Vector-based nonlinear upconversion applying center-weighted medians

authored by: Holger Blume
Abstract: One important task in the field of digital video signal processing is the conversion of one standard into another with different field and scan rates. Therefore we have developed a vector based nonlinear upconversion algorithm which applies nonlinear center weighted median filters (CWM). Assuming a 2-channel model of the human visual system with different spatio temporal characteristics, there are contrary demands for the CWM filters. We can meet these demands by a vertical band separation and an application of so-called temporally and spatially dominated CWMs. Hereby errors of the separated channels can be orthogonalized and avoided by an adequate splitting of the spectrum. By this we have achieved a very robust vector error tolerant up-conversion method which significantly improves the interpolation quality. By an appropriate choice of the CWM filter root structures main picture elements are interpolated correctly also if faulty vector fields occur. In order to demonstrate correctness of the deduced interpolation scheme picture content is classified. These classes are distinguished by correct or incorrect vector assignment and correlated or noncorrelated picture content. The mode of operation of the new algorithm is portrayed for each class. Whereas the mode of operation for correlated picture content can be shown by object models this is shown for noncorrelated picture content by the distribution function of the applied CWM filters. The new algorithm has been verified as well by an objective evaluation method the PSNR (peak signal to noise ratio) measurement as by a comprehensive subjective test series.
External Organisation(s): TU Dortmund University
Type: Conference contribution
Pages: 142-153
No. of pages: 12
Publication date: 25.03.1996
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1117/12.235826 (Access: Closed)