This report describes the development and prototype implementation of a method for baking and compression of lightmaps, in an environment with dynamic lights. The method described can achieve more than 95 % compression eciency, and can be easily tuned with only two parameters. Even without specic tuning, the prototype consistently achieves signalto- noise ratios above 30 dB, reaching 60 dB in some scenes. Compression is achieved in four steps, rst by using image segmentation and function approximation to reduce the data-size and then using a predictive quantizer approach based on the PNG-lters together with an open-source compression algorithm. Both compression and decompression can be adapted for asynchronous and multi-threaded execution. / Denna report beskriver utvecklingen av en metod for bakning och komprimering av dynamiska ljuskartor, i renderingar med dynamiska ljuskallor. Metoden uppnar mer an 95 % storleksreduktion, och kan enkelt anpassas for olika ljuskartor med tva variabler. Aven utan speci- ka anpassningar uppnas en signal-to-noise niva over 30 dB, och narmare 60 dB i vissa scener. Komprimering sker i fyra steg, forst genom bildsegmentering och linjar funktionsapproximation, foljt av predictive quantization och en vanlig komprimeringsalgorithm. Bade komprimering och dekomprimering kan anpassas for asynkron och ertradig exekvering.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:oru-45438 |
| Date | January 2015 |
| Creators | Olsson, Tom |
| Publisher | Örebro universitet, Institutionen för naturvetenskap och teknik |
| 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 |
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