Abstract: A computer graphics system renders an image on a display device using improved pre-filtering techniques that minimize aliasing artifacts in the image, particularly at the endpoints of lines. To anti-alias the image, a plurality of edges are placed near a line in the image. An edge function represents the edge. This edge function is multiplied by a scale factor to produce a distance function. This scale factor is the reciprocal of the Euclidean length of the line. The distance function is evaluated to determine the distance of selected pixels from each edge in units of pixels. These distances determine the intensity value for each selected pixel. Pixels on or beyond an edge, with respect to the line, are given a minimum intensity value; pixels inside all edges are given intensity values corresponding to their distances from the edge. An intensity function describing a relationship between pixel distances from the edges and their corresponding intensity values is developed.

Abstract: A graphics system for storing and editing graphic images represented by digital data, includes a frame memory for storing pixel data representing graphic images including first and second graphic objects. The pixel data is stored at addresses, each being associated with one or more graphic fragment forming the first and second graphic objects. First and second addresses are respectively associated with those of the graphic fragments forming the first and second graphic objects. A memory controller controls writing and reading the pixel data to and from the frame memory. A fragment editor is provided to receive the pixel data read from the first address and modify the associated fragment with the received pixel data so as to form modified pixel data. An address detector detects the first address responsive to a request to read the pixel data from the first address and the second address responsive to a subsequent request to read pixel data from the second address.