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()
#	User	Rev	Content
1	greg	3.1	/* 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	greg	3.2	#define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
22	greg	3.1	/* 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			*/