Described herein is a method for identifying an interference pigment in a coating. Also described herein is a corresponding device and a computer-readable medium.

There is provided an apparatus and method for determining metameric settings for a nonlinear light source comprising a set of N primaries. Spectral data indicative of a spectral output of each of the N primaries at each of a plurality of predetermined intensity values is received. The method comprises determining, in dependence on the received data, a relationship for each of the N primaries between intensity and spectral output over at least a portion of a visible spectrum; determining a first activation corresponding to activation of a first photoreceptor type and a second activation corresponding to activation of a second photoreceptor type in dependence on the determined relationship for each of the N primaries; and selecting a background set of intensity values and a modulation set of intensity values of the N primaries. The background set and modulation set are selected such that a difference between the determined first activation corresponding to the background set and the determined first activation corresponding to the modulation set is according to a first criteria; and a difference between the determined second activation corresponding to the background set and the determined second activation corresponding to the modulation set is according to a second criteria.

Disclosed is a method for organizing a substantially uniform system of colorimetry comprising the steps of (i) taking a pseudoinverse of a matrix containing intensity values for an existing non-uniform color-matching functions; (ii) optionally normalizing the pseudoinverse matrix from step (i); (iii) empirically determining an opponency transformation matrix based on a plurality of substantially uniformly spaced color standards; (iv) transforming the matrix from step (ii) to a color opponency color coordinate utilizing the opponency transformation matrix from step (iii) to obtain a Red-Green, Yellow-Blue and Lightness (RG, YB and LT) color matching functions; and (v) transforming the RG, YB and LT color matching functions from step (iv) non-linearly to color matching functions that produce colors recognizable as being uniform by human vision; wherein after step (v) the existing non-uniform color matching functions are transformed into substantially uniform color matching functions.

A system includes at least one processor configured to function as a color verification unit configured to execute color verification by using a colorimetric value acquired by colorimetry of a sheet output by an image forming apparatus, and a determination unit configured to determine an adjustment function to be executed by the image forming apparatus or an image processing apparatus connected to the image forming apparatus from among a plurality of adjustment functions, based on a result of the color verification.

A system includes at least one processor configured to function as a color verification unit configured to execute color verification by using a colorimetric value acquired by colorimetry of a sheet output by an image forming apparatus, and a determination unit configured to determine an adjustment function to be executed by the image forming apparatus or an image processing apparatus connected to the image forming apparatus from among a plurality of adjustment functions, based on a result of the color verification.

The invention generally relates to optical filters that provide regulation and/or enhancement of chromatic and luminous aspects of the color appearance of light to human vision, generally to applications of such optical filters, to therapeutic applications of such optical filters, to industrial and safety applications of such optical filters when incorporated, for example, in radiation-protective eyewear, to methods of designing such optical filters, to methods of manufacturing such optical filters, and to designs and methods of incorporating such optical filters into apparatus including, for example, eyewear and illuminants.

A method for evaluating the suitability of a mobile device having a camera for performing an analytical measurement based on a color formation reaction. A mobile device is provided and is used to take an image of a reference color field of an object. A color coordinate of pixels of a region of interest within the image is determined and a histogram analysis is performed on a distribution of the color coordinates of the pixels. The width of a color peak within the distribution from the histogram analysis is ascertained and compared with a threshold value to thereby determine suitability of the mobile device for performing the analytical measurement based on the color formation reaction.

In an example, an example article may include a spatially variant microreplicated layer optically coupled to a wavelength selective filter. The wavelength selective filter may have a light incidence angle-dependent optical band. The spatially variant microreplicated layer may be configured to transmit light to a first optical region of the wavelength selective filter at a first predetermined incidence angle and to a second optical region of the wavelength selective filter at a second predetermined incidence angle.

In an example, an example article may include a spatially variant microreplicated layer optically coupled to a wavelength selective filter. The wavelength selective filter may have a light incidence angle-dependent optical band. The spatially variant microreplicated layer may be configured to transmit light to a first optical region of the wavelength selective filter at a first predetermined incidence angle and to a second optical region of the wavelength selective filter at a second predetermined incidence angle.

The present disclosure relates generally to signal encoding for printed objects such as product packaging, labels and hangtags. One implementation obtains a color image representing CMY color channels, and alters the color image to include an encoded signal by altering values representing CIELAB a* and b*, all the while keeping L* on or within a predetermined tolerance of a contour representing a constant value. Other implementations are provided.