src/common/tonemap.h

/* RCSid $Id: tonemap.h,v 3.31 2021/03/18 16:56:03 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 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 */
        void            *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 */
        void            *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 {
        void *          (*Init)(TMstruct *tms);
        void            (*NewSpace)(TMstruct *tms);
        void            (*Free)(void *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, void *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).
        Lddyn   -       the display's dynamic range (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:	3.32
Committed:	Sat Jan 15 16:57:46 2022 UTC (2 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad5R4, HEAD
Changes since 3.31:	+6 -9 lines
Log Message:	refactor: eliminated use of MEM_PTR and (char *) for untyped memory
#	User	Rev	Content
1	greg	3.32	/* RCSid $Id: tonemap.h,v 3.31 2021/03/18 16:56:03 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	greg	3.27	#ifndef HIST_TYP
67			#define HIST_TYP unsigned long
68			#endif
69	greg	3.29	#ifndef TMAP_TYP
70			#define TMAP_TYP uint16
71			#endif
72	greg	3.4
73	greg	3.1	extern char tmErrorMessage[]; / error messages */
74
75			typedef short TMbright; /* encoded luminance type */
76
77			/* basic tone mapping data structure */
78	greg	3.20	typedef struct {
79	greg	3.1	int flags; /* flags of what to do */
80			RGBPRIMP monpri; /* monitor RGB primaries */
81			double mongam; /* monitor gamma value (approx.) */
82			COLOR clf; /* computed luminance coefficients */
83	greg	3.4	int cdiv[3]; /* computed color divisors */
84	greg	3.1	RGBPRIMP inppri; /* current input primaries */
85			double inpsf; /* current input scalefactor */
86	greg	3.32	void inpdat; / current input client data */
87	greg	3.1	COLORMAT cmat; /* color conversion matrix */
88	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
89	greg	3.27	HIST_TYP histo; / input histogram */
90	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
91	greg	3.27	TMAP_TYP lumap; / computed luminance map */
92	greg	3.32	void pd[TM_MAXPKG]; / pointers to private data */
93	greg	3.18	int lastError; /* last error incurred */
94			const char lastFunc; / error-generating function name */
95	greg	3.17	} TMstruct;
96	greg	3.4
97			/* conversion package functions */
98			struct tmPackage {
99	greg	3.32	void * (Init)(TMstruct tms);
100	greg	3.17	void (NewSpace)(TMstruct tms);
101	greg	3.32	void (Free)(void pp);
102	greg	3.4	};
103			/* our list of conversion packages */
104			extern struct tmPackage *tmPkg[TM_MAXPKG];
105			extern int tmNumPkgs; /* number of registered packages */
106
107
108	greg	3.1	/** Useful Macros **/
109
110	greg	3.4	/* compute luminance from encoded value */
111	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
112	greg	3.1
113	greg	3.4	/* does tone mapping need color matrix? */
114			#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
115
116			/* register a conversion package */
117			#define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
118			(tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
119
120			/* get the specific package's data */
121			#define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
122
123
124	greg	3.1	/** Library Function Calls **/
125
126	greg	3.21	extern TMbright
127			tmCvLuminance(double lum);
128			/*
129			Convert a single luminance value to an encoded brightness value.
130			*/
131	greg	3.1
132	greg	3.22	extern int
133			tmCvLums(TMbright ls, float scan, int len);
134			/*
135			Convert luminance values to encoded brightness values using lookup.
136
137			ls - returned encoded luminance values.
138			scan - input scanline.
139			len - scanline length.
140
141			returns - 0 on success, TM_E_* on error.
142			*/
143
144	greg	3.17	extern TMstruct *
145	greg	3.1	tmInit(int flags, RGBPRIMP monpri, double gamval);
146			/*
147	greg	3.17	Allocate and initialize new tone mapping.
148	greg	3.1
149			flags - TM_F_* flags indicating what is to be done.
150			monpri - display monitor primaries (Note 1).
