opencv 3, blobdetection, The function/feature is not implemented () in detectAndCompute

Question

I have a problem with opencv 3: I want to use a feature detector, SimpleBlobDetector, about to use filters by convexity and circularity. But when I try to execute the code, the

Answer 1

Thanks for the response.

I use detect (like I said in my previous message). I think the detect function probably uses detectAndCompute.

The lack of descriptor can be the problem indeed, because I already had an equivalent problem with Emgu (the C# version of opencv) until I found a developer note saying that the method wasn't corrected yet and the descriptor was the cause.

For others who have the same problem, I finally used cv::findContours instead of the blob detector. It works much better, without any problem. To replace the convexity detection, you can evaluate it using the fullness (shape area / bounding box area). To replace the circularity, use the following formula:

circle area / bounding box area = PI/4

I hope this will hope other people.