Coding characteristics of the pixel-adaptive DPCM utilizing the variable-length-codes

Author

Saigusa, Masahito ; Arazaki, Shin-Ichi ; Hashiguchi, Sumihisa ; Ohki, Makoto ; Uchiyama, Masayuki ; Itoh, Fumiyoshi

Author_Institution

Fac. of Eng., Yamanashi Univ., Kofu, Japan

Volume

37

Issue

1

fYear

1991

fDate

2/1/1991 12:00:00 AM

Firstpage

74

Lastpage

80

Abstract

The coding characteristics of a modified DPCM (differential pulse code modulation) method for data compression of still images for digital still cameras are described. In pixel adaptive DPCM, the pixels are classified into eight groups according to the magnitude of the prediction error of preceding pixels, and the prediction error signals of each group are quantized using eight nonlinear quantizers, each of which is designed optimally to each group. The performance of the pixel adaptive DPCM can be improved by utilizing the variable bit-rate scheme. It is shown in an example that the signal-to-noise ratio can be improved to 48 dB by 6 dB at 3.0 b/pixel, that this improvement is due to the relief of the slope overloading at the edges, and that the spectrum of the coding errors is distributed uniformly in the 2-D spatial frequency region

Keywords

codes; coding errors; data compression; encoding; picture processing; pulse-code modulation; 2-D spatial frequency; 48 dB; coding errors spectrum; data compression; differential pulse code modulation; digital still cameras; nonlinear quantizers; pixel adaptive DPCM; prediction error signals; signal-to-noise ratio; still images; variable bit-rate; Data compression; Digital cameras; Digital modulation; Frequency; Image coding; Modulation coding; Pulse compression methods; Pulse modulation; Signal design; Signal to noise ratio;

fLanguage

English

Journal_Title

Consumer Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0098-3063

Type

jour

DOI

10.1109/30.73638

Filename

73638