src/px/ra_gif.c

#ifndef lint
static const char       RCSid[] = "$Id: ra_gif.c,v 2.10 2003/07/27 22:12:03 schorsch Exp $";
#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  <math.h>

#include  "platform.h"
#include  "color.h"
#include  "resolu.h"
#include  "clrtab.h"

#define MAXCOLORS               256

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

int currow;
long  picstart;
BYTE  clrtab[256][3];

extern int  samplefac;


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;

typedef int ifun_t(int x, int y); /* required by the GIF code below */

static void getrow(int  y);
static void mkclrmap(int        nc);
static void mkgrymap(int        nc);
static ifun_t getgifpix;

static void GIFEncode(FILE *fp, int GWidth, int GHeight, int GInterlace,
                int Background, int BitsPerPixel, int Red[], int Green[], int Blue[],
                ifun_t* GetPixel);


int
main(int  argc, char  *argv[])
{
        int  bitsperpix;
        int  i;
        SET_DEFAULT_BINARY();
        SET_FILE_BINARY(stdin);
        SET_FILE_BINARY(stdout);
        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);
}


static void
getrow(                 /* 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);
        }
}


static void
mkclrmap(                       /* 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);
}


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

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


static int
getgifpix(                      /* get a single pixel from our picture */
        int  x,
        int  y
)
{
        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-Ziv compression based on "compress".
 *
 */

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

#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;

static void BumpPixel(void);
static int GIFNextPixel(ifun_t* getpixel);
static void Putword(int w, FILE *fp);
static void compress(int init_bits, FILE *outfile, ifun_t* ReadValue);


/* 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;

static void output(code_int  code);
static void cl_block(void);
static void cl_hash(count_int hsize);
static void writeerr(void);

static void char_init(void);
static void char_out(int c);
static void flush_char(void);
static void gammawarp(short *sbuf, float gam, int n);


/*
 * Bump the 'curx' and 'cury' to point to the next pixel
 */
static void
BumpPixel(void)
{
    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
 */
static int
GIFNextPixel(
        ifun_t* getpixel
)
{
    int r;

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

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

    cur_accum = 0; /* globals */
    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
 */
static void
Putword(
        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 */

/*
 *
 * 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;

static void
compress(
        int init_bits,
        FILE *outfile,
        ifun_t* 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 };

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

static void
cl_hash(          /* 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;
}

static void
writeerr(void)
{
        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
 */
static void
char_init(void)
{
        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.
 */
static void
char_out(
        int c
)
{
        accum[ a_count++ ] = c;
        if( a_count >= 254 )
                flush_char();
}

/*
 * Flush the packet to disk, and reset the accumulator
 */
static void
flush_char(void)
{
        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];

