src/px/ra_gif.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 * Convert from Radiance picture file to Compuserve GIF.
 * Currently, we don't know how to get back.
 */

#include  <stdio.h>

#include  <time.h>

#include  "color.h"

#include  "resolu.h"

#ifdef MSDOS
#include  <fcntl.h>
#endif

#include  <math.h>

#define MAXCOLORS               256

int rmap[MAXCOLORS];
int gmap[MAXCOLORS];
int bmap[MAXCOLORS];

int currow;

extern long  ftell();

long  picstart;

BYTE  clrtab[256][3];

extern int  samplefac;

extern int  getgifpix();

COLR    *scanln;
BYTE    *pixscan;

int  xmax, ymax;                        /* picture size */

double  gamv = 2.2;                     /* gamma correction */

int  greyscale = 0;                     /* convert to B&W? */

int  dither = 1;                        /* dither colors? */

int  bradj = 0;                         /* brightness adjustment */

int  ncolors = 0;                       /* number of colors requested */

char  *progname;


main(argc, argv)
int  argc;
char  *argv[];
{
        int  bitsperpix;
        int  i;
#ifdef MSDOS
        extern int  _fmode;
        _fmode = O_BINARY;
        setmode(fileno(stdin), O_BINARY);
        setmode(fileno(stdout), O_BINARY);
#endif
        progname = argv[0];
        samplefac = 0;

        for (i = 1; i < argc; i++)
                if (argv[i][0] == '-')
                        switch (argv[i][1]) {
                        case 'g':
                                gamv = atof(argv[++i]);
                                break;
                        case 'b':
                                greyscale = 1;
                                break;
                        case 'd':
                                dither = !dither;
                                break;
                        case 'c':
                                ncolors = atoi(argv[++i]);
                                break;
                        case 'e':
                                if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
                                        goto userr;
                                bradj = atoi(argv[++i]);
                                break;
                        case 'n':
                                samplefac = atoi(argv[++i]);
                                break;
                        default:
                                goto userr;
                        }
                else
                        break;

        if (i < argc-2)
                goto userr;
        if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) {
                fprintf(stderr, "%s: cannot open input \"%s\"\n",
                                progname, argv[i]);
                exit(1);
        }
        if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) {
                fprintf(stderr, "%s: cannot open output \"%s\"\n",
                                progname, argv[i+1]);
                exit(1);
        }
        if (checkheader(stdin, COLRFMT, NULL) < 0 ||
                        fgetresolu(&xmax, &ymax, stdin) < 0) {
                fprintf(stderr, "%s: bad picture format\n", progname);
                exit(1);
        }
        picstart = ftell(stdin);
        currow = -1;
        scanln = (COLR *)malloc(xmax*sizeof(COLR));
        if (scanln == NULL) {
                fprintf(stderr, "%s: out of memory\n", progname);
                exit(1);
        }
                                /* set up gamma correction */
        setcolrgam(gamv);
                                /* figure out the bits per pixel */
        if (ncolors < 2 | ncolors > MAXCOLORS)
                ncolors = MAXCOLORS;
        for (bitsperpix = 1; ncolors > 1<<bitsperpix; bitsperpix++)
                ;
                                /* compute color map */
        if (greyscale)
                mkgrymap(ncolors);
        else
                mkclrmap(ncolors);
                                /* convert image */
        GIFEncode(stdout, xmax, ymax, 0, 0, bitsperpix,
                        rmap, gmap, bmap, getgifpix);
        exit(0);
userr:
        fprintf(stderr,
        "Usage: %s [-b][-d][-n samp][-c ncolors][-g gamv][-e +/-stops] input [output]\n",
                        progname);
        exit(1);
}


getrow(y)                       /* get the specified row from our image */
int  y;
{
        if (y == currow)
                return;
        if (y < currow) {
                fseek(stdin, picstart, 0);
                currow = -1;
        }
        do
                if (freadcolrs(scanln, xmax, stdin) < 0) {
                        fprintf(stderr, "%s: error reading picture (y==%d)\n",
                                        progname, ymax-1-y);
                        exit(1);
                }
        while (++currow < y);
        if (bradj)
                shiftcolrs(scanln, xmax, bradj);
        colrs_gambs(scanln, xmax);
        if (pixscan != NULL)
                if (samplefac)
                        neu_dith_colrs(pixscan, scanln, xmax);
                else
                        dith_colrs(pixscan, scanln, xmax);
}


mkclrmap(nc)                    /* make our color map */
int     nc;
{
        register int    i;

        if ((samplefac ? neu_init(xmax*ymax) : new_histo(xmax*ymax)) == -1)
                goto memerr;
        for (i = 0; i < ymax; i++) {
                getrow(i);
                if (samplefac)
                        neu_colrs(scanln, xmax);
                else
                        cnt_colrs(scanln, xmax);
        }
        if (samplefac)
                neu_clrtab(nc);
        else
                new_clrtab(nc);
        for (i = 0; i < nc; i++) {
                rmap[i] = clrtab[i][RED];
                gmap[i] = clrtab[i][GRN];
                bmap[i] = clrtab[i][BLU];
        }
        if (dither && (pixscan = (BYTE *)malloc(xmax)) == NULL)
                goto memerr;
        return;
memerr:
        fprintf(stderr, "%s: out of memory\n", progname);
        exit(1);
}


mkgrymap(nc)
int     nc;
{
        register int    i;

        for (i = 0; i < nc; i++) {
                rmap[i] =
                gmap[i] =
                bmap[i] = ((unsigned)i<<8)/nc;
        }
}


int
getgifpix(x, y)                 /* get a single pixel from our picture */
int  x, y;
{
        int pix;

        getrow(y);
        if (greyscale)
                return((normbright(scanln[x])*ncolors)>>8);
        if (pixscan != NULL)
                return(pixscan[x]);
        return(samplefac ? neu_map_pixel(scanln[x]) : map_pixel(scanln[x]));
}


