This volume, the fifth in the series, examines the definition, study and use of the wavelet transform in communications for two-dimensional (2-D) digital signals. The transform is used for signal reorganization before compression and the trade-off between these two steps and the whole compression process is discussed.
The five chapters specifically present the theory of wavelets applied to images, then applications of compression of still images and sequences. Chapter 1 introduces biorthogonal bases of compactly supported wavelets: this generalization of orthonormal wavelet theory allows the use of linear phase filters. A non rectangular wavelet representation of 2-D signals is developed in the second chapter: the properties usually used with wavelets, phase, linearity, and regularity are discussed. Chapter 3 is composed of three parts: a description of commonly used biorthogonal wavelets; a presentation of vector quantization algorithms; a consideration of lattice vector quantization followed by a discussion of the bit allocation procedure (with experimental results given). The fourth chapter deals with a region-based discrete wavelet transform for image coding. Chapter 5 investigates the transmission of image sequences: wavelet transforms and motion estimation are detailed in a multiconstraint approach of image sequence coding.
scaling function. Multiresolution analysis and digital filter banks. Quality criteria for wavelets used in image processing. Biorthogonal wavelets. Extension to the bidimensional case. Statistical properties of wavelets coefficients. Conclusion. Appendix A. Bibliography. Vector Quantization. Introduction. Quantization. Codebook entropy. Vector quantization versus scalar quantization. Codebook design. Lattice Vector Quantization (LVQ). Bit allocation procedure. Experimental Results. Introduction. Lattice vector quantizer design. Coding under psychovisual considerations. Dyadic or quincunx scheme for coding? Appendix B. Bibliography. Conclusion. Acknowledgments. A Region-Based Discrete Wavelet Transform (RBDWT) for Image Coding (H.J. Barnard, J.H. Weber, J. Biemond). Abstract. Introduction. The discrete wavelet transform. Region-based coding. Principle of the region-based discrete wavelet transform. Scope and organization. The Implementation of the RBDWT. Decomposition of the segmentation mask. Filtering and downsampling with the RBDWT. The Coding Scheme. The segmentation. The bit allocation. The quantization. Comparison to the Standard DWT Coding Scheme. Theoretical advantages and disadvantages of the RBDWT coding scheme. Experimental comparison of the RBDWT and the standard DWT coding schemes. Multiresolution coding of images using the RBDWT. Application to video coding. Conclusions and Further Research. Bibliography. Wavelet Transform and Motion Estimation for Image Sequence Coding: A Multiconstraint Approach (N. Baaziz, C. Labit). Abstract. Introduction. Multiresolution Representations of Image Sequences. A generalized typology of multiresolution decompositions. Comparison based on local and global subband entropies. Discussion. Monoresolution Motion Estimation Framework. Adaptive pel-recursive motion estimation algorithm. Wiener-based algorithm. Modified Wiener-based approach. Multiresolution Motion Estimation. Problem statement. Multigrid Walker-Rao algorithm on wavelet pyramids. Multiconstraint Algorithm. Discussion. References.