src/common/tonemap.h

/* RCSid $Id: tonemap.h,v 3.29 2021/01/07 19:13:57 greg Exp $ */
/*
 * Header file for tone mapping functions.
 *
 * Include after "color.h"
 */
#ifndef _RAD_TONEMAP_H_
#define _RAD_TONEMAP_H_

#include        "tiff.h"        /* needed for int32, etc. */

#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      (uby8 *)NULL    /* indicate no chrominance */
#define TM_NOCHROMP     (uby8 **)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     256             /* brightness scale factor (integer) */

#define TM_NOBRT        (~0x7fff)       /* bogus brightness value */
#define TM_NOLUM        (1e-17)         /* ridiculously small luminance */

#define TM_BRES         4096            /* luminance tone-map resolution */

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


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

#ifndef MEM_PTR
#define MEM_PTR         void *
#endif
#ifndef HIST_TYP
#define HIST_TYP        unsigned long
#endif
#ifndef TMAP_TYP
#define TMAP_TYP        uint16
#endif

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

typedef short   TMbright;               /* encoded luminance type */

                                /* basic tone mapping data structure */
typedef struct {
        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 */
        MEM_PTR         inpdat;         /* current input client data */
        COLORMAT        cmat;           /* color conversion matrix */
        TMbright        hbrmin, hbrmax; /* histogram brightness limits */       
        HIST_TYP        *histo;         /* input histogram */
        TMbright        mbrmin, mbrmax; /* mapped brightness limits */
        TMAP_TYP        *lumap;         /* computed luminance map */
        MEM_PTR         pd[TM_MAXPKG];  /* pointers to private data */
        int             lastError;      /* last error incurred */
        const char      *lastFunc;      /* error-generating function name */
} TMstruct;

                                /* conversion package functions */
struct tmPackage {
        MEM_PTR         (*Init)(TMstruct *tms);
        void            (*NewSpace)(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 TMbright
tmCvLuminance(double lum);
/*
        Convert a single luminance value to an encoded brightness value.
 */

extern int
tmCvLums(TMbright *ls, float *scan, int len);
/*
        Convert luminance values to encoded brightness values using lookup.

        ls      -       returned encoded luminance values.
        scan    -       input scanline.
        len     -       scanline length.

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

extern TMstruct *
tmInit(int flags, RGBPRIMP monpri, double gamval);
/*
        Allocate and initialize new tone mapping.

        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 tone-mapping pointer, or NULL if no memory.
*/

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

        tms     -       tone mapping structure pointer.
        pri     -       RGB color input primaries (Note 1).
        sf      -       scale factor to get to luminance in cd/m^2.
        dat     -       application-specific data (NULL if not needed)

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

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

        tms     -       tone mapping structure pointer.
*/

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

        tms     -       tone mapping structure pointer.
        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(TMstruct *tms, double expmult, double gamval, double Lddyn);
/*
        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.
        
        tms     -       tone mapping structure pointer.
        expmult -       the fixed exposure multiplier to use.
        gamval  -       display gamma response (0. for default).
        Ldmax   -       maximum display luminance in cd/m^2 (0. for default).

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

extern int
tmComputeMapping(TMstruct *tms, 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.

        tms     -       tone mapping structure pointer.
        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(TMstruct *tms, uby8 *ps, TMbright *ls, uby8 *cs, int len);
/*
        Apply tone mapping function to pixel values.

        tms     -       tone mapping structure pointer.
        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 TMstruct *
tmDup(TMstruct *orig);
/*
        Duplicate the given tone mapping into a new struct.

        orig    -       tone mapping structure to duplicate.

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

extern void
tmDone(TMstruct *tms);
/*
        Free data associated with the given tone mapping structure.

        tms     -       tone mapping structure to free.
*/

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

        tms     -       tone mapping structure pointer.
        ls      -       returned encoded luminance values.
        scan    -       input scanline.
        len     -       scanline length.