/*
 * SCARY GIF code follows . . . . sorry.
 *
 * Based on GIFENCOD by David Rowley <[email protected]>.A
 * Lempel-Zim compression based on "compress".
 *
 */

/*****************************************************************************
 *
 * GIFENCODE.C    - GIF Image compression interface
 *
 * GIFEncode( FName, GHeight, GWidth, GInterlace, Background,
 *            BitsPerPixel, Red, Green, Blue, GetPixel )
 *
 *****************************************************************************/
typedef int (* ifunptr)();

#define TRUE 1
#define FALSE 0

int Width, Height;
int curx, cury;
long CountDown;
int Pass;
int Interlace;
unsigned long cur_accum = 0;
int cur_bits = 0;

/*
 * Bump the 'curx' and 'cury' to point to the next pixel
 */
BumpPixel()
{
    curx++;
    if( curx == Width ) {
        curx = 0;
        if( !Interlace ) {
            cury++;
        } else {
            switch( Pass ) {
                case 0:
                    cury += 8;
                    if( cury >= Height ) {
                        Pass++;
                        cury = 4;
                    } 
                    break;
                case 1:
                    cury += 8;
                        if( cury >= Height ) {
                            Pass++;
                            cury = 2;
                        }
                        break;
                case 2:
                    cury += 4;
                    if( cury >= Height ) {
                        Pass++;
                        cury = 1;
                    }
                    break;
                case 3:
                    cury += 2;
                    break;
            }
        }
    }
}

/*
 * Return the next pixel from the image
 */
GIFNextPixel( getpixel )
ifunptr getpixel;
{
    int r;

    if( CountDown == 0 )
        return EOF;
    CountDown--;
    r = (*getpixel)( curx, cury );
    BumpPixel();
    return r;
}

/*
 * public GIFEncode
 */
GIFEncode( fp, GWidth, GHeight, GInterlace, Background,
           BitsPerPixel, Red, Green, Blue, GetPixel )
FILE *fp;
int GWidth, GHeight;
int GInterlace;
int Background;
int BitsPerPixel;
int Red[], Green[], Blue[];
ifunptr GetPixel;
{
    int B;
    int RWidth, RHeight;
    int LeftOfs, TopOfs;
    int Resolution;
    int ColorMapSize;
    int InitCodeSize;
    int i;

    long cur_accum = 0;
    cur_bits = 0;

    Interlace = GInterlace;
    ColorMapSize = 1 << BitsPerPixel;
    RWidth = Width = GWidth;
    RHeight = Height = GHeight;
    LeftOfs = TopOfs = 0;
    Resolution = BitsPerPixel;

    CountDown = (long)Width * (long)Height;
    Pass = 0;
    if( BitsPerPixel <= 1 )
        InitCodeSize = 2;
    else
        InitCodeSize = BitsPerPixel;
    curx = cury = 0;
    fwrite( "GIF87a", 1, 6, fp );
    Putword( RWidth, fp );
    Putword( RHeight, fp );
    B = 0x80;       /* Yes, there is a color map */
    B |= (Resolution - 1) << 5;
    B |= (BitsPerPixel - 1);
    fputc( B, fp );
    fputc( Background, fp );
    fputc( 0, fp );
    for( i=0; i<ColorMapSize; i++ ) {
        fputc( Red[i], fp );
        fputc( Green[i], fp );
        fputc( Blue[i], fp );
    }
    fputc( ',', fp );
    Putword( LeftOfs, fp );
    Putword( TopOfs, fp );
    Putword( Width, fp );
    Putword( Height, fp );
    if( Interlace )
        fputc( 0x40, fp );
    else
        fputc( 0x00, fp );
    fputc( InitCodeSize, fp );
    compress( InitCodeSize+1, fp, GetPixel );
    fputc( 0, fp );
    fputc( ';', fp );
    fclose( fp );
}

/*
 * Write out a word to the GIF file
 */
Putword( w, fp )
int w;
FILE *fp;
{
    fputc( w & 0xff, fp );
    fputc( (w/256) & 0xff, fp );
}


/***************************************************************************
 *
 *  GIFCOMPR.C       - GIF Image compression routines
 *
 *  Lempel-Ziv compression based on 'compress'.  GIF modifications by
 *  David Rowley ([email protected])
 *
 ***************************************************************************/

#define CBITS    12
#define HSIZE  5003            /* 80% occupancy */

/*
 * a code_int must be able to hold 2**CBITS values of type int, and also -1
 */
typedef int             code_int;
typedef long int        count_int;
typedef unsigned char   char_type;

/*
 *
 * GIF Image compression - modified 'compress'
 *
 * Based on: compress.c - File compression ala IEEE Computer, June 1984.
 *
 * By Authors:  Spencer W. Thomas       (decvax!harpo!utah-cs!utah-gr!thomas)
 *              Jim McKie               (decvax!mcvax!jim)
 *              Steve Davies            (decvax!vax135!petsd!peora!srd)
 *              Ken Turkowski           (decvax!decwrl!turtlevax!ken)
 *              James A. Woods          (decvax!ihnp4!ames!jaw)
 *              Joe Orost               (decvax!vax135!petsd!joe)
 *
 */
#include <ctype.h>

