| 摘要 |
<p>Motion compensation of a sequence of image fields (0-5) is carried out in the frequency domain using phase correlation (10) between corresponding picture areas of a pair of time-spaced, input fields (1, 4) to produce a set of motion-vector estimates that are used for filtering the relevant areas of each field (1; 4) of the pair by interpolation (11; 12) with the corresponding area of its preceding and following input-fields (0, 2; 3, 5) of the sequence, to produce a frame-approximation to that field (1; 4) through combination of the individually-filtered areas. The filtering in each case involves respective application (24-26 of weighting coefficients to corresponding spatial-frequency components of the relevant picture areas of three fields, and summation (28) of the weighted components, the coefficients being calculated or selected (27) according to the motion-vector estimate associated with each picture area. Repetition of the phase-correlation step (13) using the frame-approximations refines each motion-vector estimate for repeating the three-field interpolation processes (14, 15) to derive better frame-approximations. Transformation from the frequency to special domain (34) takes place after two or more reiterations, or when convergence is reached for all constituent picture areas.</p> |
