dct.c

this code is a implementation of the Discrete cosinuss transformation. In this code I have used the

#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#define  PI 3.1415926


typedef struct BMP_struct {
	char	signature[2];	// BM (Bitmap windows), BA (Bitmap OS/2), CI (Icone couleur OS/2),...
	int	filesize;	// Taille totale du fichier BMP
	int	offset;
	int	headersize;
	int	imageHsize;
	int	imageVsize;
	int	plans;
	int	bpp;		// nombre de bits par pixel
	int	compression;
	int	imagesize;
	int	Hres;		// r閟olution horizontale
	int	Vres;		// r閟olution verticale
	int	colors;		// nombre de couleurs
	int	primarycolors;
	unsigned char *palette;
	unsigned char **data;
} BMPImageStruct;

double  **in,**dct;
BMPImageStruct passage,passage1;

int hex2dec (unsigned char *hex, int n) // Conversion d'un nombre cod