Disclosed is a process for determining a plurality of color quality indicators for controlling the color of a coating. Colorimetric coordinates of a color reference and the coating are ascertained for a plurality of coated surface elements using a spectrophotometer at a number of measurement geometries and a number of light sources. For each measurement geometry and each light source, color differences are calculated from the colorimetric coordinates of the color reference and the coating of the plurality of coated surface elements. The respective colorimetric coordinates are normalized with one weighting factor. Each of the plurality of color quality indicators is determined by means of a mapping, of functional values onto a scale value of a predetermined scale. The functional values are determined in each case for the number of measurement geometries and the number of light sources by means of a mathematical relationship.

The method includes inputting a specification of a desired combination of a first component and a second component of a composition, wherein the components are a solid and a dispersant, via a user interface of a computer system; carrying out a database query with the desired combination of the first component and the second component as the search criterion, wherein in the case where the database query supplies a known composition that meets the search criterion, the known composition is output, wherein in the opposite case, a further database query of a composition including the first component and the second component, serving as the search criterion, is carried out to find a candidate composition that includes one of the two components as well as a substitute component instead of the other component; and carrying out further steps for generating the formulation and outputting the composition.

A color tone quantification device for a glossy color, in which the correlation with the color tone of the glossy color visually perceived by humans is further enhanced, is provided. The device comprises a coefficient calculation unit that calculates a coefficient calculated in consideration of a spatial distribution which is to be used to correct the chromaticity measured by a method including a specular reflection component obtained by measuring the reflection light obtained by reflection of measurement light to an area of an object; a chromaticity calculation unit that calculates an effective chromaticity obtained by weighting the chromaticity measured by the method including the specular reflection component with the coefficient calculated by the coefficient calculation unit; and an output unit that outputs the effective chromaticity as a stimulus value representing a glossy color of the area in a color space.

An optical sensor comprises at least four detection channels, where each detection channel comprises a photodetector and a filter with a respective transmission spectrum. The transmission spectra of the at least four filters are different from one another, and the transmission spectra are set such that each of the three CIE color matching functions is a linear combination of the transmission spectra of at least two of the filters. Furthermore, a method for detecting electromagnetic radiation is provided.

A process for determining a tooth color of a filling or another restoration is provided which in particular is produced using composite materials, wherein at least one tooth is scanned or is visually detected. The process is characterized in that natural teeth are spectrally measured in advance, that the color values measured within a color space are classified into several, in particular four, categories which each form a color cloud extending in a three-dimensional fashion within the color space, which is done with the help of a structuring algorithm, in particular a Nearest Neighbour Algorithm, or a symmetry recognition algorithm, and that the tooth color of the filling is determined by means of evaluating to which category the tooth scanned has the smallest color distance, or to which color cloud the tooth scanned belongs.

An apparatus for measuring a spectrum includes a light source array configured to emit light towards an object, a photodetector configured to detect light reflected by the object; and a processor configured to measure, using the light source array and the photodetector, a plurality of temperature correction spectra based on a temperature change of the light source array, obtain a light source temperature drift vector by analyzing the measured plurality of temperature correction spectra, measure, using the light source array and the photodetector, an analysis spectrum by using the light source array and the photodetector, and adjust the measured analysis spectrum to reduce an effect of the temperature change of the light source array by using the obtained light source temperature drift vector.

A measurement apparatus includes: a light source configured to irradiate a measurement region of skin whose color is to be measured with light; a light receiving unit configured to receive reflected light from the measurement region or transmitted light that has passed through the measurement region; a calculation unit configured to repeatedly obtain determination information and color information relating to the color of the measurement region, based on a light-receiving result of the light receiving unit; and a selection unit configured to select a measurement result of a color of the skin from the repeatedly-obtained color information, based on a temporal change in the determination information.

Certain examples described herein relate to color spaces. In some cases, first and second sets of output color values representable in an output color space are obtained. The first and second sets of output color values correspond to first and second operating states of a printing system respectively. Each output color value in the first and second sets has corresponding coordinates in a colorimetry space. The first and second sets of output color values define respective first and second gamuts in the colorimetry space. First and second colorimetry values in an intersection of the first and second gamuts in the colorimetry space are selected, the selecting based on the respective colorimetry of the first and second colorimetry values and a predetermined transition region in an input color space. For an input color value located in the predetermined transition region of the input color space, a corresponding target colorimetry value located between the first and second colorimetry values in the colorimetry space is obtained. First and second output color values are derived based on the target colorimetry value and the first and second sets of output color values, respectively. First and second mappings between the input color space and the output color space are generated by respectively assigning the first and second output color values to the input color value.

Certain examples described herein relate to color spaces. In some cases, first and second sets of output color values representable in an output color space are obtained. The first and second sets of output color values correspond to first and second operating states of a printing system respectively. Each output color value in the first and second sets has corresponding coordinates in a colorimetry space. The first and second sets of output color values define respective first and second gamuts in the colorimetry space. First and second colorimetry values in an intersection of the first and second gamuts in the colorimetry space are selected, the selecting based on the respective colorimetry of the first and second colorimetry values and a predetermined transition region in an input color space. For an input color value located in the predetermined transition region of the input color space, a corresponding target colorimetry value located between the first and second colorimetry values in the colorimetry space is obtained. First and second output color values are derived based on the target colorimetry value and the first and second sets of output color values, respectively. First and second mappings between the input color space and the output color space are generated by respectively assigning the first and second output color values to the input color value.

A method and device for measuring dominant wavelength and color purity of LED lamp, and an electronic equipment. The method includes: establishing standard data; calculating difference and distance between chromaticity coordinate in the standard data and the chromaticity coordinate of equal-energy white light; calculating an included angle between a vector formed by the chromaticity coordinate of equal-energy white light to each standard chromaticity coordinate and a positive direction of x axis; performing a one-way processing on the included angle to form included angle data; calculating an included angle intermediate value; determining minimum and maximum values of the included angle intermediate value; calculating a dominant wavelength coefficient and a measured included angle intermediate value; calculating a wavelength interval corresponding to the included angle intermediate value; calculating a dominant wavelength intermediate value and x difference by interpolation calculation; and obtaining dominant wavelength and color purity of the LED lamp.