#define ARGVAL() (*++(*argv) || (--argc && *++argv))

int n_bits;                        /* number of bits/code */
int maxbits = CBITS;                /* user settable max # bits/code */
code_int maxcode;                  /* maximum code, given n_bits */
code_int maxmaxcode = (code_int)1 << CBITS; /* should NEVER generate this code */
# define MAXCODE(n_bits)        (((code_int) 1 << (n_bits)) - 1)

count_int htab [HSIZE];
unsigned short codetab [HSIZE];
#define HashTabOf(i)       htab[i]
#define CodeTabOf(i)    codetab[i]

code_int hsize = HSIZE;                 /* for dynamic table sizing */

/*
 * To save much memory, we overlay the table used by compress() with those
 * used by decompress().  The tab_prefix table is the same size and type
 * as the codetab.  The tab_suffix table needs 2**CBITS characters.  We
 * get this from the beginning of htab.  The output stack uses the rest
 * of htab, and contains characters.  There is plenty of room for any
 * possible stack (stack used to be 8000 characters).
 */
#define tab_prefixof(i) CodeTabOf(i)
#define tab_suffixof(i)        ((char_type *)(htab))[i]
#define de_stack               ((char_type *)&tab_suffixof((code_int)1<<CBITS))

code_int free_ent = 0;                  /* first unused entry */

/*
 * block compression parameters -- after all codes are used up,
 * and compression rate changes, start over.
 */
int clear_flg = 0;
int offset;
long int in_count = 1;            /* length of input */
long int out_count = 0;           /* # of codes output (for debugging) */

/*
 * compress stdin to stdout
 *
 * Algorithm:  use open addressing double hashing (no chaining) on the
 * prefix code / next character combination.  We do a variant of Knuth's
 * algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
 * secondary probe.  Here, the modular division first probe is gives way
 * to a faster exclusive-or manipulation.  Also do block compression with
 * an adaptive reset, whereby the code table is cleared when the compression
 * ratio decreases, but after the table fills.  The variable-length output
 * codes are re-sized at this point, and a special CLEAR code is generated
 * for the decompressor.  Late addition:  construct the table according to
 * file size for noticeable speed improvement on small files.  Please direct
 * questions about this implementation to ames!jaw.
 */

int g_init_bits;
FILE *g_outfile;
int ClearCode;
int EOFCode;

compress( init_bits, outfile, ReadValue )
int init_bits;
FILE *outfile;
ifunptr ReadValue;
{
    register long fcode;
    register code_int i = 0;
    register int c;
    register code_int ent;
    register code_int disp;
    register code_int hsize_reg;
    register int hshift;

    /*
     * Set up the globals:  g_init_bits - initial number of bits
     *                      g_outfile   - pointer to output file
     */
    g_init_bits = init_bits;
    g_outfile = outfile;
    /*
     * Set up the necessary values
     */
    offset = 0;
    out_count = 0;
    clear_flg = 0;
    in_count = 1;
    maxcode = MAXCODE(n_bits = g_init_bits);
    ClearCode = (1 << (init_bits - 1));
    EOFCode = ClearCode + 1;
    free_ent = ClearCode + 2;
    char_init();
    ent = GIFNextPixel( ReadValue );
    hshift = 0;
    for ( fcode = (long) hsize;  fcode < 65536L; fcode *= 2L )
        hshift++;
    hshift = 8 - hshift;                /* set hash code range bound */
    hsize_reg = hsize;
    cl_hash( (count_int) hsize_reg);            /* clear hash table */
    output( (code_int)ClearCode );
    while ( (c = GIFNextPixel( ReadValue )) != EOF ) {
        in_count++;
        fcode = (long) (((long) c << maxbits) + ent);
        /* i = (((code_int)c << hshift) ~ ent);    /* xor hashing */
        i = (((code_int)c << hshift) ^ ent);    /* xor hashing */
        if ( HashTabOf (i) == fcode ) {
            ent = CodeTabOf (i);
            continue;
        } else if ( (long)HashTabOf (i) < 0 )      /* empty slot */
            goto nomatch;
        disp = hsize_reg - i;           /* secondary hash (after G. Knott) */
        if ( i == 0 )
            disp = 1;
probe:
        if ( (i -= disp) < 0 )
            i += hsize_reg;
        if ( HashTabOf (i) == fcode ) {
            ent = CodeTabOf (i);
            continue;
        }
        if ( (long)HashTabOf (i) > 0 )
            goto probe;
nomatch:
        output ( (code_int) ent );
        out_count++;
        ent = c;
        if ( free_ent < maxmaxcode ) {
            CodeTabOf (i) = free_ent++; /* code -> hashtable */
            HashTabOf (i) = fcode;
        } else
                cl_block();
    }
    /*
     * Put out the final code.
     */
    output( (code_int)ent );
    out_count++;
    output( (code_int) EOFCode );
    return;
}

