Coding of deinterlaced image sequences

Vandendorpe, Luc [UCL] Cuvelier, L. Maison, B. Delogne, Paul [UCL]

This paper investigates a coding method for interlaced image sequences which uses deinterlaced images as an intermediate format. The purpose of this method is threefold: firstly, to achieve a higher coding gain, as the processing of progressive pictures raises much less difficulty than the processing of interlaced ones; secondly, to provide an intermediate step toward the development of a fully progressive production and transmission chain; and finally to open the way to efficient solutions for important image processing issues such as frame rate conversion and compatibility. In previous work by the authors (1994), an interlace-to-progressive converter was proposed. It was based on theoretically correct generalized interpolation formulas, working under the assumption of a uniform translational motion. The scheme proposed here makes use of this converter to produce the progressive images from the interlaced source, which are coded and then re-interlaced. Another solution is considered, with the purpose of improving the coding efficiency alone. It is based on an intermediate progressive format at half the original temporal sampling rate. However, in that case, some additional information needs to be transmitted in order to accurately recover the full rate interlaced signal. The two methods mentioned above are described in some detail and tested on actual sequences. The picture quality is assessed, both objectively and subjectively, and conclusions are drawn.