Image and Text Compression

James A. Storer Computer Science Dept. Brandeis University Waltham, MA 02254 Data compression is the process of encoding a body of data to reduce stor­ age requirements. With Lossless compression, data can be decompressed to be identical to the original, whereas with lossy compression, decompressed data may be an acceptable approximation (according to some fidelity criterion) to the original. For example, with digitized video, it may only be necessary that the decompressed video look as good as the original to the human eye. The two primary functions of data compression are: Storage: The capacity of a storage device can be effectively increased with data compression software or hardware that compresses a body of data on its way to the storage device and decompress it when it is retrieved. Communications: The bandwidth of a digital communication link can be effectively increased by compressing data at the sending end and decom­ pressing data at the receiving end. Here it can be crucial that compression and decompression can be performed in real time. This book presents exciting recent research on the compression of images and text. Part 1 presents the (lossy) image compression techniques of vector quantization, iterated transforms (fractal compression), and techniques that employ optical hardware. Part 2 presents the (lossless) text compression techniques of arithmetic coding, context modeling, and dictionary methods (LZ methods); this part of the book also addresses practical massively parallel architectures for text compression. Part 3 presents theoretical work in coding theory that has applications to both text and image compression. The book ends with an extensive bibliography of data compression papers and books which can serve as a valuable aid to researchers in the field. Points of Interest: Data compression is becoming a key factor in the digital storage of text, speech graphics, images, and video, digital communications, data bases, and supercomputing. The book addresses `hot' data compression topics such as vector quantization, fractal compression, optical data compression hardware, massively parallel hardware, LZ methods, arithmetic coding. Contributors are all accomplished researchers. Extensive bibliography to aid researchers in the field. Front Matter....Pages i-viii Front Matter....Pages 1-1 Image Compression and Tree-Structured Vector Quantization....Pages 3-34 Fractal Image Compression Using Iterated Transforms....Pages 35-61 Optical Techniques for Image Compression*....Pages 63-82 Front Matter....Pages 83-83 Practical Implementations of Arithmetic Coding....Pages 85-112 Context Modeling for Text Compression....Pages 113-144 Ziv-Lempel Compressors with Deferred-Innovation....Pages 145-157 Massively Parallel Systolic Algorithms for Real-Time Dictionary-Based Text Compression....Pages 159-178 Front Matter....Pages 179-179 Variations on a Theme by Gallager....Pages 181-213 On the Coding Delay of a General Coder....Pages 215-252 Finite State Two-Dimensional Compressibility....Pages 253-275 Back Matter....Pages 277-354