src/common/tonemap.h

/* RCSid $Id: tonemap.h,v 3.13 2003/06/06 16:38:47 schorsch Exp $ */
/*
 * Header file for tone mapping functions.
 *
 * Include after "color.h"
 */
#ifndef _RAD_TONEMAP_H_
#define _RAD_TONEMAP_H_
#ifdef __cplusplus
extern "C" {
#endif

/****    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 */
#define TM_E_CODERR1    6               /* code consistency error 1 */
#define TM_E_CODERR2    7               /* code consistency error 2 */


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

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

#define TM_NOBRT        (-1<<15)        /* bogus brightness value */
#define TM_NOLUM        (1e-17)         /* ridiculously small luminance */

#define TM_MAXPKG       8               /* maximum number of color formats */


/****    Global Data Types and Structures    ****/

#ifndef MEM_PTR
#define MEM_PTR         void *
#endif

extern char     *tmErrorMessage[];      /* error messages */
extern int      tmLastError;            /* last error incurred by library */
extern char     *tmLastFunction;        /* error-generating function name */

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.) */
        COLOR           clf;            /* computed luminance coefficients */
        int             cdiv[3];        /* computed color divisors */
        RGBPRIMP        inppri;         /* current input primaries */
        double          inpsf;          /* current input scalefactor */
        COLORMAT        cmat;           /* color conversion matrix */
        TMbright        hbrmin, hbrmax; /* histogram brightness limits */       
        int             *histo;         /* input histogram */
        TMbright        mbrmin, mbrmax; /* mapped brightness limits */
        unsigned short  *lumap;         /* computed luminance map */
        struct tmStruct *tmprev;        /* previous tone mapping */
        MEM_PTR         pd[TM_MAXPKG];  /* pointers to private data */
}       *tmTop;                 /* current tone mapping stack */

                                /* conversion package functions */
struct tmPackage {
        MEM_PTR         (*Init)(struct tmStruct *tms);
        void            (*NewSpace)(struct tmStruct *tms);
        void            (*Free)(MEM_PTR pp);
};
                                /* our list of conversion packages */
extern struct tmPackage *tmPkg[TM_MAXPKG];
extern int      tmNumPkgs;      /* number of registered packages */


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

                                /* compute luminance from encoded value */
#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))

                                /* does tone mapping need color matrix? */
#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)

                                /* register a conversion package */
#define tmRegPkg(pf)    ( tmNumPkgs >= TM_MAXPKG ? -1 : \
                                (tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )

                                /* get the specific package's data */
#define tmPkgData(t,i)  ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))


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


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
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
tmFixedMapping(double expmult, double gamval);
/*
        Assign a fixed, linear tone-mapping using the given multiplier,
        which is the ratio of maximum output to uncalibrated input.
        This mapping will be used in subsequent calls to tmMapPixels()
        until a new tone mapping is computed.
        Only the min. and max. values are used from the histogram.
        
        expmult -       the fixed exposure multiplier to use.
        gamval  -       display gamma response (0. for default).
        returns -       0 on success, TM_E_* on error.
*/

extern int
tmComputeMapping(double gamval, double Lddyn, double Ldmax);
/*
        Compute tone mapping function from the current histogram.
        This mapping will be used in subsequent calls to tmMapPixels()
        until a new tone mapping is computed.
        I.e., calls to tmAddHisto() have no immediate effect.