151			gamval - display gamma response (can be approximate).
152
153	greg	3.17	returns - new tone-mapping pointer, or NULL if no memory.
154	greg	3.1	*/
155
156			extern int
157	greg	3.32	tmSetSpace(TMstruct tms, RGBPRIMP pri, double sf, void dat);
158	greg	3.1	/*
159			Set color primaries and scale factor for incoming scanlines.
160
161	greg	3.17	tms - tone mapping structure pointer.
162	greg	3.1	pri - RGB color input primaries (Note 1).
163			sf - scale factor to get to luminance in cd/m^2.
164	greg	3.19	dat - application-specific data (NULL if not needed)
165	greg	3.1
166			returns - 0 on success, TM_E_* code on failure.
167			*/
168
169			extern void
170	greg	3.17	tmClearHisto(TMstruct *tms);
171	greg	3.1	/*
172			Clear histogram for current tone mapping.
173	greg	3.17
174			tms - tone mapping structure pointer.
175	greg	3.1	*/
176
177			extern int
178	greg	3.17	tmAddHisto(TMstruct tms, TMbright ls, int len, int wt);
179	greg	3.1	/*
180			Add brightness values to current histogram.
181
182	greg	3.17	tms - tone mapping structure pointer.
183	greg	3.1	ls - encoded luminance values.
184			len - number of luminance values.
185			wt - integer weight to use for each value (usually 1 or -1).
186
187			returns - 0 on success, TM_E_* on error.
188			*/
189
190			extern int
191	greg	3.30	tmFixedMapping(TMstruct *tms, double expmult, double gamval, double Lddyn);
192	greg	3.11	/*
193			Assign a fixed, linear tone-mapping using the given multiplier,
194			which is the ratio of maximum output to uncalibrated input.
195			This mapping will be used in subsequent calls to tmMapPixels()
196			until a new tone mapping is computed.
197			Only the min. and max. values are used from the histogram.
198
199	greg	3.17	tms - tone mapping structure pointer.
200	greg	3.11	expmult - the fixed exposure multiplier to use.
201			gamval - display gamma response (0. for default).
202	greg	3.31	Lddyn - the display's dynamic range (0. for default).
203	greg	3.18
204	greg	3.11	returns - 0 on success, TM_E_* on error.
205			*/
206
207			extern int
208	greg	3.17	tmComputeMapping(TMstruct *tms, double gamval, double Lddyn, double Ldmax);
209	greg	3.1	/*
210	greg	3.11	Compute tone mapping function from the current histogram.
211			This mapping will be used in subsequent calls to tmMapPixels()
212			until a new tone mapping is computed.
213			I.e., calls to tmAddHisto() have no immediate effect.
214	greg	3.1
215	greg	3.17	tms - tone mapping structure pointer.
216	greg	3.1	gamval - display gamma response (0. for default).
217			Lddyn - the display's dynamic range (0. for default).
218			Ldmax - maximum display luminance in cd/m^2 (0. for default).
219
220			returns - 0 on success, TM_E_* on failure.
221			*/
222
223			extern int
224	greg	3.26	tmMapPixels(TMstruct tms, uby8 ps, TMbright ls, uby8 cs, int len);
225	greg	3.1	/*
226			Apply tone mapping function to pixel values.
227
228	greg	3.17	tms - tone mapping structure pointer.
229	greg	3.1	ps - returned pixel values (Note 2).
230			ls - encoded luminance values.
231			cs - encoded chrominance values (Note 2).
232			len - number of pixels.
233
234			returns - 0 on success, TM_E_* on failure.
235			*/
236
237	greg	3.17	extern TMstruct *
238			tmDup(TMstruct *orig);
239	greg	3.3	/*
240	greg	3.17	Duplicate the given tone mapping into a new struct.
241	greg	3.3
242	greg	3.17	orig - tone mapping structure to duplicate.
243	greg	3.18
244	greg	3.17	returns - pointer to new struct, or NULL on error.
