src/common/tonemap.h

/* RCSid $Id: tonemap.h,v 3.12 2003/02/25 02:47:22 greg Exp $ */
/*
 * Header file for tone mapping functions.
 *
 * Include after "color.h"
 */
#ifndef _RAD_TONEMAP_H_
#define _RAD_TONEMAP_H_
#ifdef __cplusplus
extern "C" {
#endif


#include "copyright.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 */
#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:	3.13
Committed:	Fri Jun 6 16:38:47 2003 UTC (20 years, 10 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 3.12:	+8 -24 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	schorsch	3.13	/* RCSid $Id: tonemap.h,v 3.12 2003/02/25 02:47:22 greg 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	greg	3.4
13	schorsch	3.13
14			#include "copyright.h"
15
16	greg	3.1	/** Argument Macros **/
17			/* Flags of what to do */
18			#define TM_F_HCONTR 01 /* human contrast sensitivity */
19			#define TM_F_MESOPIC 02 /* mesopic color sensitivity */
20			#define TM_F_LINEAR 04 /* linear brightness mapping */
21			#define TM_F_ACUITY 010 /* acuity adjustment */
22			#define TM_F_VEIL 020 /* veiling glare */
23			#define TM_F_CWEIGHT 040 /* center weighting */
24			#define TM_F_FOVEAL 0100 /* use foveal sample size */
25			#define TM_F_BW 0200 /* luminance only */
26	greg	3.2	#define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
27	greg	3.1	/* combined modes */
28			#define TM_F_CAMERA 0
29			#define TM_F_HUMAN (TM_F_HCONTR\|TM_F_MESOPIC\|TM_F_VEIL\|\
30			TM_F_ACUITY\|TM_F_FOVEAL)
31			#define TM_F_UNIMPL (TM_F_CWEIGHT\|TM_F_VEIL\|TM_F_ACUITY\|TM_F_FOVEAL)
32
33			/* special pointer values */
34			#define TM_XYZPRIM (RGBPRIMP)NULL /* indicate XYZ primaries (Note 1) */
35			#define TM_NOCHROM (BYTE )NULL / indicate no chrominance */
36			#define TM_NOCHROMP (BYTE *)NULL / indicate no chrominances */
37			#define TM_GETFILE (FILE )NULL / indicate file must be opened */
38	gwlarson	3.8
39	greg	3.1
40			/** Error Return Values **/
41
42			#define TM_E_OK 0 /* normal return status */
43			#define TM_E_NOMEM 1 /* out of memory */
44			#define TM_E_ILLEGAL 2 /* illegal argument value */
45			#define TM_E_TMINVAL 3 /* no valid tone mapping */
46			#define TM_E_TMFAIL 4 /* cannot compute tone mapping */
47			#define TM_E_BADFILE 5 /* cannot open or understand file */
48	greg	3.4	#define TM_E_CODERR1 6 /* code consistency error 1 */
49			#define TM_E_CODERR2 7 /* code consistency error 2 */
50	greg	3.1
51	greg	3.4
52	greg	3.1	/** Conversion Constants and Table Sizes **/
53
54			#define TM_BRTSCALE 128 /* brightness scale factor (integer) */
55
56	gwlarson	3.10	#define TM_NOBRT (-1<<15) /* bogus brightness value */
57	greg	3.11	#define TM_NOLUM (1e-17) /* ridiculously small luminance */
58	gwlarson	3.10
59	greg	3.4	#define TM_MAXPKG 8 /* maximum number of color formats */
60	greg	3.1
61
62	greg	3.4	/** Global Data Types and Structures **/
63
64			#ifndef MEM_PTR
65			#define MEM_PTR void *
66			#endif
67
68	greg	3.1	extern char tmErrorMessage[]; / error messages */
69	gregl	3.6	extern int tmLastError; /* last error incurred by library */
70			extern char tmLastFunction; / error-generating function name */
71	greg	3.1
72			typedef short TMbright; /* encoded luminance type */
73
74			/* basic tone mapping data structure */
75			extern struct tmStruct {
76			int flags; /* flags of what to do */
77			RGBPRIMP monpri; /* monitor RGB primaries */
78			double mongam; /* monitor gamma value (approx.) */
79			COLOR clf; /* computed luminance coefficients */
80	greg	3.4	int cdiv[3]; /* computed color divisors */
81	greg	3.1	RGBPRIMP inppri; /* current input primaries */
82			double inpsf; /* current input scalefactor */
