This paper presents a multistage tree-structured vector quantization (MTVQ) scheme for line spectral frequencies (LSF), where two advantages exist: It supports embedded quantization which is required for scalable coder designs, and the tree-structure at each stage can be relied on to accelerate the encoding process. The different codebook design strategies suitable for MTVQ are analyzed. Two speech coding standards are modified by replacing their original LSF quantizers with an MTVQ; it is shown that graceful quality degradation can be obtained for the synthetic speech when the number of bits available for LSF decoding is decremented one-by-one. Moreover, the search complexity is substantially reduced with slight performance degradation

A DCT-based image watermarking algorithm is described, where the original image is not required for watermark recovery, and is achieved by inserting the watermark in subimages obtained through subsampling.

The problem of vector quantizing the parameters of a neural network is addressed, followed by a discussion of different algorithms applicable for quantizer design. Optimal, as well as several suboptimal quantization schemes are described. Simulations involving nonlinear prediction of speech signals are presented to compare the performance of different quantization techniques. Performance evaluation conducted uncover the tradeoffs in implementational complexity. Among the three examined suboptimal quantization schemes, it is shown that the multistage quantizer offers the best tradeoff between complexity and performance.

Resolution degradation due to gradient coil deformation and vibration in NMR microscopy is investigated using finite element analysis. From the analysis, deformations due to the Lorentz force can be as large as 1-10 mum depending on the gradient strength and coil frame material. Thus, these deformations can be one of the major resolution limiting factors in NMR microscopy. Coil vibration, which depends on the input current waveform and resolution degradation due to time-variant deformation and time-invariant deformation are investigated by numerical simulations.