NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
An efficient system for reliably transmitting image and video data over low bit rate noisy channelsThis research project is intended to develop an efficient system for reliably transmitting image and video data over low bit rate noisy channels. The basic ideas behind the proposed approach are the following: employ statistical-based image modeling to facilitate pre- and post-processing and error detection, use spare redundancy that the source compression did not remove to add robustness, and implement coded modulation to improve bandwidth efficiency and noise rejection. Over the last six months, progress has been made on various aspects of the project. Through our studies of the integrated system, a list-based iterative Trellis decoder has been developed. The decoder accepts feedback from a post-processor which can detect channel errors in the reconstructed image. The error detection is based on the Huber Markov random field image model for the compressed image. The compression scheme used here is that of JPEG (Joint Photographic Experts Group). Experiments were performed and the results are quite encouraging. The principal ideas here are extendable to other compression techniques. In addition, research was also performed on unequal error protection channel coding, subband vector quantization as a means of source coding, and post processing for reducing coding artifacts. Our studies on unequal error protection (UEP) coding for image transmission focused on examining the properties of the UEP capabilities of convolutional codes. The investigation of subband vector quantization employed a wavelet transform with special emphasis on exploiting interband redundancy. The outcome of this investigation included the development of three algorithms for subband vector quantization. The reduction of transform coding artifacts was studied with the aid of a non-Gaussian Markov random field model. This results in improved image decompression. These studies are summarized and the technical papers included in the appendices.
Document ID
19950005351
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Costello, Daniel J., Jr. (Notre Dame Univ. IN, United States)
Huang, Y. F. (Notre Dame Univ. IN, United States)
Stevenson, Robert L. (Notre Dame Univ. IN, United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1994
Subject Category
Computer Programming And Software
Report/Patent Number
NASA-CR-196802
NAS 1.26:196802
Accession Number
95N11764
Funding Number(s)
CONTRACT_GRANT: NAG3-1549
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available