US 7,397,582 B2 · Color characterization with enhanced purity

Abstract

The present invention creates a color transform for transforming color image data from a device-independent color space to a device-dependent color space of a color device. A forward model is accessed which transforms color image data from the device-dependent color space to the device-independent color space. The forward model is iteratively inverted to obtain a plurality of distinct device-dependent data point value sets, wherein the device-dependent data point value sets are colorimetrically identical to each other in the device-independent color space. One device-dependent data point value set is then selected from the plurality of distinct device-dependent data point value sets based on the application of a color purity function to the plurality of distinct device-dependent data point value sets. The color transform is populated with the selected device-dependent data point value set. Because one device-dependent data point value set is selected from the plurality of obtained distinct device-dependent data point value sets based on the application of a color purity function, the inverse color transform provides the best color estimate among all color candidates that are colorimetrically equivalent, and accurately recovers original device-dependent color space values.

Claims37

Dependent claims

A method for creating a color transform for transforming color image data from a device-independent color space to a device-dependent color space of a color device, the method comprising the steps of:

accessing a forward model which transforms color image data from the device-dependent color space to the device-independent color space;
iteratively inverting the forward model to obtain a plurality of distinct device-dependent data point value sets for one device-independent value set in the forward model;
calculating color purity of each of the plurality of distinct device-dependent data point value sets;
selecting one device-dependent data point value set from the plurality of distinct device-dependent data point value sets based on the calculated color purity;
and
populating the color transform with the selected device-dependent data point value set.

3 more elements

A method for creating an inverse color transform for transforming color image data from a device-independent color space to a device-dependent color space of a color device, the method comprising the steps of:

accessing a forward model which transforms color image data from the device-dependent color space to the device-independent color space;
performing an iterative algorithm using predesignated initial device-dependent data point values and using one device-independent data point value set from the forward model to obtain a first set of device-dependent data point values;
generating new initial device-dependent data point values based on the obtained first set of device-dependent data point values;
performing the iterative algorithm using the generated new initial device-dependent data point values and using said one device-independent data point value set from the forward model to obtain a second set of device-dependent data point values;
calculating color purity of the first set of device-dependent data point values and the second set of device-dependent data point values;
selecting between the first set of device-dependent data point values and the second set of device-dependent data point values based on the calculated color purities of the first set of device-dependent data point values and the second set of device-dependent data point values;
and
populating the inverse color transform with the selected set of device-dependent data point values.

5 more elements

Dependencies are inferred from the claim text.

Color characterization with enhanced purity

Life of this patent

Color characterization with enhanced purity

Life of this patent

Abstract

Claims37