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

    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:	2.11
Committed:	Sun Mar 28 20:33:14 2004 UTC (20 years, 1 month ago) by schorsch
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R7P2, rad3R7P1, rad4R0, rad3R6, rad3R6P1, rad3R8, rad3R9
Changes since 2.10:	+113 -70 lines
Log Message:	Continued ANSIfication, and other fixes and clarifications.
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	schorsch	2.11	static const char RCSid[] = "$Id: ra_gif.c,v 2.10 2003/07/27 22:12:03 schorsch Exp $";
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	#include <time.h>
11	schorsch	2.8	#include <math.h>
12	greg	2.1
13	schorsch	2.8	#include "platform.h"
14	greg	2.1	#include "color.h"
15			#include "resolu.h"
16	schorsch	2.11	#include "clrtab.h"
17	greg	2.1
18			#define MAXCOLORS 256
19
20			int rmap[MAXCOLORS];
21			int gmap[MAXCOLORS];
22			int bmap[MAXCOLORS];
23
24			int currow;
25			long picstart;
26	greg	2.4	BYTE clrtab[256][3];
27	greg	2.1
28	greg	2.4	extern int samplefac;
29
30	greg	2.1
31			COLR *scanln;
32	greg	2.2	BYTE *pixscan;
33	greg	2.1
34			int xmax, ymax; /* picture size */
35			double gamv = 2.2; /* gamma correction */
36			int greyscale = 0; /* convert to B&W? */
37	greg	2.2	int dither = 1; /* dither colors? */
38	greg	2.1	int bradj = 0; /* brightness adjustment */
39	greg	2.6	int ncolors = 0; /* number of colors requested */
40
41	greg	2.1	char *progname;
42
43	schorsch	2.11	typedef int ifun_t(int x, int y); /* required by the GIF code below */
44
45			static void getrow(int y);
46			static void mkclrmap(int nc);
47			static void mkgrymap(int nc);
48			static ifun_t getgifpix;
49
50			static void GIFEncode(FILE *fp, int GWidth, int GHeight, int GInterlace,
51			int Background, int BitsPerPixel, int Red[], int Green[], int Blue[],
52			ifun_t* GetPixel);
53	greg	2.1
54	schorsch	2.11
55			int
56			main(int argc, char *argv[])
57	greg	2.1	{
58			int bitsperpix;
59			int i;
60	schorsch	2.8	SET_DEFAULT_BINARY();
61			SET_FILE_BINARY(stdin);
62			SET_FILE_BINARY(stdout);
63	greg	2.1	progname = argv[0];
64	greg	2.4	samplefac = 0;
65	greg	2.1
66			for (i = 1; i < argc; i++)
67			if (argv[i][0] == '-')
68			switch (argv[i][1]) {
69			case 'g':
70			gamv = atof(argv[++i]);
71			break;
72			case 'b':
73			greyscale = 1;
74			break;
75	greg	2.2	case 'd':
76			dither = !dither;
77			break;
78	greg	2.1	case 'c':
79			ncolors = atoi(argv[++i]);
80			break;
81			case 'e':
82			if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
83			goto userr;
84			bradj = atoi(argv[++i]);
85			break;
86	greg	2.4	case 'n':
87			samplefac = atoi(argv[++i]);
88			break;
89	greg	2.1	default:
90			goto userr;
91			}
92			else
93			break;
94
95			if (i < argc-2)
96			goto userr;
97			if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) {
98			fprintf(stderr, "%s: cannot open input \"%s\"\n",
99			progname, argv[i]);
100			exit(1);
101			}
102			if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) {
103			fprintf(stderr, "%s: cannot open output \"%s\"\n",
104			progname, argv[i+1]);
105			exit(1);
106			}
107			if (checkheader(stdin, COLRFMT, NULL) < 0 \|\|
108			fgetresolu(&xmax, &ymax, stdin) < 0) {
109			fprintf(stderr, "%s: bad picture format\n", progname);
110			exit(1);
111			}
112			picstart = ftell(stdin);
113			currow = -1;
114			scanln = (COLR )malloc(xmaxsizeof(COLR));
115			if (scanln == NULL) {
116			fprintf(stderr, "%s: out of memory\n", progname);
117			exit(1);
118			}
119			/* set up gamma correction */
120			setcolrgam(gamv);
121			/* figure out the bits per pixel */
