src/common/tonemap.h

/* RCSid: $Id$ */
/*
 * Header file for tone mapping functions.
 *
 * Include after "color.h"
 */

/* ====================================================================
 * The Radiance Software License, Version 1.0
 *
 * Copyright (c) 1990 - 2002 The Regents of the University of California,
 * through Lawrence Berkeley National Laboratory.   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *         notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *           if any, must include the following acknowledgment:
 *             "This product includes Radiance software
 *                 (http://radsite.lbl.gov/)
 *                 developed by the Lawrence Berkeley National Laboratory
 *               (http://www.lbl.gov/)."
 *       Alternately, this acknowledgment may appear in the software itself,
 *       if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
 *       and "The Regents of the University of California" must
 *       not be used to endorse or promote products derived from this
 *       software without prior written permission. For written
 *       permission, please contact [email protected].
 *
 * 5. Products derived from this software may not be called "Radiance",
 *       nor may "Radiance" appear in their name, without prior written
 *       permission of Lawrence Berkeley National Laboratory.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
 * information on Lawrence Berkeley National Laboratory, please see
 * <http://www.lbl.gov/>.
 */

#ifdef __cplusplus
extern "C" {
#endif

/****    Argument Macros    ****/
                                /* Flags of what to do */
#define TM_F_HCONTR     01              /* human contrast sensitivity */
#define TM_F_MESOPIC    02              /* mesopic color sensitivity */
#define TM_F_LINEAR     04              /* linear brightness mapping */
#define TM_F_ACUITY     010             /* acuity adjustment */
#define TM_F_VEIL       020             /* veiling glare */
#define TM_F_CWEIGHT    040             /* center weighting */
#define TM_F_FOVEAL     0100            /* use foveal sample size */
#define TM_F_BW         0200            /* luminance only */
#define TM_F_NOSTDERR   0400            /* don't report errors to stderr */
                                /* combined modes */
#define TM_F_CAMERA     0
#define TM_F_HUMAN      (TM_F_HCONTR|TM_F_MESOPIC|TM_F_VEIL|\
                                TM_F_ACUITY|TM_F_FOVEAL)
#define TM_F_UNIMPL     (TM_F_CWEIGHT|TM_F_VEIL|TM_F_ACUITY|TM_F_FOVEAL)

                                /* special pointer values */
#define TM_XYZPRIM      (RGBPRIMP)NULL  /* indicate XYZ primaries (Note 1) */
#define TM_NOCHROM      (BYTE *)NULL    /* indicate no chrominance */
#define TM_NOCHROMP     (BYTE **)NULL   /* indicate no chrominances */
#define TM_GETFILE      (FILE *)NULL    /* indicate file must be opened */


/****    Error Return Values    ****/

#define TM_E_OK         0               /* normal return status */
#define TM_E_NOMEM      1               /* out of memory */
#define TM_E_ILLEGAL    2               /* illegal argument value */
#define TM_E_TMINVAL    3               /* no valid tone mapping */
#define TM_E_TMFAIL     4               /* cannot compute tone mapping */
#define TM_E_BADFILE    5               /* cannot open or understand file */
#define TM_E_CODERR1    6               /* code consistency error 1 */
#define TM_E_CODERR2    7               /* code consistency error 2 */


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

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

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

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


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

#ifndef MEM_PTR
#define MEM_PTR         void *
#endif

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

typedef short   TMbright;               /* encoded luminance type */

                                /* basic tone mapping data structure */
extern struct tmStruct {
        int             flags;          /* flags of what to do */
        RGBPRIMP        monpri;         /* monitor RGB primaries */
        double          mongam;         /* monitor gamma value (approx.) */
        COLOR           clf;            /* computed luminance coefficients */
        int             cdiv[3];        /* computed color divisors */
        RGBPRIMP        inppri;         /* current input primaries */
        double          inpsf;          /* current input scalefactor */
        COLORMAT        cmat;           /* color conversion matrix */
        TMbright        hbrmin, hbrmax; /* histogram brightness limits */       
        int             *histo;         /* input histogram */
        TMbright        mbrmin, mbrmax; /* mapped brightness limits */
        unsigned short  *lumap;         /* computed luminance map */
        struct tmStruct *tmprev;        /* previous tone mapping */
        MEM_PTR         pd[TM_MAXPKG];  /* pointers to private data */
}       *tmTop;                 /* current tone mapping stack */

