From: Vadim Pisarevsky <no@email>
Date: Mon, 22 Nov 2010 12:16:38 +0000 (+0000)
Subject: decreased the lower canny threshold in HoughCircles, helps to detect some circles... 
X-Git-Tag: accepted/tizen/6.0/unified/20201030.111113~8378
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ce41f74ab4f93dde759e531ea86d3ad6c69e6798;p=platform%2Fupstream%2Fopencv.git

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

diff --git a/modules/imgproc/src/hough.cpp b/modules/imgproc/src/hough.cpp
index bd0fc361..60b3be9 100644
--- 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 );