Object Instance Annotation With Deep Extreme Level Set Evolution

In this paper, we tackle the task of interactive object segmentation. We revive the old ideas on level set segmentation which framed object annotation as curve evolution. Carefully designed energy functions ensured that the curve was well aligned with image boundaries, and generally "well behaved". The Level Set Method can handle objects with complex shapes and topological changes such as merging and splitting, thus able to deal with occluded objects and objects with holes. We propose Deep Extreme Level Set Evolution that combines powerful CNN models with level set optimization in an end-to-end fashion. Our method learns to predict evolution parameters conditioned on the image and evolves the predicted initial contour to produce the final result. We make our model interactive by incorporating user clicks on the extreme boundary points, following DEXTR. We show that our approach significantly outperforms DEXTR on the static Cityscapes dataset and the video segmentation benchmark DAVIS, and performs on par on PASCAL and SBD.