245	greg	3.3	*/
246
247	greg	3.1	extern void
248	greg	3.17	tmDone(TMstruct *tms);
249	greg	3.1	/*
250			Free data associated with the given tone mapping structure.
251
252			tms - tone mapping structure to free.
253			*/
254
255	greg	3.11	extern int
256	greg	3.22	tmCvGrays(TMstruct tms, TMbright ls, float *scan, int len);
257	greg	3.11	/*
258	greg	3.22	Convert gray float scanline to encoded luminance.
259	greg	3.11
260	greg	3.17	tms - tone mapping structure pointer.
261	greg	3.11	ls - returned encoded luminance values.
262			scan - input scanline.
263			len - scanline length.
264
265			returns - 0 on success, TM_E_* on error.
266			*/
267
268			extern int
269	greg	3.26	tmCvColors(TMstruct tms, TMbright ls, uby8 cs, COLOR scan, int len);
270	greg	3.11	/*
271	greg	3.22	Convert RGB/XYZ float scanline to encoded luminance and chrominance.
272	greg	3.11
273	greg	3.17	tms - tone mapping structure pointer.
274	greg	3.11	ls - returned encoded luminance values.
275	greg	3.22	cs - returned encoded chrominance values (Note 2).
276	greg	3.11	scan - input scanline.
277			len - scanline length.
278
279			returns - 0 on success, TM_E_* on error.
280			*/
281
282			extern int
283	greg	3.26	tmCvColrs(TMstruct tms, TMbright ls, uby8 cs, COLR scan, int len);
284	greg	3.11	/*
285			Convert RGBE/XYZE scanline to encoded luminance and chrominance.
286
287	greg	3.17	tms - tone mapping structure pointer.
288	greg	3.11	ls - returned encoded luminance values.
289			cs - returned encoded chrominance values (Note 2).
290			scan - input scanline.
291			len - scanline length.
292
293			returns - 0 on success, TM_E_* on error.
294			*/
295
296			extern int
297	greg	3.26	tmLoadPicture(TMstruct tms, TMbright lpp, uby8 cpp, int xp, int *yp,
298	greg	3.11	char fname, FILE fp);
299			/*
300			Load Radiance picture and convert to tone mapping representation.
301			Memory for the luminance and chroma arrays is allocated using
302			malloc(3), and should be freed with free(3) when no longer needed.
303			Calls tmSetSpace() to calibrate input color space.
304
305	greg	3.17	tms - tone mapping structure pointer.
306	greg	3.11	lpp - returned array of encoded luminances, picture ordering.
307			cpp - returned array of encoded chrominances (Note 2).
308			xp, yp - returned picture dimensions.
309			fname - picture file name.
310			fp - pointer to open file (Note 3).
311
312			returns - 0 on success, TM_E_* on failure.
313			*/
314
315			extern int
316	greg	3.26	tmMapPicture(uby8 *psp, int xp, int *yp, int flags,
317	greg	3.11	RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
318			char fname, FILE fp);
319			/*
320			Load and apply tone mapping to Radiance picture.
321			If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
322			calls pcond to perform the actual conversion, which takes
323			longer but gives access to all the TM_F_* features.
324			Memory for the final pixel array is allocated using malloc(3),
325			and should be freed with free(3) when it is no longer needed.
326
327			psp - returned array of tone mapped pixels, picture ordering.
328			xp, yp - returned picture dimensions.
329			flags - TM_F_* flags indicating what is to be done.
330			monpri - display monitor primaries (Note 1).
331			gamval - display gamma response.
332			Lddyn - the display's dynamic range (0. for default).
333			Ldmax - maximum display luminance in cd/m^2 (0. for default).
334			fname - picture file name.
335			fp - pointer to open file (Note 3).
336
337			returns - 0 on success, TM_E_* on failure.
338			*/
339
340	greg	3.15	extern int
341	greg	3.26	tmCvRGB48(TMstruct tms, TMbright ls, uby8 cs, uint16 (scan)[3],
342	greg	3.17	int len, double gv);
343	greg	3.15	/*
344			Convert 48-bit RGB scanline to encoded luminance and chrominance.
345
346	greg	3.17	tms - tone mapping structure pointer.
