US 6,982,723 B1
Method and apparatus for eliminating unwanted steps at edges in graphic representations in the line raster
Markus Szymaniak, Berlin (Germany)
Assigned to GMD-Forschungszentrum Informationstechnik GmbH, Sankt Augustin (Germany)
Filed on Aug. 30, 1999, as Appl. No. 9/385,822.
Claims priority of application No. 198 40 529 (DE), filed on Aug. 30, 1998.
Int. Cl. G09G 5/00 (2006.01); G06K 9/40 (2006.01)
U.S. Cl. 345—611 15 Claims
OG exemplary drawing
 
1. A method of eliminating unwanted steps at edges in image representations in the line raster, the image representations comprising pixels generated by rasterization of an original unrastered image, in particular in on-line operation, characterized by the steps:
a) application of an edge operator to a rastered image portion for coarsely ascertaining at least one rastered edge configuration in the rastered image portion,
b) determining the position of at least a first pixel from the amount of those pixels which form the rastered edge configuration or adjoin said rastered edge configuration,
c) approximation of a straight line for ascertaining a probable configuration of the unrastered image edge in the proximity of the first pixel,
d) ascertaining a criterion from the approximation straight line and the position of the first pixel for mixing a color X to the color C in the first pixel considered, and
e) mixing the ascertained color X to the color C in the first pixel considered.