Hewlett-packard Development Company, L.P.

Dongli Yang

Philip Cowan

Yifeng Wu

Kevin R Hudson

Huanzhao Zeng

Philip B Cowan

A color space conversion technique uses a set of control lines in a first color space. Each control line includes several control points having predetermined values in a second color space. A planar region is identified among the set of control lines in the first color space. The planar region contains a number of target points that are to be interpolated from the first color space to the second color space. The planar region is partitioned into at least a first area and a quadrangular area. Target points in the quadrangular area correspond to a different set of colorants from the second color space than target points in the first area. A quadrangular interpolation is applied to the target points in the quadrangular area to determine corresponding values in the second color space based at least in part on the predetermined values of control points bounding the quadrangular area.

Color space conversion using interpolation

A method of an embodiment of he invention is disclosed in which image data is bi-directionally color calibrated using one or more online color calibration tables. The image data, as has been bi-directionally color calibrated is output.

Online bi-directional color calibration

A systems and method for printer calibration creates linearization tables by receiving optical density related measurements for a primary ink in a group of one or more print heads printing with the primary ink, selecting from the group of print heads at least two print heads that deliver a range of optical densities when printing with the one or more primary ink, generating prebuilt linearization tables corresponding to the at least two print heads that compensate for different ink drop weights printed by the at least two print heads, and providing the prebuilt linearization tables and at least a portion of the optical density related measurements to a calibration routine that interpolates the prebuilt linearization tables to create an actual linearization table for the primary ink printed by a print head. The prebuilt linearization tables and measurements related to optical density calibrate a primary ink printed by a print head, by receiving two or more prebuilt linearization tables for a corresponding two or more print heads that compensate for different ink drop weights printed by the two or more print heads, determining a measurement related to optical density when the print head prints the primary ink at a selected gray level, comparing the measurement related to optical density produced by the print head with measurements related to optical density when the two or more print heads print the primary ink at the selected gray level, and estimating the linearization table for the primary ink based upon the prebuilt linearization tables for the two or more print heads and the comparison of the measurement related to optical density of the print head and the two or more print heads.

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Vancouver, WA, United States of America

Dongli Yang