OpenCV之邻域运算之最值滤波

写了一段小程序，分享给大家！

//====================================================================
// 作者   : quarryman
// 邮箱   : quarrying{at}qq.com
// 主页   : http://blog.csdn.net/quarryman
// 日期   : 2013年08月03日
// 描述   : 实现最值滤波，非最值抑制
//====================================================================
#include <cv.h>
#include <highgui.h>
#define max(a,b)            (((a) > (b)) ? (a) : (b))
#define min(a,b)            (((a) < (b)) ? (a) : (b))

CvRect kcvRectIntersection(CvRect rect1,CvRect rect2)
{
	CvRect rect;
	rect.x=max(rect1.x, rect2.x);
	rect.y=max(rect1.y, rect2.y);
	rect.width=min(rect1.x+rect1.width, rect2.x+rect2.width);
	rect.width=rect.width-rect.x;
	rect.height=min(rect1.y+rect1.height, rect2.y+rect2.height);
	rect.height=rect.height-rect.y;
	return rect;
}

CvRect kcvGetRectFromCenterAndSize(int cx, int cy, int w, int h=0)
{
	CvRect rect;
	rect.x=cx-(w>>1);
	rect.y=cy-(h>>1);
	rect.width=w;
	rect.height=(h==0?w:h);
	return rect;
}

int minValue(IplImage* img,CvRect rect)
{
	uchar minval=255;
	for(int i=rect.y;i<rect.y+rect.height;++i)
	{
		for(int j=rect.x;j<rect.x+rect.width;++j)
		{
			if(CV_IMAGE_ELEM(img,uchar,i,j)<minval)
			{
				minval=CV_IMAGE_ELEM(img,uchar,i,j);
			}
		}
	}
	return minval;
}

int maxValue(IplImage* img,CvRect rect)
{
	uchar maxval=0;
	for(int i=rect.y;i<rect.y+rect.height;++i)
	{
		for(int j=rect.x;j<rect.x+rect.width;++j)
		{
			if(CV_IMAGE_ELEM(img,uchar,i,j)>maxval)
			{
				maxval=CV_IMAGE_ELEM(img,uchar,i,j);
			}
		}
	}
	return maxval;
}

enum
{
	KCV_MAX,		// 最大值滤波器，类似于形态学膨胀
	KCV_MIN,		// 最小值滤波器，类似于形态学腐蚀
	KCV_NMS_MAX,	// 非最大值抑制
	KCV_NMS_MIN		// 非最小值抑制
};

void maxminFilter(IplImage* src,IplImage* dst,int width,int height=0,int mode=KCV_MAX)
{
	for(int j=0;j<src->width;++j)
	{
		for(int i=0;i<src->height;++i)
		{
			CvRect rect1=cvRect(0,0,src->width,src->height);
			CvRect rect2=kcvGetRectFromCenterAndSize(j,i,width,height);
			CvRect rect=kcvRectIntersection(rect1,rect2);
			switch(mode)
			{
			case KCV_MAX:
				CV_IMAGE_ELEM(dst,uchar,i,j)=maxValue(src,rect);
				break;
			case KCV_MIN:
				CV_IMAGE_ELEM(dst,uchar,i,j)=minValue(src,rect);
				break;
			case KCV_NMS_MAX:
				if(CV_IMAGE_ELEM(src,uchar,i,j)!=maxValue(src,rect))
				{
					CV_IMAGE_ELEM(dst,uchar,i,j)=0;
				}
				else
				{
					CV_IMAGE_ELEM(dst,uchar,i,j)=CV_IMAGE_ELEM(src,uchar,i,j);
				}
				break;
			case KCV_NMS_MIN:
				if(CV_IMAGE_ELEM(src,uchar,i,j)!=minValue(src,rect))
				{
					CV_IMAGE_ELEM(dst,uchar,i,j)=255;
				}
				else
				{
					CV_IMAGE_ELEM(dst,uchar,i,j)=CV_IMAGE_ELEM(src,uchar,i,j);
				}
				break;
			}
		}
	}
}

int main()
{
	IplImage* src=cvLoadImage("lena.jpg",0);
	IplImage* dst=cvCreateImage(cvGetSize(src),8,1);
	cvNamedWindow("original image");
	cvShowImage("original image",src);

	maxminFilter(src,dst,5,5,KCV_MAX);
	cvNamedWindow("maximum filter");
	cvShowImage("maximum filter",dst);
	cvSaveImage("maximum filter.jpg",dst);

	maxminFilter(src,dst,5,5,KCV_MIN);
	cvNamedWindow("minimum filter");
	cvShowImage("minimum filter",dst);
	cvSaveImage("minimum filter.jpg",dst);

	maxminFilter(src,dst,5,5,KCV_NMS_MAX);
	cvNamedWindow("non-maximum suppression");
	cvShowImage("non-maximum suppression",dst);
	cvSaveImage("non-maximum suppression.jpg",dst);

	maxminFilter(src,dst,5,5,KCV_NMS_MIN);
	cvNamedWindow("non-minimum suppression");
	cvShowImage("non-minimum suppression",dst);
	cvSaveImage("non-minimum suppression.jpg",dst);

	cvWaitKey(0);
	cvDestroyAllWindows();
	cvReleaseImage(&src);
	cvReleaseImage(&dst);

	return 0;
}

最大值滤波结果：

最小值滤波结果：

非最大值抑制结果：

非最小值抑制结果：