/*****************************************************************
 * TAG( output )
 *
 * Output the given code.
 * Inputs:
 *      code:   A n_bits-bit integer.  If == -1, then EOF.  This assumes
 *              that n_bits =< (long)wordsize - 1.
 * Outputs:
 *      Outputs code to the file.
 * Assumptions:
 *      Chars are 8 bits long.
 * Algorithm:
 *      Maintain a CBITS character long buffer (so that 8 codes will
 * fit in it exactly).  Use the VAX insv instruction to insert each
 * code in turn.  When the buffer fills up empty it and start over.
 */

unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
                                  0x001F, 0x003F, 0x007F, 0x00FF,
                                  0x01FF, 0x03FF, 0x07FF, 0x0FFF,
                                  0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };

output( code )
code_int  code;
{
    cur_accum &= masks[ cur_bits ];
    if( cur_bits > 0 )
        cur_accum |= ((long)code << cur_bits);
    else
        cur_accum = code;
    cur_bits += n_bits;
    while( cur_bits >= 8 ) {
        char_out( (unsigned int)(cur_accum & 0xff) );
        cur_accum >>= 8;
        cur_bits -= 8;
    }

    /*
     * If the next entry is going to be too big for the code size,
     * then increase it, if possible.
     */
   if ( free_ent > maxcode || clear_flg ) {
            if( clear_flg ) {
                maxcode = MAXCODE (n_bits = g_init_bits);
                clear_flg = 0;
            } else {
                n_bits++;
                if ( n_bits == maxbits )
                    maxcode = maxmaxcode;
                else
                    maxcode = MAXCODE(n_bits);
            }
    }
    if( code == EOFCode ) {
        /*
         * At EOF, write the rest of the buffer.
         */
        while( cur_bits > 0 ) {
                char_out( (unsigned int)(cur_accum & 0xff) );
                cur_accum >>= 8;
                cur_bits -= 8;
        }
        flush_char();
        fflush( g_outfile );
        if( ferror( g_outfile ) )
                writeerr();
    }
}

/*
 * Clear out the hash table
 */
cl_block ()             /* table clear for block compress */
{
        cl_hash ( (count_int) hsize );
        free_ent = ClearCode + 2;
        clear_flg = 1;
        output( (code_int)ClearCode );
}

cl_hash(hsize)          /* reset code table */
register count_int hsize;
{
        register count_int *htab_p = htab+hsize;
        register long i;
        register long m1 = -1;

        i = hsize - 16;
        do {                            /* might use Sys V memset(3) here */
                *(htab_p-16) = m1;
                *(htab_p-15) = m1;
                *(htab_p-14) = m1;
                *(htab_p-13) = m1;
                *(htab_p-12) = m1;
                *(htab_p-11) = m1;
                *(htab_p-10) = m1;
                *(htab_p-9) = m1;
                *(htab_p-8) = m1;
                *(htab_p-7) = m1;
                *(htab_p-6) = m1;
                *(htab_p-5) = m1;
                *(htab_p-4) = m1;
                *(htab_p-3) = m1;
                *(htab_p-2) = m1;
                *(htab_p-1) = m1;
                htab_p -= 16;
        } while ((i -= 16) >= 0);
        for ( i += 16; i > 0; i-- )
                *--htab_p = m1;
}

writeerr()
{
        printf( "error writing output file\n" );
        exit(1);
}

/******************************************************************************
 *
 * GIF Specific routines
 *
 ******************************************************************************/

/*
 * Number of characters so far in this 'packet'
 */
int a_count;

/*
 * Set up the 'byte output' routine
 */
char_init()
{
        a_count = 0;
}

/*
 * Define the storage for the packet accumulator
 */
char accum[256];

/*
 * Add a character to the end of the current packet, and if it is 254
 * characters, flush the packet to disk.
 */
char_out( c )
int c;
{
        accum[ a_count++ ] = c;
        if( a_count >= 254 )
                flush_char();
}

/*
 * Flush the packet to disk, and reset the accumulator
 */
flush_char()
{
        if( a_count > 0 ) {
                fputc( a_count, g_outfile );
                fwrite( accum, 1, a_count, g_outfile );
                a_count = 0;
        }
}

static float curgamma;
static short gamtab[256];

gammawarp(sbuf,gam,n)
short *sbuf;
float gam;
int n;
{
    int i;
    float f;

