Abstract: Area-sampling is the simplest method for line anti-aliasing. Applied to the line scan conversion, it determines the pixel color by calculating the overlapping area between the pixel and the straight line to achieve the line anti-aliasing. In view of the overlap calculation, a new computational method based on the scan line is presented in this paper. Utilizing the continuity of both the scan line and the linear primitives, the method turns the overlap area into the sum of the length of the segments cut by the straight line from the scan line, and overcomes the problem of low efficiency of the traditional overlapping area calculation method. The method opens a new way for the overlapping area computation in the area-sampling.

Key words: line scan conversion, area sampling, scan line, overlapping area

摘要： 区域取样是最简单的反走样方法，将其应用于直线的扫描转换中，通过计算像素与直线重叠面积改变像素的颜色，以达到直线反走样的目的。针对区域取样中的重叠面积计算，提出基于扫描线的重叠面积计算方法，利用扫描线的连续性和直线图元的连续性，将重叠面积转换为扫描线被直线所截线段长度的叠加，克服了传统重叠面积计算方法效率低的问题。该方法为区域取样的重叠面积计算开辟了新的思路。

关键词: 直线扫描转换, 区域取样, 扫描线, 重叠面积