Extending RD-OPT with global thresholding for JPEG optimization

Author

Ratnakar, Viresh ; Livny, Miron

Author_Institution

Dept. of Comput. Sci., Wisconsin Univ., Madison, WI, USA

fYear

1996

fDate

Mar/Apr 1996

Firstpage

379

Lastpage

386

Abstract

In this paper, the RD-OPT algorithm for optimizing discrete cosine transform quantization tables [Ratnakar and Livny, 1995] is extended to incorporate global thresholding. Performance gains are possible by zeroing off some DCT coefficients in DCT-based image compression. We describe a global thresholding scheme, in which the zeroing thresholds for coefficients can be arbitrarily different from those determined by the quantization table. Unlike local thresholding [Crouse and Ramchandran, 1995], the zeroing decisions are not made separately for each image block. This simplifies the use of thresholding, is easier to optimize and is almost as effective as local thresholding

Keywords

data compression; discrete cosine transforms; image coding; optimisation; transform coding; DCT-based image compression; JPEG optimization; RD-OPT; algorithm; discrete cosine transform quantization tables; global thresholding; performance gains; zeroing; Decoding; Discrete cosine transforms; Discrete transforms; Heart; Image coding; Optimized production technology; Performance gain; Quantization; Rate-distortion; Video compression;

fLanguage

English

Publisher

ieee

Conference_Titel

Data Compression Conference, 1996. DCC '96. Proceedings

Conference_Location

Snowbird, UT

ISSN

1068-0314

Print_ISBN

0-8186-7358-3

Type

conf

DOI

10.1109/DCC.1996.488343

Filename

488343