Patent ID: 7847940

Claim:
A method for calibrating an imaging head comprising a plurality of imaging channels, the method comprising: imaging a regular pattern of features within one or more swaths imaged by the imaging head, wherein the regular pattern of features: repeats in at least a sub-scan direction, and comprises at least a first feature which is imaged by a first portion of the plurality of imaging channels, and second feature which is imaged by a second portion of the plurality of imaging channels, both the first and second portions being less than all of the imaging channels, and both the first feature and the second feature being imaged within a same one of the one or more swaths; measuring an optical property of each of the first and second features; and based at least in part on the measured optical property, adjusting one or more imaging channels within at least one of: the first portion of the plurality of imaging channels, and the second portion of the plurality of imaging channels, wherein: the optical properties of the first and second features are made substantially equal upon a subsequent imaging of the regular pattern of features.