Light Field Coding Using Panoramic Projection
2014 (English)Student thesis
A new generation of 3d displays provides depth perception without the need for glasses and allows the viewer to see content from many different directions. Providing video for these displays requires capturing the scene by several cameras at different viewpoints, the data from which together forms light field video. To encode such video with existing video coding requires a large amount of data and it increases quickly with a higher number of views, which this application needs. One such coding is the multiview extension of High Efficiency Video Coding (mv-hevc), which encodes a number of similar video streams as different layers. A new coding scheme for light field video, called Panoramic Light Field (plf), is implemented and evaluated in this thesis. The main idea behind the coding is to project all points in a scene that are visible from any of the viewpoints to a single, global view, similar to how texture mapping maps a texture onto a 3d model in computer graphics. Whereas objects ordinarily shift position in the frame as the camera position changes, this is not the case when using this projection. A visible point in space is projected to the same image pixel regardless of viewpoint, resulting in large similarities between images from different viewpoints. The similarity between the layers in light field video helps to achieve more efficient compression when the projection is combined with existing multiview coding. In order to evaluate the scheme, 3d content was created and software was developed to encode it using plf. Video using this coding is compared to existing technology: a straightforward encoding of the views using mvhevc. The results show that the plf coding performs better on the sample content at lower quality levels, while it is worse at higher bitrate due to quality loss from the projection procedure. It is concluded that plf is a promising technology and suggestions are given for future research that may improve its performance further.
Nya tekniker är under utveckling för 3D-bildskärmar kan visa light field: bilder och video som spelas in med arrayer av kameror. Sådan video kräver stora datamängder. En ny kodning av light field, syftande till att uppnå ett bättre förhållande mellan bildkvalitet och bitrate, utvärderas i det här examensarbetet.
Place, publisher, year, edition, pages
2014. , 51 p.
Light field, Video coding, Compression, 3D imaging
Computer Science Media and Communications Telecommunications
IdentifiersURN: urn:nbn:se:bth-6039Local ID: oai:bth.se:arkivex3E8DCCAAD5960586C1257DFF00591D17OAI: oai:DiVA.org:bth-6039DiVA: diva2:833456
UppsokSocial and Behavioural Science, Law