Accession Number : ADA294959

Title :   Image Compression Scheme for Network Transmission.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Seng, Lim

PDF Url : ADA294959

Report Date : MAR 1995

Pagination or Media Count : 66

Abstract : In this thesis a scheme is proposed for still image compression for realtime transmission over a packet switched network. A layered image compression scheme based on the quad tree decomposition technique (QTD) is developed. The image is decomposed into three layers, where layers are added to a base image to incrementally improve the quality of the reconstructed image. The performance of the QTD is enhanced by adding a DCT algorithm with adaptive bit allocation and a region of interest methodology. The quad tree is then extended to a nona tree whereby pixel blocks of size 3 x 3 are processed instead of 2 x 2. Results are presented to provide a visual subjective perception of the proposed scheme. Depending on the number of layers transmitted, the compression gains range from 60:1 to 16:1. It is shown that the proposed scheme exhibits graceful degradation of the reconstructed image and some error tolerant capabilities.

Descriptors :   *IMAGE PROCESSING, *DATA COMPRESSION, *VIDEO NETWORKS, *PACKET SWITCHING, ALGORITHMS, DEGRADATION, DATA TRANSMISSION SYSTEMS, REAL TIME, LAYERS, THESES, TRANSMITTANCE, TREES, IMAGES, ERRORS, TOLERANCE, VISUAL PERCEPTION, PIXELS, DECOMPOSITION, IMAGE RESTORATION.

Subject Categories : Electrical and Electronic Equipment
      Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE