Joint Optimization of Segmentation and Color Clustering
Binary energy optimization is a popular approach for segmenting an image into foreground/background regions. To model region appearance, color, a relatively high dimensional feature, should be handled effectively. A full color histogram is usually too sparse to be reliable. One approach is to reduce dimensionality by color space clustering. Another popular approach is to fit GMMs for soft color space clustering. These approaches work well when the foreground/background are sufficiently distinct. In cases of more subtle difference in appearance, both approaches may reduce or even eliminate foreground/background distinction. This happens because either color clustering is performed completely independently from segmentation, as a preprocessing step (in clustering), or independently for the foreground and independently for the background (in GMM). We propose to make clustering an integral part of segmentation, by including a new clustering term in the energy. Our energy favors clusterings that make foreground/ background appearance more distinct. Exact optimization is not feasible, therefore we develop an approximate algorithm. We show the advantage of including the color clustering term into the energy function on camouflage images, as well as standard segmentation datasets.