src/common/tonemap.h

/* RCSid $Id: tonemap.h,v 3.26 2011/05/20 02:06:38 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_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
#define TMAP_TYP        unsigned short

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);
/*
        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).

        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:	3.27
Committed:	Wed Jan 6 19:25:00 2021 UTC (4 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.26:	+8 -4 lines
Log Message:	refactor: added defined types for histogram and map tables
#	User	Rev	Content
1	greg	3.27	/* RCSid $Id: tonemap.h,v 3.26 2011/05/20 02:06:38 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	3.4	#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	greg	3.27	#ifndef HIST_TYP
68			#define HIST_TYP unsigned long
69			#endif
70			#define TMAP_TYP unsigned short
71	greg	3.4
72	greg	3.1	extern char tmErrorMessage[]; / error messages */
73
74			typedef short TMbright; /* encoded luminance type */
75
76			/* basic tone mapping data structure */
77	greg	3.20	typedef struct {
78	greg	3.1	int flags; /* flags of what to do */
79			RGBPRIMP monpri; /* monitor RGB primaries */
80			double mongam; /* monitor gamma value (approx.) */
81			COLOR clf; /* computed luminance coefficients */
82	greg	3.4	int cdiv[3]; /* computed color divisors */
83	greg	3.1	RGBPRIMP inppri; /* current input primaries */
84			double inpsf; /* current input scalefactor */
85	greg	3.19	MEM_PTR inpdat; /* current input client data */
86	greg	3.1	COLORMAT cmat; /* color conversion matrix */
87	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
88	greg	3.27	HIST_TYP histo; / input histogram */
89	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
90	greg	3.27	TMAP_TYP lumap; / computed luminance map */
91	greg	3.4	MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
92	greg	3.18	int lastError; /* last error incurred */
93			const char lastFunc; / error-generating function name */
94	greg	3.17	} TMstruct;
95	greg	3.4
96			/* conversion package functions */
97			struct tmPackage {
98	greg	3.17	MEM_PTR (Init)(TMstruct tms);
99			void (NewSpace)(TMstruct tms);
100	greg	3.4	void (*Free)(MEM_PTR pp);
101			};
102			/* our list of conversion packages */
103			extern struct tmPackage *tmPkg[TM_MAXPKG];
104			extern int tmNumPkgs; /* number of registered packages */
105
106
107	greg	3.1	/** Useful Macros **/
108
109	greg	3.4	/* compute luminance from encoded value */
110	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
111	greg	3.1
112	greg	3.4	/* does tone mapping need color matrix? */
113			#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
114
115			/* register a conversion package */
116			#define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
117			(tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
118
119			/* get the specific package's data */
120			#define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
121
122
123	greg	3.1	/** Library Function Calls **/
124
125	greg	3.21	extern TMbright
126			tmCvLuminance(double lum);
127			/*
128			Convert a single luminance value to an encoded brightness value.
129			*/
130	greg	3.1
131	greg	3.22	extern int
132			tmCvLums(TMbright ls, float scan, int len);
133			/*
134			Convert luminance values to encoded brightness values using lookup.
135
136			ls - returned encoded luminance values.
137			scan - input scanline.
138			len - scanline length.
139
140			returns - 0 on success, TM_E_* on error.
141			*/
142
143	greg	3.17	extern TMstruct *
144	greg	3.1	tmInit(int flags, RGBPRIMP monpri, double gamval);
145			/*
146	greg	3.17	Allocate and initialize new tone mapping.
147	greg	3.1
148			flags - TM_F_* flags indicating what is to be done.
149			monpri - display monitor primaries (Note 1).
150			gamval - display gamma response (can be approximate).
151
152	greg	3.17	returns - new tone-mapping pointer, or NULL if no memory.
153	greg	3.1	*/
154
155			extern int
156	greg	3.19	tmSetSpace(TMstruct *tms, RGBPRIMP pri, double sf, MEM_PTR dat);
157	greg	3.1	/*
158			Set color primaries and scale factor for incoming scanlines.
159
160	greg	3.17	tms - tone mapping structure pointer.
161	greg	3.1	pri - RGB color input primaries (Note 1).
162			sf - scale factor to get to luminance in cd/m^2.
163	greg	3.19	dat - application-specific data (NULL if not needed)
164	greg	3.1
165			returns - 0 on success, TM_E_* code on failure.
166			*/
167
168			extern void
169	greg	3.17	tmClearHisto(TMstruct *tms);
170	greg	3.1	/*
171			Clear histogram for current tone mapping.
172	greg	3.17
173			tms - tone mapping structure pointer.
174	greg	3.1	*/
175
176			extern int
177	greg	3.17	tmAddHisto(TMstruct tms, TMbright ls, int len, int wt);
178	greg	3.1	/*
179			Add brightness values to current histogram.
180
181	greg	3.17	tms - tone mapping structure pointer.
182	greg	3.1	ls - encoded luminance values.
183			len - number of luminance values.
184			wt - integer weight to use for each value (usually 1 or -1).
185
186			returns - 0 on success, TM_E_* on error.