                                /* conversion package functions */
#ifdef  NOPROTO
struct tmPackage {
        MEM_PTR         (*Init)();      /* initialize private data */
        void            (*NewSpace)();  /* new input color space (optional) */
        void            (*Free)();      /* free private data */
};
#else
struct tmPackage {
        MEM_PTR         (*Init)(struct tmStruct *tms);
        void            (*NewSpace)(struct tmStruct *tms);
        void            (*Free)(MEM_PTR pp);
};
#endif
                                /* 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    ****/

#ifdef  NOPROTO

extern struct tmStruct  *tmInit(), *tmPop(), *tmDup();
extern int      tmSetSpace(), tmPull(), tmPush();
extern void     tmClearHisto(), tmDone();
extern int      tmAddHisto();
extern int      tmFixedMapping(), tmComputeMapping(), tmMapPixels();
extern int      tmCvColors(), tmCvGrays(), tmCvColrs();
extern int      tmLoadPicture(), tmMapPicture();

#else

extern struct tmStruct *
tmInit(int flags, RGBPRIMP monpri, double gamval);
/*
        Initialize new tone mapping and push it onto stack.

        flags   -       TM_F_* flags indicating what is to be done.
        monpri  -       display monitor primaries (Note 1).
        gamval  -       display gamma response (can be approximate).

        returns -       new tmTop, or NULL if insufficient memory.
*/

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

        pri     -       RGB color input primaries (Note 1).
        sf      -       scale factor to get to luminance in cd/m^2.

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

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

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

        ls      -       encoded luminance values.
        len     -       number of luminance values.
        wt      -       integer weight to use for each value (usually 1 or -1).

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

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

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

        gamval  -       display gamma response (0. for default).
        Lddyn   -       the display's dynamic range (0. for default).
        Ldmax   -       maximum display luminance in cd/m^2 (0. for default).

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

extern int
tmMapPixels(BYTE *ps, TMbright *ls, BYTE *cs, int len);
/*
        Apply tone mapping function to pixel values.

        ps      -       returned pixel values (Note 2).
        ls      -       encoded luminance values.
        cs      -       encoded chrominance values (Note 2).
        len     -       number of pixels.

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

extern struct tmStruct *
tmPop(void);
/*
        Pops current tone mapping from stack.

        returns -       pointer to tone mapping structure, or NULL if none.
*/

extern int
tmPull(struct tmStruct *tms);
/*
        Pull tone mapping from anywhere in stack.

        tms     -       tone mapping structure to find.

        returns -       1 if found in stack, 0 otherwise.
*/

extern int
tmPush(struct tmStruct *tms);
/*
        Make tone mapping active by (pulling it and) pushing it to the top.

        tms     -       initialized tone mapping structure.

        returns -       0 on success, TM_E_* if tms is invalid.
*/

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

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

extern void
tmDone(struct tmStruct *tms);
/*
        Free data associated with the given tone mapping structure.
        Calls tmPull() first to remove it from the stack if present.
        The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
        all have the same effect, which is to remove and free
        the current tone mapping.

        tms     -       tone mapping structure to free.
*/

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

        ls      -       returned encoded luminance values.
        cs      -       returned encoded chrominance values (Note 2).
        scan    -       input scanline.
        len     -       scanline length.

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

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

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

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

extern int
tmCvColrs(TMbright *ls, BYTE *cs, COLR *scan, int len);
/*
        Convert RGBE/XYZE scanline to encoded luminance and chrominance.

        ls      -       returned encoded luminance values.
        cs      -       returned encoded chrominance values (Note 2).
        scan    -       input scanline.
        len     -       scanline length.

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

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

        lpp     -       returned array of encoded luminances, picture ordering.
        cpp     -       returned array of encoded chrominances (Note 2).
        xp, yp  -       returned picture dimensions.
        fname   -       picture file name.
        fp      -       pointer to open file (Note 3).

