The present invention relates to dropout control in which one or more samples
are added to adjacent samples that fall within an image outline. The samples are
used in sub-pixel rendering to compensate for unnaturally thin or faint object
stems. Horizontal dropout control operations are provided to add samples to sets
of horizontally adjacent samples such that each set of samples comprises a minimum
number of samples. Vertical dropout control operations are provided to position
samples such that the weighted anti-aliasing filtering will take sufficient account
of the samples. In one embodiment, an associative table is utilized to calculate
alternative patterns of samples. In another embodiment, the baseline of an object
is used in the dropout control operations to reduce artifacts that can be created
by the addition of samples in the vertical direction.
