Asymmetric and compressed logarithmic number systems for multimedia coprocessor (invited paper)

Author

Arnold, Mark G.

Author_Institution

Lehigh Univ., Bethlehem, PA, USA

Volume

2

fYear

2003

fDate

9-12 Nov. 2003

Firstpage

1426

Abstract

The logarithmic number system (LNS) represents a real number with its sign and the logarithm of its absolute value. Inexpensive logarithmic arithmetic has shorter word length than fixed point. Conventional LNS is symmetrical: every reciprocal is representable. This paper proposes asymmetrical LNS (one sixteenth to 2048) with acceptable visual quality for MPEG decoding that saves one bit compared to conventional LNS. Novel compression saves another bit with only slight image degradation and allows 8 by 8 matrices to fit in 64 (not 128) bytes. The proposed LNS inverse discrete cosine transform (IDCT) coprocessor is compatible with conventional byte-sized packed-arithmetic SIMD architectures.

Keywords

coprocessors; discrete cosine transforms; multimedia communication; MPEG decoding; Moving Picture Experts Group; asymmetric logarithmic number system; compressed logarithmic number system; inverse discrete cosine transform; multimedia coprocessor; real number; Coprocessors; Decoding; Degradation; Dynamic range; Fixed-point arithmetic; Image coding; Multimedia systems; Sawing machines; Symmetric matrices; Transform coding;

fLanguage

English

Publisher

ieee

Conference_Titel

Signals, Systems and Computers, 2004. Conference Record of the Thirty-Seventh Asilomar Conference on

Print_ISBN

0-7803-8104-1

Type

conf

DOI

10.1109/ACSSC.2003.1292221

Filename

1292221