    if(gam!=curgamma) {
        for(i=0; i<256; i++) 
            gamtab[i] = 255*pow(i/255.0,gam)+0.5;
        curgamma = gam;
    }
    while(n--) {
        *sbuf = gamtab[*sbuf];
        sbuf++;
    }
}
Revision:	2.7
Committed:	Sat Feb 22 02:07:27 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R5
Changes since 2.6:	+3 -4 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	2.1	#ifndef lint
2	greg	2.7	static const char RCSid[] = "$Id$";
3	greg	2.1	#endif
4			/*
5			* Convert from Radiance picture file to Compuserve GIF.
6			* Currently, we don't know how to get back.
7			*/
8
9			#include <stdio.h>
10	greg	2.7
11			#include <time.h>
12	greg	2.1
13			#include "color.h"
14
15			#include "resolu.h"
16
17			#ifdef MSDOS
18			#include <fcntl.h>
19			#endif
20
21			#include <math.h>
22
23			#define MAXCOLORS 256
24
25			int rmap[MAXCOLORS];
26			int gmap[MAXCOLORS];
27			int bmap[MAXCOLORS];
28
29			int currow;
30
31			extern long ftell();
32
33			long picstart;
34
35	greg	2.4	BYTE clrtab[256][3];
36	greg	2.1
37	greg	2.4	extern int samplefac;
38
39	greg	2.1	extern int getgifpix();
40
41			COLR *scanln;
42	greg	2.2	BYTE *pixscan;
43	greg	2.1
44			int xmax, ymax; /* picture size */
45
46			double gamv = 2.2; /* gamma correction */
47
48			int greyscale = 0; /* convert to B&W? */
49
50	greg	2.2	int dither = 1; /* dither colors? */
51
52	greg	2.1	int bradj = 0; /* brightness adjustment */
53
54	greg	2.6	int ncolors = 0; /* number of colors requested */
55
56	greg	2.1	char *progname;
57
58
59			main(argc, argv)
60			int argc;
61			char *argv[];
62			{
63			int bitsperpix;
64			int i;
65			#ifdef MSDOS
66			extern int _fmode;
67			_fmode = O_BINARY;
68			setmode(fileno(stdin), O_BINARY);
69			setmode(fileno(stdout), O_BINARY);
70			#endif
71			progname = argv[0];
72	greg	2.4	samplefac = 0;
73	greg	2.1
74			for (i = 1; i < argc; i++)
75			if (argv[i][0] == '-')
76			switch (argv[i][1]) {
77			case 'g':
78			gamv = atof(argv[++i]);
79			break;
80			case 'b':
81			greyscale = 1;
82			break;
83	greg	2.2	case 'd':
84			dither = !dither;
85			break;
86	greg	2.1	case 'c':
87			ncolors = atoi(argv[++i]);
88			break;
89			case 'e':
90			if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
91			goto userr;
92			bradj = atoi(argv[++i]);
93			break;
94	greg	2.4	case 'n':
95			samplefac = atoi(argv[++i]);
96			break;
97	greg	2.1	default:
98			goto userr;
99			}
100			else
101			break;
102
103			if (i < argc-2)
104			goto userr;
105			if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) {
106			fprintf(stderr, "%s: cannot open input \"%s\"\n",
107			progname, argv[i]);
108			exit(1);
109			}
110			if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) {
111			fprintf(stderr, "%s: cannot open output \"%s\"\n",
112			progname, argv[i+1]);
113			exit(1);
114			}
115			if (checkheader(stdin, COLRFMT, NULL) < 0 \|\|
116			fgetresolu(&xmax, &ymax, stdin) < 0) {
117			fprintf(stderr, "%s: bad picture format\n", progname);
118			exit(1);
119			}
120			picstart = ftell(stdin);
121			currow = -1;
122			scanln = (COLR )malloc(xmaxsizeof(COLR));
123			if (scanln == NULL) {
124			fprintf(stderr, "%s: out of memory\n", progname);
125			exit(1);
126			}
127			/* set up gamma correction */
128			setcolrgam(gamv);
129			/* figure out the bits per pixel */
130			if (ncolors < 2 \| ncolors > MAXCOLORS)
131			ncolors = MAXCOLORS;
132			for (bitsperpix = 1; ncolors > 1<<bitsperpix; bitsperpix++)
133			;
134			/* compute color map */
135			if (greyscale)
136			mkgrymap(ncolors);
137			else
138			mkclrmap(ncolors);
139			/* convert image */
140			GIFEncode(stdout, xmax, ymax, 0, 0, bitsperpix,
141			rmap, gmap, bmap, getgifpix);
142			exit(0);
143			userr:
144			fprintf(stderr,
145	greg	2.5	"Usage: %s [-b][-d][-n samp][-c ncolors][-g gamv][-e +/-stops] input [output]\n",
146	greg	2.1	progname);
147			exit(1);
148			}
149
150
151			getrow(y) /* get the specified row from our image */
152			int y;
153			{
154			if (y == currow)
155			return;
156			if (y < currow) {
157			fseek(stdin, picstart, 0);
158			currow = -1;
159			}
160			do
161			if (freadcolrs(scanln, xmax, stdin) < 0) {
162			fprintf(stderr, "%s: error reading picture (y==%d)\n",
163			progname, ymax-1-y);
164	greg	2.3	exit(1);
165	greg	2.1	}
166			while (++currow < y);
167			if (bradj)
168			shiftcolrs(scanln, xmax, bradj);
169			colrs_gambs(scanln, xmax);
170	greg	2.2	if (pixscan != NULL)
171	greg	2.4	if (samplefac)
172			neu_dith_colrs(pixscan, scanln, xmax);
173			else
174			dith_colrs(pixscan, scanln, xmax);
175	greg	2.1	}
176
177
178			mkclrmap(nc) /* make our color map */
179			int nc;
180			{
181			register int i;
182
183	greg	2.4	if ((samplefac ? neu_init(xmaxymax) : new_histo(xmaxymax)) == -1)
184			goto memerr;
185	greg	2.1	for (i = 0; i < ymax; i++) {
186			getrow(i);
187	greg	2.4	if (samplefac)
188			neu_colrs(scanln, xmax);
189			else
190			cnt_colrs(scanln, xmax);
191	greg	2.1	}
192	greg	2.4	if (samplefac)
193			neu_clrtab(nc);
194			else
195			new_clrtab(nc);
196	greg	2.1	for (i = 0; i < nc; i++) {
