First Advisor

Fu Li

Date of Publication

2-4-1997

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Electrical and Computer Engineering

Department

Electrical and Computer Engineering

Subjects

Image processing -- Digital techniques, Coding theory, Image compression -- Data processing

DOI

10.15760/etd.7256

Physical Description

1 online resource, (82p.)

Abstract

Presently Block-based Discrete Cosine Transform (BDCT) image coding techniques are widely used in image and video compression applications such as JPEG and MPEG. At a moderate bit rate, BDCT is usually a quite satisfactory solution to most of practical coding applications. However, for high rate compression it produces noticeable blocking and ringing artifacts in the decompressed image. It has been an active research area for a decade for reducing these artifacts. In this thesis, a novel post-processing algorithm is proposed to remove the blocking and ringing artifacts at low bit rate. It is non-iterative and uses both spatial and transform domain approaches. The main steps in this algorithm include block classification, boundary low-pass filtering and mid-point interpolation, edge detection and region merge, and DCT coefficient constraint. The improvement is demonstrated both subjectively and objectively. The extension from .still images to video is also discussed at the end.

Comments

If you are the rightful copyright holder of this dissertation or thesis and wish to have it removed from the Open Access Collection, please submit a request to pdxscholar@pdx.edu and include clear identification of the work, preferably with URL.

Persistent Identifier

https://archives.pdx.edu/ds/psu/30881

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