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

extern int
tmCvColors(TMstruct *tms, TMbright *ls, uby8 *cs, COLOR *scan, int len);
/*
        Convert RGB/XYZ float scanline to encoded luminance and chrominance.

        tms     -       tone mapping structure pointer.
        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(TMstruct *tms, TMbright *ls, uby8 *cs, COLR *scan, int len);
/*
        Convert RGBE/XYZE scanline to encoded luminance and chrominance.

        tms     -       tone mapping structure pointer.
        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(TMstruct *tms, TMbright **lpp, uby8 **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.

        tms     -       tone mapping structure pointer.
        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(uby8 **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.
        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.
*/

extern int
tmCvRGB48(TMstruct *tms, TMbright *ls, uby8 *cs, uint16 (*scan)[3],
                int len, double gv);
/*
        Convert 48-bit RGB scanline to encoded luminance and chrominance.

        tms     -       tone mapping structure pointer.
        ls      -       returned encoded luminance values.
        cs      -       returned encoded chrominance values (Note 2).
        scan    -       input scanline.
        len     -       scanline length.
        gv      -       input gamma value.

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

extern int
tmCvGray16(TMstruct *tms, TMbright *ls, uint16 *scan, int len, double gv);
/*
        Convert 16-bit gray scanline to encoded luminance.

        tms     -       tone mapping structure pointer.
        ls      -       returned encoded luminance values.
        scan    -       input scanline.
        len     -       scanline length.
        gv      -       input gamma value.

