HoughCircles detects too small circles (Bug #518)

Added by Maximilian Matthe over 14 years ago. Updated over 14 years ago.

Status:Done Start date:
Priority:High Due date:
Assignee:- % Done:

0%
Category:imgproc, video
Target version:-
Affected version: Operating System:
Difficulty: HW Platform:
Pull request:

Description

Hey guys,

I've found a bug with cv::HoughCircles. It detects circles, that do not lie in the specified radius range. See accompanying files.

Screenshot description: The window "hough" contains the detected circles in gray. The three white ones describe the range of accepted radius. The bottomleft-circle e.g. is definitely too small.

Im actually using OpenCV2.1 on Windows 7, 32bit, compiled with VS2005 SP1

Regards, Max

1.jpg - sample image (15 kB) Maximilian Matthe, 2010-08-07 12:37 pm

hough.cpp - sample code (1.3 kB) Maximilian Matthe, 2010-08-07 12:37 pm

screen.jpg - Screenshot of problem (162.5 kB) Maximilian Matthe, 2010-08-07 12:38 pm

Related issues

related to Patch #951: HoughCircles low resolution Done

Associated revisions

Revision ce41f74a
Added by Vadim Pisarevsky over 14 years ago

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

Revision e18427b1
Added by Vadim Pisarevsky over 14 years ago

another fix on the ticket #518 - ignore all the circles with radius outside of the specified range

Revision 7cd4edd6
Added by Andrey Kamaev about 12 years ago

Merge pull request #518 from asmorkalov:ts_refactor

History

#2
Updated by Vadim Pisarevsky over 14 years ago

Ok, the problem is fixed in r3978. Circle radius calculation can still be improved, but from now on it should not return circles with radius outside of the specified range.

BTW, thanks for the good test sample and the image! Can we re-use the image for our automated tests for this algorithm?

  • Status changed from Open to Done
  • (deleted custom field) set to fixed

#3
Updated by Maximilian Matthe over 14 years ago

Uh, thats nice if it works now. I've not tried it yet.

Yes, you are allowed to use the image or code for automated tests.

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