libtthimage/Lib/calculs.c

/*
                    calculs.c
		    ---------

    voir aussi: distances.c
*/

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

#include   "../tthimage.h"

/*::------------------------------------------------------------------::*/
/*          pour les performances, cette fonction
            pourrait devenir une #macro ?
*/
int
Image_clamp_pixel(int value)
{
if (value < 0)      return 0;
if (value > 255)    return 255;
return value;
}
/*::------------------------------------------------------------------::*/
/*						new, 2001 June
 *
 *	23 Fev 2002: parfois (recurse ?) on passe plein de fois dans
 *	cette fonction. Est-il raisonnable d'optimiser en passant par
 *	les accès direct à la mémoire ? Oui, si on améliore les 
 *	controles de XY ...
 */
int 
Image_stats_zone_0(Image_Desc *img, Image_Rect *zone,
				int *pmr, int *pmg, int *pmb,
				int *pdr, int *pdg, int *pdb)
{
int	x, y;
int	r, g, b;
int	r0, r1, g0, g1, b0, b1;
long	pixels = 0;

if ( (zone->w < 2) || (zone->h < 2) )
	{
	Image_dump_rect(zone, "stat_zone_0: too small!", 0);
	return RECT_TOO_SMALL;
	}

*pmr = *pmg = *pmb = 0;
r0 = g0 = b0 = 300;
r1 = g1 = b1 = -10;

for (x=0; x<zone->w; x++)
	{
	for (y=0; y<zone->h; y++)
		{
		r = (img->Rpix[y+zone->y])[x+zone->x];
		g = (img->Gpix[y+zone->y])[x+zone->x];
		b = (img->Bpix[y+zone->y])[x+zone->x];

		*pmr += r;
		*pmg += g;
		*pmb += b;

		if (r > r1)		r1 = r;
		if (r < r0)		r0 = r;

		if (g > g1)		g1 = g;
		if (g < g0)		g0 = g;

		if (b > b1)		b1 = b;
		if (b < b0)		b0 = b;

		pixels ++;
		}
	}

#if DEBUG_LEVEL > 3
fprintf(stderr, "Calc zone 0: sommes  %d  %d  %d\n", *pmr, *pmg, *pmb);
#endif

*pmr /= (zone->w*zone->h);
*pmg /= (zone->w*zone->h);
*pmb /= (zone->w*zone->h);

if (NULL != pdr) *pdr = r1 - r0;
if (NULL != pdr) *pdg = g1 - g0;
if (NULL != pdr) *pdb = b1 - b0;

/* XXX TO BE GARDED ABOUT NULL PTRS 
if ( (*pdr<0) || (*pdg<0) || (*pdb<0) )
	{
	Image_dump_rect(zone, "negative in stat_zone_0", 0);
	fprintf(stderr, "%ld  /  %d %d    %d %d    %d %d\n",
				pixels, r0, r1, g0, g1, b0, b1);
	}
XXX */
return OLL_KORRECT;
}
/*::------------------------------------------------------------------::*/
/*
 *	reserved for debugging the library. (never finished work :)
 */
int
Image_quelques_calculs(Image_Desc *image)
{
long    surface, somme;
int     x, y, r, g, b, idx;
int     *compte4bits;

surface = image->width * image->height;
printf("surface de l'image = %ld pixels\n", surface);

if ( (compte4bits = (int *)calloc(1<<12, sizeof(int))) == NULL )
    {
    fprintf(stderr, "erreur calloc(surface)\n");
    return 1;
    }

for (x=0; x<image->width; x++)
    {
    for (y=0; y<image->height; y++)
        {
        r = (image->Rpix[y])[x] >> 4;
        g = (image->Gpix[y])[x] >> 4;
        b = (image->Bpix[y])[x] >> 4;
        idx = (r<<8) | (g<<4) | b;
        compte4bits[idx]++;
        }
    }

somme = 0;

for (idx=0; idx<(1<<12); idx++)
    {
    if (compte4bits[idx])   somme++;
    }
printf("la somme '4bits' est %ld\n", somme);

