Patent ID: 7639377

Claim:
A dither pattern generating apparatus comprising: a generator to generate a plurality of measurement patterns on the basis of a plurality of dither patterns corresponding to a measurement pattern; a sensor to measure a density within an image output device of each of said generated plurality of measurement patterns; an obtaining unit to obtain a change in environment in which the apparatus is used; a corrector; a converter to convert a sensor value of each of the plurality of measurement patterns obtained by said sensor into a print density based on a conversion algorithm; wherein the corrector corrects the sensor value obtained by said sensor or the conversion algorithm of said converter in accordance with a result obtained in said obtaining unit; a calculator to calculate a γ characteristic curve associating the plurality of measurement patterns with print densities on the basis of the print densities of the plurality of measurement patterns converted by said converter; and a dither pattern generator to generate a dither pattern on the basis of said calculated γ characteristic curve.