This looks remarkably similar to what "star girl" is working on, http://www.mathworks.com/matlabcentral/answers/24720-shape-based-object-identification-from-an-image
Please expand on what you are trying to do. The picture has several round shapes that are the same size that need to be distinguished between by examining their shapes? Or the picture has several round shapes of different sizes that need to be distinguished by examining their sizes? Or is "round" just an approximate description of the true shape and you need to be able to distinguish between spheroids with various major and minor axes? Or you need to handle various Superegg as well?
