libtthimage/Lib/col4bits.c

/*
			col4bits.c

	this module is dedicated to functions who works on 
	4096 colors images. You got four bits by components.
*/

#include   <stdio.h>
#include   <stdlib.h>

#include   "../tthimage.h"

/*::------------------------------------------------------------------::*/
int Image_col4bits_and(Image_Desc *src, Image_Desc *dst)
{
int	foo;

if ((foo=Image_compare_desc(src, dst))) {
	fprintf(stderr, "%s : images not compatibles\n", __func__);
	return foo;
	}

foo = Image_copy(src, dst);
if (foo) {
	fprintf(stderr, "In %s: copy: err #%d %s\n", __func__,
					foo, Image_err2str(foo));
	return foo;
	}
foo = Image_and_pix(dst, 0xf0, 0xf0, 0xf0);
if (foo) {
	fprintf(stderr, "In %s: and pix: err #%d %s\n", __func__,
					foo, Image_err2str(foo));
	return foo;
	}

return OLL_KORRECT;
}
/*::------------------------------------------------------------------::*/
struct elem
	{
	long	compte;
	int	rgb;
	};

static int compare_compteur(struct elem *p1, struct elem *p2)
{
/* printf("%8d %8d\n", p1->compte, p2->compte); */
return (p2->compte - p1->compte);
}
static int compare_teinte(struct elem *p1, struct elem *p2)
{
int	r1, g1, b1, r2, b2, g2;

r1 = (( (p1->rgb) >>8)&0xf)<<4; 
g1 = (( (p1->rgb) >>4)&0xf)<<4; 
b1 = ( (p1->rgb) &0xf)<<4;

r2 = (( (p2->rgb) >>8)&0xf)<<4; 
g2 = (( (p2->rgb) >>4)&0xf)<<4; 
b2 = ( (p2->rgb) &0xf)<<4;

/* printf("%8d %8d\n", p1->compte, p2->compte);
 return (p1->rgb - p2->rgb); */

return ( (r1+g1+b1) - (r2+g2+b2) );
}

/*::------------------------------------------------------------------::*/

#define TAILLE	(1<<12)
int Image_calc_Map_4bits(Image_Desc *img, RGB_map *map, int nbre)
{
long	surface, maxi;
int	x, y, r, g, b, idx;

struct elem	elems[TAILLE];

#if DEBUG_LEVEL
fprintf(stderr, "  Calc map 4 bits: nbre = %d\n", nbre);
#endif

if ( (nbre<1) || (nbre>255) ) {
	fprintf(stderr, "Calc map 4 bits: nbre %d out of range\n", nbre);
	return BAD_COLOR_NUMBER;
	}

surface = img->width * img->height;
#if DEBUG_LEVEL
fprintf(stderr, "  calc Map 4 bits: surface de l'image = %ld pixels\n", surface);
#endif

for (x=0; x<TAILLE; x++) {
	elems[x].compte = 0L;
	elems[x].rgb = x;
	}

maxi = 0L;
for (x=0; x<img->width; x++) {
    for (y=0; y<img->height; y++) {
        r = (img->Rpix[y])[x] >> 4;
        g = (img->Gpix[y])[x] >> 4;
        b = (img->Bpix[y])[x] >> 4;
        idx = (r<<8) | (g<<4) | b;

	if (idx >= TAILLE) {
		fprintf(stderr, "FATAL ERROR in %s\n", __func__);
		exit(5);
		}
	elems[idx].compte++;
	if (elems[idx].compte > maxi)
		maxi = elems[idx].compte;
        }
    }
#if DEBUG_LEVEL
fprintf(stderr, "  Map4bits: compte maximum     = %ld\n", maxi);
#endif

/*
 *	trier la table pour avoir les couleurs les plus
 *	frequentes en haut.
 */
qsort(elems, TAILLE, sizeof(struct elem), compare_compteur);

/*
 *	trier la palette, certe, mais dans quel ordre ?
  *     28 Jan 2002: why ?
 */
qsort(elems, nbre, sizeof(struct elem), compare_teinte);

/*
 *	recopier les 'nbre' entrees hautes dans la palette
 */
for(x=0; x<nbre; x++) {
	y = elems[x].rgb;

	r = ((y>>8)&0xf)<<4; 
	g = ((y>>4)&0xf)<<4; 
	b = (y&0xf)<<4;

	/* printf("%06x %02x %02x %02x\n", x, r, g, b); */
	map->red[x] = r;
	map->green[x] = g;
	map->blue[x] = b;
	}
map->nbre = nbre;

#if DEBUG_LEVEL
fprintf(stderr, "Image_calc_Map_4bits: fini!\n");
#endif

return FUNC_IS_BETA;
}
/*::------------------------------------------------------------------::*/