Object proposal via depth connectivity constrained grouping

Object proposal aims to detect category-independent object candidates with a limited number of bounding boxes. In this paper, we propose a novel object proposal method on RGB-D images with the constraint of depth connectivity, which can improve the key techniques in grouping based object proposal effectively, including segment generation, hypothesis expansion and candidate ranking. Given an RGB-D image, we first generate segments using depth aware hierarchical segmentation. Next, we combine the segments into hypotheses hierarchically on each level, and further expand these hypotheses to object candidates using depth connectivity constrained region growing. Finally, we score the object candidates based on their color and depth features, and select the ones with the highest scores as the object proposal result. We validated the proposed method on the largest RGB-D image data set for object proposal, and our method is superior to the state-of-the-art methods.