decreased the lower canny threshold in HoughCircles, helps to detect some circles in low-contrast images (ticket #518)

14 years ago · ce41f74ab4
parent 732bd621bb
commit ce41f74ab4
1 changed files with 1 additions and 1 deletions
--- a/modules/imgproc/src/hough.cpp
+++ b/modules/imgproc/src/hough.cpp
@ -817,7 +817,7 @@ icvHoughCirclesGradient( CvMat* img, float dp, float min_dist,
    CvSeqReader reader;

    edges = cvCreateMat( img->rows, img->cols, CV_8UC1 );
-    cvCanny( img, edges, MAX(canny_threshold/2,1), canny_threshold, 3 );
+    cvCanny( img, edges, MAX(canny_threshold/5,1), canny_threshold, 3 );

    dx = cvCreateMat( img->rows, img->cols, CV_16SC1 );
    dy = cvCreateMat( img->rows, img->cols, CV_16SC1 );