find_contours() may return multiple masks

[00ffcc]

find_contours() may return multiple masks, which causes #47 (comment)

[miquel-espinosa]

This will only select the first annotation. But what if there is a single instance that has multiple parts like one of the comments was mentioning?

But if an object is occluded into two unconnected parts, should the masks of these two parts be preserved? Is there a way to solve this problem?