opencv轮廓提取

#include<iostream>
#include<opencv2\opencv.hpp>
#include<opencv2\highgui\highgui.hpp>
#include<opencv2\imgproc\imgproc.hpp>

int main()
{
	//打开要识别字符的图像
	IplImage *image = cvLoadImage("../../hello.png");
	if (image == NULL)
	{
		std::cout << "错误：无法打开该图像文件！" << std::endl;
	}
	//转换到灰度图像
	IplImage *img_gray = cvCreateImage(cvGetSize(image), image->depth, 1);
	cvCvtColor(image, img_gray, CV_BGR2GRAY);
	//二值化
	IplImage *img_value = cvCreateImage(cvGetSize(img_gray), image->depth, 1);
	cvThreshold(img_gray, img_value, 100, 255, CV_THRESH_BINARY_INV);
	//寻找轮廓
	CvMemStorage *pStorage = cvCreateMemStorage(0);
	CvSeq *pConInner = NULL;
	int num = cvFindContours(img_value, pStorage, &pConInner, sizeof(CvContour),
		CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);
	//根据轮廓坐标使用方框标出来
	for (int i = 0; i < num; i++)
	{

		CvRect rc = cvBoundingRect(pConInner);
		cvDrawRect(image, cvPoint(rc.x, rc.y), cvPoint(rc.x + rc.width, rc.y + rc.height), CV_RGB(255, 0, 0));
		pConInner = pConInner->h_next;
	}
	//显示图像
	cvNamedWindow("image", 0);
	cvNamedWindow("image_gray", 0);
	cvNamedWindow("img_value", 0);
	cvShowImage("image", image);
	cvShowImage("image_gray", img_gray);
	cvShowImage("img_value", img_value);
	cvWaitKey(0);
}