Complexity scalable motion-compensated temporal filtering

Abstract

Computer networks and the internet have taken an important role in modern society. Together with their development, the need for digital video transmission over these networks has grown. To cope with the user demands and limitations of the network, compression of the video material has become an important issue. Additionally, many video-applications require flexibility in terms of scalability and complexity (e.g. HD/SD-TV, video-surveillance). Current ITU-T and ISO/IEC video compression standards (MPEG-x, H.26-x) lack efficient support for these types of scalability. Waveletbased compression techniques have been proposed to tackle this problem, of which the Motion Compensated Temporal Filtering (MCTF)-based architectures couple state-of-the-art performance with full (quality, resolution, and frame-rate) scalability. However, a significant drawback of these architectures is their high complexity. The computational and memory complexity of both spatial domain (SD) MCTF and in-band (IB) MCTF video codec instantiations are examined in this study. Comparisons in terms of complexity versus performance are presented for both types of codecs. The paper indicates how complexity scalability can be achieved in such video-codecs, and analyses some of the trade-offs between complexity and coding performance. Finally, guidelines on how to implement a fully scalable video-codec that incorporates quality, temporal, resolution and complexity scalability are proposed.

Complexity scalability in video coding based on in-band motion-compensated temporal filtering

“…The profiling results showed that the complete-to-overcomplete discrete wavelet transform is responsible for about half of the total memory accesses performed by the codec. Thus the conclusion can be drawn that, in order to support a broad set of "complexity profiles" in the IBMCTF architecture, extensive memory optimizations need to be performed on the CODWT module [15]. Finally, an important aspect that needs to be investigated is how to achieve complexity scalability in the CODWT.…”

“…Extensive experimental results are reported in [15]. The profiling results showed that the complete-to-overcomplete discrete wavelet transform is responsible for about half of the total memory accesses performed by the codec.…”