| 摘要 |
<p>An efficient motion estimation technique for an arbitrarily-shaped video object reduces the number of searches for motion estimation for shape coding and texture coding. The technique can be easily employed in an MPEG-4 encoder for coding Video Object Planes (VOPs). In a pixel loop, an mxm block (720) traverses a reference video image (700) with the video object (710), and the alpha plane value of each pixel is examined. If the alpha plane values in a block are not all the same, this indicates the block overlaps the object boundary. Accordingly, a shape coding mask value for the coordinate of a reference pixel (722) in the block, such as the top, left pixel, is set to '1'. A texture coding mask is defined similarly when the blocks overlap or are inside the object.</p> |
