The goal of data compression is to represent an information
source (e.g. a data file, a speech signal, an image, or a video signal) as accurately as possible using the fewest number of bits.
Theory of Data Compression:
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This page includes an overview of the theory, source modeling
(including a statistical study of English text),
entropy rate, Shannon lossless source coding theorem, rate-distortion
theory, a discussion of the gap between theory and practice, and
Blahut algorithm. A list of recommended
books on data-compression
theory and some seminal papers (e.g., Shannon's 1948 paper A Mathematical
Theory of Communications) are also included.
Lossless Data Compression:
- Description of Huffman coding
and Lempel-Ziv coding (including an animation of the Huffman design
algorithm and an animation of the Lempel-Ziv
encoding). A performance comparison is also included.
Vector Quantization:
- Description of the Linde Buzo Gray vector quantizer (VQ) design algorithm. Includes a two-dimensional animation
of the LBG-VQ design algorithm.
Speech Compression:
- Description of the LPC model, LPC vocoder, CELP coder, and ADPCM
coder. A comparison of these coders and references are also included.
Image Compression:
- A demonstration of JPEG/JPEG2000 compression of color and gray-scaled images.
Download:
- Key papers on data compression and various source code (e.g., vector quantizer
design using the LBG algorithm) are available.
Links:
- Links to web sites relating to data compression. You many
add your link if you wish.
Nam Phamdo
Department of Electrical and Computer Engineering
State University of New York
Stony Brook, NY 11794-2350
phamdo@ieee.org
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