An aluminum can wherein, when the light reflected by the outer surface of the body portion of the aluminum can is evaluated based on the LCH method by using a multi-angle spectral colorimeter, the aluminum can features a ratio C.sub.15h/C.sub.15w of 0.6 to 1.4, the ratio C.sub.15h/C.sub.15w being that of a saturation value C.sub.15h of the light reflected at 15 degrees in the direction of height and a saturation value C.sub.15w of the light reflected at an angle 15 of degrees in the circumferential direction based on the light regularly reflected from the light that is incident at 45 degrees in the direction of height and in the circumferential direction.

A system for the automatic grading of a cut/polished gemstone (SUT) includes an enclosure with a stage for mounting the cut/polished SUT. The enclosure further includes one or more sources of broadband visible (BBV) light, the sources of BBV light being controllable by a programmable controller; an image sensor for capturing a plurality of images of a mounted SUT, and one or more sources of UV light mounted within the enclosure. The controller captures images of the mounted SUT from one or more selected angles relative to the sensor elevation axis and relative to the position of the SUT on the stage rotation axis; an image capturing module is configured for processing the one or more images; and, a light grade calculation module is configured for grading the cut/polished SUT using light indicative parameters from at least a part of the one or more images captured.

First and second sets of appearance attributes are obtained. The first set is associated with a target material. It comprises measured appearance attributes (54) of the target material. The second set is associated with a candidate material. It comprises candidate appearance attributes that are based on appearance attributes associated with one or more reference materials. A geometric model of at least one virtual object (72) is obtained, the geometric model defining a three-dimensional surface geometry. A scene comprising the at least one virtual object (72) is visualized. First and second portions of the virtual object (72) are visualized using the first and second sets of appearance attributes, respectively. Each of the first and second sets of appearance attributes comprises texture attributes in the form of a plurality of sets of image data. The image data in one of the sets may be based on texture attributes of the other set, or the image data in the second set may be synthesized from image data associated with a plurality of constituent materials of the candidate material.

An optical characteristic measurement device has a measurement opening, includes a first optical measurement unit and a second optical measurement unit that measure different optical characteristics with different geometries with respect to a measurement target facing the measurement opening, and further includes a processing unit that corrects a measurement value obtained in the second optical measurement unit based on a measurement value obtained in the first optical measurement unit. The first optical measurement unit includes an illumination optical system that illuminates the measurement target facing the measurement opening, a first light receiving optical system that collects light reflected by the measurement target, and a first light receiving unit that receives light collected by the first light receiving optical system and outputs the light as a measurement signal, and has a diffuse reflection surface that diffuses and reflects incident light to the illumination optical system or the first light receiving optical system. The second optical measurement unit includes a light projecting optical system that projects light from a direction inclined by a predetermined angle with respect to a normal line of a measurement surface of the measurement target facing the measurement opening, a second light receiving optical system that collects light reflected by the measurement target in a regular reflection direction, and a second light receiving unit that receives light collected by the second light receiving optical system and outputs the light as a measurement signal.

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.

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 computer-implemented method for identifying an effect pigment, the method comprising executing, on at least one processor of at least one computer, steps of: a) acquiring sample image data describing a digital image of a layer comprising a sample effect pigment b) determining, based on the sample image data, sparkle point data describing a sample distribution of sparkle points defined by the digital image, wherein the sample distribution is defined in an N-dimensional color space, wherein N is an integer value equal to or larger than 3; c) determining, based on the sparkle point data, sparkle point transformation data describing a transformation of the sample distribution into an (N−1)-dimensional color space; d) determining, based on the sparkle point transformation data, sparkle point distribution geometry data describing a geometry of the sample distribution; e) acquiring reference distribution geometry data describing a geometry of a reference distribution of sparkle points in the (N−1)-dimensional color space; f) acquiring reference distribution association data describing an association between the reference distribution and an identifier of the reference distribution; g) determining, based on the sparkle point distribution geometry data and the reference distribution geometry data and the reference distribution association data, sample pigment identity data describing an identity of the sample effect pigment.

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.

The color strength of a colored batch containing effect pigments can be measured and corrected using one or more non-uniformly weighted factors to determine, at a plurality of combinations of illumination angles and measurement angles, and at one or more wavelengths, the color and intensity of light reflected or absorbed by a coating film made from the batch in comparison to a reference color strength. Based on such comparison, let-downs or batches may be passed, rejected, mixed or otherwise dispersed. The composition of such let-downs or batches may also or instead be adjusted by adding non-effect pigments, effect pigments, binder, carrier, binder, or non-effect or effect pigments dispersed in either or both of a carrier and binder, in order to correct the let-down or batch color strength to within a desired tolerance of the reference color strength.

In accordance with one or more implementations of the apparatus, system and methods described, a sample measurement device is provided that is configured to measure the color of a sample. The sample measurement device includes at least one light source configured to illuminate the sample; at least one light sensor configured to output a signal in response to light emitted by light source and reflected off the sample being received by at least a portion of the light sensor; and a processor configured to receive the signal and calculate a color value for the sample, the processor configured to calculate the color value by at least adjusting the signal using a calibration factor.