Multiple description coding in the quincunx sub-sampling lattice with diamond-shape DCT

Pixel-domain sub-sampling based on the quincunx lattice is one of the traditional approaches to carry out multiple description coding (MDC). Unfortunately, the re-alignment (either horizontal or vertical) would deteriorate the sample correlation within each description, thus leading to a lower coding efficiency. In this paper, we propose to apply a diamond-shape DCT on the quincunx sub-sampling lattice to create an MDC representation. A theoretical analysis is first presented assuming the covariance matrix of the Toeplitz type. The results show that such DS-DCT can achieve a better coding gain as well as energy packing efficiency as compared to the normal DCT with re-alignment. Then, the proposed DS-DCT is tested on various images using the standard JPEG compression scheme and the results show that it out-performs the traditional re-alignment approach by a similar margin as obtained in our theoretical analysis.