Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: One of the problems with any deep space communication system is that information may
be altered or lost during transmission due to channel noise. It is known that any damage
to the bit stream may lead to objectionable visual quality distortion of images at the
decoder. The purpose of this thesis is to design an error correction and data compression
algorithm for image protection, which will allow the communication bandwidth to be
better utilized. The work focuses on Sunsat (Stellenbosch Satellite) images as test
images. Investigations were done on the JPEG 2000 compression algorithm's robustness
to random errors, putting more emphasis on how much of the image is degraded after
compression. Implementation of both the error control coding and data compression
strategy is then applied to a set of test images. The FEe algorithm combats some if not
all of the simulated random errors introduced by the channel. The results illustrates that
the error correction of random errors is achieved by a factor of 100 times (xl00) on all
test images and that the probability of error of 10-2in the channel (10-4for image data)
shows that the errors causes little degradation on the image quality. / AFRIKAANSE OPSOMMING: Een van die probleme met kommunikasie in die ruimte is dat informasie mag verlore
gaan en! of gekorrupteer word deur ruis gedurende versending deur die kanaal. Dit is
bekend dat enige skade aan die bisstroom mag lei tot hinderlike vervorming van die
beelde wat op aarde ontvang word. Die doel van hierdie tesis om foutkorreksie en
datakompressie te ontwikkel wat die satelliet beelde sal beskerm gedurende versending
en die kommunikasie kanaal se bandwydte beter sal benut. Die werk fokus op SUNSAT
(Stellenbosch Universiteit Satelliet) se beelde as toetsbeelde. Ondersoeke is gedoen na
die JPEG2000 kompressie algoritme se bestandheid teen toevalsfoute, met klem op
hoeveel die beeld gedegradeer word deur die bisfoute wat voorkom. Beide die
kompressie en die foutkorreksie is ge-implementeer en aangewend op die toetsbeelde.
Die foutkorreksie bestry die gesimuleerde toevalsfoute, soos wat dit op die kanaal
voorkom. Die resultate toon dat die foutkorreksie die toevalsfoute met 'n faktor 100
verminder, en dat 'n foutwaarskynlikheid van 10-2 op die kanaal (10-4 op die beelddata)
weinig degradering in die beeldkwaliteit veroorsaak.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52181 |
| Date | 12 1900 |
| Creators | Sefara, Mamphoko Nelly |
| Contributors | Lourens, J. G., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 107 p. |
| Rights | Stellenbosch University |
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