187			*/
188
189			extern int
190	greg	3.17	tmFixedMapping(TMstruct *tms, double expmult, double gamval);
191	greg	3.11	/*
192			Assign a fixed, linear tone-mapping using the given multiplier,
193			which is the ratio of maximum output to uncalibrated input.
194			This mapping will be used in subsequent calls to tmMapPixels()
195			until a new tone mapping is computed.
196			Only the min. and max. values are used from the histogram.
197
198	greg	3.17	tms - tone mapping structure pointer.
199	greg	3.11	expmult - the fixed exposure multiplier to use.
200			gamval - display gamma response (0. for default).
201	greg	3.18
202	greg	3.11	returns - 0 on success, TM_E_* on error.
203			*/
204
205			extern int
206	greg	3.17	tmComputeMapping(TMstruct *tms, double gamval, double Lddyn, double Ldmax);
207	greg	3.1	/*
208	greg	3.11	Compute tone mapping function from the current histogram.
209			This mapping will be used in subsequent calls to tmMapPixels()
210			until a new tone mapping is computed.
211			I.e., calls to tmAddHisto() have no immediate effect.
212	greg	3.1
213	greg	3.17	tms - tone mapping structure pointer.
214	greg	3.1	gamval - display gamma response (0. for default).
215			Lddyn - the display's dynamic range (0. for default).
216			Ldmax - maximum display luminance in cd/m^2 (0. for default).
217
218			returns - 0 on success, TM_E_* on failure.
219			*/
220
221			extern int
222	greg	3.26	tmMapPixels(TMstruct tms, uby8 ps, TMbright ls, uby8 cs, int len);
223	greg	3.1	/*
224			Apply tone mapping function to pixel values.
225
226	greg	3.17	tms - tone mapping structure pointer.
227	greg	3.1	ps - returned pixel values (Note 2).
228			ls - encoded luminance values.
229			cs - encoded chrominance values (Note 2).
230			len - number of pixels.
231
232			returns - 0 on success, TM_E_* on failure.
233			*/
234
235	greg	3.17	extern TMstruct *
236			tmDup(TMstruct *orig);
237	greg	3.3	/*
238	greg	3.17	Duplicate the given tone mapping into a new struct.
239	greg	3.3
240	greg	3.17	orig - tone mapping structure to duplicate.
241	greg	3.18
242	greg	3.17	returns - pointer to new struct, or NULL on error.
243	greg	3.3	*/
244
245	greg	3.1	extern void
246	greg	3.17	tmDone(TMstruct *tms);
247	greg	3.1	/*
248			Free data associated with the given tone mapping structure.
249
250			tms - tone mapping structure to free.
251			*/
252
253	greg	3.11	extern int
254	greg	3.22	tmCvGrays(TMstruct tms, TMbright ls, float *scan, int len);
255	greg	3.11	/*
256	greg	3.22	Convert gray float scanline to encoded luminance.
257	greg	3.11
258	greg	3.17	tms - tone mapping structure pointer.
259	greg	3.11	ls - returned encoded luminance values.
260			scan - input scanline.
261			len - scanline length.
262
263			returns - 0 on success, TM_E_* on error.
264			*/
265
266			extern int
267	greg	3.26	tmCvColors(TMstruct tms, TMbright ls, uby8 cs, COLOR scan, int len);
268	greg	3.11	/*
269	greg	3.22	Convert RGB/XYZ float scanline to encoded luminance and chrominance.
270	greg	3.11
271	greg	3.17	tms - tone mapping structure pointer.
272	greg	3.11	ls - returned encoded luminance values.
273	greg	3.22	cs - returned encoded chrominance values (Note 2).
274	greg	3.11	scan - input scanline.
275			len - scanline length.
276
277			returns - 0 on success, TM_E_* on error.
278			*/
279
280			extern int
281	greg	3.26	tmCvColrs(TMstruct tms, TMbright ls, uby8 cs, COLR scan, int len);
282	greg	3.11	/*
283			Convert RGBE/XYZE scanline to encoded luminance and chrominance.
284
285	greg	3.17	tms - tone mapping structure pointer.
286	greg	3.11	ls - returned encoded luminance values.
287			cs - returned encoded chrominance values (Note 2).
288			scan - input scanline.
289			len - scanline length.
290
291			returns - 0 on success, TM_E_* on error.
292			*/
293
294			extern int
295	greg	3.26	tmLoadPicture(TMstruct tms, TMbright lpp, uby8 cpp, int xp, int *yp,
296	greg	3.11	char fname, FILE fp);
297			/*
298			Load Radiance picture and convert to tone mapping representation.
299			Memory for the luminance and chroma arrays is allocated using
300			malloc(3), and should be freed with free(3) when no longer needed.
301			Calls tmSetSpace() to calibrate input color space.
302
303	greg	3.17	tms - tone mapping structure pointer.
304	greg	3.11	lpp - returned array of encoded luminances, picture ordering.
305			cpp - returned array of encoded chrominances (Note 2).
306			xp, yp - returned picture dimensions.
307			fname - picture file name.
308			fp - pointer to open file (Note 3).
309
310			returns - 0 on success, TM_E_* on failure.
