直方图均衡化代码

from http://blog.sina.com.cn/s/blog_5f99444c0101bnr1.html

#include

#include "cv.h"

#include "highgui.h"

using namespace std;

//直方图均衡化

int main()

{

IplImage *src,*dst;

IplImage *srcPrj,*dstPrj;

int width,height,widthStep;

int prjheight;

int histogram[256]={0};

int i,j;

uchar *pdata,*pdst;

src = cvLoadImage("pic.jpg",0); //读取灰度图

dst = cvCreateImage(cvGetSize(src),IPL_DEPTH_8U,1);

width = src->width;height = src->height;widthStep = src->widthStep;

pdata = (uchar*)src->imageData;

for(i=0;i

for(j=0;j

histogram[pdata[i*widthStep+j]]++; //统计灰度直方图

}

}

prjheight = height*20;

srcPrj = cvCreateImage(cvSize(1024,prjheight),IPL_DEPTH_8U,1);

cvZero(srcPrj); //清零

for(i=0;i<1024;i++){

for(j=prjheight-1;j>prjheight-1-histogram[i/4] && j>=0;j--)

srcPrj->imageData[j*1024+i] = 255;

}

cvSaveImage("srcPrj.bmp",srcPrj);

//下面进行直方图均衡

double map[256];int sum=0;

//计算映射表

for(i=0;i<256;i++){

sum += histogram[i];

map[i] = (double)sum*255/(width*height) + 0.5;

}

//输出数据赋值

pdst = (uchar*)dst->imageData;

for(i=0;i

for(j=0;j

pdst[i*widthStep+j] = map[pdata[i*widthStep+j]];

}

}

cvSaveImage("dst.bmp",dst); //保存直方图均衡化后的图像

//计算灰度直方图

memset(histogram,0,sizeof(int)*256);

for(i=0;i

for(j=0;j

histogram[pdst[i*widthStep+j]]++; //统计灰度直方图

}

}

// prjheight = height*width/8;

dstPrj = cvCreateImage(cvSize(1024,prjheight),IPL_DEPTH_8U,1);

cvZero(dstPrj); //清零

for(i=0;i<1024;i++){

for(j=prjheight-1;j>prjheight-1-histogram[i/4] && j>=0;j--)

dstPrj->imageData[j*1024+i] = 255;

}

cvSaveImage("dstPrj.bmp",dstPrj);

cvReleaseImage(&src);

cvReleaseImage(&dst);

cvReleaseImage(&srcPrj);

cvReleaseImage(&dstPrj);

return 0;

}

原图及其灰度直方图：

 

直方图均衡化后的图像及其灰度直方图：