122	schorsch	2.10	if ((ncolors < 2) \| (ncolors > MAXCOLORS))
123	greg	2.1	ncolors = MAXCOLORS;
124			for (bitsperpix = 1; ncolors > 1<<bitsperpix; bitsperpix++)
125			;
126			/* compute color map */
127			if (greyscale)
128			mkgrymap(ncolors);
129			else
130			mkclrmap(ncolors);
131			/* convert image */
132			GIFEncode(stdout, xmax, ymax, 0, 0, bitsperpix,
133			rmap, gmap, bmap, getgifpix);
134			exit(0);
135			userr:
136			fprintf(stderr,
137	greg	2.5	"Usage: %s [-b][-d][-n samp][-c ncolors][-g gamv][-e +/-stops] input [output]\n",
138	greg	2.1	progname);
139			exit(1);
140			}
141
142
143	schorsch	2.11	static void
144			getrow( /* get the specified row from our image */
145			int y
146			)
147	greg	2.1	{
148			if (y == currow)
149			return;
150			if (y < currow) {
151			fseek(stdin, picstart, 0);
152			currow = -1;
153			}
154			do
155			if (freadcolrs(scanln, xmax, stdin) < 0) {
156			fprintf(stderr, "%s: error reading picture (y==%d)\n",
157			progname, ymax-1-y);
158	greg	2.3	exit(1);
159	greg	2.1	}
160			while (++currow < y);
161			if (bradj)
162			shiftcolrs(scanln, xmax, bradj);
163			colrs_gambs(scanln, xmax);
164	schorsch	2.9	if (pixscan != NULL) {
165	greg	2.4	if (samplefac)
166			neu_dith_colrs(pixscan, scanln, xmax);
167			else
168			dith_colrs(pixscan, scanln, xmax);
169	schorsch	2.9	}
170	greg	2.1	}
171
172
173	schorsch	2.11	static void
174			mkclrmap( /* make our color map */
175			int nc
176			)
177	greg	2.1	{
178			register int i;
179
180	greg	2.4	if ((samplefac ? neu_init(xmaxymax) : new_histo(xmaxymax)) == -1)
181			goto memerr;
182	greg	2.1	for (i = 0; i < ymax; i++) {
183			getrow(i);
184	greg	2.4	if (samplefac)
185			neu_colrs(scanln, xmax);
186			else
187			cnt_colrs(scanln, xmax);
188	greg	2.1	}
189	greg	2.4	if (samplefac)
190			neu_clrtab(nc);
191			else
192			new_clrtab(nc);
193	greg	2.1	for (i = 0; i < nc; i++) {
194			rmap[i] = clrtab[i][RED];
195			gmap[i] = clrtab[i][GRN];
196			bmap[i] = clrtab[i][BLU];
197			}
198	greg	2.4	if (dither && (pixscan = (BYTE *)malloc(xmax)) == NULL)
199			goto memerr;
200			return;
201			memerr:
202			fprintf(stderr, "%s: out of memory\n", progname);
203			exit(1);
204	greg	2.1	}
205
206
207	schorsch	2.11	static void
208			mkgrymap(
209			int nc
210			)
211	greg	2.1	{
212			register int i;
213
214			for (i = 0; i < nc; i++) {
215			rmap[i] =
216			gmap[i] =
217			bmap[i] = ((unsigned)i<<8)/nc;
218			}
219			}
220
221
222	schorsch	2.11	static int
223			getgifpix( /* get a single pixel from our picture */
224			int x,
225			int y
226			)
227	greg	2.1	{
228			getrow(y);
229			if (greyscale)
230	greg	2.6	return((normbright(scanln[x])*ncolors)>>8);
231	greg	2.2	if (pixscan != NULL)
232			return(pixscan[x]);
233	greg	2.4	return(samplefac ? neu_map_pixel(scanln[x]) : map_pixel(scanln[x]));
234	greg	2.1	}
235
236
237			/*
238			* SCARY GIF code follows . . . . sorry.
239			*
240			* Based on GIFENCOD by David Rowley <[email protected]>.A
241	schorsch	2.11	* Lempel-Ziv compression based on "compress".
242	greg	2.1	*
243			*/
244
245			/*****************************************************************************
246			*
247			* GIFENCODE.C - GIF Image compression interface
248			*
249			* GIFEncode( FName, GHeight, GWidth, GInterlace, Background,
250			* BitsPerPixel, Red, Green, Blue, GetPixel )
251			*
252			*****************************************************************************/
253
254			#define TRUE 1
255			#define FALSE 0
256
257			int Width, Height;
258			int curx, cury;
259			long CountDown;
260			int Pass;
261			int Interlace;
