Optimization Issues in Digital Filter Banks

这个项目处理的是有效传输和存储信息的压缩。信息可以是最一般的类型，但这里的方法考虑到数据中的冗余，它表示为谱分布。这是在称为子带编码的压缩方案的帮助下完成的。在该方案中，可以利用频谱特征以及属于人类感知系统（如听觉或视觉系统）的信号特征。我们正在解决子带码设计和实现中的几个基本问题。本项目考虑了正交和双正交子带编码器的优化问题。我们还解决了非均匀子带编码器的情况，这是最适合音频和图像编码的情况；以及非带限信号的采样和重构理论，展示了如何利用这种理论来量化和压缩数据。这方面的研究将过采样模数转换器家族推广到无带宽限制信号的情况。另一个正在研究的课题是一类特殊的子带编码器，称为循环编码器，它可能具有更高的编码效率。这个类对于独立数据的短块压缩特别有用。

This project deals with the compression of information for efficient transmission and storage. The information can be of the most general kind, but the approach here takes into account the redundancy in the data which expresses itself as a spectral distribution . This is done with the help of a compression scheme called subband coding. In this scheme, the spectral characteristics as well as the characteristics of the signal, which pertain to the human perceptive systems such as the hearing or visual system, can be exploited. We are addressing several fundamental issues in the design and implementation of subband codes. The optimization of orthonormal as well as biorthogonal subband coders is being considered in this project. We are also addressing the cases of nonuniform subband coders, which are most appropriate for the case of audio and image coding; and the theory of sampling and reconstruction of non bandlimited signals, showing how such a theory can be exploited in quantization and compression of data. This aspect of the research generalizes the family of oversampled analog- to-digital converters to the case of non bandlimited signals. Another topic under investigation is a special class of subband coders called cyclic coders, which are potentially capable of greater coding efficiency. This class is especially useful for the compression of short blocks of independent data.