C语言实现直方图均衡化

#include <cv.h>
#include <highgui.h>
#include <iostream>
using namespace std;

int main(int argc, char** argv)
{
	//载入图片
	int i=0, j=0, temp=0;
	IplImage * img = cvLoadImage("D:\\2.jpg", CV_LOAD_IMAGE_GRAYSCALE);//图片路径
	int height = img->height;
	int width  = img->width;
	int step   = img->widthStep;
	uchar *data = (uchar*)img->imageData;
	float size = height*width;

	//直方图
	unsigned int hist[256] = {0};
	for (i=0; i<height; i++)
	{
		for (j=0; j<width; j++)
		{
			temp = data[i*step+j];
			hist[temp]++;
		}
	}
	//归一化直方图
	float histPDF[256] = {0};
	for (i=0; i<255; i++)
	{
		histPDF[i]=(float)hist[i]/size;
	}
	//累积直方图
	float histCDF[256] = {0};
	for (i=0; i<256; i++)
	{
		if (0==i) histCDF[i] = histPDF[i];
		else histCDF[i] = histCDF[i-1] + histPDF[i];
	}
	//直方图均衡化,映射
	int histEQU[256] = {0};
	for (i=0; i<256; i++)
	{
		histEQU[i] = (int)(255.0 * histCDF[i] + 0.5);
	}
	for (i=0; i<height; i++)
	{
		for (j=0; j<width; j++)
		{
			temp = data[i*step+j];
			data[i*step+j] = histEQU[temp];
		}
	}


	cvNamedWindow("demo", CV_WINDOW_AUTOSIZE);
	cvShowImage("demo", img);
	cvWaitKey(0);
	cvDestroyWindow("demo");
	cvReleaseImage(&img);
	return 0;
}