Real-time filtering and detection of dynamics for compression of HDTV

The preprocessing of video sequences for data compressing is discussed. The end goal associated with this is a compression system for HDTV capable of transmitting perceptually lossless sequences at under one bit per pixel. Two subtopics were emphasized to prepare the video signal for more efficient coding: (1) nonlinear filtering to remove noise and shape the signal spectrum to take advantage of insensitivities of human viewers; and (2) segmentation of each frame into temporally dynamic/static regions for conditional frame replenishment. The latter technique operates best under the assumption that the sequence can be modelled as a superposition of active foreground and static background. The considerations were restricted to monochrome data, since it was expected to use the standard luminance/chrominance decomposition, which concentrates most of the bandwidth requirements in the luminance. Similar methods may be applied to the two chrominance signals

Integrating vision modules with coupled MRFs

A. I. Laboratory Working Papers are produced for internal circulation and contain proteins, lipids, cholesterol, polysorbate-80, and other compounds unsuitable for external exposure. It is not intended that material in this paper be applied externally; it is intended for internal consumption only. Serving suggestion: add taco sauce (not included).I outline a project for integrating several early visual modalities based on coupled Markov Random Fields models of the physical processes underlying image formation, such as depth, albedo and orientation of surfaces. The key ideas are: a) to use as input data estimates of the various processes and their discontinuities, computed by several different algorithms. b) to implement with MRFs the physical and geometrical constraints of local "continuity" of the processes and of their discontinuities. Processes are coupled to each other: the most common form of coupling is a veto — one process vetoing another — as in the case of discontinuities and the associated continuous field.MIT Artificial Intelligence Laborator