差分熵计算

//  定义控制台应用程序的入口点。


#include <stdio.h>
#include <math.h>
#include <string.h>
#include <malloc.h>

#define MAX_VALUE 256
#define MAX_DIFF_VALUE 2*MAX_VALUE
#define IMAGE_WIDTH 256

void usage(void);
float ent(float p[], int num_symbols);

void main(int argc, char **argv)
{
char infile[80]; //the file name of the input image file
int i,j,k; 

FILE *ifp;
unsigned char* img_content; /*pointer to an array for the content of the file */
int size;
int freq[MAX_DIFF_VALUE];
float prob[MAX_DIFF_VALUE];
int diff;

float entropy;

//open input image file