| 摘要 |
A motion estimation and compensation technique is provided for interlaced digital video such as video object planes (VOPs). Predictor motion vectors for use in differentially encoding a current field coded macroblock (700) are obtained using the median of motion vectors (MV1, MV2, MV3) of surrounding blocks or macroblocks (712, 722, 732). When a surrounding macroblock (820) is itself interlaced coded, an average motion vector for that macroblock is used, with fractional pixel values being mapped to the half-pixel. When the current block (912) is not interlaced coded but a surrounding block (820) is, the field motion vectors may be used individually or averaged. In a repetitive padding technique for an interlaced coded VOP (1,010), the even (0, 2, ..., 14) and odd (1, 3, ..., 15) lines of the VOP and surrounding block (1,000) are grouped. Within each field (1,210, 1,220), exterior pixels (1,6) are padded by setting them to the value of the nearest boundary pixel (0,6), or to an average of two boundary pixels (0,6; 1,7). The lines are then reordered to provide a single padded reference VOP image. |
