Filling shapes in a binary image

Hello all,

A fairly new Max/MSP and Jitter user here with quite a specific question. Is there an external or an easy way of filling in a shape in a binary image? I'd like to find a way of filling in my hand with white to make the hand more distinct and easier to track, live from a webcam feed as seen in the picture below. As there are inconsistencies with the contour I'd imagine this might be quite difficult. If anyone knows to point me in the right direction, that'd be extremely helpful. Hope this all makes sense!