A method for sharpening the corners of digital image data within an
anti-aliasing image path so as to overcome corner rounding when displayed
or printed. The method comprises stepping a window across the image data
and comparing that windowed data to templates or performing Boolean logic
and arithmetic operations on the image data. Upon determining a match or
a corner detection, pixel values are substituted in the identified pixel
locations to achieve a clustering of the substituted pixel values about
the corner structure producing a corner-enhanced digital image. Filtering
and sampling are then performed according to an anti-alias operation to
the corner-enhanced image to produce an anti-aliased corner enhanced
image. The data substitution will achieve a localized clustering or "ear"
of toner/ink, or in the alternative for inside corners the localized
clustered absence of toner/ink. The result of this clustering is a
sharpening of the corners so that they display or print as intended by
the bitmap.