| 摘要 |
<p>Block matching is well known as a robust and intuitively simple method of motion estimation for television pictures. However, when the purpose of the motion estimation is to provide accurate interpolation between images, for example in a 50 Hz to 100 Hz upconverter, conventional block matching suffers from the problem that the blocks are situated in the original fields rather than in the fields to be interpolated, leading to possible errors in the calculated motion field. The invention uses two-sided block matching. The search window (BSW and FSW) is shared between the two input fields (BF, FF) in such a way that the candidate motion vectors related to the candidate pixel blocks (CPBB and CPBF) all pass through the same points in the field (IF) to be interpolated. Thus, the 'current block' becomes a notional area in the field to be interpolated, and each of the two search windows extends to half the maximum motion vector in each direction. Each motion vector points forward (FHMV) to the forward field (FF) by half its value and backward (BHMV) to the backward field (BF) by half its value. Two-sided block matching solves the positional error problem because the current blocks IFB cover the interpolated field and are correctly placed in the interpolated field, and it solves the problem of gaps and conflicts because every point in the interpolated field has precisely one motion vector assigned to it.</p> |
