Interpolative Multiresolution Coding of Advanced TV with Subchannels
K.M. Uz, Martin Vetterli, Didier J. LeGall · Kluwer Academic Publishers eBooks · 2006
The evolution of the current television standards toward increased quality and realism builds on higher spatial resolution, wider aspect ratio, better chroma resolution, digital audio (CD–quality) and possibly a new scanning format. In addition to the high bandwidth requirements, transmission systems for advanced television face the challenge that the quality has to be maintained throughout the system: for this reason component signals will be preferred over composite and digital representation over analog. The bandwidth requirements for advanced television (typically more than 1 Gbits/sec) ask for powerful digital compression schemes so as to make transmission and storage manageable. The quality requirements and the high resolution of advanced television material make very high signal to noise ratios necessary. It is therefore required to develop source coding schemes for digital video signals which achieve a compression of an order of magnitude or more at the highest possible quality. Two specific cases of interest are contribution quality advanced television at around 100-140 Mbits/sec (where objective quality has to be nearly perfect to allow post processing like chroma-keying) and distribution quality for the consumer at rates which are 2–5 times lower and where high subjective quality is required. Besides production and distribution of advanced television (ATV), another application of great interest is the coding for digital storage media (e.g. VTR, CD–ROM), where it is desirable to be able to access any segment of the data, as well as to browse the data (i.e. fast forward or reverse search). Currently, there is an on-going debate between proponents of interlaced and non-interlaced (also called sequential or progressive) scanning formats for ATV. Both formats have their respective advantages: interlaced scanning saves bandwidth and is well matched to current display and camera technology, and non-interlaced scanning is better suited for graphics and movie applications. In this paper, we will thus deal with both scanning formats. Our approach to the compression problem of ATV is based on the concept of multiresolution (MR) representation of signals. This concept has emerged as a powerful tool both for representation and for coding purposes. Then, we choose a finite