Patent ID: 8610944

Claim:
A method of achieving process-direction sub-raster magnification correction using non-redundant overwriting, the method comprising: determining process-direction magnification errors on both sides of a printed sheet and a magnification compensation factor for the printed sheet via a control device in a printing system; receiving raster data from a digital image path in the printing system; buffering the raster data in a raster memory buffer in the printing system for overwriting a swath of pixel data; extracting raster data from the buffer according to a plurality of non-redundant overwriting (NRO) resampling calculations for magnification correction, wherein the NRO resampling calculations comprise: B (1, i,j ), n ( i )=FLOOR[¼+ i (1− m )]=CEIL[ i (1− m )−¾] and B (2, i,j ), n ( i )=FLOOR[¾+ i (1− m )]=CEIL[ i (1− m )−¼] where: i=raster line number, j=cross-process pixel number, B(1, i, j)=Output bit written on actual raster number i, pixel j with pass (power) 1, B(2, i, j)=Output bit written on actual raster number i, pixel j with pass (power) 2, Δ=Actual raster spacing, m=Desired magnification change; and using the extracted raster data to drive a raster imager in the printing system.