Two-dimensional non separable adaptive lifting scheme for still and stereo image coding

Many existing works related to lossy-to-lossless image compression are based on the lifting concept. However, it has been observed that the separable lifting scheme structure presents some limitations be-cause of the separable processing performed along the image lines and columns. In this paper, we propose to use a 2D non separable lifting scheme decomposition that enables progressive reconstruc-tion and exact decoding of images. More precisely, we focus on the optimization of all the involved decomposition operators. In this re-spect, we design the prediction filters by minimizing the variance of the detail signals. Concerning the update filters, we propose a new optimization criterion which aims at reducing the inherent aliasing artefacts. Simulations carried out on still and stereo images show the benefits which can be drawn from the proposed optimization of the lifting operators. Index Terms — lossy-to-lossless image compression, lifting schemes, separable transforms, non separable transforms, adaptive transforms, multiresolution analysis, stereo coding. 1