347	greg	3.15	ls - returned encoded luminance values.
348			cs - returned encoded chrominance values (Note 2).
349			scan - input scanline.
350			len - scanline length.
351			gv - input gamma value.
352
353			returns - 0 on success, TM_E_* on error.
354			*/
355
356			extern int
357	greg	3.17	tmCvGray16(TMstruct tms, TMbright ls, uint16 *scan, int len, double gv);
358	greg	3.15	/*
359			Convert 16-bit gray scanline to encoded luminance.
360
361	greg	3.17	tms - tone mapping structure pointer.
362	greg	3.15	ls - returned encoded luminance values.
363			scan - input scanline.
364			len - scanline length.
365			gv - input gamma value.
366	greg	3.4
367	greg	3.15	returns - 0 on success, TM_E_* on error.
368			*/
369	greg	3.4
370	greg	3.1	/** Notes **/
371			/*
372			General:
373
374			The usual sequence after calling tmInit() is to convert some
375			pixel values to chroma and luminance encodings, which can
376			be passed to tmAddHisto() to put into the tone mapping histogram.
377			This histogram is then used along with the display parameters
378	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
379	greg	3.1	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
380			is set.) The encoded chroma and luminance values may then be
381			passed to tmMapPixels() to apply the computed tone mapping in
382			a second pass.
383
384			Especially for RGBE colors in the same color space as the
385			target display, the conversion to chroma and luminance values
386			is fast enough that it may be recomputed on the second pass
387			if memory is at a premium. (Since the chroma values are only
388			used during final mapping, setting the cs parameter to TM_NOCHROM
389			on the first pass will save time.) Another memory saving option
390			if third and subsequent passes are not needed is to use the
391	greg	3.3	same array to store the mapped pixels as used to store
392	greg	3.1	the encoded chroma values. This way, only two extra bytes
393			for storing encoded luminances are required per pixel. This
394			is the method employed by tmMapPicture(), for example.
395			*/
396			/*
397			Note 1:
398
399			All RGBPRIMP values should be pointers to static structures.
400			I.e., the same pointer should be used for the same primaries,
401			and those primaries should not change from one call to the next.
402			This is because the routines use the pointer value to identify
403			computed conversion matrices, so the matrices do not have to be
404			rebuilt each time. If you are using the standard primaries,
405			use the standard primary pointer, stdprims.
406
407			To indicate a set of input primaries are actually CIE XYZ,
408			the TM_XYZPRIM macro may be passed. If the input primaries
409			are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
410			By default, the input primaries equal the monitor primaries
411			and the scalefactor is set to WHTEFFICACY in tmInit().
412			*/
413			/*
414			Note 2:
415
416			Chrominance is optional in most of these routines, whether
417			TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
418			TM_NOCHROMP for picture reading) indicates that returned
419			color values are not desired.
420
421			If TM_NOCHROM is passed to a mapping routine expecting chroma
422			input, it will do without it and return luminance channel
423			rather than RGB pixel values. Otherwise, the array for
424			returned pixel values may be the same array used to pass
425			encoded chrominances if no other mappings are desired.
426			*/
427			/*
428			Note 3:
429
430			Picture files may either be opened by the calling routine or by
431			the library function. If opened by the calling routine, the
432			pointer to the stream is passed, which may be a pipe or other
433			non-seekable input as it is only read once. It must be
434			positioned at the beginning when the function is called, and it
435			will be positioned at the end on return. It will not be closed.
436			If the passed stream pointer is TM_GETFILE, then the library
437			function will open the file, read its contents and close it
438			before returning, whether or not an error was encountered.
439			*/
440	greg	3.11
441			#ifdef __cplusplus
442			}
443			#endif
444	schorsch	3.13	#endif /* _RAD_TONEMAP_H_ */
445