Accurate Light Field Depth Estimation Using Multi-Orientation Partial Angular Coherence

Occlusion is a critical issue that affects the accuracy for light field depth estimation. In the presence of occlusions, the photo-consistency property is broken, making ambiguity near occlusion areas. In this paper, we proposed using multi-orientation partial angular coherence to achieve accurate depth estimation by which the occlusions are explicitly treated. Unlike previous approaches, the correspondence is partially measured along several lines with different directions. We show that depending on the occlusion edge orientation, the pixels along the occlusion orientation still preserve photo-consistency. By computing the partial angular coherence in four potential directions, we can obtain a sharp initial depth map. Since occlusions are precisely tackled, the outliers can be mostly removed by fast guided filtering on the cost volume. As a result, the depth accuracy at occlusion boundaries is greatly improved. The proposed method can obtain sharp transition edges at occlusion boundaries and has no requirement for extra edge information. Experimental results on a recent benchmark demonstrate that the proposed method outperforms the state-of-the-art algorithms in the accuracy metrics. Further experiments on real-world scenes also show the superior performance of the proposed method.