Order-Preserving Moves for Graph-Cut-Based Optimization

— In the last decade, graph-cut optimization has been popular for a variety of labeling problems. Typically graph-cut methods are used to incorporate smoothness constraints on a labeling, encouraging most nearby pixels to have equal or similar labels. In addition to smoothness, ordering constraints on labels are also useful. For example, in object segmentation, a pixel with a “car wheel” label may be prohibited above a pixel with a “car roof” label. We observe that the commonly used graphcut α-expansion move algorithm is more likely to get stuck in a local minimum when ordering constraints are used. For a certain model with ordering constraints, we develop new graphcut moves which we call order-preserving. The advantage of orderpreserving moves is that they act on all labels simultaneously, unlike α-expansion. More importantly, for most labels α, the set of α-expansion moves is strictly smaller than the set of order-preserving moves. This helps to explain why in practice ...

• Type: Journal
• Year: 2010
• Where: PAMI
• Authors: Xiaoqing Liu, Olga Veksler, Jagath Samarabandu
• Keywords: Label, Order-preserving Moves, PAMI 2010, Pixel