In today's video delivery and broadcast networks, issues of copyright protection have become more urgent than in analog times, since the copying of digital video does not result in the decrease in quality that occurs when analog video is copied. One method of copyright protection is to embed a digital code, a"watermark", into the video sequence. The watermark can then unambiguously identify the copyright holder of the video sequence. Watermarks can also be used to identify the purchaser of a video sequence, which is called "fingerprinting". The objective of this master thesis was to implement a program that would insert watermarks into video sequences and also detect if a given video sequence contains a givenwatermark. The video standard I chose to use was the H.264 standard (also known as MPEG4 AVC) as it offers a significant efficiency improvement over the previous video compression standards. A couple of tests that can be considered representative for most image manipulations and attacks were performed. The program passed all tests, suggesting that the watermarking mechanism of this thesis can be expected to be rather robust, at least for the video sequence used. By looking at the watermarked video sequences and comparing them to the originals, or measuring the signal to noise ratio, one can also see that the watermarks are unobtrusive. The execution times were also measured. Compared to coding and decoding a H.264 video stream, the time it takes to insert and extract watermarks was much less. Calculating a threshold takes roughly double the time as decoding the sequence, though.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:liu-2352 |
| Date | January 2004 |
| Creators | Bergkvist, David |
| Publisher | Linköpings universitet, Institutionen för systemteknik, Institutionen för systemteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | LiTH-ISY-Ex, ; 3516 |
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