我所知的opencv中分割函数：watershed（只是看看效果，不能返回每类pixel类属），cvsegmentImage，cvPyrSegmentation（返回pixel类属）

金字塔分割原理篇在这里，本文只提供代码。

Segment函数：

#include<cv.h>
#include <cvaux.h>
#include <opencv\cxcore.hpp>
#include <opencv.hpp>
#include <nonfree.hpp>
#include <core/core.hpp>
#include <imgproc/imgproc.hpp>
#include <imgproc/imgproc_c.h>
#include <vector>
#include <map>
#include <highgui.h>
using namespace std;
using namespace cv;
void Segment(IplImage* I)
{

	////////////////////parameters initialization//////////////////////
	int mode = CV_RETR_LIST;
	int level = 2, block_size = 1000;
	CvMemStorage* storage = cvCreateMemStorage(block_size);
	CvSeq* components;
	double threshold1 = 100,threshold2 = 50;

	IplImage *src = cvCreateImage(cvGetSize(I),IPL_DEPTH_8U,1);
	cvCvtColor(I,src,CV_RGB2GRAY);
	IplImage* dst = cvCreateImage(cvGetSize(I),IPL_DEPTH_8U,1);

	src->width = dst->width = (I->width & -(1 << level));
	src->height = dst->height = (I->height & -(1 << level));

	//////////////////////Segment/////////////////////////
	cvPyrSegmentation(src,dst,storage,&components,level,threshold1,threshold2);
	int ncomp = components->total;
	cout<<"segemented into "<<ncomp<<" components."<<endl;

	//////////////////////////Get Components/////////////////////////////
	map<int, int>mapping;//map color value to component id (classify)
	for (int i = 0; i<ncomp; i++)//foreach connection component
	{
		CvConnectedComp* cc = (CvConnectedComp*) cvGetSeqElem(components,i);
		cvDrawRect(dst,cvPoint(cc->rect.x,cc->rect.y),cvPoint(cc->rect.x+cc->rect.width,cc->rect.y+cc->rect.height),cvScalar(255,255,0));
		mapping.insert(pair<int,int>(cc->value.val[0],i));
	}
	cvShowImage("segementation",dst);
	waitKey();
	cvReleaseMemStorage(&storage);
}

彩色图分割版本：

void Segment(IplImage* I)
{
	////////////////////parameters initialization//////////////////////
	int mode = CV_RETR_LIST;
	int level = 2, block_size = 1000;
	CvMemStorage* storage = cvCreateMemStorage(block_size);
	CvSeq* components;
	double threshold1 = 10,threshold2 = 50;

	IplImage *src = cvCreateImage(cvGetSize(I),IPL_DEPTH_8U,3);
	src = cvCloneImage(I);
	IplImage* dst = cvCreateImage(cvGetSize(I),IPL_DEPTH_8U,3);

	src->width = dst->width = (I->width & -(1 << level));
	src->height = dst->height = (I->height & -(1 << level));

	//////////////////////Segment/////////////////////////
	cvPyrSegmentation(src,dst,storage,&components,level,threshold1,threshold2);
	int ncomp = components->total;
	cout<<"segemented into "<<ncomp<<" components."<<endl;

	//////////////////////////Get Components/////////////////////////////
	map<int, int>mapping;//map color value to component id (classify)
	for (int i = 0; i<ncomp; i++)//foreach connection component
	{
		CvConnectedComp* cc = (CvConnectedComp*) cvGetSeqElem(components,i);
		cvDrawRect(dst,cvPoint(cc->rect.x,cc->rect.y),cvPoint(cc->rect.x+cc->rect.width,cc->rect.y+cc->rect.height),cvScalar(255,255,0));
		mapping.insert(pair<int,int>(cc->value.val[0],i));
	}
	cvShowImage("segementation",dst);
	waitKey();
	cvReleaseMemStorage(&storage);
}

opencv 金字塔图像分割