Browse Prior Art Database

Sub-Band Coding of Digital Images Using Absolute Moment Block Truncation

IP.com Disclosure Number: IPCOM000107591D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 79K

Publishing Venue

IBM

Related People

Ma, KK: AUTHOR

Abstract

The major artifact of absolute moment block truncation coding (AMBTC) of images is the blocking effect or grid noise, present especially at low bit rates. Conventionally, reduction of the blocking effect is achieved by post-processing. This article presents a new sub-band coding method, called sub-band AMBTC, by combining the sub-band coding (frequency-domain approach) and the AMBTC (time-domain approach) to effectively eliminate the blocking effect, from which the AMBTC severely suffers.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Sub-Band Coding of Digital Images Using Absolute Moment Block Truncation

       The major artifact of absolute moment block truncation
coding (AMBTC) of images is the blocking effect or grid noise,
present especially at low bit rates.  Conventionally, reduction of
the blocking effect is achieved by post-processing.  This article
presents a new sub-band coding method, called sub-band AMBTC, by
combining the sub-band coding (frequency-domain approach) and the
AMBTC (time-domain approach) to effectively eliminate the blocking
effect, from which the AMBTC severely suffers.

      AMBTC is an improved version of block truncation coding (BTC).
The BTC algorithm uses a one-bit (i.e., two levels, 0 and 1)
nonparametric quantizer to preserve the local moments on each of the
non- overlapping n x n blocks of the digitized image.  BTC preserves
the first sample moment and the sample variance of each block.  On
the other hand, AMBTC preserves the first sample moment (as BTC does)
and the first absolute central moment of each block. As a result,
AMBTC outperforms BTC in three aspects: faster computation, easier
implementation, and better image quality.  Both BTC and AMBTC are
time- domain compression techniques.  Hence, it is appropriate to
view AMBTC as a full-band AMBTC (versus sub-band AMBTC).  Sub-band
coding, which bridges waveform coding and perceptual coding, can be
viewed as a signal representation scheme through the frequency domain
and has been applied to image an...