311			*/
312
313			extern int
314	greg	3.26	tmMapPicture(uby8 *psp, int xp, int *yp, int flags,
315	greg	3.11	RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
316			char fname, FILE fp);
317			/*
318			Load and apply tone mapping to Radiance picture.
319			If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
320			calls pcond to perform the actual conversion, which takes
321			longer but gives access to all the TM_F_* features.
322			Memory for the final pixel array is allocated using malloc(3),
323			and should be freed with free(3) when it is no longer needed.
324
325			psp - returned array of tone mapped pixels, picture ordering.
326			xp, yp - returned picture dimensions.
327			flags - TM_F_* flags indicating what is to be done.
328			monpri - display monitor primaries (Note 1).
329			gamval - display gamma response.
330			Lddyn - the display's dynamic range (0. for default).
331			Ldmax - maximum display luminance in cd/m^2 (0. for default).
332			fname - picture file name.
333			fp - pointer to open file (Note 3).
334
335			returns - 0 on success, TM_E_* on failure.
336			*/
337
338	greg	3.15	extern int
339	greg	3.26	tmCvRGB48(TMstruct tms, TMbright ls, uby8 cs, uint16 (scan)[3],
340	greg	3.17	int len, double gv);
341	greg	3.15	/*
342			Convert 48-bit RGB scanline to encoded luminance and chrominance.
343
344	greg	3.17	tms - tone mapping structure pointer.
345	greg	3.15	ls - returned encoded luminance values.
346			cs - returned encoded chrominance values (Note 2).
347			scan - input scanline.
348			len - scanline length.
349			gv - input gamma value.
350
351			returns - 0 on success, TM_E_* on error.
352			*/
353
354			extern int
355	greg	3.17	tmCvGray16(TMstruct tms, TMbright ls, uint16 *scan, int len, double gv);
356	greg	3.15	/*
357			Convert 16-bit gray scanline to encoded luminance.
358
359	greg	3.17	tms - tone mapping structure pointer.
360	greg	3.15	ls - returned encoded luminance values.
361			scan - input scanline.
362			len - scanline length.
363			gv - input gamma value.
364	greg	3.4
365	greg	3.15	returns - 0 on success, TM_E_* on error.
366			*/
367	greg	3.4
368	greg	3.1	/** Notes **/
369			/*
370			General:
371
372			The usual sequence after calling tmInit() is to convert some
373			pixel values to chroma and luminance encodings, which can
374			be passed to tmAddHisto() to put into the tone mapping histogram.
375			This histogram is then used along with the display parameters
376	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
377	greg	3.1	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
378			is set.) The encoded chroma and luminance values may then be
379			passed to tmMapPixels() to apply the computed tone mapping in
380			a second pass.
381
382			Especially for RGBE colors in the same color space as the
383			target display, the conversion to chroma and luminance values
384			is fast enough that it may be recomputed on the second pass
385			if memory is at a premium. (Since the chroma values are only
386			used during final mapping, setting the cs parameter to TM_NOCHROM
387			on the first pass will save time.) Another memory saving option
388			if third and subsequent passes are not needed is to use the
389	greg	3.3	same array to store the mapped pixels as used to store
390	greg	3.1	the encoded chroma values. This way, only two extra bytes
391			for storing encoded luminances are required per pixel. This
392			is the method employed by tmMapPicture(), for example.
393			*/
394			/*
395			Note 1:
396
397			All RGBPRIMP values should be pointers to static structures.
398			I.e., the same pointer should be used for the same primaries,
399			and those primaries should not change from one call to the next.
400			This is because the routines use the pointer value to identify
401			computed conversion matrices, so the matrices do not have to be
402			rebuilt each time. If you are using the standard primaries,
403			use the standard primary pointer, stdprims.
404
405			To indicate a set of input primaries are actually CIE XYZ,
406			the TM_XYZPRIM macro may be passed. If the input primaries
407			are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
408			By default, the input primaries equal the monitor primaries
409			and the scalefactor is set to WHTEFFICACY in tmInit().
410			*/
411			/*
412			Note 2:
413
414			Chrominance is optional in most of these routines, whether
415			TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
416			TM_NOCHROMP for picture reading) indicates that returned
417			color values are not desired.
418
419			If TM_NOCHROM is passed to a mapping routine expecting chroma
420			input, it will do without it and return luminance channel
421			rather than RGB pixel values. Otherwise, the array for
422			returned pixel values may be the same array used to pass
423			encoded chrominances if no other mappings are desired.
424			*/
425			/*
426			Note 3:
427
428			Picture files may either be opened by the calling routine or by
429			the library function. If opened by the calling routine, the
430			pointer to the stream is passed, which may be a pipe or other
431			non-seekable input as it is only read once. It must be
432			positioned at the beginning when the function is called, and it
433			will be positioned at the end on return. It will not be closed.
434			If the passed stream pointer is TM_GETFILE, then the library
435			function will open the file, read its contents and close it
436			before returning, whether or not an error was encountered.
437			*/
438	greg	3.11
439			#ifdef __cplusplus
440			}
441			#endif
442	schorsch	3.13	#endif /* _RAD_TONEMAP_H_ */
443