請問各位大哥大姊，我把圖得到的向量利用hough transform找出兩條直線後，該怎麼計算出這兩條直線的角度是多少？以下是用opencv寫出來的hough transform程式會得到兩條線，該怎麼計算這兩條線的角度？？例如以手來比喻：右手平行為一條線是0度，而左手向上傾斜45度為另一條線是135度，而中間的夾角麻煩各位高手指導該怎麼計算！謝謝！ 


[code cpp]
IplImage* src = cvLoadImage( "1.bmp", 0 );
CvMemStorage* storage = cvCreateMemStorage(0);
CvSeq* lines = 0; #if 0 lines = cvHoughLines2( src, storage, CV_HOUGH_STANDARD, 1, CV_PI/180, 100, 0, 0 );
for(int i = 0; i < MIN(lines->total); i )
{
float* line = (float*)cvGetSeqElem(lines,i);
float rho = line[0];
float theta = line[1];
CvPoint pt1, pt2;
double a = cos(theta), b = sin(theta);
double x0 = a*rho, y0 = b*rho;
pt1.x = cvRound(x0 1000*(-b));
pt1.y = cvRound(y0 1000*(a));
pt2.x = cvRound(x0 - 1000*(-b));
pt2.y = cvRound(y0 - 1000*(a));
cvLine( src, pt1, pt2, cvScalar( (100), (0), (0)), 5, CV_AA, 0 );
}

#else
lines = cvHoughLines2( src, storage, CV_HOUGH_PROBABILISTIC, 1, CV_PI/180, 67, 30, 10 );
for(int i = 0; i < lines->total; i )
{
CvPoint* line = (CvPoint*)cvGetSeqElem(lines,i);
cvLine( src, line[0], line[1], cvScalar( (100), (0), (0)), 5, CV_AA, 0 );
}

#endif
cvNamedWindow( "Source", 1 );
cvShowImage( "Source", src );
cvWaitKey(0);
}[/code]

編輯記錄

算各線的斜率 y=ax+b
求出各線在平面的角度

各線的角度差應該就是你要的

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Kenji Gan