Patent ID: 6088041
Filing Date: 2000-07-11
Classification: G06T

Abstract:
A method of dropout control for scan conversion of a glyph comprising a plurality of discrete line segments and spline segments, comprising:detecting each intersection of one of said plurality of said segments, each of said intersections representing a transition entry defined by pixel coordinates and a transition sense value, and placing in response thereto each transition entry into one of a pair of transition tables, said transition tables having opposite transition sense values;detecting a potential dropout in response to a selected pair of said transition entries generated by first and second ones of said plurality of segments crossing a particular one of plurality of scan lines, said selected pair of transition entries being in said transition tables for a same location of said pixel coordinates through which said particular scan line passes and having opposite transition sense values;retrieving from said transition tables said pixel coordinates associated with said selected pair of transition entries;determining with sub-pixel accuracy first scan-direction coordinates for the intersection of said first segment and said particular scan line based upon the type of said first segment;determining with sub-pixel accuracy second scan-direction coordinates for the intersection of said second segment and said particular scan line based upon the type of said second segment, anddetermining a pixel having a pixel center nearest to a midpoint between said first and second scan-direction coordinates and activating the pixel having said nearest pixel center.