Gaps in canny-detected edges

asked 2012-12-16 13:04:38 -0600

walkingbeard
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Hi,

I'm having trouble detecting edges with the Canny function. Despite running on a binary image (shouldn't that be easy?) there are gaps in the final contour. Maybe I'm using the wrong parameters, but I'm a little unclear on what each one does.

I am running cv::Canny(imgOut, imgOut, 0, 0, 3, true) on: image description and getting:

Here is a zoom. Currently, the red pixel is actually black, but it needs to come out white. Can this be reasonably achieved? image description

Make thanks!

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answered 2012-12-17 01:43:54 -0600

Haris

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Morphological Operations may help you.

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Yes, amazing advice. Thank you so much

Dodo ( 2014-12-28 14:54:54 -0600 )edit

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answered 2012-12-17 00:01:00 -0600

Daniil Osokin

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Hi! You can try to increase aperture size (like 5 or more), also try to run findContours instead of Canny.

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answered 2012-12-17 04:35:18 -0600

venky
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Hi, One option may be to use the laplacian option in Canny Canny( InputArray image, OutputArray edges, double threshold1, double threshold2, int apertureSize=3, bool L2gradient=false ); make the L2gradient=true and check the result out.

If possible try to check if the Matlab canny detector gives the same result. As suggested by Daniil Osokin you could use find contours as an alternate if you have only Binary images.

Thanks Venky

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Gaps in canny-detected edges

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