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

/****    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:	3.30
Committed:	Tue Mar 2 20:09:14 2021 UTC (3 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.29:	+3 -2 lines
Log Message:	perf: added handling of blacks in linear tone-mapping
#	User	Rev	Content
1	greg	3.30	/* RCSid $Id: tonemap.h,v 3.29 2021/01/07 19:13:57 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	schorsch	3.16
10	greg	3.23	#include "tiff.h" /* needed for int32, etc. */
11	schorsch	3.16
12	greg	3.11	#ifdef __cplusplus
13			extern "C" {
14			#endif
15	greg	3.15
16	greg	3.1	/** Argument Macros **/
17	greg	3.20	/* flags of what to do */
18	greg	3.1	#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	greg	3.26	#define TM_NOCHROM (uby8 )NULL / indicate no chrominance */
36			#define TM_NOCHROMP (uby8 *)NULL / indicate no chrominances */
37	greg	3.1	#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	greg	3.25	#define TM_BRTSCALE 256 /* brightness scale factor (integer) */
55	greg	3.1
56	greg	3.27	#define TM_NOBRT (~0x7fff) /* bogus brightness value */
57	greg	3.11	#define TM_NOLUM (1e-17) /* ridiculously small luminance */
58	gwlarson	3.10
59	greg	3.28	#define TM_BRES 4096 /* luminance tone-map resolution */
60
61	greg	3.4	#define TM_MAXPKG 8 /* maximum number of color formats */
62	greg	3.1
63
64	greg	3.4	/** Global Data Types and Structures **/
65
66			#ifndef MEM_PTR
67			#define MEM_PTR void *
68			#endif
69	greg	3.27	#ifndef HIST_TYP
70			#define HIST_TYP unsigned long
71			#endif
72	greg	3.29	#ifndef TMAP_TYP
73			#define TMAP_TYP uint16
74			#endif
75	greg	3.4
76	greg	3.1	extern char tmErrorMessage[]; / error messages */
77
78			typedef short TMbright; /* encoded luminance type */
79
80			/* basic tone mapping data structure */
81	greg	3.20	typedef struct {
82	greg	3.1	int flags; /* flags of what to do */
83			RGBPRIMP monpri; /* monitor RGB primaries */
84			double mongam; /* monitor gamma value (approx.) */
85			COLOR clf; /* computed luminance coefficients */
86	greg	3.4	int cdiv[3]; /* computed color divisors */
87	greg	3.1	RGBPRIMP inppri; /* current input primaries */
88			double inpsf; /* current input scalefactor */
89	greg	3.19	MEM_PTR inpdat; /* current input client data */
90	greg	3.1	COLORMAT cmat; /* color conversion matrix */
91	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
92	greg	3.27	HIST_TYP histo; / input histogram */
93	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
94	greg	3.27	TMAP_TYP lumap; / computed luminance map */
95	greg	3.4	MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
96	greg	3.18	int lastError; /* last error incurred */
97			const char lastFunc; / error-generating function name */
98	greg	3.17	} TMstruct;
99	greg	3.4
100			/* conversion package functions */
101			struct tmPackage {
102	greg	3.17	MEM_PTR (Init)(TMstruct tms);
103			void (NewSpace)(TMstruct tms);
104	greg	3.4	void (*Free)(MEM_PTR pp);
105			};
106			/* our list of conversion packages */
107			extern struct tmPackage *tmPkg[TM_MAXPKG];
108			extern int tmNumPkgs; /* number of registered packages */
109
110
111	greg	3.1	/** Useful Macros **/
112
113	greg	3.4	/* compute luminance from encoded value */
114	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
115	greg	3.1
116	greg	3.4	/* does tone mapping need color matrix? */
117			#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
118
119			/* register a conversion package */
120			#define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
121			(tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
122
123			/* get the specific package's data */
124			#define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
125
126
127	greg	3.1	/** Library Function Calls **/
128
129	greg	3.21	extern TMbright
130			tmCvLuminance(double lum);
131			/*
132			Convert a single luminance value to an encoded brightness value.
133			*/
134	greg	3.1
135	greg	3.22	extern int
136			tmCvLums(TMbright ls, float scan, int len);
137			/*
138			Convert luminance values to encoded brightness values using lookup.
139
140			ls - returned encoded luminance values.
141			scan - input scanline.
142			len - scanline length.
143
144			returns - 0 on success, TM_E_* on error.
145			*/
146
147	greg	3.17	extern TMstruct *
148	greg	3.1	tmInit(int flags, RGBPRIMP monpri, double gamval);
149			/*
150	greg	3.17	Allocate and initialize new tone mapping.
151	greg	3.1
152			flags - TM_F_* flags indicating what is to be done.
153			monpri - display monitor primaries (Note 1).
154			gamval - display gamma response (can be approximate).
155
156	greg	3.17	returns - new tone-mapping pointer, or NULL if no memory.
157	greg	3.1	*/
158
159			extern int
160	greg	3.19	tmSetSpace(TMstruct *tms, RGBPRIMP pri, double sf, MEM_PTR dat);
161	greg	3.1	/*
162			Set color primaries and scale factor for incoming scanlines.
163
164	greg	3.17	tms - tone mapping structure pointer.
165	greg	3.1	pri - RGB color input primaries (Note 1).
166			sf - scale factor to get to luminance in cd/m^2.
167	greg	3.19	dat - application-specific data (NULL if not needed)
168	greg	3.1
169			returns - 0 on success, TM_E_* code on failure.
170			*/
171
172			extern void
173	greg	3.17	tmClearHisto(TMstruct *tms);
174	greg	3.1	/*
175			Clear histogram for current tone mapping.
176	greg	3.17
177			tms - tone mapping structure pointer.
