Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: We design and implement a prototype digital watermarking scheme that uses
spread-transform dither modulation to embed hidden binary message signals
into uncompressed digital video signals. The hidden messages are intended
to identify the original recipient of a particular copy of a digital video, so
that in the event that a pirate copy of that video is found, the recipient can be
incriminated as a pirate. We test the ability of the watermark signal to survive
various modifications to the watermarked video, including lossy compression,
frame deletion, and amplitude scaling. We find that the scheme performs
well when watermarked videos remain uncompressed, but the scheme is not
sufficiently robust against lossy compression. We also implement a dynamic
traitor tracing scheme based on the scheme of Fiat and Tassa, which is designed
to identify a group of pirates who combine their watermarked videos in an
attempt to defeat the watermarking scheme. We test the traitor tracing scheme
in a simulated digitally watermarked video broadcast system where a pirate
rebroadcast is monitored. We find that when the pirate rebroadcast is delayed,
our traitor tracing scheme identifies and disconnects the pirates more quickly
than the scheme of Fiat and Tassa. / AFRIKAANSE OPSOMMING: Ons ontwerp en implementeer ’n digitale watermerkskema-prototipe wat
strektransform-bibbermodulasie gebruik om binêre boodskapseine in digitale
videoseine te verskuil. Die doel van die versteekte boodskappe is om die oorspronklike
ontvanger van ’n bepaalde digitale video-afskrif te identifiseer. Indien
’n onwettige afskrif van die video ontdek word, kan die oorspronklike
ontvanger daarvoor verantwoordelik gehou word. Ons toets die vermoë van
die watermerksein om verskeie veranderinge aan die gewatermerkte video te
oorleef, byvoorbeeld kompressie, die verwydering van videorame, en amplitudeskalering.
Die skema vaar goed in die afwesigheid van videokompressie,
maar is nie robuus wanneer die video beduidend saamgepers word nie. Ons
implementeer ook ’n dinamiese skema vir verraaier-opsporing, gebaseer op ’n
tegniek deur Fiat en Tassa. Die doel van hierdie skema is om groepe gebruikers
te identifiseer wat saamwerk om ’n watermerkskema te kul deur gewatermerkte
videos te kombineer. Ons toets die verraaier-opsporingskema in ’n
simulasie van ’n gewatermerkte video-uitsendingstelsel wat ’n roofuitsending
monitor. Wanneer die roofuitsending vertraag is, vind ons dat die voorgestelde
verraaier-opsporingskema die skuldige gebruikers vinniger uitwys as die skema
van Fiat en Tassa.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/96068 |
| Date | 12 1900 |
| Creators | Salotto, Antony |
| Contributors | Van Rooyen, G-J., Stellenbosch University. Faculty of Engineering. Department 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 | xix, 90 p. : ill. |
| Rights | Stellenbosch University |
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