262			unsigned long cur_accum = 0;
263			int cur_bits = 0;
264
265	schorsch	2.11	static void BumpPixel(void);
266			static int GIFNextPixel(ifun_t* getpixel);
267			static void Putword(int w, FILE *fp);
268			static void compress(int init_bits, FILE outfile, ifun_t ReadValue);
269
270
271			/* a code_int must be able to hold 2*CBITS values of type int, and also -1 /
272			typedef int code_int;
273			typedef long int count_int;
274			typedef unsigned char char_type;
275
276			static void output(code_int code);
277			static void cl_block(void);
278			static void cl_hash(count_int hsize);
279			static void writeerr(void);
280
281			static void char_init(void);
282			static void char_out(int c);
283			static void flush_char(void);
284			static void gammawarp(short *sbuf, float gam, int n);
285
286
287	greg	2.1	/*
288			* Bump the 'curx' and 'cury' to point to the next pixel
289			*/
290	schorsch	2.11	static void
291			BumpPixel(void)
292	greg	2.1	{
293			curx++;
294			if( curx == Width ) {
295			curx = 0;
296			if( !Interlace ) {
297			cury++;
298			} else {
299			switch( Pass ) {
300			case 0:
301			cury += 8;
302			if( cury >= Height ) {
303			Pass++;
304			cury = 4;
305			}
306			break;
307			case 1:
308			cury += 8;
309			if( cury >= Height ) {
310			Pass++;
311			cury = 2;
312			}
313			break;
314			case 2:
315			cury += 4;
316			if( cury >= Height ) {
317			Pass++;
318			cury = 1;
319			}
320			break;
321			case 3:
322			cury += 2;
323			break;
324			}
325			}
326			}
327			}
328
329			/*
330			* Return the next pixel from the image
331			*/
332	schorsch	2.11	static int
333			GIFNextPixel(
334			ifun_t* getpixel
335			)
336	greg	2.1	{
337			int r;
338
339			if( CountDown == 0 )
340			return EOF;
341			CountDown--;
342			r = (*getpixel)( curx, cury );
343			BumpPixel();
344			return r;
345			}
346
347			/*
348			* public GIFEncode
349			*/
350	schorsch	2.11	static void
351			GIFEncode(
352			FILE *fp,
353			int GWidth,
354			int GHeight,
355			int GInterlace,
356			int Background,
357			int BitsPerPixel,
358			int Red[],
359			int Green[],
360			int Blue[],
361			ifun_t* GetPixel
362			)
363	greg	2.1	{
364			int B;
365			int RWidth, RHeight;
366			int LeftOfs, TopOfs;
367			int Resolution;
368			int ColorMapSize;
369			int InitCodeSize;
370			int i;
371
372	schorsch	2.11	cur_accum = 0; /* globals */
373	greg	2.1	cur_bits = 0;
374
375			Interlace = GInterlace;
376			ColorMapSize = 1 << BitsPerPixel;
377			RWidth = Width = GWidth;
378			RHeight = Height = GHeight;
379			LeftOfs = TopOfs = 0;
380			Resolution = BitsPerPixel;
381
382			CountDown = (long)Width * (long)Height;
383			Pass = 0;
384			if( BitsPerPixel <= 1 )
385			InitCodeSize = 2;
386			else
387			InitCodeSize = BitsPerPixel;
388			curx = cury = 0;
389			fwrite( "GIF87a", 1, 6, fp );
390			Putword( RWidth, fp );
391			Putword( RHeight, fp );
392			B = 0x80; /* Yes, there is a color map */
393			B \|= (Resolution - 1) << 5;
394			B \|= (BitsPerPixel - 1);
395			fputc( B, fp );
396			fputc( Background, fp );
397			fputc( 0, fp );
398			for( i=0; i<ColorMapSize; i++ ) {
399			fputc( Red[i], fp );
400			fputc( Green[i], fp );
401			fputc( Blue[i], fp );
402			}
403			fputc( ',', fp );
404			Putword( LeftOfs, fp );
405			Putword( TopOfs, fp );
406			Putword( Width, fp );
407			Putword( Height, fp );
408			if( Interlace )
409			fputc( 0x40, fp );
410			else
411			fputc( 0x00, fp );
412			fputc( InitCodeSize, fp );
413			compress( InitCodeSize+1, fp, GetPixel );
414			fputc( 0, fp );
415			fputc( ';', fp );
416			fclose( fp );
417			}
418
419			/*
420			* Write out a word to the GIF file
