Frank Bosveld

Refinement system for hierarchical video coding

The Broadband Integrated Services Digital Network (BISDN) based on lightwave technology is supposed to become the all-purpose exchange area communications network of the future. All digital video services are integrated with applications ranging from videophone teleconferencing to digital TV (signals according to the CCIR rec. 601) and High Definition TV (HDTV) distribution. A desirable feature of the various video services is the upward and downward compatibility in resolution in order to guarantee a free exchange of services transmitters and receivers. This paper proposes an n-level progressive hierachical intraframe coding scheme based on subband coding. In this scheme several spatial low-resolution services are available as subsets of the coded HDTV data which can directly be received at lower bit rates. Progressive coding of the HDTV signal is employed in order to prevent quantization errors from propagating to higher resolution signals. Special attention is given to the design of the quantizers required for the progressive coding and to the incorporation of the side panels coding.

Hierarchical coding of HDTV

Abstract The Broadband Integrated Services Digital Network (BISDN) based on lightwave technology is supposed to become the all-purpose exchange area communication network of the future. All digital services are integrated with applications ranging from facsimile, videophone, teleconferencing to digital standard-resolution TV — sometimes referred to as Extended Quality TV (EQTV) — and High Definition TV (HDTV). In order to make efficient use of the available network bandwidth hierarchical coding schemes combine the necessary data compressions of the HDTV and EQTV signals such that the HDTV signal can be transmitted at 135 Mbit/s with the embedded EQTV signal coded in a sub-channel of approximately 35 Mbit/s. This paper investigates in detail three possible coding strategies for fixed bit-rate hierarchical coding schemes, namely distributed coding, error feedback coding and selective coding. With the aid of the rate distortionn theory it is determined under which conditions both EQTV and HDTV are encoded optimally for each of the three strategies. These conditions are verified with three introduced hierarchical subband coding schemes, namely the Distributed system, the Refinement system and the Selection system, which are direct implementations of the three coding strategies. It is concluded that if both EQTV and HDTV have to be encoded optimally, the error feedback coding strategy is the best suitable one because this strategy is able to cancel propagation of coding errors of the EQTV signal into the reconstructed HDTV signal.

Rate constrained multiresolution transmission of video

Multiresolution transmission of compressed video is performed using subbands. Multistage quantization is necessary for efficient embedded video transmission on rate constrained channels. This paper investigates the performance of a number of multistage scalar quantization techniques: concatenated coding, conditional entropy coding and conditional quantization. Intraframe as well as interframe coding approaches are investigated with these multistage quantization techniques on high definition and standard definition source material. >

Hierarchical video coding using a spatio-temporal subband decomposition

Compatibility among video contribution and distribution standards is becoming increasingly important due to emerging new services within broadband communication networks. A compatible video data compression system that uses nonorthogonal spatio-temporal subband decompositions is introduced. It supports a hierarchy of video standards, including both progressively scanned and interlaced signals. Simulations show that the quality of the encoded signals is mainly determined by the near-perfect behavior of the spatio-temporal filter and decimation units.<<ETX>>

Compatible spatio-temporal subband encoding of HDTV

Abstract Compatibility among video contribution and distribution standards is becoming increasingly important due to emerging new services in broadband communication networks. This paper introduces three compatible video data compression systems that are based on spatio-temporal subband decompositions. The first system provides for spatial compatibility of video services having diffferent resolutions. The other two systems provide also for temporal compatibility, thus supporting hierarchies of video standards including both progressively scanned and interlaced signals. Simulations show that high-quality results and good compression ratios can be obtained in general.

Hierarchical subband coding of HDTV in BISDN

Two intraframe hierarchical coding schemes based on a subband coding strategy are proposed for the broadband integrated services digital network (BISDN). High-definition TV (HDTV) and extended-quality TV (EQTV) coexist on the network. The two schemes presented code the HDTV signal for the 135 Mb/s channel, while the EQTV signal is coded for the 45 Mb/s subchannel. A theoretical analysis of hierarchical coding shows that if the EQTV signal is coded first and the HDTV signal is coded next, it is possible to obtain two optimally coded signal. This is realized in the first hierarchical coding scheme: the refinement system. An alternative for the refinement system is the selection system, which optimally codes the HDTV signal only, but has a simpler coding structure. The higher complexity of the refinement system results in higher-quality EQTV.<<ETX>>

Compatible HDTV transmission using conditional entropy coding

The authors thoroughly investigate the performance of multistage scalar quantization and investigate three encoding strategies: concatenated coding, conditional entropy coding, and conditional uniform quantization. It is shown that the coding performance of a multistage quantized subband is inferior to that of direct (i.e., single stage) quantization. Conditional entropy coding and conditional uniform quantization partly eliminate this loss.<<ETX>>

Compatible video compression using subband and motion compensation techniques

Compatible or hierarchical video compression schemes are of interest especially due to emerging broadband networks and over-the-air digital transmission links. The embedded transmission of low resolution video signals should, however, not affect the coding efficiency of the highest resolution video signal. For digital terrestrial broadcasting applications, the use of motion information is necessary to sufficiently compress the hierarchical layers. This paper investigates the possibility of in-band motion compensation in a hierarchical subband coding scheme, and proposes a compatible transmission scheme using PRMF filter banks and embedded quantization.

Hierarchical Video Coding Using 3D Subband Decompositions

In recent years, there has been an increasing interest in bandwidth compression of digital high quality video for the Broadband Integrated Digital Network (BISDN) [l, 2, 31. This future network based on lightwave technology using ATM and intelligent networking will become the all-purpose exchange area network. BISDN facilitates the distribution of narrowand wideband video services like videophone, digital TV and high definition TV (HDTV). Downwardand upward compatibility of these video services will provide the consumer an easy access to all video services using a single display device. Therefore, a lot of research is directed towards the so-called hierarchical coding schemes, which can provide these compatibilities by splitting the source signal into several hierarchical layers. Generally, the lowest layer contains a low-pass version of the source signal while the other layers contain additional detail information. Receivers are able to visualize any video service at their (fixed resolution) monitor by collecting the required layers from an ATM channel. Hierarchical datacompression schemes for HDTV must be able to support a hierarchy of video services (for example Table 1). The decomposition of the HDTV signal (HDP) requires a spatial-temporal filtering in order to separate the spectra of the successive services and layers. A subband approach for this decomposition seems very appropiate because perfect reconstruction of the HDTV signal is achievable [3] and layers can be defined as a collection of subbands [a]. After the layers are generated by the spatio-temporal decomposition bank they are subsequently coded at a fraction of the H4 channel capacity (135 Mbit/s) of the BISDN network. In order to guarantuee a high quality HDTV reconstruction, the propagation of the quantization errors of lower (low-resolution) layers must be eliminated. These layers are therefore coded progressively which means that part of the bit rates available for the higher layers is spent on eliminating the coding errors resulting from lower layers. Hierarchical coding schemes for HDTV consisting of two levels have been investigated.[l]. These systems are able to code the HDTV signal at 135 Mbit/s while a standard-resolution TV signal is available at 45 Mbit/s. Extended schemes supporting three or four progressivescan video formats are proposed and are all based on spatial (2D) subband decompositions [a]. The first results on temporal decomposition structures for hierarchical coding purposes are reported by Vetterli [3]. These decompositions are based on subbands with rectangular