cvFindChessboardCorners finding some of the corners in the wrong places (Bug #488)

Added by Cristian Dima over 14 years ago. Updated almost 13 years ago.

Status:Done Start date:
Priority:Low Due date:
Assignee:Ilya Lysenkov % Done:

0%
Category:calibration, 3d
Target version:2.4.0
Affected version: Operating System:
Difficulty: HW Platform:
Pull request:

Description

Hello,

I have noticed that in some cases such as the ones in the images I am attaching, the cvFindChessboardCorners reports finding the correct number of corners although the corners are outside of the image. This tends to happen when the calibration target is right next to the edge of the image, so I am wondering if there is an easy way to add a a check for this.

I generated the images I am attaching with OpenCV 2.1, using the CV_CALIB_CB_ADAPTIVE_THRESH |
CV_CALIB_CB_NORMALIZE_IMAGE |
CV_CALIB_CB_FILTER_QUADS
flags for the function call.

In case I am breaking any rules about ticket submissions, I apologize in advance.
Thanks, Cris.

leftImage_0275.jpg (51.3 kB) Cristian Dima, 2010-07-23 01:17 am

leftImageCorners_0275.jpg (59.3 kB) Cristian Dima, 2010-07-23 01:17 am

leftImage_0316.jpg (49.7 kB) Cristian Dima, 2010-07-23 01:17 am

leftImageCorners_0316.jpg (57.9 kB) Cristian Dima, 2010-07-23 01:18 am

leftImage_0318.jpg (50.9 kB) Cristian Dima, 2010-07-23 01:18 am

leftImageCorners_0318.jpg (61 kB) Cristian Dima, 2010-07-23 01:18 am

Associated revisions

Revision f3874abf
Added by Andrey Kamaev about 12 years ago

Merge pull request #488 from AnnaKogan8:updated-ABI-compliance-descriptor-script

History

#1
Updated by Alexander Shishkov about 13 years ago

  • Description changed from Hello, I have noticed that in some cases such as the ones in the images I am... to Hello, I have noticed that in some cases such as the ones in the images I am... More

#2
Updated by Alexander Shishkov almost 13 years ago

  • Target version deleted ()

#3
Updated by Andrey Kamaev almost 13 years ago

  • Category changed from imgproc, video to calibration, 3d

#4
Updated by Alexander Shishkov almost 13 years ago

  • Priority changed from Normal to Low

#5
Updated by Ilya Lysenkov almost 13 years ago

  • Assignee set to Ilya Lysenkov

#6
Updated by Ilya Lysenkov almost 13 years ago

Thank you for the report.

In fact, OpenCV performs such a check that corners should be at least 8 pixels away from the border. So now it works correctly on your images and findChessboardCorners returns zero, that is the chessboard is not detected because some corners are not seen. I've added your images to the OpenCV test system in r7690 to ensure that it will work correctly in future too.

Don't you mind about usage of your images in the OpenCV public repository?

  • Status changed from Open to Done

#7
Updated by Alexander Shishkov almost 13 years ago

  • Target version set to 2.4.0

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