421			*/
422	schorsch	2.11	static void
423			Putword(
424			int w,
425			FILE *fp
426			)
427	greg	2.1	{
428			fputc( w & 0xff, fp );
429			fputc( (w/256) & 0xff, fp );
430			}
431
432
433			/***************************************************************************
434			*
435			* GIFCOMPR.C - GIF Image compression routines
436			*
437			* Lempel-Ziv compression based on 'compress'. GIF modifications by
438			* David Rowley ([email protected])
439			*
440			***************************************************************************/
441
442			#define CBITS 12
443			#define HSIZE 5003 /* 80% occupancy */
444
445			/*
446			*
447			* GIF Image compression - modified 'compress'
448			*
449			* Based on: compress.c - File compression ala IEEE Computer, June 1984.
450			*
451			* By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
452			* Jim McKie (decvax!mcvax!jim)
453			* Steve Davies (decvax!vax135!petsd!peora!srd)
454			* Ken Turkowski (decvax!decwrl!turtlevax!ken)
455			* James A. Woods (decvax!ihnp4!ames!jaw)
456			* Joe Orost (decvax!vax135!petsd!joe)
457			*
458			*/
459			#include <ctype.h>
460
461			#define ARGVAL() (++(argv) \|\| (--argc && *++argv))
462
463			int n_bits; /* number of bits/code */
464			int maxbits = CBITS; /* user settable max # bits/code */
465			code_int maxcode; /* maximum code, given n_bits */
466			code_int maxmaxcode = (code_int)1 << CBITS; /* should NEVER generate this code */
467			# define MAXCODE(n_bits) (((code_int) 1 << (n_bits)) - 1)
468
469			count_int htab [HSIZE];
470			unsigned short codetab [HSIZE];
471			#define HashTabOf(i) htab[i]
472			#define CodeTabOf(i) codetab[i]
473
474			code_int hsize = HSIZE; /* for dynamic table sizing */
475
476			/*
477			* To save much memory, we overlay the table used by compress() with those
478			* used by decompress(). The tab_prefix table is the same size and type
479			* as the codetab. The tab_suffix table needs 2**CBITS characters. We
480			* get this from the beginning of htab. The output stack uses the rest
481			* of htab, and contains characters. There is plenty of room for any
482			* possible stack (stack used to be 8000 characters).
483			*/
484			#define tab_prefixof(i) CodeTabOf(i)
485			#define tab_suffixof(i) ((char_type *)(htab))[i]
486			#define de_stack ((char_type *)&tab_suffixof((code_int)1<<CBITS))
487
488			code_int free_ent = 0; /* first unused entry */
489
490			/*
491			* block compression parameters -- after all codes are used up,
492			* and compression rate changes, start over.
493			*/
494			int clear_flg = 0;
495			int offset;
496			long int in_count = 1; /* length of input */
497			long int out_count = 0; /* # of codes output (for debugging) */
498
499			/*
500			* compress stdin to stdout
501			*
502			* Algorithm: use open addressing double hashing (no chaining) on the
503			* prefix code / next character combination. We do a variant of Knuth's
504			* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
505			* secondary probe. Here, the modular division first probe is gives way
506			* to a faster exclusive-or manipulation. Also do block compression with
507			* an adaptive reset, whereby the code table is cleared when the compression
508			* ratio decreases, but after the table fills. The variable-length output
509			* codes are re-sized at this point, and a special CLEAR code is generated
510			* for the decompressor. Late addition: construct the table according to
511			* file size for noticeable speed improvement on small files. Please direct
512			* questions about this implementation to ames!jaw.
513			*/
