最小二乘法拟合椭圆

#include "cv.h" #include "highgui.h" int slider_pos = 70; IplImage *image02 = 0, *image03 = 0, *image04 = 0; void process_image(int h); int main( int argc, char** argv ) { const char* filename = argc == 2 ? argv[1] : (char*)"stuff.jpg"; // 读入图像，强制为灰度图像 if( (image03 = cvLoadImage(filename, 0)) == 0 ) return -1; // Create the destination images image02 = cvCloneImage( image03 ); image04 = cvCloneImage( image03 ); // Create windows. cvNamedWindow("Source", 1); cvNamedWindow("Result", 1); // Show the image. cvShowImage("Source", image03); // Create toolbars. HighGUI use. cvCreateTrackbar( "Threshold", "Result", &slider_pos, 255, process_image ); process_image(0); // Wait for a key stroke; the same function arranges events processing cvWaitKey(0); cvReleaseImage(&image02); cvReleaseImage(&image03); cvDestroyWindow("Source"); cvDestroyWindow("Result"); return 0; } // Define trackbar callback functon. This function find contours, // draw it and approximate it by ellipses. void process_image(int h) { CvMemStorage* stor; CvSeq* cont; CvBox2D32f* box; CvPoint* PointArray; CvPoint2D32f* PointArray2D32f; // 创建动态结构序列 stor = cvCreateMemStorage(0); cont = cvCreateSeq(CV_SEQ_ELTYPE_POINT, sizeof(CvSeq), sizeof(CvPoint) , stor); // 二值话图像. cvThreshold( image03, image02, slider_pos, 255, CV_THRESH_BINARY ); // 寻找所有轮廓. cvFindContours( image02, stor, &cont, sizeof(CvContour), CV_RETR_LIST, CV_CHAIN_APPROX_NONE, cvPoint(0,0)); // Clear images. IPL use. cvZero(image02); cvZero(image04); // 本循环绘制所有轮廓并用椭圆拟合. for(;cont;cont = cont->h_next) { int i; // Indicator of cycle. int count = cont->total; // This is number point in contour CvPoint center; CvSize size; // Number point must be more than or equal to 6 (for cvFitEllipse_32f). if( count < 6 ) continue; // Alloc memory for contour point set. PointArray = (CvPoint*)malloc( count*sizeof(CvPoint) ); PointArray2D32f= (CvPoint2D32f*)malloc( count*sizeof(CvPoint2D32f) ); // Alloc memory for ellipse data. box = (CvBox2D32f*)malloc(sizeof(CvBox2D32f)); // Get contour point set. cvCvtSeqToArray(cont, PointArray, CV_WHOLE_SEQ); // Convert CvPoint set to CvBox2D32f set. for(i=0; i<count; i++) { PointArray2D32f[i].x = (float)PointArray[i].x; PointArray2D32f[i].y = (float)PointArray[i].y; } //拟合当前轮廓. cvFitEllipse(PointArray2D32f, count, box); // 绘制当前轮廓. cvDrawContours(image04,cont,CV_RGB(255,255,255), CV_RGB(255,255,255),0,1,8,cvPoint(0,0)); // Convert ellipse data from float to integer representation. center.x = cvRound(box->center.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; // Draw ellipse. cvEllipse(image04, center, size, box->angle, 0, 360, CV_RGB(0,0,255), 1, CV_AA, 0); // Free memory. free(PointArray); free(PointArray2D32f); free(box); } // Show image. HighGUI use. cvShowImage( "Result", image04 ); }