#include"cv.h" 

#include"highgui.h" 

#include<iostream> 

using namespace std;  

double focus(IplImage* image);  

int main() { 

 IplImage* previous1;  

IplImage* previous2;  

IplImage* previous3;  

IplImage* previous4;  

 previous1=cvLoadImage("e://temporary/test01.bmp",); 

 previous2=cvLoadImage("e://temporary/test02.bmp",); 

 previous3=cvLoadImage("e://temporary/test03.bmp",); 

 previous4=cvLoadImage("e://temporary/test04.bmp",);  

 if(previous1!=&&previous2!=&&previous3!=&&previous4!=) 

 { 

  cvNamedWindow("previous1",); 

  cvShowImage("previous1",previous1);   cvNamedWindow("previous2",); 

  cvShowImage("previous2",previous2);   cvNamedWindow("previous3",); 

  cvShowImage("previous3",previous3);   cvNamedWindow("previous4",); 

  cvShowImage("previous4",previous4);  

  cout<<"The definition of the previous1 is: "<<focus(previous1)<<endl; 

  cout<<"The definition of the previous2 is: "<<focus(previous2)<<endl; 

  cout<<"The definition of the previous3 is: "<<focus(previous3)<<endl; 

  cout<<"The definition of the previous4 is: "<<focus(previous4)<<endl; 

  //关掉窗口，结束   cvWaitKey(0);  

  cvDestroyWindow("previous1");  

 cvReleaseImage(&previous1); 

  cvDestroyWindow("previous2"); 

  cvReleaseImage(&previous2);  

 cvDestroyWindow("previous3");   

cvReleaseImage(&previous3);  

 cvDestroyWindow("previous4");   

cvReleaseImage(&previous4);   return ;  } 

 return -; 

}  

double focus(IplImage* image) { 

 IplImage* picone=cvCreateImage(cvGetSize(image),,);  

 cvCvtColor(image,picone,CV_BGR2YCrCb);  

 CvScalar gety; 

 double z=,zy1=,zy2=,total=;  double gety1=,gety2=;  double final=;  

 for(int ix=;ix<(picone->height);ix++) 

  { 

   gety1=;   

 gety2=;   

 zy1=;   

 zy2=;  

   for(int jy=;jy<(picone->width);jy++) 

   { 

    gety=cvGet2D(picone,ix,jy); 

    z=0.5*gety.val[]-gety1+0.5*gety2+zy1-0.5*zy2;   

  total=total+z;     

gety2=gety1; 

    gety1=gety.val[];     zy2=zy1;     zy1=z;  

  }  

} 

 cvReleaseImage(&picone); 

 final=abs(total/((image->height)*(image->width)));  

 return final; 

}