Cost-effective binary printer models for multi-color printers by improved reflectance modeling and patch clustering
AssigneeXerox Corporation
InventorsVishal Monga, Shen-Ge Wang, Raja Bala
Life of this patent
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Abstract
Systems and methods are described that facilitate reducing a number of patches used in characterizing a color halftone printer via a binary color printer model. A binary printer model involves printing of a fundamental set of color binary patterns that encompass all possible halftone outputs. A k-center clustering technique is employed to automatically find and eliminate redundancies in the initial set of binary color patterns. Once the number of patches is reduced to an acceptable number, a multiplicative reflectance model is applied that better approximates the physical process and therefore improves accuracy.
Claims20
A method of halftone-independent characterization of color printers, comprising:
- initially printing and measuring a complete color patch set comprising all possible (N) binary 2×2 patterns printable by a P-colorant printer, where N, P are both integers, in order to produce an initial set of measurements in a perceptual color space;
- performing a multidimensional clustering that partitions the complete patch set into K clusters, where K is an integer less than N, and produces a reduced set of K color patches, wherein each patch is a representative member of a cluster;
- decomposing each of the said K color patches as overlaps of L basis binary 2×2 patterns where L is less than K, and wherein each of the basis binary 2×2 patterns contain fewer colorants than the color binary patterns in the complete patch set;
- at run-time, printing and measuring the said L binary 2×2 color patterns within the reduced patch set;
- predicting K color measurements in the reduced patch set using the color measurements of the said L basis binary 2×2 color patterns to predict and a multiplicative reflectance model;
- predicting the color measurements of the complete set of N binary 2×2 patterns using said predicted K color measurements of the reduced patch set and cluster membership information;
- and
- deriving a P-colorant 2×2 binary printer model using said predicted measurements.
A system that facilitates halftone-independent characterization of color printers, comprising:
- a printer that initially prints and measures a complete color patch set comprising a complete set of N possible binary 2×2 patterns printable by a P-colorant printer, where N, P are integers, in order to produce an initial set of measurements in a perceptual color space;
- a processor that executes computer-executable instructions stored to a memory, including instructions for:
- performing a multidimensional clustering that partitions the complete patch set into K clusters, where K is an integer smaller than N and produces a reduces set of K color patches, wherein each patch is a representative member of a cluster;
- at run time, printing and measuring the L basis 2×2 binary color patterns within the reduced patch set, where L is an integer less than K;
- predicting K color measurements in the reduced patch set using the color measurements of the L basis binary 2×2 color patterns and a multiplicative reflectance model;
- predicting N color measurements of the complete set of N binary 2×2 patterns using the predicted K color measurements of the reduced patch set and cluster membership information;
- and
- deriving a P-colorant 2×2 binary printer model from the N predicted color measurements.
An apparatus for performing halftone-independent characterization of color printers, comprising:
- means for initially printing and measuring a complete color patch set comprising all possible (N) binary 2×2 patterns printable by a P-colorant printer, where N, P are both integers, in order to produce an initial set of measurements in a perceptual color space;
- means for performing a multidimensional clustering that partitions the complete patch set into K clusters, where K is an integer significantly smaller than N, and produces a reduced set of K color patches, wherein each patch is a representative member of a cluster;
- means for decomposing each of the said K color patches as overlaps of L basis binary 2×2 patterns where L is less than K, and wherein each of the basis binary 2×2 patterns contain fewer colorants than the color binary patterns in the complete patch set;
- means for printing and measuring, at run time, the said L binary 2×2 color patterns within the reduced patch set;
- means for predicting the K color measurements in the reduced patch set using the color measurements of the said L basis binary 2×2 color patterns to predict and a multiplicative reflectance model;
- means for predicting the color measurements of the complete set of N binary 2×2 patterns using said predicted K color measurements of the reduced patch set and cluster membership information;
- and
- means for deriving a P-colorant 2×2 binary printer model using said predicted measurements.
Dependencies are inferred from the claim text.