Meanshift/Camshift just on segmented foreground?

edit

Hi,

At the moment I'm detecting movement by segmenting foreground and background. This gives me blobs which after I've tidied up a bit I'm trying to run camshift on. My probably very silly question is should I run camshift on the backprojected foreground image (with the initial window around the blob) or in the original unsegmented backprojected image (again with the initial window around the blob location)?

Theoretically which one is better? The foreground image seems best to me as the target will most likely be surrounded by low probability pixelsand hence much encouragement for the gradient ascent to the true target in the new image. However, what do people normally do and why?

Thanks