1) */
30	#define TM_NOCHROM (BYTE )NULL / indicate no chrominance */
31	#define TM_NOCHROMP (BYTE *)NULL / indicate no chrominances */
32	#define TM_GETFILE (FILE )NULL / indicate file must be opened */
33
34	/** Error Return Values **/
35
36	#define TM_E_OK 0 /* normal return status */
37	#define TM_E_NOMEM 1 /* out of memory */
38	#define TM_E_ILLEGAL 2 /* illegal argument value */
39	#define TM_E_TMINVAL 3 /* no valid tone mapping */
40	#define TM_E_TMFAIL 4 /* cannot compute tone mapping */
41	#define TM_E_BADFILE 5 /* cannot open or understand file */
42
43	/** Conversion Constants and Table Sizes **/
44
45	#define TM_BRTSCALE 128 /* brightness scale factor (integer) */
46
47	#define TM_GAMTSZ 1024 /* gamma lookup table size */
48
49	/** Global Data Structures **/
50
51	extern char tmErrorMessage[]; / error messages */
52
53	typedef short TMbright; /* encoded luminance type */
54
55	/* basic tone mapping data structure */
56	extern struct tmStruct {
57	int flags; /* flags of what to do */
58	RGBPRIMP monpri; /* monitor RGB primaries */
59	double mongam; /* monitor gamma value (approx.) */
60	BYTE gamb[TM_GAMTSZ];/* gamma lookup table from mongam */
61	COLOR clf; /* computed luminance coefficients */
62	COLR clfb; /* normalized version of clf */
63	RGBPRIMP inppri; /* current input primaries */
64	double inpsf; /* current input scalefactor */
65	TMbright inpsfb; /* encoded version of inpsf */
66	COLORMAT cmat; /* color conversion matrix */
67	TMbright brmin, brmax; /* input brightness limits */
68	int histo; / input histogram */
69	unsigned short lumap; / computed luminance map */
70	struct tmStruct tmprev; / previous tone mapping */
71	} tmTop; / current tone mapping stack */
72
73	/** Useful Macros **/
74
75	#define tmLuminance(li) exp((li)/(double)TM_BRTSCALE)
76
77	/** Library Function Calls **/
78
79	#ifdef NOPROTO
80
81	extern struct tmStruct tmInit(), tmPop();
82	extern void tmClearHisto(), tmDone();
83	extern int tmSetSpace(), tmCvColors(), tmCvColrs();
84	extern int tmAddHisto(), tmComputeMapping(), tmMapPixels();
85	extern int tmLoadPicture(), tmMapPicture(), tmPull(), tmPush();
86
87	#else
88
89	extern struct tmStruct *
90	tmInit(int flags, RGBPRIMP monpri, double gamval);
91	/*
92	Initialize new tone mapping and push it onto stack.
93
94	flags - TM_F_* flags indicating what is to be done.
95	monpri - display monitor primaries (Note 1).
96	gamval - display gamma response (can be approximate).
97
98	returns - new tmTop, or NULL if insufficient memory.
99	*/
100
101	extern int
102	tmSetSpace(RGBPRIMP pri, double sf);
103	/*
104	Set color primaries and scale factor for incoming scanlines.
105
106	pri - RGB color input primaries (Note 1).
107	sf - scale factor to get to luminance in cd/m^2.
108
109	returns - 0 on success, TM_E_* code on failure.
110	*/
111
112	extern void
113	tmClearHisto(void);
114	/*
115	Clear histogram for current tone mapping.
116	*/
117
118	extern int
119	tmCvColors(TMbright ls, BYTE cs, COLOR *scan, int len);
120	/*
121	Convert RGB/XYZ float scanline to encoded luminance and chrominance.
122
123	ls - returned encoded luminance values.
124	cs - returned encoded chrominance values (Note 2).
125	scan - input scanline.
126	len - scanline length.
127
128	returns - 0 on success, TM_E_* on error.
129	*/
130
131	extern int
132	tmCvColrs(TMbright ls, BYTE cs, COLR *scan, int len);
133	/*
134	Convert RGBE/XYZE scanline to encoded luminance and chrominance.
135
136	ls - returned encoded luminance values.
137	cs - returned encoded chrominance values (Note 2).
138	scan - input scanline.
139	len - scanline length.
140
141	returns - 0 on success, TM_E_* on error.
142	*/
143
144	extern int
145	tmAddHisto(TMbright *ls, int len, int wt);
146	/*
147	Add brightness values to current histogram.
148
149	ls - encoded luminance values.
150	len - number of luminance values.
151	wt - integer weight to use for each value (usually 1 or -1).
152
153	returns - 0 on success, TM_E_* on error.
154	*/
155
156	extern int
157	tmComputeMapping(double gamval, double Lddyn, double Ldmax);
158	/*
159	Compute tone mapping function.
160
161	gamval - display gamma response (0. for default).
162	Lddyn - the display's dynamic range (0. for default).
163	Ldmax - maximum display luminance in cd/m^2 (0. for default).
164
165	returns - 0 on success, TM_E_* on failure.
166	*/
167
168	extern int
169	tmMapPixels(BYTE ps, TMbright ls, BYTE *cs, int len);
170	/*
171	Apply tone mapping function to pixel values.
172
173	ps - returned pixel values (Note 2).
174	ls - encoded luminance values.
175	cs - encoded chrominance values (Note 2).