83			COLORMAT cmat; /* color conversion matrix */
84	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
85	greg	3.1	int histo; / input histogram */
86	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
87	greg	3.1	unsigned short lumap; / computed luminance map */
88			struct tmStruct tmprev; / previous tone mapping */
89	greg	3.4	MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
90	greg	3.1	} tmTop; / current tone mapping stack */
91	greg	3.4
92			/* conversion package functions */
93			struct tmPackage {
94			MEM_PTR (Init)(struct tmStruct tms);
95	greg	3.11	void (NewSpace)(struct tmStruct tms);
96	greg	3.4	void (*Free)(MEM_PTR pp);
97			};
98			/* our list of conversion packages */
99			extern struct tmPackage *tmPkg[TM_MAXPKG];
100			extern int tmNumPkgs; /* number of registered packages */
101
102
103	greg	3.1	/** Useful Macros **/
104
105	greg	3.4	/* compute luminance from encoded value */
106	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
107	greg	3.1
108	greg	3.4	/* does tone mapping need color matrix? */
109			#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
110
111			/* register a conversion package */
112			#define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
113			(tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
114
115			/* get the specific package's data */
116			#define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
117
118
119	greg	3.1	/** Library Function Calls **/
120
121
122			extern struct tmStruct *
123			tmInit(int flags, RGBPRIMP monpri, double gamval);
124			/*
125			Initialize new tone mapping and push it onto stack.
126
127			flags - TM_F_* flags indicating what is to be done.
128			monpri - display monitor primaries (Note 1).
129			gamval - display gamma response (can be approximate).
130
131			returns - new tmTop, or NULL if insufficient memory.
132			*/
133
134			extern int
135			tmSetSpace(RGBPRIMP pri, double sf);
136			/*
137			Set color primaries and scale factor for incoming scanlines.
138
139			pri - RGB color input primaries (Note 1).
140			sf - scale factor to get to luminance in cd/m^2.
141
142			returns - 0 on success, TM_E_* code on failure.
143			*/
144
145			extern void
146			tmClearHisto(void);
147			/*
148			Clear histogram for current tone mapping.
149			*/
150
151			extern int
152			tmAddHisto(TMbright *ls, int len, int wt);
153			/*
154			Add brightness values to current histogram.
155
156			ls - encoded luminance values.
157			len - number of luminance values.
158			wt - integer weight to use for each value (usually 1 or -1).
159
160			returns - 0 on success, TM_E_* on error.
161			*/
162
163			extern int
164	greg	3.11	tmFixedMapping(double expmult, double gamval);
165			/*
166			Assign a fixed, linear tone-mapping using the given multiplier,
167			which is the ratio of maximum output to uncalibrated input.
168			This mapping will be used in subsequent calls to tmMapPixels()
169			until a new tone mapping is computed.
170			Only the min. and max. values are used from the histogram.
171
172			expmult - the fixed exposure multiplier to use.
173			gamval - display gamma response (0. for default).
174			returns - 0 on success, TM_E_* on error.
175			*/
176
177			extern int
178	greg	3.1	tmComputeMapping(double gamval, double Lddyn, double Ldmax);
179			/*
180	greg	3.11	Compute tone mapping function from the current histogram.
181			This mapping will be used in subsequent calls to tmMapPixels()
182			until a new tone mapping is computed.
183			I.e., calls to tmAddHisto() have no immediate effect.
184	greg	3.1
185			gamval - display gamma response (0. for default).
