| 摘要 |
A method is provided for the display of images in the form of an image object defined in a first pixel plane overlying a background defined in a further pixel plane. In order to counteract aliasing effects at display time, the edge pixels at the boundary of object and background are displayed with a transparency value comprising contributions from the corresponding pixel in both the first and further planes. Step discontinuities in the image edge have a slope characteristic applied across them and, for each pixel crossed by the slope characteristic, the relative areas of the pixel above and below the slope are calculated. The relative contributions of the image and background pixels are then set according to this relation. The slope characteristic may be a straight line (as shown) or some other suitable function such as a parabolic curve.
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