Question

基于opencv进行canny变换和hough变换后，如何计算直线与水平方向的角度？

我想将hough后的边缘直线选取最长的一根，求出它与水平方向的夹角度数，并输出，这样该怎么修改下这个程序呢？#include<cv.h>#include<highgui.h><p> </p><p>#pragma comment(lib, "cv.lib")#pragma comment(lib, "cxcore.lib")#pragma comment(lib, "highgui.lib")</p>int main(){ IplImage* pImgSrc = NULL; //源图像 IplImage* pImg8u = NULL; //灰度图 IplImage* pImgCanny = NUL

L; //边缘检测后的图 IplImage* pImgDst = NULL; //在图像上画上检测到的直线后的图像 CvSeq* lines = NULL; CvMemStorage* storage = NULL; /*边缘检测*/ pImgSrc = cvLoadImage ("1.jpg", 1); pImg8u = cvCreateImage (cvGetSize(pImgSrc), IPL_DEPTH_8U, 1); pImgCanny = cvCreateImage (cvGetSize(pImgSrc), IPL_DEPTH_8U, 1); pImgDst = cvCreateImage (cvGetSize(pImgSrc), IPL_DEPTH_8U, 1); cvCvtColor (pImgSrc, pImg8u, CV_BGR2GRAY); cvCanny (pImg8u, pImgCanny, 20, 200, 3); /*检测直线*/ storage = cvCreateMemStorage (0); lines = cvHoughLines2 (pImgCanny, storage, CV_HOUGH_PROBABILISTIC, 1, CV_PI/180, 80, 200, 10); pImgDst = cvCreateImage (cvGetSize(pImgSrc), IPL_DEPTH_8U, 3); cvCvtColor (pImg8u, pImgDst, CV_GRAY2BGR); /*在pImgDst上画出检测到的直线*/ for (int i = 0; i < lines->total; i++) { CvPoint* line = (CvPoint*)cvGetSeqElem (lines, i); cvLine (pImgDst, line[0], line[1], CV_RGB(255,0,0), 3, 8); } cvNamedWindow ("src",1); cvNamedWindow ("canny", 1); cvNamedWindow ("hough", 1); cvShowImage ("src", pImgSrc); cvShowImage ("canny", pImgCanny); cvShowImage ("hough", pImgDst); cvWaitKey (0); cvReleaseImage (&pImgSrc); cvReleaseImage (&pImg8u); cvReleaseImage (&pImgCanny); cvReleaseImage (&pImgDst); cvReleaseMemStorage (&storage); return 0;}

Answer 1

直线上的两个不同的点都得到了，那么它的斜率之类不都可以得到了，接下来它与任何方向的夹角都可以计算了。如果你对icvHoughLinesProbabilistic()这个函数比较熟悉的话，可以尝试修改这个函数，那么它就可以直接输出直线的rho和theta，这样就不用你自己再计算夹角了。你的代码中实际也是调用的icvHoughLinesProbabilistic()这个函数，尝试修改它吧。。。