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

extern int
tmMapPicture(BYTE **psp, int *xp, int *yp, int flags,
                RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
                char *fname, FILE *fp);
/*
        Load and apply tone mapping to Radiance picture.
        Stack is restored to its original state upon return.
        If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
        calls pcond to perform the actual conversion, which takes
        longer but gives access to all the TM_F_* features.
        Memory for the final pixel array is allocated using malloc(3),
        and should be freed with free(3) when it is no longer needed.

        psp     -       returned array of tone mapped pixels, picture ordering.
        xp, yp  -       returned picture dimensions.
        flags   -       TM_F_* flags indicating what is to be done.
        monpri  -       display monitor primaries (Note 1).
        gamval  -       display gamma response.
        Lddyn   -       the display's dynamic range (0. for default).
        Ldmax   -       maximum display luminance in cd/m^2 (0. for default).
        fname   -       picture file name.
        fp      -       pointer to open file (Note 3).

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

#endif


/****    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
Revision:	3.11
Committed:	Sat Feb 22 02:07:22 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 3.10:	+173 -82 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	User	Rev	Content
1	greg	3.11	/* RCSid: $Id$ */
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
8	greg	3.11	/* ====================================================================
9			* The Radiance Software License, Version 1.0
10			*
11			* Copyright (c) 1990 - 2002 The Regents of the University of California,
12			* through Lawrence Berkeley National Laboratory. All rights reserved.
13			*
14			* Redistribution and use in source and binary forms, with or without
15			* modification, are permitted provided that the following conditions
16			* are met:
17			*
18			* 1. Redistributions of source code must retain the above copyright
19			* notice, this list of conditions and the following disclaimer.
20			*
21			* 2. Redistributions in binary form must reproduce the above copyright
22			* notice, this list of conditions and the following disclaimer in
23			* the documentation and/or other materials provided with the
24			* distribution.
25			*
26			* 3. The end-user documentation included with the redistribution,
27			* if any, must include the following acknowledgment:
28			* "This product includes Radiance software
29			* (http://radsite.lbl.gov/)
30			* developed by the Lawrence Berkeley National Laboratory
31			* (http://www.lbl.gov/)."
32			* Alternately, this acknowledgment may appear in the software itself,
33			* if and wherever such third-party acknowledgments normally appear.
34			*
35			* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
36			* and "The Regents of the University of California" must
37			* not be used to endorse or promote products derived from this
38			* software without prior written permission. For written
39			* permission, please contact [email protected].
40			*
41			* 5. Products derived from this software may not be called "Radiance",
42			* nor may "Radiance" appear in their name, without prior written
43			* permission of Lawrence Berkeley National Laboratory.
44			*
45			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
46			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
47			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
48			* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
49			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
52			* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
53			* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
54			* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
55			* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56			* SUCH DAMAGE.
