Abstract/Details

A hybrid image data compression scheme using quaternary decomposition and vector quantization of DCT coefficients

Thede, Leslie D. 
 The University of Toledo ProQuest Dissertations Publishing,  1989. 9015896.

Abstract (summary)

This research investigates a hybrid data compression scheme applicable to both single frame color images and color image sequences. It uses a form of classified vector quantization (VQ) based upon the quaternary decomposition of image blocks into 32 x 32(x4), 16 x 16(x4), 8 x 8(x4) or 4 x 4(x4) sub-blocks before either a 2-D or 3-D discrete cosine transform (DCT) is used to encode the blocks. The coefficients of the DCT's are then zonal sampled and vector quantized. The codebooks for the VQ are generated by either a random or a clustering process for the single frame images, while only the clustering process is used for the image sequences. Each of the initial codebooks is optimized by both the Linde-Buzo-Gray (LBG) method and a simulated annealing (SA) method. In addition a method of selective multistage vector quantization (SMVQ) is investigated in which only those vectors not matched well enough by a codebook vector are allowed a second stage of VQ.

Results indicate that the SA algorithm does indeed produce better results than the LBG method, although the effects are masked by the combination of vectors for the final reconstruction. The compression scheme produces very good results for single frame images at a bit rate of.858 bpp, while the image sequences are processed to a similar quality at a bit rate of.395 bpp. When the SMVQ method is used the bit rates increase by approximately.15 bpp in both the single frame and sequence cases, with improved quality in the reconstructed images, especially in the lower quality cases.

Indexing (details)


Subject
Electrical engineering;
Systems design;
Computer science
Classification
0544: Electrical engineering
0790: Systems design
0984: Computer science
Identifier / keyword
Applied sciences
Title
A hybrid image data compression scheme using quaternary decomposition and vector quantization of DCT coefficients
Author
Thede, Leslie D.
Number of pages
244
Degree date
1989
School code
0232
Source
DAI-B 51/01, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9798617045958
Advisor
Kwatra, S. C.
University/institution
The University of Toledo
University location
United States -- Ohio
Degree
Ph.D.
Source type
Dissertation or Thesis
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
9015896
ProQuest document ID
303826006
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/docview/303826006