True Motion-Compensated De-Interlacing Algorithm

Abstract

This paper presents a true motion-compensated de-interlacing (TMCD) algorithm based on a fast true motion estimation scheme. The fast true motion estimation scheme, designated as a variable block size true motion estimation for a translated motion model (VBTME), finds block-based true motion vectors within interlaced fields and then uses these true motion vectors to construct corresponding de-interlaced frames. Although the real motions of a majority of the objects within an interlaced field can be accurately represented by using block-based true motion vectors, the motions of certain objects (e.g., those which disappear suddenly or are occluded by other objects) cannot be adequately compensated by using such vectors, and therefore, the corresponding pixels must be further refined by an alternative method. Accordingly, a TMCD applies a set of three decisional rules and then selects either a new spatial edge direction indicated interpolation method or a traditional temporal mean filter to interpolate those pixels which cannot be adequately compensated by using true motion vectors. The experimental results show that by comparing the PSNR values for CIF format video sequences obtained by a 4-field adaptive motion-compensated (4F-AMC) de-interlacing scheme and a selective motion-compensated (SMC) de-interlacing scheme to a TMCD scheme, an average PSNR improvement of 1.37 and 6.36 dB is achieved, respectively. Furthermore, compared to the motion estimation schemes used in a 4F-AMC and a SMC, the VBTME reduces motion estimation time by 96 and 69%, respectively. Finally, it is shown that the visual quality of videos with a CCIR601 format de-interlaced using a TMCD is better than that obtained by using a 4F-AMC de-interlacing scheme.