57			* ====================================================================
58			*
59			* This software consists of voluntary contributions made by many
60			* individuals on behalf of Lawrence Berkeley National Laboratory. For more
61			* information on Lawrence Berkeley National Laboratory, please see
62			* <http://www.lbl.gov/>.
63			*/
64
65			#ifdef __cplusplus
66			extern "C" {
67			#endif
68	greg	3.4
69	greg	3.1	/** Argument Macros **/
70			/* Flags of what to do */
71			#define TM_F_HCONTR 01 /* human contrast sensitivity */
72			#define TM_F_MESOPIC 02 /* mesopic color sensitivity */
73			#define TM_F_LINEAR 04 /* linear brightness mapping */
74			#define TM_F_ACUITY 010 /* acuity adjustment */
75			#define TM_F_VEIL 020 /* veiling glare */
76			#define TM_F_CWEIGHT 040 /* center weighting */
77			#define TM_F_FOVEAL 0100 /* use foveal sample size */
78			#define TM_F_BW 0200 /* luminance only */
79	greg	3.2	#define TM_F_NOSTDERR 0400 /* don't report errors to stderr */
80	greg	3.1	/* combined modes */
81			#define TM_F_CAMERA 0
82			#define TM_F_HUMAN (TM_F_HCONTR\|TM_F_MESOPIC\|TM_F_VEIL\|\
83			TM_F_ACUITY\|TM_F_FOVEAL)
84			#define TM_F_UNIMPL (TM_F_CWEIGHT\|TM_F_VEIL\|TM_F_ACUITY\|TM_F_FOVEAL)
85
86			/* special pointer values */
87			#define TM_XYZPRIM (RGBPRIMP)NULL /* indicate XYZ primaries (Note 1) */
88			#define TM_NOCHROM (BYTE )NULL / indicate no chrominance */
89			#define TM_NOCHROMP (BYTE *)NULL / indicate no chrominances */
90			#define TM_GETFILE (FILE )NULL / indicate file must be opened */
91	gwlarson	3.8
92	greg	3.1
93			/** Error Return Values **/
94
95			#define TM_E_OK 0 /* normal return status */
96			#define TM_E_NOMEM 1 /* out of memory */
97			#define TM_E_ILLEGAL 2 /* illegal argument value */
98			#define TM_E_TMINVAL 3 /* no valid tone mapping */
99			#define TM_E_TMFAIL 4 /* cannot compute tone mapping */
100			#define TM_E_BADFILE 5 /* cannot open or understand file */
101	greg	3.4	#define TM_E_CODERR1 6 /* code consistency error 1 */
102			#define TM_E_CODERR2 7 /* code consistency error 2 */
103	greg	3.1
104	greg	3.4
105	greg	3.1	/** Conversion Constants and Table Sizes **/
106
107			#define TM_BRTSCALE 128 /* brightness scale factor (integer) */
108
109	gwlarson	3.10	#define TM_NOBRT (-1<<15) /* bogus brightness value */
110	greg	3.11	#define TM_NOLUM (1e-17) /* ridiculously small luminance */
111	gwlarson	3.10
112	greg	3.4	#define TM_MAXPKG 8 /* maximum number of color formats */
113	greg	3.1
114
115	greg	3.4	/** Global Data Types and Structures **/
116
117			#ifndef MEM_PTR
118			#define MEM_PTR void *
119			#endif
120
121	greg	3.1	extern char tmErrorMessage[]; / error messages */
122	gregl	3.6	extern int tmLastError; /* last error incurred by library */
123			extern char tmLastFunction; / error-generating function name */
124	greg	3.1
125			typedef short TMbright; /* encoded luminance type */
126
127			/* basic tone mapping data structure */
128			extern struct tmStruct {
129			int flags; /* flags of what to do */
130			RGBPRIMP monpri; /* monitor RGB primaries */
131			double mongam; /* monitor gamma value (approx.) */
132			COLOR clf; /* computed luminance coefficients */
133	greg	3.4	int cdiv[3]; /* computed color divisors */
134	greg	3.1	RGBPRIMP inppri; /* current input primaries */
135			double inpsf; /* current input scalefactor */
136			COLORMAT cmat; /* color conversion matrix */
137	gregl	3.7	TMbright hbrmin, hbrmax; /* histogram brightness limits */
138	greg	3.1	int histo; / input histogram */
139	gregl	3.7	TMbright mbrmin, mbrmax; /* mapped brightness limits */
140	greg	3.1	unsigned short lumap; / computed luminance map */
141			struct tmStruct tmprev; / previous tone mapping */
142	greg	3.4	MEM_PTR pd[TM_MAXPKG]; /* pointers to private data */
143	greg	3.1	} tmTop; / current tone mapping stack */
144	greg	3.4
145			/* conversion package functions */
146			#ifdef NOPROTO
147			struct tmPackage {
148			MEM_PTR (Init)(); / initialize private data */
