Every printing
system has characteristic defects which detract from high quality printing. Xerographic printing systems show defects such as banding, mottled colors in large fill areas, trail-edge deletion and starvation where toner concentrations drop at certain color edges, misregistration, and so on. Ink jet printing systems can show ink bleeding, streaking in the direction of head movement, and so on. One approach to reducing printer defects is to refine the electro-
mechanics for more precise printing. Another approach which works for predictable defects is to modify the
digital data being sent to the printer to pre-compensate for the defect. The prior art does this to a limited extent for individual object types (strokes, fills, images, text, etc.) and for misregistered color edges (
trapping). This invention extends the range of edge-related defects that can be both predicted and pre-compensated for. An embodiment of the invention is described which pre-compensates for defects such as trail-edge deletion, starvation, misregistration, halo, etc. by identifying runs of color which meet the criteria likely to cause the effect and applying a function f(edge-distance, object-type) to such runs to modify them appropriately. Both the prediction criteria and the functions applied are anamorphic (the scan direction and process direction are treated differently) and object-optimized (object attributes are taken into account). Further, both prediction criteria and applied correction functions allow user-settable input.