椭圆拟合

#include "cv.h"
#include "highgui.h"


int slider_pos=70;//阈值


IplImage *image02 =0,*image03 = 0,*image04 = 0;
void process_image(int h);


int main(int argc ,char **argv)
{
const char *filename ="rice.png";
if ((image03 = cvLoadImage(filename,0))==0)//读入图像为灰度图像
{
return -1;
}
image02 = cvCloneImage(image03);
image04 = cvCloneImage(image03);


cvNamedWindow("Source",1);
cvNamedWindow("Result",1);


cvShowImage("Source",image03);


cvCreateTrackbar("Threshold","Result",&slider_pos,255,process_image);


process_image(0);


cvWaitKey(0);
cvSaveImage("1.jpg",image04);


cvReleaseImage(&image02);
cvReleaseImage(&image03);


cvDestroyWindow("Source");
cvDestroyWindow("Result");
return 0;


}


//这个函数寻找出轮廓、用椭圆拟合画出
void process_image(int h)
{
CvMemStorage *stor;
CvSeq *cont;
CvBox2D32f *box;
CvPoint *PointArray;
CvPoint2D32f *PointArray2D32f;


stor = cvCreateMemStorage(0);
cont = cvCreateSeq(CV_SEQ_ELTYPE_POINT,sizeof(CvSeq),sizeof(CvPoint),stor);


cvThreshold(image03,image02,slider_pos,255,CV_THRESH_BINARY);


cvFindContours(image02,stor,&cont,sizeof(CvContour),
CV_RETR_LIST,CV_CHAIN_APPROX_NONE,cvPoint(0,0));


cvZero(image02);
cvZero(image04);


//绘制所有轮廓并用椭圆拟合
for (;cont;cont = cont ->h_next)
{
int i;
int count= cont->total;//轮廓个数
CvPoint center;
CvSize size;


/*个数必须大于6，这是cvFitEllipse_32f的要求*/
if (count<6) { continue; } //分配内存给点集 PointArray = (CvPoint *)malloc(count*sizeof(CvPoint)); PointArray2D32f = (CvPoint2D32f*)malloc(count*sizeof(CvPoint2D32f)); //分配内存给椭圆数据 box = (CvBox2D32f *)malloc(sizeof(CvBox2D32f)); //得到点集（这个方法值得借鉴） cvCvtSeqToArray(cont,PointArray,CV_WHOLE_SEQ); //将CvPoint点集转化为CvBox2D32f集合 for (i=0;icenter.x);
center.y = cvRound(box->center.y);
size.width = cvRound(box->size.width*0.5);
size.height = cvRound(box->size.height*0.5);
box->angle = -box->angle;

//画椭圆
cvEllipse(image04,center,size,box->angle,0,360,CV_RGB(0,0,255),1,CV_AA,0);

free(PointArray);
free(PointArray2D32f);
free(box);
}
cvShowImage("Result",image04);
}