149			void (NewSpace)(); / new input color space (optional) */
150			void (Free)(); / free private data */
151			};
152			#else
153			struct tmPackage {
154			MEM_PTR (Init)(struct tmStruct tms);
155	greg	3.11	void (NewSpace)(struct tmStruct tms);
156	greg	3.4	void (*Free)(MEM_PTR pp);
157			};
158			#endif
159			/* our list of conversion packages */
160			extern struct tmPackage *tmPkg[TM_MAXPKG];
161			extern int tmNumPkgs; /* number of registered packages */
162
163
164	greg	3.1	/** Useful Macros **/
165
166	greg	3.4	/* compute luminance from encoded value */
167	greg	3.11	#define tmLuminance(li) exp((li)*(1./TM_BRTSCALE))
168	greg	3.1
169	greg	3.4	/* does tone mapping need color matrix? */
170			#define tmNeedMatrix(t) ((t)->monpri != (t)->inppri)
171
172			/* register a conversion package */
173			#define tmRegPkg(pf) ( tmNumPkgs >= TM_MAXPKG ? -1 : \
174			(tmPkg[tmNumPkgs] = (pf), tmNumPkgs++) )
175
176			/* get the specific package's data */
177			#define tmPkgData(t,i) ((t)->pd[i]!=NULL ? (t)->pd[i] : (*tmPkg[i]->Init)(t))
178
179
180	greg	3.1	/** Library Function Calls **/
181
182	greg	3.4	#ifdef NOPROTO
183	greg	3.1
184	greg	3.3	extern struct tmStruct tmInit(), tmPop(), *tmDup();
185	greg	3.11	extern int tmSetSpace(), tmPull(), tmPush();
186	greg	3.1	extern void tmClearHisto(), tmDone();
187	greg	3.11	extern int tmAddHisto();
188			extern int tmFixedMapping(), tmComputeMapping(), tmMapPixels();
189			extern int tmCvColors(), tmCvGrays(), tmCvColrs();
190			extern int tmLoadPicture(), tmMapPicture();
191	greg	3.1
192			#else
193
194			extern struct tmStruct *
195			tmInit(int flags, RGBPRIMP monpri, double gamval);
196			/*
197			Initialize new tone mapping and push it onto stack.
198
199			flags - TM_F_* flags indicating what is to be done.
200			monpri - display monitor primaries (Note 1).
201			gamval - display gamma response (can be approximate).
202
203			returns - new tmTop, or NULL if insufficient memory.
204			*/
205
206			extern int
207			tmSetSpace(RGBPRIMP pri, double sf);
208			/*
209			Set color primaries and scale factor for incoming scanlines.
210
211			pri - RGB color input primaries (Note 1).
212			sf - scale factor to get to luminance in cd/m^2.
213
214			returns - 0 on success, TM_E_* code on failure.
215			*/
216
217			extern void
218			tmClearHisto(void);
219			/*
220			Clear histogram for current tone mapping.
221			*/
222
223			extern int
224			tmAddHisto(TMbright *ls, int len, int wt);
225			/*
226			Add brightness values to current histogram.
227
228			ls - encoded luminance values.
229			len - number of luminance values.
230			wt - integer weight to use for each value (usually 1 or -1).
231
232			returns - 0 on success, TM_E_* on error.
233			*/
234
235			extern int
236	greg	3.11	tmFixedMapping(double expmult, double gamval);
237			/*
238			Assign a fixed, linear tone-mapping using the given multiplier,
239			which is the ratio of maximum output to uncalibrated input.
240			This mapping will be used in subsequent calls to tmMapPixels()
241			until a new tone mapping is computed.
242			Only the min. and max. values are used from the histogram.
243
244			expmult - the fixed exposure multiplier to use.
245			gamval - display gamma response (0. for default).
246			returns - 0 on success, TM_E_* on error.
247			*/
248
249			extern int
250	greg	3.1	tmComputeMapping(double gamval, double Lddyn, double Ldmax);
251			/*
252	greg	3.11	Compute tone mapping function from the current histogram.
253			This mapping will be used in subsequent calls to tmMapPixels()
254			until a new tone mapping is computed.
255			I.e., calls to tmAddHisto() have no immediate effect.
256	greg	3.1
257			gamval - display gamma response (0. for default).
258			Lddyn - the display's dynamic range (0. for default).
259			Ldmax - maximum display luminance in cd/m^2 (0. for default).
260
261			returns - 0 on success, TM_E_* on failure.
262			*/
263
264			extern int
265			tmMapPixels(BYTE ps, TMbright ls, BYTE *cs, int len);
266			/*
267			Apply tone mapping function to pixel values.
