Peter Hans Westerink

Facts and fiction: Some aspects regarding the design of digital television cameras using CCD image sensors

The architecture of CCD sensors and their relationship to digital processing of images requires a re‐examination of traditional analog signal processing conventions. Digital processing now requires different methods of analysis and processing in areas such as frequencv response, noise, and scanning techniques. The purpose of this paper is to encourage researchers and engineers to forget some of the traditional analog practices and have them step up to the future with an open mind.©1994 John Wiley & Sons Inc

Segmentation-based image compression for video cassette recorders

Studio-quality video cassette recorders used for editing need intraframe compression schemes that can compress/decompress an image many times without appreciable degradation. They also require fast-forward playback of a low-quality image using only a small part of the compressed data. A system with these features is reported, based on image segmentation. A segmented approximation to the original image is losslessly encoded and a residual image is created. The lossless coding scheme is motivated by examining the constraints caused by channel errors and trick play modes. The residual image is coded by a conventional data compression technique. By preserving the main image features with a lossless code, the multi- generation performance is stabilized. Because segmentation is shift-invariant, edits that include x-y shifting between generations do not degrade performance. This paper reports a new segmentation algorithm. It has high resolution, obtained in part by a newly designed edgeness measurement. Using this, images are segmented to pixel accuracy by an algorithm which is only O[n] in complexity. Multi-generation simulations of sequences with 4:1 compression ratios are presented at both normal and shuttle speeds, using both sub-band and DCT residual coders.