197			rmap[i] = clrtab[i][RED];
198			gmap[i] = clrtab[i][GRN];
199			bmap[i] = clrtab[i][BLU];
200			}
201	greg	2.4	if (dither && (pixscan = (BYTE *)malloc(xmax)) == NULL)
202			goto memerr;
203			return;
204			memerr:
205			fprintf(stderr, "%s: out of memory\n", progname);
206			exit(1);
207	greg	2.1	}
208
209
210			mkgrymap(nc)
211			int nc;
212			{
213			register int i;
214
215			for (i = 0; i < nc; i++) {
216			rmap[i] =
217			gmap[i] =
218			bmap[i] = ((unsigned)i<<8)/nc;
219			}
220			}
221
222
223			int
224			getgifpix(x, y) /* get a single pixel from our picture */
225			int x, y;
226			{
227			int pix;
228
229			getrow(y);
230			if (greyscale)
231	greg	2.6	return((normbright(scanln[x])*ncolors)>>8);
232	greg	2.2	if (pixscan != NULL)
233			return(pixscan[x]);
234	greg	2.4	return(samplefac ? neu_map_pixel(scanln[x]) : map_pixel(scanln[x]));
235	greg	2.1	}
236
237
238			/*
239			* SCARY GIF code follows . . . . sorry.
240			*
241			* Based on GIFENCOD by David Rowley <[email protected]>.A
242			* Lempel-Zim compression based on "compress".
243			*
244			*/
245
246			/*****************************************************************************
247			*
248			* GIFENCODE.C - GIF Image compression interface
249			*
250			* GIFEncode( FName, GHeight, GWidth, GInterlace, Background,
251			* BitsPerPixel, Red, Green, Blue, GetPixel )
252			*
253			*****************************************************************************/
254			typedef int (* ifunptr)();
255
256			#define TRUE 1
257			#define FALSE 0
258
259			int Width, Height;
260			int curx, cury;
261			long CountDown;
262			int Pass;
263			int Interlace;
264			unsigned long cur_accum = 0;
265			int cur_bits = 0;
266
267			/*
268			* Bump the 'curx' and 'cury' to point to the next pixel
269			*/
270			BumpPixel()
271			{
272			curx++;
273			if( curx == Width ) {
274			curx = 0;
275			if( !Interlace ) {
276			cury++;
277			} else {
278			switch( Pass ) {
279			case 0:
280			cury += 8;
281			if( cury >= Height ) {
282			Pass++;
283			cury = 4;
284			}
285			break;
286			case 1:
287			cury += 8;
288			if( cury >= Height ) {
289			Pass++;
290			cury = 2;
291			}
292			break;
293			case 2:
294			cury += 4;
295			if( cury >= Height ) {
296			Pass++;
297			cury = 1;
298			}
299			break;
300			case 3:
301			cury += 2;
302			break;
303			}
304			}
305			}
306			}
307
308			/*
309			* Return the next pixel from the image
310			*/
311			GIFNextPixel( getpixel )
312			ifunptr getpixel;
313			{
314			int r;
315
316			if( CountDown == 0 )
317			return EOF;
318			CountDown--;
319			r = (*getpixel)( curx, cury );
320			BumpPixel();
321			return r;
322			}
323
324			/*
325			* public GIFEncode
326			*/
327			GIFEncode( fp, GWidth, GHeight, GInterlace, Background,
328			BitsPerPixel, Red, Green, Blue, GetPixel )
329			FILE *fp;
330			int GWidth, GHeight;
331			int GInterlace;
332			int Background;
333			int BitsPerPixel;
334			int Red[], Green[], Blue[];
335			ifunptr GetPixel;
336			{
337			int B;
338			int RWidth, RHeight;
339			int LeftOfs, TopOfs;
340			int Resolution;
341			int ColorMapSize;
342			int InitCodeSize;
343			int i;
344
345			long cur_accum = 0;
346			cur_bits = 0;
347
348			Interlace = GInterlace;
349			ColorMapSize = 1 << BitsPerPixel;
350			RWidth = Width = GWidth;
351			RHeight = Height = GHeight;
352			LeftOfs = TopOfs = 0;
353			Resolution = BitsPerPixel;
354
355			CountDown = (long)Width * (long)Height;
356			Pass = 0;
357			if( BitsPerPixel <= 1 )
358			InitCodeSize = 2;
359			else
360			InitCodeSize = BitsPerPixel;
361			curx = cury = 0;
362			fwrite( "GIF87a", 1, 6, fp );
363			Putword( RWidth, fp );
364			Putword( RHeight, fp );
365			B = 0x80; /* Yes, there is a color map */
366			B \|= (Resolution - 1) << 5;
367			B \|= (BitsPerPixel - 1);
368			fputc( B, fp );
369			fputc( Background, fp );
370			fputc( 0, fp );
371			for( i=0; i<ColorMapSize; i++ ) {
372			fputc( Red[i], fp );
373			fputc( Green[i], fp );
374			fputc( Blue[i], fp );
375			}
376			fputc( ',', fp );
377			Putword( LeftOfs, fp );
378			Putword( TopOfs, fp );
379			Putword( Width, fp );
380			Putword( Height, fp );
381			if( Interlace )
382			fputc( 0x40, fp );
383			else
384			fputc( 0x00, fp );
385			fputc( InitCodeSize, fp );
386			compress( InitCodeSize+1, fp, GetPixel );
387			fputc( 0, fp );
388			fputc( ';', fp );
389			fclose( fp );
390			}
391
392			/*
393			* Write out a word to the GIF file
394			*/
395			Putword( w, fp )
396			int w;
397			FILE *fp;
398			{
399			fputc( w & 0xff, fp );
400			fputc( (w/256) & 0xff, fp );
401			}
402
403
404			/***************************************************************************
405			*
406			* GIFCOMPR.C - GIF Image compression routines
407			*
408			* Lempel-Ziv compression based on 'compress'. GIF modifications by
409			* David Rowley ([email protected])
410			*
411			***************************************************************************/
412
413			#define CBITS 12
414			#define HSIZE 5003 /* 80% occupancy */
415