268
269			ps - returned pixel values (Note 2).
270			ls - encoded luminance values.
271			cs - encoded chrominance values (Note 2).
272			len - number of pixels.
273
274			returns - 0 on success, TM_E_* on failure.
275			*/
276
277			extern struct tmStruct *
278			tmPop(void);
279			/*
280			Pops current tone mapping from stack.
281
282			returns - pointer to tone mapping structure, or NULL if none.
283			*/
284
285			extern int
286			tmPull(struct tmStruct *tms);
287			/*
288			Pull tone mapping from anywhere in stack.
289
290			tms - tone mapping structure to find.
291
292			returns - 1 if found in stack, 0 otherwise.
293			*/
294
295			extern int
296			tmPush(struct tmStruct *tms);
297			/*
298			Make tone mapping active by (pulling it and) pushing it to the top.
299
300			tms - initialized tone mapping structure.
301
302			returns - 0 on success, TM_E_* if tms is invalid.
303			*/
304
305	greg	3.3	extern struct tmStruct *
306			tmDup(void);
307			/*
308			Duplicate the current tone mapping into a new structure on the stack.
309
310			returns - pointer to new top, or NULL on error.
311			*/
312
313	greg	3.1	extern void
314			tmDone(struct tmStruct *tms);
315			/*
316			Free data associated with the given tone mapping structure.
317			Calls tmPull() first to remove it from the stack if present.
318			The calls tmDone(tmPop()), tmDone(tmTop) and tmDone(NULL)
319			all have the same effect, which is to remove and free
320			the current tone mapping.
321
322			tms - tone mapping structure to free.
323			*/
324
325	greg	3.11	extern int
326			tmCvColors(TMbright ls, BYTE cs, COLOR *scan, int len);
327			/*
328			Convert RGB/XYZ float scanline to encoded luminance and chrominance.
329
330			ls - returned encoded luminance values.
331			cs - returned encoded chrominance values (Note 2).
332			scan - input scanline.
333			len - scanline length.
334
335			returns - 0 on success, TM_E_* on error.
336			*/
337
338			extern int
339			tmCvGrays(TMbright ls, float scan, int len);
340			/*
341			Convert gray float scanline to encoded luminance.
342
343			ls - returned encoded luminance values.
344			scan - input scanline.
345			len - scanline length.
346
347			returns - 0 on success, TM_E_* on error.
348			*/
349
350			extern int
351			tmCvColrs(TMbright ls, BYTE cs, COLR *scan, int len);
352			/*
353			Convert RGBE/XYZE scanline to encoded luminance and chrominance.
354
355			ls - returned encoded luminance values.
356			cs - returned encoded chrominance values (Note 2).
357			scan - input scanline.
358			len - scanline length.
359
360			returns - 0 on success, TM_E_* on error.
361			*/
362
363			extern int
364			tmLoadPicture(TMbright lpp, BYTE cpp, int xp, int yp,
365			char fname, FILE fp);
366			/*
367			Load Radiance picture and convert to tone mapping representation.
368			Memory for the luminance and chroma arrays is allocated using
369			malloc(3), and should be freed with free(3) when no longer needed.
370			Calls tmSetSpace() to calibrate input color space.
371
372			lpp - returned array of encoded luminances, picture ordering.
373			cpp - returned array of encoded chrominances (Note 2).
374			xp, yp - returned picture dimensions.
375			fname - picture file name.
376			fp - pointer to open file (Note 3).
377
378			returns - 0 on success, TM_E_* on failure.
379			*/
380
381			extern int
382			tmMapPicture(BYTE *psp, int xp, int *yp, int flags,
383			RGBPRIMP monpri, double gamval, double Lddyn, double Ldmax,
384			char fname, FILE fp);
385			/*
386			Load and apply tone mapping to Radiance picture.
387			Stack is restored to its original state upon return.
388			If fp is TM_GETFILE and (flags&TM_F_UNIMPL)!=0, tmMapPicture()
389			calls pcond to perform the actual conversion, which takes
390			longer but gives access to all the TM_F_* features.
391			Memory for the final pixel array is allocated using malloc(3),
392			and should be freed with free(3) when it is no longer needed.
393
394			psp - returned array of tone mapped pixels, picture ordering.