186			Lddyn - the display's dynamic range (0. for default).
187			Ldmax - maximum display luminance in cd/m^2 (0. for default).
188
189			returns - 0 on success, TM_E_* on failure.
190			*/
191
192			extern int
193			tmMapPixels(BYTE ps, TMbright ls, BYTE *cs, int len);
194			/*
195			Apply tone mapping function to pixel values.
196
197			ps - returned pixel values (Note 2).
198			ls - encoded luminance values.
199			cs - encoded chrominance values (Note 2).
200			len - number of pixels.
201
202			returns - 0 on success, TM_E_* on failure.
203			*/
204
205			extern struct tmStruct *
206			tmPop(void);
207			/*
208			Pops current tone mapping from stack.
209
210			returns - pointer to tone mapping structure, or NULL if none.
211			*/
212
213			extern int
214			tmPull(struct tmStruct *tms);
215			/*
216			Pull tone mapping from anywhere in stack.
217
218			tms - tone mapping structure to find.
219
220			returns - 1 if found in stack, 0 otherwise.
221			*/
222
223			extern int
224			tmPush(struct tmStruct *tms);
225			/*
226			Make tone mapping active by (pulling it and) pushing it to the top.
227
228			tms - initialized tone mapping structure.
229
230			returns - 0 on success, TM_E_* if tms is invalid.
231			*/
232
233	greg	3.3	extern struct tmStruct *
234			tmDup(void);
235			/*
236			Duplicate the current tone mapping into a new structure on the stack.
237
238			returns - pointer to new top, or NULL on error.
239			*/
240
241	greg	3.1	extern void
242			tmDone(struct tmStruct *tms);
243			/*
244			Free data associated with the given tone mapping structure.
245			Calls tmPull() first to remove it from the stack if present.
246			The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
247			all have the same effect, which is to remove and free
248			the current tone mapping.
249
250			tms - tone mapping structure to free.
251			*/
252
253	greg	3.11	extern int
254			tmCvColors(TMbright ls, BYTE cs, COLOR *scan, int len);
255			/*
256			Convert RGB/XYZ float scanline to encoded luminance and chrominance.
257
258			ls - returned encoded luminance values.
259			cs - returned encoded chrominance values (Note 2).
260			scan - input scanline.
261			len - scanline length.
262
263			returns - 0 on success, TM_E_* on error.
264			*/
265
266			extern int
267			tmCvGrays(TMbright ls, float scan, int len);
268			/*
269			Convert gray float scanline to encoded luminance.
270
271			ls - returned encoded luminance values.
272			scan - input scanline.
273			len - scanline length.
274
275			returns - 0 on success, TM_E_* on error.
276			*/
277
278			extern int
279			tmCvColrs(TMbright ls, BYTE cs, COLR *scan, int len);
280			/*
281			Convert RGBE/XYZE scanline to encoded luminance and chrominance.
282
283			ls - returned encoded luminance values.
284			cs - returned encoded chrominance values (Note 2).
285			scan - input scanline.
286			len - scanline length.
287
288			returns - 0 on success, TM_E_* on error.
289			*/
290
291			extern int
292			tmLoadPicture(TMbright lpp, BYTE cpp, int xp, int yp,
293			char fname, FILE fp);
294			/*
295			Load Radiance picture and convert to tone mapping representation.
296			Memory for the luminance and chroma arrays is allocated using
297			malloc(3), and should be freed with free(3) when no longer needed.
298			Calls tmSetSpace() to calibrate input color space.
299
300			lpp - returned array of encoded luminances, picture ordering.
301			cpp - returned array of encoded chrominances (Note 2).
302			xp, yp - returned picture dimensions.
303			fname - picture file name.
304			fp - pointer to open file (Note 3).
305
306			returns - 0 on success, TM_E_* on failure.