416			/*
417			* a code_int must be able to hold 2**CBITS values of type int, and also -1
418			*/
419			typedef int code_int;
420			typedef long int count_int;
421			typedef unsigned char char_type;
422
423			/*
424			*
425			* GIF Image compression - modified 'compress'
426			*
427			* Based on: compress.c - File compression ala IEEE Computer, June 1984.
428			*
429			* By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
430			* Jim McKie (decvax!mcvax!jim)
431			* Steve Davies (decvax!vax135!petsd!peora!srd)
432			* Ken Turkowski (decvax!decwrl!turtlevax!ken)
433			* James A. Woods (decvax!ihnp4!ames!jaw)
434			* Joe Orost (decvax!vax135!petsd!joe)
435			*
436			*/
437			#include <ctype.h>
438
439			#define ARGVAL() (++(argv) \|\| (--argc && *++argv))
440
441			int n_bits; /* number of bits/code */
442			int maxbits = CBITS; /* user settable max # bits/code */
443			code_int maxcode; /* maximum code, given n_bits */
444			code_int maxmaxcode = (code_int)1 << CBITS; /* should NEVER generate this code */
445			# define MAXCODE(n_bits) (((code_int) 1 << (n_bits)) - 1)
446
447			count_int htab [HSIZE];
448			unsigned short codetab [HSIZE];
449			#define HashTabOf(i) htab[i]
450			#define CodeTabOf(i) codetab[i]
451
452			code_int hsize = HSIZE; /* for dynamic table sizing */
453
454			/*
455			* To save much memory, we overlay the table used by compress() with those
456			* used by decompress(). The tab_prefix table is the same size and type
457			* as the codetab. The tab_suffix table needs 2**CBITS characters. We
458			* get this from the beginning of htab. The output stack uses the rest
459			* of htab, and contains characters. There is plenty of room for any
460			* possible stack (stack used to be 8000 characters).
461			*/
462			#define tab_prefixof(i) CodeTabOf(i)
463			#define tab_suffixof(i) ((char_type *)(htab))[i]
464			#define de_stack ((char_type *)&tab_suffixof((code_int)1<<CBITS))
465
466			code_int free_ent = 0; /* first unused entry */
467
468			/*
469			* block compression parameters -- after all codes are used up,
470			* and compression rate changes, start over.
471			*/
472			int clear_flg = 0;
473			int offset;
474			long int in_count = 1; /* length of input */
475			long int out_count = 0; /* # of codes output (for debugging) */
476
477			/*
478			* compress stdin to stdout
479			*
480			* Algorithm: use open addressing double hashing (no chaining) on the
481			* prefix code / next character combination. We do a variant of Knuth's
482			* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
483			* secondary probe. Here, the modular division first probe is gives way
484			* to a faster exclusive-or manipulation. Also do block compression with
485			* an adaptive reset, whereby the code table is cleared when the compression
486			* ratio decreases, but after the table fills. The variable-length output
487			* codes are re-sized at this point, and a special CLEAR code is generated
488			* for the decompressor. Late addition: construct the table according to
489			* file size for noticeable speed improvement on small files. Please direct
490			* questions about this implementation to ames!jaw.
491			*/
492
493			int g_init_bits;
494			FILE *g_outfile;
495			int ClearCode;
496			int EOFCode;
497
498			compress( init_bits, outfile, ReadValue )
499			int init_bits;
500			FILE *outfile;
501			ifunptr ReadValue;
502			{
503			register long fcode;
504			register code_int i = 0;
505			register int c;
506			register code_int ent;
507			register code_int disp;
508			register code_int hsize_reg;
509			register int hshift;
510
511			/*
512			* Set up the globals: g_init_bits - initial number of bits
513			* g_outfile - pointer to output file
514			*/
515			g_init_bits = init_bits;
516			g_outfile = outfile;
517			/*
518			* Set up the necessary values
519			*/
520			offset = 0;
521			out_count = 0;
522			clear_flg = 0;
523			in_count = 1;
524			maxcode = MAXCODE(n_bits = g_init_bits);
525			ClearCode = (1 << (init_bits - 1));
526			EOFCode = ClearCode + 1;
527			free_ent = ClearCode + 2;
528			char_init();
529			ent = GIFNextPixel( ReadValue );
530			hshift = 0;
531			for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L )
532			hshift++;
533			hshift = 8 - hshift; /* set hash code range bound */
534			hsize_reg = hsize;
535			cl_hash( (count_int) hsize_reg); /* clear hash table */
536			output( (code_int)ClearCode );
537			while ( (c = GIFNextPixel( ReadValue )) != EOF ) {
538			in_count++;
539			fcode = (long) (((long) c << maxbits) + ent);
540			/* i = (((code_int)c << hshift) ~ ent); /* xor hashing */
541			i = (((code_int)c << hshift) ^ ent); /* xor hashing */
542			if ( HashTabOf (i) == fcode ) {
543			ent = CodeTabOf (i);
544			continue;
545			} else if ( (long)HashTabOf (i) < 0 ) /* empty slot */
546			goto nomatch;
547			disp = hsize_reg - i; /* secondary hash (after G. Knott) */
548			if ( i == 0 )
549			disp = 1;
550			probe:
551			if ( (i -= disp) < 0 )
552			i += hsize_reg;
553			if ( HashTabOf (i) == fcode ) {
