| 4ce741 | 1997-05-29 | Mirar (Pontus Hagland) | |
|
| e3cb4b | 1997-04-03 | Mirar (Pontus Hagland) | |
|
| 4ce741 | 1997-05-29 | Mirar (Pontus Hagland) | | **! note
**! $Id: dct.c,v 1.8 1997/05/29 19:37:25 mirar Exp $<br>
|
| e3cb4b | 1997-04-03 | Mirar (Pontus Hagland) | | **! class image
*/
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | |
#include "global.h"
#include <math.h>
#include <ctype.h>
#include "stralloc.h"
#include "global.h"
|
| bb55f8 | 1997-03-16 | Fredrik Hübinette (Hubbe) | | #include "pike_macros.h"
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | | #include "object.h"
#include "constants.h"
#include "interpret.h"
#include "svalue.h"
#include "array.h"
#include "error.h"
#include "image.h"
extern struct program *image_program;
#define THIS ((struct image *)(fp->current_storage))
#define THISOBJ (fp->current_object)
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)<(b)?(b):(a))
#define testrange(x) max(min((x),255),0)
static const double c0=0.70710678118654752440;
static const double pi=3.14159265358979323846;
|
| e3cb4b | 1997-04-03 | Mirar (Pontus Hagland) | | |
| ba09c2 | 1997-04-30 | Mirar (Pontus Hagland) | | **!
**! note
**! Do NOT use this function if you don't know what
**! you're dealing with! Read some signal theory first...
|
| e3cb4b | 1997-04-03 | Mirar (Pontus Hagland) | | **! returns the new image object
**! arg int newx
**! arg int newy
**! new image size in pixels
**!
*/
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | | void image_dct(INT32 args)
{
rgbd_group *area,*val;
struct object *o;
struct image *img;
INT32 x,y,u,v;
double xsz2,ysz2,enh,xp,yp,dx,dy;
double *costbl;
rgb_group *pix;
if (!THIS->img) error("no image\n");
|
| b82986 | 1997-03-10 | Henrik Grubbström (Grubba) | | fprintf(stderr,"%lu bytes, %lu bytes\n",
(unsigned long)(sizeof(rgbd_group)*THIS->xsize*THIS->ysize),
(unsigned long)(sizeof(rgb_group)*THIS->xsize*THIS->ysize+1));
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | |
if (!(area=malloc(sizeof(rgbd_group)*THIS->xsize*THIS->ysize+1)))
error("Out of memory\n");
if (!(costbl=malloc(sizeof(double)*THIS->xsize+1)))
{
free(area);
error("Out of memory\n");
}
|
| e70975 | 1997-03-12 | Fredrik Hübinette (Hubbe) | | o=clone_object(image_program,0);
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | | img=(struct image*)(o->storage);
*img=*THIS;
if (args>=2
&& sp[-args].type==T_INT
&& sp[1-args].type==T_INT)
{
img->xsize=max(1,sp[-args].u.integer);
img->ysize=max(1,sp[1-args].u.integer);
}
else error("Illegal arguments to image->dct()\n");
|
| e3cb4b | 1997-04-03 | Mirar (Pontus Hagland) | | if (!(img->img=(rgb_group*)malloc(sizeof(rgb_group)*
img->xsize*img->ysize+1)))
|
| ab6aec | 1997-02-11 | Fredrik Hübinette (Hubbe) | | {
free(area);
free(costbl);
free_object(o);
error("Out of memory\n");
}
xsz2=THIS->xsize*2.0;
ysz2=THIS->ysize*2.0;
enh=(8.0/THIS->xsize)*(8.0/THIS->ysize);
for (u=0; u<THIS->xsize; u++)
{
double d,z0;
rgbd_group sum;
for (v=0; v<THIS->ysize; v++)
{
d=(u?1:c0)*(v?1:c0)/4.0;
sum.r=sum.g=sum.b=0;
pix=THIS->img;
for (x=0; x<THIS->xsize; x++)
costbl[x]=cos( (2*x+1)*u*pi/xsz2 );
for (y=0; y<THIS->ysize; y++)
{
z0=cos( (2*y+1)*v*pi/ysz2 );
for (x=0; x<THIS->xsize; x++)
{
double z;
z = costbl[x] * z0;
sum.r+=pix->r*z;
sum.g+=pix->g*z;
sum.b+=pix->b*z;
pix++;
}
}
sum.r*=d;
sum.g*=d;
sum.b*=d;
area[u+v*THIS->xsize]=sum;
}
fprintf(stderr,"."); fflush(stderr);
}
fprintf(stderr,"\n");
dx=((double)(THIS->xsize-1))/(img->xsize);
dy=((double)(THIS->ysize-1))/(img->ysize);
pix=img->img;
for (y=0,yp=0; y<img->ysize; y++,yp+=dy)
{
double z0;
rgbd_group sum;
for (x=0,xp=0; x<img->xsize; x++,xp+=dx)
{
sum.r=sum.g=sum.b=0;
val=area;
for (u=0; u<THIS->xsize; u++)
costbl[u]=cos( (2*xp+1)*u*pi/xsz2 );
for (v=0; v<THIS->ysize; v++)
{
z0=cos( (2*yp+1)*v*pi/ysz2 )*(v?1:c0)/4.0;
for (u=0; u<THIS->xsize; u++)
{
double z;
z = (u?1:c0) * costbl[u] * z0;
sum.r+=val->r*z;
sum.g+=val->g*z;
sum.b+=val->b*z;
val++;
}
}
sum.r*=enh;
sum.g*=enh;
sum.b*=enh;
pix->r=testrange(((int)(sum.r+0.5)));
pix->g=testrange(((int)(sum.g+0.5)));
pix->b=testrange(((int)(sum.b+0.5)));
pix++;
}
fprintf(stderr,"."); fflush(stderr);
}
free(area);
free(costbl);
pop_n_elems(args);
push_object(o);
}
|