Method and apparatus for calibrating a digital color reproduction apparatus

Abstract

A digital color reproduction apparatus of the type having a scanner for scanning a color image to produce scanner color signals representing the color image, a digital image processor for processing the scanner color signals to produce printer color signals, and a printer responsive to the printer color signals for reproducing the color image is said to be "closed" when the original color image and the reproduced color image are on the same medium. For a closed color reproduction system, the color transform from scanner color signals to printer color signals can be implemented using the tri-linear interpolation based on a 3D calibration lookup table. The 3D calibration lookup table can be derived automatically by: a) determining the relationship between equal printer color signals and averaged scanner color signals; b) based on the determined relationship, generating a set of color patches on the printer that are uniformly distributed in scanner color signal space; c) scanning the color patches to generate a lookup table relating printer color signals to scanner color signals; and d) inverting the lookup table to generate the calibration lookup table.

Dependencies are inferred from the claim text.