Patent ID: 8665492

Claim:
An image processing apparatus comprising: a printing unit configured to print an evaluation image in which a plurality of color patches and a plurality of reference patches are placed on a same main scanning line; a measuring unit configured to measure density of the evaluation image printed by the printing unit; a first calculating unit configured to calculate densities of virtual reference patches at locations of the color patches on the main scanning line using the densities of the plurality of reference patches measured by the measuring unit; a density irregularity correction unit configured to perform density irregularity correction in a main scanning direction using the densities of the plurality of reference patches measured by the measuring unit and the densities of the virtual reference patches calculated by the first calculating unit; a second calculating unit configured to calculate densities of virtual color patches at locations of the reference patches on the main scanning line using the densities of the plurality of color patches measured by the measuring unit; an obtaining unit configured to obtain density variations with respect to the densities of the plurality of color patches measured by the measuring unit and the densities of the virtual color patches calculated by the second calculating unit, the density variations arising due to the density irregularity correction performed by the density irregularity correction unit; and a density tone correction unit configured to perform density tone correction using the density variations obtained by the obtaining unit and the densities of the plurality of color patches measured by the measuring unit.