554			ent = CodeTabOf (i);
555			continue;
556			}
557			if ( (long)HashTabOf (i) > 0 )
558			goto probe;
559			nomatch:
560			output ( (code_int) ent );
561			out_count++;
562			ent = c;
563			if ( free_ent < maxmaxcode ) {
564			CodeTabOf (i) = free_ent++; /* code -> hashtable */
565			HashTabOf (i) = fcode;
566			} else
567			cl_block();
568			}
569			/*
570			* Put out the final code.
571			*/
572			output( (code_int)ent );
573			out_count++;
574			output( (code_int) EOFCode );
575			return;
576			}
577
578			/*****************************************************************
579			* TAG( output )
580			*
581			* Output the given code.
582			* Inputs:
583			* code: A n_bits-bit integer. If == -1, then EOF. This assumes
584			* that n_bits =< (long)wordsize - 1.
585			* Outputs:
586			* Outputs code to the file.
587			* Assumptions:
588			* Chars are 8 bits long.
589			* Algorithm:
590			* Maintain a CBITS character long buffer (so that 8 codes will
591			* fit in it exactly). Use the VAX insv instruction to insert each
592			* code in turn. When the buffer fills up empty it and start over.
593			*/
594
595			unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
596			0x001F, 0x003F, 0x007F, 0x00FF,
597			0x01FF, 0x03FF, 0x07FF, 0x0FFF,
598			0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
599
600			output( code )
601			code_int code;
602			{
603			cur_accum &= masks[ cur_bits ];
604			if( cur_bits > 0 )
605			cur_accum \|= ((long)code << cur_bits);
606			else
607			cur_accum = code;
608			cur_bits += n_bits;
609			while( cur_bits >= 8 ) {
610			char_out( (unsigned int)(cur_accum & 0xff) );
611			cur_accum >>= 8;
612			cur_bits -= 8;
613			}
614
615			/*
616			* If the next entry is going to be too big for the code size,
617			* then increase it, if possible.
618			*/
619			if ( free_ent > maxcode \|\| clear_flg ) {
620			if( clear_flg ) {
621			maxcode = MAXCODE (n_bits = g_init_bits);
622			clear_flg = 0;
623			} else {
624			n_bits++;
625			if ( n_bits == maxbits )
626			maxcode = maxmaxcode;
627			else
628			maxcode = MAXCODE(n_bits);
629			}
630			}
631			if( code == EOFCode ) {
632			/*
633			* At EOF, write the rest of the buffer.
634			*/
635			while( cur_bits > 0 ) {
636			char_out( (unsigned int)(cur_accum & 0xff) );
637			cur_accum >>= 8;
638			cur_bits -= 8;
639			}
640			flush_char();
641			fflush( g_outfile );
642			if( ferror( g_outfile ) )
643			writeerr();
644			}
645			}
646
647			/*
648			* Clear out the hash table
649			*/
650			cl_block () /* table clear for block compress */
651			{
652			cl_hash ( (count_int) hsize );
653			free_ent = ClearCode + 2;
654			clear_flg = 1;
655			output( (code_int)ClearCode );
656			}
657
658			cl_hash(hsize) /* reset code table */
659			register count_int hsize;
660			{
661			register count_int *htab_p = htab+hsize;
662			register long i;
663			register long m1 = -1;
664
665			i = hsize - 16;
666			do { /* might use Sys V memset(3) here */
667			*(htab_p-16) = m1;
668			*(htab_p-15) = m1;
669			*(htab_p-14) = m1;
670			*(htab_p-13) = m1;
671			*(htab_p-12) = m1;
672			*(htab_p-11) = m1;
673			*(htab_p-10) = m1;
674			*(htab_p-9) = m1;
675			*(htab_p-8) = m1;
676			*(htab_p-7) = m1;
677			*(htab_p-6) = m1;
678			*(htab_p-5) = m1;
679			*(htab_p-4) = m1;
680			*(htab_p-3) = m1;
681			*(htab_p-2) = m1;
682			*(htab_p-1) = m1;
683			htab_p -= 16;
684			} while ((i -= 16) >= 0);
685			for ( i += 16; i > 0; i-- )
686			*--htab_p = m1;
687			}
688
689			writeerr()
690			{
691			printf( "error writing output file\n" );
692			exit(1);
693			}
694
695			/******************************************************************************
696			*
697			* GIF Specific routines
698			*
699			******************************************************************************/
700
701			/*
702			* Number of characters so far in this 'packet'
703			*/
704			int a_count;
705
706			/*
707			* Set up the 'byte output' routine
708			*/
709			char_init()
710			{
711			a_count = 0;
712			}
713
714			/*
715			* Define the storage for the packet accumulator
716			*/
717			char accum[256];
718
719			/*
720			* Add a character to the end of the current packet, and if it is 254
721			* characters, flush the packet to disk.
722			*/
723			char_out( c )
724			int c;
725			{
726			accum[ a_count++ ] = c;
727			if( a_count >= 254 )
728			flush_char();
729			}
730
731			/*
732			* Flush the packet to disk, and reset the accumulator
733			*/
734			flush_char()
735			{
736			if( a_count > 0 ) {
737			fputc( a_count, g_outfile );
738			fwrite( accum, 1, a_count, g_outfile );
739			a_count = 0;
740			}
741			}
742
743			static float curgamma;
744			static short gamtab[256];
745
746			gammawarp(sbuf,gam,n)
747			short *sbuf;
748			float gam;
749			int n;
750			{
751			int i;
752			float f;
753
754			if(gam!=curgamma) {
755			for(i=0; i<256; i++)
756			gamtab[i] = 255*pow(i/255.0,gam)+0.5;
757			curgamma = gam;
758			}
759			while(n--) {
760			sbuf = gamtab[sbuf];
761			sbuf++;
762			}
763			}