Utilization of non-printing high-spatial-frequency auxiliary pixels are
introduced into the bitmap of a font to obtain local control of the text image
development by modification of local average voltage in the development nip. These
auxiliary pixels embody frequencies or levels of charge that are past the threshold
for printing on the Modulation Transfer Function (MTF) curve, and therefore by
themselves result in no toner deposition on the resultant page. These auxiliary
pixels will however, position the toner cloud by modulating it and compensate for
cleaning field and toner supply effects. This will better position the toner cloud
to ensure adequate toner supply to all parts of the font so that the desired printing
pixels will print as intended.