Improved side information generation for distributed video coding

Abstract

Distributed video coding (DVC) is a video coding paradigm allowing low complexity encoding for emerging applications such as wireless video surveillance. Side information (SI) generation is a key function in the DVC decoder, and plays a key-role in determining the performance of the codec. This paper proposes an improved SI generation for DVC, which exploits both spatial and temporal correlations in the sequences. Partially decoded Wyner-Ziv (WZ) frames, based on initial SI by motion compensated temporal interpolation, are exploited to improve the performance of the whole SI generation. More specifically, an enhanced temporal frame interpolation is proposed, including motion vector refinement and smoothing, optimal compensation mode selection, and a new matching criterion for motion estimation. The improved SI technique is also applied to a new hybrid spatial and temporal error concealment scheme to conceal errors in WZ frames. Simulation results show that the proposed scheme can achieve up to 1.0 dB improvement in rate distortion performance in WZ frames for video with high motion, when compared to state-of-the-art DVC. In addition, both the objective and perceptual qualities of the corrupted sequences are significantly improved by the proposed hybrid error concealment scheme, outperforming both spatial and temporal concealments alone.

Side information improvement in transform-domain distributed video coding

“…DISCOVER codec. Also the results obtained by Petrazzuoli et al 11 and by Abou-Elailah et al 13 are shown in order to have a complete comparative analysis of the methods. Table 3 shows the average PSNR of the final SI, obtained after the refinement process, with the different methods.…”

“…We now propose a new method that consists in improving the decoded WZFs, already obtained by DISCOVER or by the method proposed by Abou-Elailah, 13 when the GOP size is larger than 2. This improvement is achieved by re-estimating the SI using the neighboring decoded frames, with an adaptive search area and a variable block size.…”

“…When the enhancement is applied on the decoded WZFs obtained by DISCOVER codec, the method is called PropA, and PropB when the improvement is carried out on the decoded WZFs obtained by the algorithm proposed by Abou-Elailah et al 13 Both methods are compared w.r.t. DISCOVER codec.…”

“…In our previous work, 13 after the decoding of each DCT band, three steps are performed in order to refine the SI: Suspicious vector detection, Refinement, and Mode decision and compensation.…”

Fusion of Global and Local Motion Estimation Using Foreground Objects for Distributed Video Coding

“…In VISNET II codec [14], a refinement process of SI is carried out after decoding all DCT bands to improve reconstruction [15]. In [16] and [17], approaches are proposed for transform-domain DVC based on the successive refinement of SI after each decoded DCT band. In [18], a solution is proposed based on the successive refinement of SI using an adaptive search area, for long duration GOPs, in transform-domain DVC.…”