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Identify irregular forms.

asked 2014-10-15 11:58:44 -0500

PucaraSouth gravatar image

updated 2014-10-17 04:08:13 -0500

berak gravatar image

Hi this is an image of a wheat apex. What im trying to do is count the amount of "fingers" located on the sides of the apex. However I'm a little bit lost deciding which function I shall use because of the irregularity of this fingers/blobs. Is it even posible to count them? I have a couple of ideas in mind, but I don't know how to translate them into functions in OpenCv.

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"I have a couple of ideas in mind" - definitely append those !

berak gravatar imageberak ( 2014-10-15 15:50:12 -0500 )edit

Hi Berak!. Well, I was thinking if I could draw a tangent line in each "finger tip" then I would be able to count each line and see the result. Or maybe identify each tip as a semi-circle, but I don't know if such and irregular shape could be consider a semi-circle. Maybe identifying the gaps between the bumps is easier. That's all I got. However I don't know if any of those things can be done in OpenCv. Thank you very much for your reply.

PucaraSouth gravatar imagePucaraSouth ( 2014-10-15 17:39:49 -0500 )edit

A challenging task! The left part could be done by efficient edge detection, but the contrast on the right kind of ruins that. Is it a symmetric shape or not?

StevenPuttemans gravatar imageStevenPuttemans ( 2014-10-16 03:48:26 -0500 )edit

It's not symmetric, and I will be uploading a better shot with a better contrast. So "efficient edge detection" tell me more about that haha :D. I know about "Canny Edge Detection", but I don't know how to analyse the final shape that canny gives you in order to count the bumps. Thank you very much StevenPuttemans!

PucaraSouth gravatar imagePucaraSouth ( 2014-10-16 07:42:31 -0500 )edit

Hmm the efficient detections is indeed the problem. What about going for a Sobel operator in Y direction, looking for a decent threshold response, then trying to fit houghlines of a fixed length range? Then you could analyze the relation between several found lines, coupling two lines as 1 segment?

StevenPuttemans gravatar imageStevenPuttemans ( 2014-10-17 04:00:55 -0500 )edit

I think you should look up some interesting literature on this topic. OpenCV won't contain a ready to use piece of software for this:

StevenPuttemans gravatar imageStevenPuttemans ( 2014-10-17 05:00:20 -0500 )edit

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answered 2014-10-17 06:06:01 -0500

PucaraSouth gravatar image

I really appreciate your ideas StevenPuttemans. I'll give it a shot. Thank you very much. If I can make it I'll let you know :D

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Asked: 2014-10-15 11:58:44 -0500

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Last updated: Oct 17 '14