Embodiments of the invention generally relate to color and appearance metric measurements and, in particular, developing instrumentation to enable self-consistent image appearance measurements within instruments of unitary construction.

A color measuring apparatus includes a measurement assembly which includes at least one illumination assembly for applying substantially parallel illumination light to a measurement spot of a measurement object and a pick-up assembly for capturing the measurement light radiated back from the measurement spot in an observation direction and for converting the same into corresponding electrical signals. The illumination assembly includes at least two illumination subassemblies which illuminate the measurement spot from different illumination sub-directions near a first preset nominal illumination direction, each with preferably parallel illumination light. By the illumination from different illumination sub-directions slightly deviating from the nominal illumination direction, angular errors of the illumination assembly can be compensated for in a simple manner.

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.

Disclosed in a method, a user interface and a system for use in determining shade of a patient's tooth, wherein a digital 3D representation including shape data and texture data for the tooth is obtained. A tooth shade value for at least one point on the tooth is determined based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values.

The invention relates to a method of determination of a matching variant of a standard colour of a repair paint matching the effect colour of an object to be repaired, the method comprising the steps of a) determination of the standard colour of the colour of the object to be repaired, and b) determination of the best matching variant of the standard colour from a given number of variant colours, wherein a swatch coated with the colour of the standard colour is visually compared under at least two different angles of illumination and/or observation with the colour to be matched, the visual deviation from the standard colour and the colour of the object to be matched being evaluated on the basis of predetermined deviations for the visual properties, wherein the predetermined visual properties comprise at least one colour property and at least one texture property, based on the predetermined deviations for the visual properties of the standard colour and the colour of the object to be matched, the best matching variant of the standard colour is determined.

Systems and method for matching appearance of a target coating on a substrate is provided herein. The system includes a coating chip including a chip coating layer. The chip coating layer has a chip coarseness. The system further includes an illumination component configured to illuminate the chip coating layer with a light having an illumination color. The chip coating layer exhibits the chip coarseness and the illumination color in the presence of the light having the illumination color. The chip coating layer exhibiting the chip coarseness and the illumination color is utilized for matching the appearance of the target coating.

A colour measurement device includes a measurement array (MA) which includes: a plurality of illumination arrays (20, 30, 40) for exposing a measurement spot (MS) on a measurement object (MO) to illumination light in an actual illumination direction (2, 3, 4) in each case, and a pick-up array (50) for detecting the measurement light reflected by the measurement spot (MS) in an actual observation direction (5) and for converting it into preferably spectral reflection factors; and a controller for the illumination arrays and the pick-up array and for processing the electrical signals produced by the pick-up array. The controller is embodied to process the measured reflection factors on the basis of a correction model, such that distortions in the measurement values as compared to nominal illumination and/or observation directions, caused by angular errors in the illumination arrays and/or the pick-up array, are corrected.

Disclosed in a method, a user interface and a system for use in determining shade of a patient's tooth, wherein a digital 3D representation including shape data and texture data for the tooth is obtained. A tooth shade value for at least one point on the tooth is determined based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values.

An apparatus that generates a color profile based on color signal values obtained by imaging and measuring a plurality of color patches, includes a first acquisition unit configured to acquire a plurality of device-dependent color signal values obtained by imaging at least one of the color patches under a plurality of geometric conditions, the plurality of geometric conditions being based on an imaging direction of each of the color patches and a direction in which a light source emits light to each of the color patches, a second acquisition unit configured to acquire a plurality of device-independent color signal values obtained by measuring at least one of the color patches under the plurality of geometric conditions, and a generation unit configured to generate the color profile based on the plurality of device-dependent color signal values and the plurality of device-independent color signal values.

A difference between a peak reflectance of a first wavelength component and a reflectance of a second wavelength component having a predetermined wavelength among reflectances of a plurality of wavelength components constituting reflected light in a highlight direction from a glitter material-containing coating film is set as a first difference value. Reflectance is measured of the first and second wavelength components of the reflected light in the highlight direction for the coating film corresponding to a measurement object. A first difference value is calculated by using the measurement result. A storage stores in advance correlation information indicating a correlation between the first difference value and an index value indicating predetermined physical characteristics of a glitter material contained in the coating film. An index value calculator calculates the index value of the coating film corresponding to the measurement object by using the correlation information and the first difference value calculated in the first calculator.