Multiple description image and video coding for wireless channels

摘要

We consider the problem of efficient image/video transmission over wireless channels. Such a problem involves good compression rates and effectiveness in presence of channel failures. In this work, we use the multiple description coding (MDC) techniques, based on Wavelet Transforms, that have been shown to be powerful against channel failures. We propose a bit allocation procedure that dispatches the source redundancy between the different channels when compressing to a target bit rate with a bounded side distortion. In this way, we develop an MDC scheme well adapted to channel noise. Then, we extend this bit allocation to video. This extension uses the 3D scan-based DWT of Parisot et al. (MMSP, IEEE, New York, 2001); that involves scan-based MDC with rate or quality control. In this work we propose to adapt redundancy between the descriptors in function of channel model and state (BER). Furthermore, the channels can have time-varying states. We consider BSC channels, Gaussian channels, and UMTS channels. The method can be efficiently extended to other channels when the channel model that matches the channel behavior is known.We evaluate the performance of the proposed MDC image/video coder for two descriptions. In a first group of simulations, we compare our application with some different MDC techniques presented by Vaishampayan (IEEE Trans. Inform. Theory 39 (3) (1993) 821) and Servetto et al. (ICIP, IEEE, Chicago, USA, 1998; IEEE Trans. Image Process. 9 (5) (2000) 813–826). In a second group of simulations, we evaluate the robustness of the proposed MDC when submitted to different kinds of channels noise.