From ce41f74ab4f93dde759e531ea86d3ad6c69e6798 Mon Sep 17 00:00:00 2001
From: Vadim Pisarevsky <no@email>
Date: Mon, 22 Nov 2010 12:16:38 +0000
Subject: [PATCH] decreased the lower canny threshold in HoughCircles, helps to
detect some circles in low-contrast images (ticket #518)
---
modules/imgproc/src/hough.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/modules/imgproc/src/hough.cpp b/modules/imgproc/src/hough.cpp
index bd0fc36151..60b3be98ed 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 );