178	greg	3.1	*/
179
180			extern int
181	greg	3.17	tmAddHisto(TMstruct tms, TMbright ls, int len, int wt);
182	greg	3.1	/*
183			Add brightness values to current histogram.
184
185	greg	3.17	tms - tone mapping structure pointer.
186	greg	3.1	ls - encoded luminance values.
187			len - number of luminance values.
188			wt - integer weight to use for each value (usually 1 or -1).
189
190			returns - 0 on success, TM_E_* on error.
191			*/
192
193			extern int
194	greg	3.30	tmFixedMapping(TMstruct *tms, double expmult, double gamval, double Lddyn);
195	greg	3.11	/*
196			Assign a fixed, linear tone-mapping using the given multiplier,
197			which is the ratio of maximum output to uncalibrated input.
198			This mapping will be used in subsequent calls to tmMapPixels()
199			until a new tone mapping is computed.
200			Only the min. and max. values are used from the histogram.
201
202	greg	3.17	tms - tone mapping structure pointer.
203	greg	3.11	expmult - the fixed exposure multiplier to use.
204			gamval - display gamma response (0. for default).
205	greg	3.30	Ldmax - maximum display luminance in cd/m^2 (0. for default).
206	greg	3.18
207	greg	3.11	returns - 0 on success, TM_E_* on error.
208			*/
209
210			extern int
211	greg	3.17	tmComputeMapping(TMstruct *tms, double gamval, double Lddyn, double Ldmax);
212	greg	3.1	/*
213	greg	3.11	Compute tone mapping function from the current histogram.
214			This mapping will be used in subsequent calls to tmMapPixels()
215			until a new tone mapping is computed.
216			I.e., calls to tmAddHisto() have no immediate effect.
217	greg	3.1
218	greg	3.17	tms - tone mapping structure pointer.
219	greg	3.1	gamval - display gamma response (0. for default).
220			Lddyn - the display's dynamic range (0. for default).
221			Ldmax - maximum display luminance in cd/m^2 (0. for default).
222
223			returns - 0 on success, TM_E_* on failure.
224			*/
225
226			extern int
227	greg	3.26	tmMapPixels(TMstruct tms, uby8 ps, TMbright ls, uby8 cs, int len);
228	greg	3.1	/*
229			Apply tone mapping function to pixel values.
230
231	greg	3.17	tms - tone mapping structure pointer.
232	greg	3.1	ps - returned pixel values (Note 2).
233			ls - encoded luminance values.
234			cs - encoded chrominance values (Note 2).
235			len - number of pixels.
236
237			returns - 0 on success, TM_E_* on failure.
238			*/
239
240	greg	3.17	extern TMstruct *
241			tmDup(TMstruct *orig);
242	greg	3.3	/*
243	greg	3.17	Duplicate the given tone mapping into a new struct.
244	greg	3.3
245	greg	3.17	orig - tone mapping structure to duplicate.
246	greg	3.18
247	greg	3.17	returns - pointer to new struct, or NULL on error.
248	greg	3.3	*/
249
250	greg	3.1	extern void
251	greg	3.17	tmDone(TMstruct *tms);
252	greg	3.1	/*
253			Free data associated with the given tone mapping structure.
254
255			tms - tone mapping structure to free.
256			*/
257
258	greg	3.11	extern int
259	greg	3.22	tmCvGrays(TMstruct tms, TMbright ls, float *scan, int len);
260	greg	3.11	/*
261	greg	3.22	Convert gray float scanline to encoded luminance.
262	greg	3.11
263	greg	3.17	tms - tone mapping structure pointer.
264	greg	3.11	ls - returned encoded luminance values.
265			scan - input scanline.
266			len - scanline length.
267
268			returns - 0 on success, TM_E_* on error.
269			*/
270
271			extern int
272	greg	3.26	tmCvColors(TMstruct tms, TMbright ls, uby8 cs, COLOR scan, int len);
273	greg	3.11	/*
274	greg	3.22	Convert RGB/XYZ float scanline to encoded luminance and chrominance.
275	greg	3.11
276	greg	3.17	tms - tone mapping structure pointer.
277	greg	3.11	ls - returned encoded luminance values.
278	greg	3.22	cs - returned encoded chrominance values (Note 2).
279	greg	3.11	scan - input scanline.
280			len - scanline length.
281
282			returns - 0 on success, TM_E_* on error.
283			*/
284
285			extern int
286	greg	3.26	tmCvColrs(TMstruct tms, TMbright ls, uby8 cs, COLR scan, int len);
287	greg	3.11	/*
288			Convert RGBE/XYZE scanline to encoded luminance and chrominance.
289
290	greg	3.17	tms - tone mapping structure pointer.
291	greg	3.11	ls - returned encoded luminance values.
292			cs - returned encoded chrominance values (Note 2).
293			scan - input scanline.
294			len - scanline length.
295
296			returns - 0 on success, TM_E_* on error.
297			*/
298
299			extern int
300	greg	3.26	tmLoadPicture(TMstruct tms, TMbright lpp, uby8 cpp, int xp, int *yp,
301	greg	3.11	char fname, FILE fp);
302			/*
303			Load Radiance picture and convert to tone mapping representation.
304			Memory for the luminance and chroma arrays is allocated using
305			malloc(3), and should be freed with free(3) when no longer needed.
306			Calls tmSetSpace() to calibrate input color space.
307
308	greg	3.17	tms - tone mapping structure pointer.
309	greg	3.11	lpp - returned array of encoded luminances, picture ordering.
310			cpp - returned array of encoded chrominances (Note 2).
311			xp, yp - returned picture dimensions.
312			fname - picture file name.
313			fp - pointer to open file (Note 3).
314
315			returns - 0 on success, TM_E_* on failure.
316			*/
317
318			extern int
319	greg	3.26	tmMapPicture(uby8 *psp, int xp, int *yp, int flags,
320	greg	3.11	RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
321			char fname, FILE fp);
322			/*
323			Load and apply tone mapping to Radiance picture.
