0
$\begingroup$

I am seeing this term in every image processing object recognition tutorial, but no one explains what this is. They only explain how to find convexity defects but what is a convexity defect?

Thank you.

$\endgroup$
2
$\begingroup$

In simple words, convexity defect is a cavity in an object (blob, contour) segmented out from an image. That means an area that do not belong to the object but located inside of its outer boundary -convex hull (read documentation of cv::convexHull function for details).

The image below shows it better than million of words. Areas between fingers (all marked with arrows) in this schematics of a hand contour are the convexity defects.

Convexity defects example

You can find the defects using OpenCV's function cv::convexityDefects.

$\endgroup$

protected by jojek Sep 22 '17 at 14:38

Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.