395			xp, yp - returned picture dimensions.
396			flags - TM_F_* flags indicating what is to be done.
397			monpri - display monitor primaries (Note 1).
398			gamval - display gamma response.
399			Lddyn - the display's dynamic range (0. for default).
400			Ldmax - maximum display luminance in cd/m^2 (0. for default).
401			fname - picture file name.
402			fp - pointer to open file (Note 3).
403
404			returns - 0 on success, TM_E_* on failure.
405			*/
406
407	greg	3.1	#endif
408	greg	3.4
409
410	greg	3.1	/** Notes **/
411			/*
412			General:
413
414			The usual sequence after calling tmInit() is to convert some
415			pixel values to chroma and luminance encodings, which can
416			be passed to tmAddHisto() to put into the tone mapping histogram.
417			This histogram is then used along with the display parameters
418	greg	3.5	by tmComputeMapping() to compute the luminance mapping function.
419	greg	3.1	(Colors are tone-mapped as they are converted if TM_F_MESOPIC
420			is set.) The encoded chroma and luminance values may then be
421			passed to tmMapPixels() to apply the computed tone mapping in
422			a second pass.
423
424			Especially for RGBE colors in the same color space as the
425			target display, the conversion to chroma and luminance values
426			is fast enough that it may be recomputed on the second pass
427			if memory is at a premium. (Since the chroma values are only
428			used during final mapping, setting the cs parameter to TM_NOCHROM
429			on the first pass will save time.) Another memory saving option
430			if third and subsequent passes are not needed is to use the
431	greg	3.3	same array to store the mapped pixels as used to store
432	greg	3.1	the encoded chroma values. This way, only two extra bytes
433			for storing encoded luminances are required per pixel. This
434			is the method employed by tmMapPicture(), for example.
435			*/
436			/*
437			Note 1:
438
439			All RGBPRIMP values should be pointers to static structures.
440			I.e., the same pointer should be used for the same primaries,
441			and those primaries should not change from one call to the next.
442			This is because the routines use the pointer value to identify
443			computed conversion matrices, so the matrices do not have to be
444			rebuilt each time. If you are using the standard primaries,
445			use the standard primary pointer, stdprims.
446
447			To indicate a set of input primaries are actually CIE XYZ,
448			the TM_XYZPRIM macro may be passed. If the input primaries
449			are unknown, it is wisest to pass tmTop->monpri to tmSetSpace().
450			By default, the input primaries equal the monitor primaries
451			and the scalefactor is set to WHTEFFICACY in tmInit().
452			*/
453			/*
454			Note 2:
455
456			Chrominance is optional in most of these routines, whether
457			TM_F_BW is set or not. Passing a value of TM_NOCHROM (or
458			TM_NOCHROMP for picture reading) indicates that returned
459			color values are not desired.
460
461			If TM_NOCHROM is passed to a mapping routine expecting chroma
462			input, it will do without it and return luminance channel
463			rather than RGB pixel values. Otherwise, the array for
464			returned pixel values may be the same array used to pass
465			encoded chrominances if no other mappings are desired.
466			*/
467			/*
468			Note 3:
469
470			Picture files may either be opened by the calling routine or by
471			the library function. If opened by the calling routine, the
472			pointer to the stream is passed, which may be a pipe or other
473			non-seekable input as it is only read once. It must be
474			positioned at the beginning when the function is called, and it
475			will be positioned at the end on return. It will not be closed.
476			If the passed stream pointer is TM_GETFILE, then the library
477			function will open the file, read its contents and close it
478			before returning, whether or not an error was encountered.
479			*/
480	greg	3.11
481			#ifdef __cplusplus
482			}
483			#endif