176	len - number of pixels.
177
178	returns - 0 on success, TM_E_* on failure.
179	*/
180
181	extern int
182	tmLoadPicture(TMbright lpp, BYTE cpp, int xp, int yp,
183	char fname, FILE fp);
184	/*
185	Load Radiance picture and convert to tone mapping representation.
186
187	lpp - returned array of encoded luminances, English ordering.
188	cpp - returned array of encoded chrominances (Note 2).
189	xp, yp - returned picture dimensions.
190	fname - picture file name.
191	fp - pointer to open file (Note 3).
192
193	returns - 0 on success, TM_E_* on failure.
194	*/
195
196	extern int
197	tmMapPicture(BYTE *psp, int xp, int *yp, int flags,
198	RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
199	char fname, FILE fp);
200	/*
201	Load and apply tone mapping to Radiance picture.
202	Stack is restored to its original state upon return.
203	If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
204	calls pcond to perform the actual conversion, which takes
205	longer but gives access to all the TM_F_* features.
206
207	psp - returned array of tone mapped pixels, English ordering.
208	xp, yp - returned picture dimensions.
209	flags - TM_F_* flags indicating what is to be done.
210	monpri - display monitor primaries (Note 1).
211	gamval - display gamma response.
212	Lddyn - the display's dynamic range (0. for default).
213	Ldmax - maximum display luminance in cd/m^2 (0. for default).
214	fname - picture file name.
215	fp - pointer to open file (Note 3).
216
217	returns - 0 on success, TM_E_* on failure.
218	*/
219
220	extern struct tmStruct *
221	tmPop(void);
222	/*
223	Pops current tone mapping from stack.
224
225	returns - pointer to tone mapping structure, or NULL if none.
226	*/
227
228	extern int
229	tmPull(struct tmStruct *tms);
230	/*
231	Pull tone mapping from anywhere in stack.
232
233	tms - tone mapping structure to find.
234
235	returns - 1 if found in stack, 0 otherwise.
236	*/
237
238	extern int
239	tmPush(struct tmStruct *tms);
240	/*
241	Make tone mapping active by (pulling it and) pushing it to the top.
242
243	tms - initialized tone mapping structure.
244
245	returns - 0 on success, TM_E_* if tms is invalid.
246	*/
247
248	extern void
249	tmDone(struct tmStruct *tms);
250	/*
251	Free data associated with the given tone mapping structure.
252	Calls tmPull() first to remove it from the stack if present.
253	The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
254	all have the same effect, which is to remove and free
255	the current tone mapping.
256
257	tms - tone mapping structure to free.
258	*/
259
260	#endif
261
262	/** Notes **/
263	/*
264	General:
265
266	The usual sequence after calling tmInit() is to convert some
267	pixel values to chroma and luminance encodings, which can
268	be passed to tmAddHisto() to put into the tone mapping histogram.
269	This histogram is then used along with the display parameters
270	by tmComputMapping() to compute the luminance mapping function.
271	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
272	is set.) The encoded chroma and luminance values may then be
273	passed to tmMapPixels() to apply the computed tone mapping in
274	a second pass.
275
276	Especially for RGBE colors in the same color space as the
277	target display, the conversion to chroma and luminance values
278	is fast enough that it may be recomputed on the second pass
279	if memory is at a premium. (Since the chroma values are only
280	used during final mapping, setting the cs parameter to TM_NOCHROM
281	on the first pass will save time.) Another memory saving option
282	if third and subsequent passes are not needed is to use the
283	same array to store the mapped pixels as is used to store
284	the encoded chroma values. This way, only two extra bytes
285	for storing encoded luminances are required per pixel. This
286	is the method employed by tmMapPicture(), for example.
287	*/
288	/*
289	Note 1:
290
291	All RGBPRIMP values should be pointers to static structures.
292	I.e., the same pointer should be used for the same primaries,
293	and those primaries should not change from one call to the next.
294	This is because the routines use the pointer value to identify
295	computed conversion matrices, so the matrices do not have to be
296	rebuilt each time. If you are using the standard primaries,
297	use the standard primary pointer, stdprims.
298
299	To indicate a set of input primaries are actually CIE XYZ,
300	the TM_XYZPRIM macro may be passed. If the input primaries
301	are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
302	By default, the input primaries equal the monitor primaries
303	and the scalefactor is set to WHTEFFICACY in tmInit().
304	*/
305	/*
306	Note 2:
307
308	Chrominance is optional in most of these routines, whether
309	TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
310	TM_NOCHROMP for picture reading) indicates that returned
311	color values are not desired.
312
313	If TM_NOCHROM is passed to a mapping routine expecting chroma
314	input, it will do without it and return luminance channel
315	rather than RGB pixel values. Otherwise, the array for
316	returned pixel values may be the same array used to pass
317	encoded chrominances if no other mappings are desired.
318	*/
319	/*
320	Note 3:
321
322	Picture files may either be opened by the calling routine or by
323	the library function. If opened by the calling routine, the
324	pointer to the stream is passed, which may be a pipe or other
325	non-seekable input as it is only read once. It must be
326	positioned at the beginning when the function is called, and it
327	will be positioned at the end on return. It will not be closed.
328	If the passed stream pointer is TM_GETFILE, then the library
329	function will open the file, read its contents and close it
330	before returning, whether or not an error was encountered.
331	*/