A two-dimensional generalised sampling theory and application to de-interlacing

Yen's generalisation of the sampling theorem has been proposed as the theoretical solution for de-interlacing by Delogne² and Vandendorpe³ The solution results in a vertical interpolation filter with coefficients that depend on the motion vector value, which uses samples that exist in the current field and additional samples from a neighbouring field shifted over (part of) a motion vector. We propose a further generalisation, where we design vector-adaptive inseparable 2D filters, which use samples from the current and the motion compensated previous field that are not available for all vectors on a vertical line. The resulting inseparable filters give a better interpolation quality at a given number of input pixels. We will show that the algorithm can be made robust against the sensitivity to inaccurate motion vectors.