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Predictive Encoding of Digitized TV Pictures

Citation

Sharma, Dhiraj Kumar (1975) Predictive Encoding of Digitized TV Pictures. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/t5n9-3a07. https://resolver.caltech.edu/CaltechTHESIS:09292021-170924946

Abstract

In this report, we consider the problem of efficient intra-frame encoding of digitized TV pictures using Differential Pulse Code Modulation (DPCM) type encoders. Our goal is to reduce the average number of bits used to encode a pixel while subjective quality of the picture still remains acceptable.

To this end, we propose some new predictors and compare them with the existing ones using the error criteria "essential maximum" and "variance" of the prediction errors. The two criteria have also been compared with respect to the subjective quality of the final encoded pictures. We propose to design the quantizers using "mean n-th power" distortion criterion. Effects of "n" on bit rate and subjective quality of the encoded picture have been studied as it varies from 1 to 6. In this way, we achieve reductions up to 6 to 1 in the bit rate with little degradation in the picture quality. We also consider the use of second and third order entropies of the encoded pictures to reduce the bit rate.

Next, we adapt the encoding procedure to local structural variations in the picture by first segmenting it in three areas of varying detail and then using the concepts developed for non-adaptive encoding to encode the three areas differently. The resulting encoder yields better picture quality than before and can be used to encode a broad class of pictures.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Electrical Engineering
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Minor Option:Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Pierce, John Robinson
Thesis Committee:
  • Pierce, John Robinson (chair)
Defense Date:19 May 1975
Funders:
Funding AgencyGrant Number
Xerox CorporationUNSPECIFIED
Bell Telephone LaboratoriesUNSPECIFIED
Record Number:CaltechTHESIS:09292021-170924946
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:09292021-170924946
DOI:10.7907/t5n9-3a07
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14378
Collection:CaltechTHESIS
Deposited By: Ben Perez
Deposited On:07 Oct 2021 18:36
Last Modified:07 Oct 2021 18:36

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