514
515			int g_init_bits;
516			FILE *g_outfile;
517			int ClearCode;
518			int EOFCode;
519
520	schorsch	2.11	static void
521			compress(
522			int init_bits,
523			FILE *outfile,
524			ifun_t* ReadValue
525			)
526	greg	2.1	{
527			register long fcode;
528			register code_int i = 0;
529			register int c;
530			register code_int ent;
531			register code_int disp;
532			register code_int hsize_reg;
533			register int hshift;
534
535			/*
536			* Set up the globals: g_init_bits - initial number of bits
537			* g_outfile - pointer to output file
538			*/
539			g_init_bits = init_bits;
540			g_outfile = outfile;
541			/*
542			* Set up the necessary values
543			*/
544			offset = 0;
545			out_count = 0;
546			clear_flg = 0;
547			in_count = 1;
548			maxcode = MAXCODE(n_bits = g_init_bits);
549			ClearCode = (1 << (init_bits - 1));
550			EOFCode = ClearCode + 1;
551			free_ent = ClearCode + 2;
552			char_init();
553			ent = GIFNextPixel( ReadValue );
554			hshift = 0;
555			for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L )
556			hshift++;
557			hshift = 8 - hshift; /* set hash code range bound */
558			hsize_reg = hsize;
559			cl_hash( (count_int) hsize_reg); /* clear hash table */
560			output( (code_int)ClearCode );
561			while ( (c = GIFNextPixel( ReadValue )) != EOF ) {
562			in_count++;
563			fcode = (long) (((long) c << maxbits) + ent);
564	schorsch	2.11	/* i = (((code_int)c << hshift) ~ ent); / / xor hashing */
565	greg	2.1	i = (((code_int)c << hshift) ^ ent); /* xor hashing */
566			if ( HashTabOf (i) == fcode ) {
567			ent = CodeTabOf (i);
568			continue;
569			} else if ( (long)HashTabOf (i) < 0 ) /* empty slot */
570			goto nomatch;
571			disp = hsize_reg - i; /* secondary hash (after G. Knott) */
572			if ( i == 0 )
573			disp = 1;
574			probe:
575			if ( (i -= disp) < 0 )
576			i += hsize_reg;
577			if ( HashTabOf (i) == fcode ) {
578			ent = CodeTabOf (i);
579			continue;
580			}
581			if ( (long)HashTabOf (i) > 0 )
582			goto probe;
583			nomatch:
584			output ( (code_int) ent );
585			out_count++;
586			ent = c;
587			if ( free_ent < maxmaxcode ) {
588			CodeTabOf (i) = free_ent++; /* code -> hashtable */
589			HashTabOf (i) = fcode;
590			} else
591			cl_block();
592			}
593			/*
594			* Put out the final code.
595			*/
596			output( (code_int)ent );
597			out_count++;
598			output( (code_int) EOFCode );
599			return;
600			}
601
602			/*****************************************************************
603			* TAG( output )
604			*
605			* Output the given code.
606			* Inputs:
607			* code: A n_bits-bit integer. If == -1, then EOF. This assumes
608			* that n_bits =< (long)wordsize - 1.
609			* Outputs:
610			* Outputs code to the file.
611			* Assumptions:
612			* Chars are 8 bits long.
613			* Algorithm:
614			* Maintain a CBITS character long buffer (so that 8 codes will
615			* fit in it exactly). Use the VAX insv instruction to insert each
616			* code in turn. When the buffer fills up empty it and start over.
617			*/
618
619			unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
620			0x001F, 0x003F, 0x007F, 0x00FF,
621			0x01FF, 0x03FF, 0x07FF, 0x0FFF,
622			0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
623
624	schorsch	2.11	static void
625			output(
626			code_int code
627			)
628	greg	2.1	{
629			cur_accum &= masks[ cur_bits ];
630			if( cur_bits > 0 )
631			cur_accum \|= ((long)code << cur_bits);
632			else
633			cur_accum = code;
634			cur_bits += n_bits;
635			while( cur_bits >= 8 ) {
636			char_out( (unsigned int)(cur_accum & 0xff) );
637			cur_accum >>= 8;
638			cur_bits -= 8;
