Boxing clever [Toshiba's Unified Digital Architecture]

The author describes how Toshiba's Unified Digital Architecture will enable the convergence of home entertainment and computing. The viable convergence platform combines the simplicity and reliability of consumer electronic (CE) appliances with a PC-like open extensible architecture optimised for the demands of A/V processing. Toshiba, a leading player in the CE appliance, PC and semiconductor industries, has formulated a proposal for a generic development platform for future-proof CE appliances designed expressly to satisfy these convergence criteria. The company has called its proposal the Unified Digital Platform (UDP). The UDP is designed to support a minimum set of common hardware components, comprising a RISC-based CPU, an MPEG -2 video decoder, an audio decoder (MPEG, Dolby), a graphics engine, a video interface, an audio interface and a network interface. Additional hardware components can be introduced to meet specific application requirements. Central to the UDP design is a data bus, the MM-bus (multimedia bus), designed to support data transfers between the system hardware components at rates consistent with the requirements of real-time A/V applications     

Facial feature estimation for model-based coding

A new method for the estimation of the facial features is proposed, which can be used in model-based coding schemes. The method combines fast algorithms from the image analysis and it can be used in conjunction with other methods for extremely low bit rate transmission of videophone pictures.<>     

Modeling and subjective assessment of cell discard in ATM video

Measurements of subjective picture impairment as a function of network loading in a simulated ATM network are reported. The simulation indicated that cells tend to be discarded in bursts, the frequency and severity of which can be related to the loading by a threshold model. The effect of the discards on broadcast-style video, coded using a single-layer H.261-type method, was found to be a function of scene content and movement at the instant of occurrence. If the visibility of cell discards is maintained at or below threshold in worst-case scenes, the study indicated that network loadings around 55% for a multiplex of 16 video sources and around 70% for a multiplex of 48 video sources are achievable.     

Use of co-occurrence matrices in the temporal domain

The concept of temporal co-occurrence matrices is introduced. The calculation and some of its features are described. Experimental results show that the temporal co-occurrence matrices can be applied to a wide range of interframe image processing, reducing the processing time involved.<>     

Generalised block-matching motion estimation using quad-treestructured spatial decomposition

A generalised block-matching motion estimation with variable-size blocks is proposed. The location and size of each block are determined from a quad-tree spatial decomposition algorithm. Experimental results with head-and-shoulders test image sequences show that motion-compensated errors with this method have lower entropy than the conventional fixed or variable-size block-matching techniques. The quality of the coded pictures under the proposed method with an H.261 codec, both subjectively and in terms of PSNR, outperforms the conventional use of fixed and variable block-size motion estimators