Regarding the segmentation phase, we were not satisfied with any existing algorithms because we wanted the tool to be as real-time as possible (for up to 4 megapixel images), so we rolled our own segmentation algorithm that has some similarities to GrabCuts (not GraphCuts).
But the binary segmentation is really only a small part of the technical challenge. You also need to figure out how to anti-alias the boundary, and remove the background halo. Simply feathering doesn't do the job unless you also erode the foreground first, which we wanted to avoid. So we developed a custom sub-pixel background-removal and anti-aliasing algorithm.
I think you guys did a great job. This is a very tough problem (speaking from experience) particularly depending on the complexity of the image. One problem we had to solve along the way for our startup is similar, but focused only on fashion related images. Quite tricky particularly if you want something automatic. Anyway cheers! :)