639			}
640
641			/*
642			* If the next entry is going to be too big for the code size,
643			* then increase it, if possible.
644			*/
645			if ( free_ent > maxcode \|\| clear_flg ) {
646			if( clear_flg ) {
647			maxcode = MAXCODE (n_bits = g_init_bits);
648			clear_flg = 0;
649			} else {
650			n_bits++;
651			if ( n_bits == maxbits )
652			maxcode = maxmaxcode;
653			else
654			maxcode = MAXCODE(n_bits);
655			}
656			}
657			if( code == EOFCode ) {
658			/*
659			* At EOF, write the rest of the buffer.
660			*/
661			while( cur_bits > 0 ) {
662			char_out( (unsigned int)(cur_accum & 0xff) );
663			cur_accum >>= 8;
664			cur_bits -= 8;
665			}
666			flush_char();
667			fflush( g_outfile );
668			if( ferror( g_outfile ) )
669			writeerr();
670			}
671			}
672
673			/*
674			* Clear out the hash table
675			*/
676	schorsch	2.11	static void
677			cl_block (void) /* table clear for block compress */
678	greg	2.1	{
679			cl_hash ( (count_int) hsize );
680			free_ent = ClearCode + 2;
681			clear_flg = 1;
682			output( (code_int)ClearCode );
683			}
684
685	schorsch	2.11	static void
686			cl_hash( /* reset code table */
687			register count_int hsize
688			)
689	greg	2.1	{
690			register count_int *htab_p = htab+hsize;
691			register long i;
692			register long m1 = -1;
693
694			i = hsize - 16;
695			do { /* might use Sys V memset(3) here */
696			*(htab_p-16) = m1;
697			*(htab_p-15) = m1;
698			*(htab_p-14) = m1;
699			*(htab_p-13) = m1;
700			*(htab_p-12) = m1;
701			*(htab_p-11) = m1;
702			*(htab_p-10) = m1;
703			*(htab_p-9) = m1;
704			*(htab_p-8) = m1;
705			*(htab_p-7) = m1;
706			*(htab_p-6) = m1;
707			*(htab_p-5) = m1;
708			*(htab_p-4) = m1;
709			*(htab_p-3) = m1;
710			*(htab_p-2) = m1;
711			*(htab_p-1) = m1;
712			htab_p -= 16;
713			} while ((i -= 16) >= 0);
714			for ( i += 16; i > 0; i-- )
715			*--htab_p = m1;
716			}
717
718	schorsch	2.11	static void
719			writeerr(void)
720	greg	2.1	{
721			printf( "error writing output file\n" );
722			exit(1);
723			}
724
725			/******************************************************************************
726			*
727			* GIF Specific routines
728			*
729			******************************************************************************/
730
731			/*
732			* Number of characters so far in this 'packet'
733			*/
734			int a_count;
735
736			/*
737			* Set up the 'byte output' routine
738			*/
739	schorsch	2.11	static void
740			char_init(void)
741	greg	2.1	{
742			a_count = 0;
743			}
744
745			/*
746			* Define the storage for the packet accumulator
747			*/
748			char accum[256];
749
750			/*
751			* Add a character to the end of the current packet, and if it is 254
752			* characters, flush the packet to disk.
753			*/
754	schorsch	2.11	static void
755			char_out(
756			int c
757			)
758	greg	2.1	{
759			accum[ a_count++ ] = c;
760			if( a_count >= 254 )
761			flush_char();
762			}
763
764			/*
765			* Flush the packet to disk, and reset the accumulator
766			*/
767	schorsch	2.11	static void
768			flush_char(void)
769	greg	2.1	{
770			if( a_count > 0 ) {
771			fputc( a_count, g_outfile );
772			fwrite( accum, 1, a_count, g_outfile );
773			a_count = 0;
774			}
775			}
776
777			static float curgamma;
778			static short gamtab[256];
779
780	schorsch	2.11	static void
781			gammawarp(
782			short *sbuf,
783			float gam,
784			int n
785			)
786	greg	2.1	{
787			int i;
788
789			if(gam!=curgamma) {
790			for(i=0; i<256; i++)
791			gamtab[i] = 255*pow(i/255.0,gam)+0.5;
792			curgamma = gam;
793			}
794			while(n--) {
795			sbuf = gamtab[sbuf];
796			sbuf++;
797			}
798			}