Geometry-based distributed coding of multi-view omnidirectional images

Abstract

This paper presents a distributed and occlusion-robust coding scheme for multi-view omnidirectional images, which relies on the geometry of the 3D scene. The Wyner-Ziv coder uses a multi-view correlation model that relates 3D features in different images using local geometric transforms in order to perform coset code design and the coset decoding of each feature. The meaningful image features are extracted by a sparse decomposition over a dictionary of localized geometric atoms. However, in such a decomposition, occlusions or low-correlated features appear as independent elements in the encoded stream, which can lead to erroneous reconstruction at the decoder. To ameliorate this problem, we propose to leave a controlled redundancy by sending additional syndrome bits that are computed by channel coding across the atoms of the Wyner-Ziv image. This offers resiliency against occlusions, or against inaccuracy in the view correlation model. The experimental results demonstrate the coding performance of the proposed scheme at low bit rate, where it performs close to the joint encoding strategy.