Multiple description coding of images can be implemented by means of simple splitting of the pixels into subsets. This can be realized via a pre- and post-processing to most standards for image communications, with obvious advantages. Unfortunately, this method suffers from high side distortion when only one description is received. In order to overcome this limitation, and to achieve better control of the central versus side distortion trade off, a method has been proposed which expands the image by zero padding in the two-dimensional DCT domain. However, the computational complexity of the preand post processing stages turns out to be considerable. In this paper, we propose a novel method based on one dimensional (either horizontal or vertical) image expansion; this technique allows for a better exploitation of the spatial data structures, and achieves a better estimation of lost descriptions. Simulation results show a noticeable performance improvement of the proposed method with respect to other zero padding techniques, in terms of both rate/distortion and computational complexity.
['Gabriella Olmo', 'Tammam Tillo']
Directional multiple description scheme for still images