#include "stdio.h"
#include "math.h"
#include "malloc.h"
#define Width 256
#define Height 256
#define N1 3
main()//信噪比
{
FILE *FileOpen(),*in1,*in2;
unsigned char *image0,*image1;
unsigned char head[54];
int k;
long double S=0,S2=0,S3=0,S1,S12,S13,mse,mse2,mse3,PSNR,PSNR1,PSNR2,PSNR3;
image0=malloc(Width*Height*N1*sizeof(unsigned char));//动态分配内存
image1=malloc(Width*Height*N1*sizeof(unsigned char));//动态分配内存
in1=fopen("lena256.bmp","rb");
in2=fopen("RE16.bmp","rb");
fread(head,54*sizeof(unsigned char),1,in1);//读出原图像输入文件头
fread(head,54*sizeof(unsigned char),1,in2);//读出重构图像输入文件头
fread(image0,Width*Height*N1*sizeof(unsigned char),1,in1);//将原图像数据整体读出
fread(image1,Width*Height*N1*sizeof(unsigned char),1,in2);//将重构图像数据整体读出
for(k=0;k<Height*Width;k++)
{
S+=(image0[3*k]-image1[3*k])*(image0[3*k]-image1[3*k]);
S2+=(image0[3*k+1]-image1[3*k+1])*(image0[3*k+1]-image1[3*k+1]);
S3+=(image0[3*k+2]-image1[3*k+2])*(image0[3*k+2]-image1[3*k+2]);
/* if(image2[3*k+1]>20)
{printf("%3d",image2[3*k+1]);}
printf("\n");
if(image2[3*k+2]>20)
{printf("%3d",image2[3*k+2]);}
printf("\n");*/
}
mse=S/(Width*Height);//计算均方差均方差
mse2=S2/(Width*Height);
mse3=S3/(Width*Height);
S1=255.0*255.0/mse;
S12=255.0*255.0/mse2;
S13=255.0*255.0/mse3;
PSNR1=10.0*(log10(S1));//计算信噪比
PSNR2=10.0*(log10(S12));
PSNR3=10.0*(log10(S13));
PSNR=(PSNR1+PSNR2+PSNR3)/3;
printf(" B psnr=%lf \n",PSNR1);
printf(" G psnr=%lf \n",PSNR2);
printf(" R psnr=%lf \n",PSNR3);
printf(" psnr=%lf \n",PSNR);
fclose(in1);
fclose(in2);
free(image0);
free(image1);
return 0;
}
