I have an image which is a binary mask, I want to characterize the contours of the black zones in the mask, I have found many tools to detect the borders between both zones but only as a new image but what I want is the description of this border, not a new image. Is there any tool which can be applied on the mask to retrieve a representation of the geometrical shape of black zones?. The representation can be either a vectorization of the shape, a polygonal approximation, chain code............All I have found about is theoretical solutions for the problem. Thanks in advance.

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