Patent ID: 7496302

Claim:
An image forming apparatus, comprising: a humidity sensing device; a print engine that includes a movable intermediate transfer member and a plurality of image-forming stations that apply image-forming material to said intermediate transfer member during a print job that generates a bitmap which comprises a plurality of pixel locations; a print media handling device that moves print media to a transfer nip, where said image-forming material is transferred from said intermediate transfer member to said print media; wherein: (a) one of the image-forming stations applies black image-forming material; (b) at least three of the other image-forming stations apply other colors that are equivalent to a process black; (c) the black image-forming station is the last of said plurality of image-forming stations to apply image-forming material to said intermediate transfer member as it travels past said image-forming stations; and (d) if said humidity sensing device determines that a high humidity conditions exists such that compensation is desired, then: (i) a first set of said pixel locations is determined where black image-forming material is placed upon said intermediate transfer member by said black image-forming station; and (ii) a second set of said pixel locations is determined that is at least a subset of the first set of said pixel locations, and, at the second set of said pixel locations, process black image-forming material is placed upon said intermediate transfer member by said at least three of the other image-forming stations.