324			If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
325			calls pcond to perform the actual conversion, which takes
326			longer but gives access to all the TM_F_* features.
327			Memory for the final pixel array is allocated using malloc(3),
328			and should be freed with free(3) when it is no longer needed.
329
330			psp - returned array of tone mapped pixels, picture ordering.
331			xp, yp - returned picture dimensions.
332			flags - TM_F_* flags indicating what is to be done.
333			monpri - display monitor primaries (Note 1).
334			gamval - display gamma response.
335			Lddyn - the display's dynamic range (0. for default).
336			Ldmax - maximum display luminance in cd/m^2 (0. for default).
337			fname - picture file name.
338			fp - pointer to open file (Note 3).
339
340			returns - 0 on success, TM_E_* on failure.
341			*/
342
343	greg	3.15	extern int
344	greg	3.26	tmCvRGB48(TMstruct tms, TMbright ls, uby8 cs, uint16 (scan)[3],
345	greg	3.17	int len, double gv);
346	greg	3.15	/*
347			Convert 48-bit RGB scanline to encoded luminance and chrominance.
348
349	greg	3.17	tms - tone mapping structure pointer.
350	greg	3.15	ls - returned encoded luminance values.
351			cs - returned encoded chrominance values (Note 2).
352			scan - input scanline.
353			len - scanline length.
354			gv - input gamma value.
355
356			returns - 0 on success, TM_E_* on error.
357			*/
358
359			extern int
360	greg	3.17	tmCvGray16(TMstruct tms, TMbright ls, uint16 *scan, int len, double gv);
361	greg	3.15	/*
362			Convert 16-bit gray scanline to encoded luminance.
363
364	greg	3.17	tms - tone mapping structure pointer.
365	greg	3.15	ls - returned encoded luminance values.
366			scan - input scanline.
367			len - scanline length.
368			gv - input gamma value.
369	greg	3.4
370	greg	3.15	returns - 0 on success, TM_E_* on error.
371			*/
372	greg	3.4
373	greg	3.1	/** Notes **/
374			/*
375			General:
376
377			The usual sequence after calling tmInit() is to convert some
378			pixel values to chroma and luminance encodings, which can
379			be passed to tmAddHisto() to put into the tone mapping histogram.
380			This histogram is then used along with the display parameters
381	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
382	greg	3.1	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
383			is set.) The encoded chroma and luminance values may then be
384			passed to tmMapPixels() to apply the computed tone mapping in
385			a second pass.
386
387			Especially for RGBE colors in the same color space as the
388			target display, the conversion to chroma and luminance values
389			is fast enough that it may be recomputed on the second pass
390			if memory is at a premium. (Since the chroma values are only
391			used during final mapping, setting the cs parameter to TM_NOCHROM
392			on the first pass will save time.) Another memory saving option
393			if third and subsequent passes are not needed is to use the
394	greg	3.3	same array to store the mapped pixels as used to store
395	greg	3.1	the encoded chroma values. This way, only two extra bytes
396			for storing encoded luminances are required per pixel. This
397			is the method employed by tmMapPicture(), for example.
398			*/
399			/*
400			Note 1:
401
402			All RGBPRIMP values should be pointers to static structures.
403			I.e., the same pointer should be used for the same primaries,
404			and those primaries should not change from one call to the next.
405			This is because the routines use the pointer value to identify
406			computed conversion matrices, so the matrices do not have to be
407			rebuilt each time. If you are using the standard primaries,
408			use the standard primary pointer, stdprims.
409
410			To indicate a set of input primaries are actually CIE XYZ,
411			the TM_XYZPRIM macro may be passed. If the input primaries
412			are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
413			By default, the input primaries equal the monitor primaries
414			and the scalefactor is set to WHTEFFICACY in tmInit().
415			*/
416			/*
417			Note 2:
418
419			Chrominance is optional in most of these routines, whether
420			TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
421			TM_NOCHROMP for picture reading) indicates that returned
422			color values are not desired.
423
424			If TM_NOCHROM is passed to a mapping routine expecting chroma
425			input, it will do without it and return luminance channel
426			rather than RGB pixel values. Otherwise, the array for
427			returned pixel values may be the same array used to pass
428			encoded chrominances if no other mappings are desired.
429			*/
430			/*
431			Note 3:
432
433			Picture files may either be opened by the calling routine or by
434			the library function. If opened by the calling routine, the
435			pointer to the stream is passed, which may be a pipe or other
436			non-seekable input as it is only read once. It must be
437			positioned at the beginning when the function is called, and it
438			will be positioned at the end on return. It will not be closed.
439			If the passed stream pointer is TM_GETFILE, then the library
440			function will open the file, read its contents and close it
441			before returning, whether or not an error was encountered.
442			*/
443	greg	3.11
444			#ifdef __cplusplus
445			}
446			#endif
447	schorsch	3.13	#endif /* _RAD_TONEMAP_H_ */
448