图像亮度、对比度调节

#include "cv.h"

#include "highgui.h"

#include <stdio.h>

int ImageAdjust(IplImage *src,IplImage *dst,

double low,double high, //x direction

double bottom,double top, //y direction

double gamma);

int main(void)

{

char *filename="lena.jpg";

IplImage *dst,*src = /blog.armyourlife.info/cvLoadImage(filename,0);

if(!src)

{

printf("Couldn't seem to Open %s, sorry/n",filename);

return -1;

}



cvNamedWindow( "src", 1 );

cvNamedWindow( "result", 1 );



// Image adjust

dst = cvCloneImage(src);

// 输入参数 [0,0.5] 和 [0.5,1], gamma=1

if( ImageAdjust( src, dst, 0, 0.5, 0.5, 1, 1)!=0)

return -1;



cvShowImage( "src", src );

cvShowImage( "result", dst );

cvWaitKey(0);

cvDestroyWindow("src");

cvDestroyWindow("result");

cvReleaseImage( &src );

cvReleaseImage( &dst );



return 0;

}

int ImageAdjust(IplImage* src, IplImage* dst,

double low, double high, // X方向：low and high are the intensities of src

double bottom, double top, // Y方向：mapped to bottom and top of dst

double gamma )

{

double low2 = low*255;

double high2 = high*255;

double bottom2 = bottom*255;

double top2 = top*255;

double err_in = high2 - low2;

double err_out = top2 - bottom2;

int x,y;

double val;

if(low<0 && low>1 && high <0 && high>1&&

bottom<0 && bottom>1 && top<0 && top>1 && low>high)

return -1;

// intensity transform

for( y = 0; y < src->height; y++)

{

for (x = 0; x < src->width; x++)

{

val = ((uchar*)(src->imageData + src->widthStep*y))[x];

val=pow((val - low2)/err_in, gamma)*err_out+bottom2;

if(val>255)

val=255;

if(val<0)

val=0; // Make sure src is in the range [low,high]

((uchar*)(dst->imageData + dst->widthStep*y))[x] = (uchar) val;

}

}

return 0;

}