Adaptive transform tree coding of images

Author

Pearlman, William A. ; Jakatdar, Priyadarshan ; Leung, May M.

Author_Institution

Dept. of Electr.-Comput. Syst. Eng., Rensselaer Polytech. Inst., Troy, NY, USA

Volume

10

Issue

5

fYear

1992

fDate

6/1/1992 12:00:00 AM

Firstpage

902

Lastpage

912

Abstract

A tree code, asymptotically optimal for stationary Gaussian sources and squared error distortion, is applied suboptimally to encode the discrete cosine transform (DCT) of image subblocks. The variance spectrum of each block DCT is estimated and specified uniquely by a set of one-dimensional autoregressive parameters. The average pel rate for each block is allowed to vary to meet the specification of the same average distortion per block. Since the variance spectrum and rate are different for every block. so is the code tree. Comparative coding simulations with a 256×256 and 512×512 image show that DCT tree coding with postcoding is clearly superior to DCT quantization and that a variable block rate assignment gains about 3 dB over a fixed block rate assignment

Keywords

encoding; picture processing; transforms; trees (mathematics); DCT tree coding; adaptive transform tree coding; average pel rate; coding simulations; discrete cosine transform; fixed block rate assignment; image coding; image subblocks; one-dimensional autoregressive parameters; postcoding; squared error distortion; stationary Gaussian sources; tree code; variable block rate assignment; variance spectrum; Acoustic distortion; Discrete cosine transforms; Discrete transforms; Encoding; Gain; Image coding; Image segmentation; Quantization; Research and development; Transform coding;

fLanguage

English

Journal_Title

Selected Areas in Communications, IEEE Journal on

Publisher

ieee

ISSN

0733-8716

Type

jour

DOI

10.1109/49.138995

Filename

138995