Evaluation of Side Information Effectiveness in Distributed Video Coding

Abstract

The rate-distortion performance of a distributed video coding system strongly depends on the characteristics of the side information. One could naïvely think that the best side information is the one with the largest PSNR with respect to the original corresponding image. However, previous works have shown that this is not always the case and a reduction of the side information MSE does not always translate into better ratedistortion performance for the complete system. The scope of this paper is to explore a set of metrics other than the PSNR and explicitly designed to classify the side information with respect to its impact on the end-to-end compression performance. A first contribution is to define an experimental framework that can be used to meaningfully compare different metrics for side information evaluation. As a second contribution, our analysis allows to understand why in some cases PSNR-based metrics provide a fairly reliable estimation of the side information quality, while in other cases they do not. This analysis also allows us to introduce a set of new metrics that are better adapted for side information effectiveness evaluation, and that are based on a suitable power of the absolute difference between side information and the original image, or on the Hamming distance between the respective transform coefficients. Besides their theoretical interest, these new metrics can also improve the rate-distortion performance of some distributed video coding systems such as the hash-based ones. We observe improvement up to 74 % rate reduction in a simple study case.

Depth-Based Multiview Distributed Video Coding

“…It can be generated, according to the frame repartition, by temporal interpolation or inter-view interpolation or by a fusion of them [17]- [21]. Several solutions [22], [23] have been explored in the literature to improve the quality of the SI and consequently the RD performance, despite improving the PSNR on SI does not imply directly maximizing RD performance [24]. As the quality of the inter-view generated SI is often poor, the RD performance of these schemes is not better than the INTRA mode of H.264/AVC [7], [25], [26].…”

Multi-View Distributed Video Coding Based on Discrete Cosine

“…With the International standard appearance of H.261, H.263, H.264/AVC, MPEG-1, MPEG-2, MPEG-4, MPEG-7, a series of video compressions, video coding technology is tending to mature; it makes video compression and communication go into a new epoch [12]. The goals which H.26X series and MPEG-X series pursuit are same, transmitting codes as little as possible, the images which get by decoding can have higher quality.…”

Novel solutions for side information generation and fusion in multiview DVC

“…This estimate is called side information (SI). It is clear that the more the SI is similar to the actual image, the less bits will be requested to correct it [9]. Therefore, side information generation is a crucial step for an efficient DVC system.…”