Started working on segmentation with Felzenszwalb's method with K-nearest graph in (hue,x,y) feature space. It seems that just hue is not enough, perhaps identifying using Lab color space might be more interesting. Also it seems to produce very fragmented segmented. A better idea might be to first use Felzenszwalb's method with a simple 4-connected or 8-connected grid graph, then fuse components which are close enough in hue in a second step.