307			*/
308
309			extern int
310			tmMapPicture(BYTE *psp, int xp, int *yp, int flags,
311			RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
312			char fname, FILE fp);
313			/*
314			Load and apply tone mapping to Radiance picture.
315			Stack is restored to its original state upon return.
316			If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
317			calls pcond to perform the actual conversion, which takes
318			longer but gives access to all the TM_F_* features.
319			Memory for the final pixel array is allocated using malloc(3),
320			and should be freed with free(3) when it is no longer needed.
321
322			psp - returned array of tone mapped pixels, picture ordering.
323			xp, yp - returned picture dimensions.
324			flags - TM_F_* flags indicating what is to be done.
325			monpri - display monitor primaries (Note 1).
326			gamval - display gamma response.
327			Lddyn - the display's dynamic range (0. for default).
328			Ldmax - maximum display luminance in cd/m^2 (0. for default).
329			fname - picture file name.
330			fp - pointer to open file (Note 3).
331
332			returns - 0 on success, TM_E_* on failure.
333			*/
334
335	greg	3.4
336
337	greg	3.1	/** Notes **/
338			/*
339			General:
340
341			The usual sequence after calling tmInit() is to convert some
342			pixel values to chroma and luminance encodings, which can
343			be passed to tmAddHisto() to put into the tone mapping histogram.
344			This histogram is then used along with the display parameters
345	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
346	greg	3.1	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
347			is set.) The encoded chroma and luminance values may then be
348			passed to tmMapPixels() to apply the computed tone mapping in
349			a second pass.
350
351			Especially for RGBE colors in the same color space as the
352			target display, the conversion to chroma and luminance values
353			is fast enough that it may be recomputed on the second pass
354			if memory is at a premium. (Since the chroma values are only
355			used during final mapping, setting the cs parameter to TM_NOCHROM
356			on the first pass will save time.) Another memory saving option
357			if third and subsequent passes are not needed is to use the
358	greg	3.3	same array to store the mapped pixels as used to store
359	greg	3.1	the encoded chroma values. This way, only two extra bytes
360			for storing encoded luminances are required per pixel. This
361			is the method employed by tmMapPicture(), for example.
362			*/
363			/*
364			Note 1:
365
366			All RGBPRIMP values should be pointers to static structures.
367			I.e., the same pointer should be used for the same primaries,
368			and those primaries should not change from one call to the next.
369			This is because the routines use the pointer value to identify
370			computed conversion matrices, so the matrices do not have to be
371			rebuilt each time. If you are using the standard primaries,
372			use the standard primary pointer, stdprims.
373
374			To indicate a set of input primaries are actually CIE XYZ,
375			the TM_XYZPRIM macro may be passed. If the input primaries
376			are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
377			By default, the input primaries equal the monitor primaries
378			and the scalefactor is set to WHTEFFICACY in tmInit().
379			*/
380			/*
381			Note 2:
382
383			Chrominance is optional in most of these routines, whether
384			TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
385			TM_NOCHROMP for picture reading) indicates that returned
386			color values are not desired.
387
388			If TM_NOCHROM is passed to a mapping routine expecting chroma
389			input, it will do without it and return luminance channel
390			rather than RGB pixel values. Otherwise, the array for
391			returned pixel values may be the same array used to pass
392			encoded chrominances if no other mappings are desired.
393			*/
394			/*
395			Note 3:
396
397			Picture files may either be opened by the calling routine or by
398			the library function. If opened by the calling routine, the
399			pointer to the stream is passed, which may be a pipe or other
400			non-seekable input as it is only read once. It must be
401			positioned at the beginning when the function is called, and it
402			will be positioned at the end on return. It will not be closed.
403			If the passed stream pointer is TM_GETFILE, then the library
404			function will open the file, read its contents and close it
405			before returning, whether or not an error was encountered.
406			*/
407	greg	3.11
408			#ifdef __cplusplus
409			}
410			#endif
411	schorsch	3.13	#endif /* _RAD_TONEMAP_H_ */
412