return 0;
}
/*::------------------------------------------------------------------::*/
/*
 *		on pourrait rapprocher cette fonction de la fonction
 *		qui calcule la couleur moyenne d'une image. 
 *		son nom est "Image_??????????????" et elle reside
 *		dans le module "colors.c".
 */
int
Image_minmax_RGB(Image_Desc *img, int *res)
{
int     x, y, r, g, b, minr, ming, minb, maxr, maxg, maxb;

minr = ming = minb = 300;
maxr = maxg = maxb = -42;

for (x=0; x<img->width; x++)
    {
    for (y=0; y<img->height; y++)
        {
	r = Image_R_pixel(img, x, y);
	if (r > maxr)		maxr = r;
	else if (r < minr)	minr = r;

	g = Image_G_pixel(img, x, y);
	if (g > maxg)		maxg = g;
	else if (g < ming)	ming = g;

	b = Image_B_pixel(img, x, y);
	if (b > maxb)		maxb = b;
	else if (b < minb)	minb = b;
        }
    }

/*
 * 	and now populate the return vector...
 */
res[0]  =  minr;	res[1]  =  maxr;
res[2]  =  ming;	res[3]  =  maxg;
res[4]  =  minb;	res[5]  =  maxb;

/*
 *	et c,a serait cool de lui faire traiter le canal alpha...
 */
res[6] = res[7] = -1;

return 0;
}
/*::------------------------------------------------------------------::*/
/*
	25 Aout 1999.
		gaffe, les @ des buffers pour les histogrames
		proviennent parfois de 'alloca'...
*/
int
Image_histo_RGB(Image_Desc *im, long *hr, long *hg, long *hb)
{
int	foo, x, y;

#if DEBUG_LEVEL > 1
fprintf(stderr, "%s : %p --> %p %p %p\n", __func__, im, hr, hg, hb);
#endif

for (foo=0; foo<256; foo++) {
	hr[foo] = 0L;
	hg[foo] = 0L;
	hb[foo] = 0L;
	}

for (y=0; y<im->height; y++) {
    for (x=0; x<im->width; x++) {
        hr[(im->Rpix[y])[x]]++;
        hg[(im->Gpix[y])[x]]++;
        hb[(im->Bpix[y])[x]]++;
        }
    }

return 0;
}
/*::------------------------------------------------------------------::*/
/*
 *	5 Fev 2001: optimization for spe3ed.
 */
int
Image_LUT_RGB(Image_Desc *src, Image_Desc *dst, int *lr, int *lg, int *lb)
{
int	x, y, foo;

if ( (foo=Image_compare_desc(src, dst)) )
    {
    fprintf(stderr, "Image_LUT_RGB: images differentes %d\n", foo);
    return foo;
    }

for (y=0; y<src->height; y++)
    {
        for (x=0; x<src->width; x++)
        {
        dst->Rpix[y][x] = lr[src->Rpix[y][x]];
        dst->Gpix[y][x] = lg[src->Gpix[y][x]];
        dst->Bpix[y][x] = lb[src->Bpix[y][x]];
        }
    }

return OLL_KORRECT;
}
/*::------------------------------------------------------------------::*/

int Image_LUT_mono(Image_Desc *src, Image_Desc *dst, int *lut)
{
int	x, y, foo;

if ( (foo=Image_compare_desc(src, dst)) )
    {
    fprintf(stderr, "%s: images differentes %d\n", __func__, foo);
    return foo;
    }

for (y=0; y<src->height; y++)
    {
    for (x=0; x<src->width; x++)
        {
        dst->Rpix[y][x] = lut[src->Rpix[y][x]];
        dst->Gpix[y][x] = lut[src->Gpix[y][x]];
        dst->Bpix[y][x] = lut[src->Bpix[y][x]];
	}
    }

return OLL_KORRECT;
}
/*::------------------------------------------------------------------::*/
/* et en parlant de LUTs, il n'y aurait pas un truc pour les LUTs
 * avec les height-fields ? */