        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 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 struct tmStruct *
tmDup(void);
/*
        Duplicate the current tone mapping into a new structure on the stack.

        returns -       pointer to new top, or NULL on error.
*/

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.
*/

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
tmCvGrays(TMbright *ls, float *scan, int len);
/*
        Convert gray float scanline to encoded luminance.

        ls      -       returned encoded luminance values.
        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
tmLoadPicture(TMbright **lpp, BYTE **cpp, int *xp, int *yp,
                char *fname, FILE *fp);
/*
        Load Radiance picture and convert to tone mapping representation.
        Memory for the luminance and chroma arrays is allocated using
        malloc(3), and should be freed with free(3) when no longer needed.
        Calls tmSetSpace() to calibrate input color space.

        lpp     -       returned array of encoded luminances, picture 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.
        Memory for the final pixel array is allocated using malloc(3),
        and should be freed with free(3) when it is no longer needed.

        psp     -       returned array of tone mapped pixels, picture 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.
*/


/****    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 tmComputeMapping() 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 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.
*/

#ifdef __cplusplus
}
#endif
#endif /* _RAD_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
#	User	Rev	Content
1	greg	3.14	/* RCSid $Id: tonemap.h,v 3.13 2003/06/06 16:38:47 schorsch Exp $ */
2	greg	3.1	/*
3			* Header file for tone mapping functions.
4	gwlarson	3.8	*
5			* Include after "color.h"
6	greg	3.1	*/
7	schorsch	3.13	#ifndef _RAD_TONEMAP_H_
8			#define _RAD_TONEMAP_H_
9	greg	3.11	#ifdef __cplusplus
10			extern "C" {
11			#endif
12	schorsch	3.13
13	greg	3.1	/** 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	greg	3.2	#define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
24	greg	3.1	/* 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	gwlarson	3.8
36	greg	3.1
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	greg	3.4	#define TM_E_CODERR1 6 /* code consistency error 1 */
46			#define TM_E_CODERR2 7 /* code consistency error 2 */
47	greg	3.1
48	greg	3.4
49	greg	3.1	/** Conversion Constants and Table Sizes **/
50
51			#define TM_BRTSCALE 128 /* brightness scale factor (integer) */
52
53	gwlarson	3.10	#define TM_NOBRT (-1<<15) /* bogus brightness value */
54	greg	3.11	#define TM_NOLUM (1e-17) /* ridiculously small luminance */
55	gwlarson	3.10
56	greg	3.4	#define TM_MAXPKG 8 /* maximum number of color formats */
57	greg	3.1
58
59	greg	3.4	/** Global Data Types and Structures **/
60
61			#ifndef MEM_PTR
62			#define MEM_PTR void *
63			#endif
64
65	greg	3.1	extern char tmErrorMessage[]; / error messages */
66	gregl	3.6	extern int tmLastError; /* last error incurred by library */
67			extern char tmLastFunction; / error-generating function name */
68	greg	3.1
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	greg	3.4	int cdiv[3]; /* computed color divisors */
78	greg	3.1	RGBPRIMP inppri; /* current input primaries */
79			double inpsf; /* current input scalefactor */
80			COLORMAT cmat; /* color conversion matrix */
81	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
82	greg	3.1	int histo; / input histogram */
83	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
84	greg	3.1	unsigned short lumap; / computed luminance map */
85			struct tmStruct tmprev; / previous tone mapping */
86	greg	3.4	MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
87	greg	3.1	} tmTop; / current tone mapping stack */
88	greg	3.4
89			/* conversion package functions */
90			struct tmPackage {
91			MEM_PTR (Init)(struct tmStruct tms);
92	greg	3.11	void (NewSpace)(struct tmStruct tms);
93	greg	3.4	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	greg	3.1	/** Useful Macros **/
101
102	greg	3.4	/* compute luminance from encoded value */
103	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
104	greg	3.1
105	greg	3.4	/* 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	greg	3.1	/** 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	greg	3.11	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	greg	3.1	tmComputeMapping(double gamval, double Lddyn, double Ldmax);
176			/*
177	greg	3.11	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	greg	3.1
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	greg	3.3	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	greg	3.1	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	greg	3.11	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	greg	3.4
333
334	greg	3.1	/** 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	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
343	greg	3.1	(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	greg	3.3	same array to store the mapped pixels as used to store
356	greg	3.1	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	greg	3.11
405			#ifdef __cplusplus
406			}
407			#endif
408	schorsch	3.13	#endif /* _RAD_TONEMAP_H_ */
409