Author:
Till Halbach
Affiliation:
Norwegian Computing Center, Norway
Keyword(s):
Still-image and video compression, Performance comparison, Dirac, Theora, H.264, Motion JPEG2000.
Related
Ontology
Subjects/Areas/Topics:
Computer Vision, Visualization and Computer Graphics
;
Image and Video Coding and Compression
;
Image Enhancement and Restoration
;
Image Formation and Preprocessing
Abstract:
This article gives a technical overview of two open and free video compression systems, Dirac and Theora I, and evaluates the rate distortion performance and visual quality of these systems regarding lossy and lossless compression, as well as intra-frame and inter-frame coding. The evaluation shows that there is a substantial performance gap of Theora and Dirac when compared to H.264- and Motion JPEG2000-compliant reference systems. However, an algorithm subset of Dirac, Dirac Pro, achieves a performance comparable to that of Motion JPEG2000, and which can be less than one dB below the PSNR performance of H.264 with TV-size and HD video material. It is further shown that the reference implementations of the codecs of concern still have potential for efficiency improvements.