Lossy compression of volumetric medical images with 3D dead-zone lattice vector quantization

This paper presents a new lossy coding scheme based on 3D Wavelet Transform and Lattice Vector Quantization for volumetric medical images. The main contribution of this work is the design of a new codebook enclosing a multidimensional dead zone during the quantization step which enables to better account correlations between neighbour voxels. Furthermore, we present an efficient rate-distortion model to simplify the bit allocation procedure for our intra-band scheme. Our algorithm has been evaluated on several CT an MR image volumes. At high compression ratios, we show that it can outperform the best existing methods in terms of rate-distortion tradeoff. In addition, our method better preserves details and produces thus reconstructed images less blurred than the well-known 3D SPIHT algorithm which stands for a reference.