Spectral irradiance distributions are calculated within a virtual environment based on arbitrary light source spectral power distributions. Architectural, horticultural and aquacultural lighting control systems use the calculated results to control both the intensity and spectral power distribution of the electric light sources. Energy consumption may be minimized while maintaining optimal occupant visual comfort and plant health.

An ambient light color sensing device adapted to determine color of ambient light and method for calibrating thereof. The ambient light color sensing device comprises a memory, a processor, and a light color sensor having a plurality of channels that detect light at different wavelengths to produce sensor readings. Wherein the processor receives sensor readings from the light color sensor, determines an interpolated spectral power distribution from the received sensor readings, converts the interpolated spectral power distribution to at least one measured light color value that quantifies color of light, and determines at least one calibrated light color value by correlating the at least one measured light color value through a calibration matrix.

A method and an ambient light color sensor adapted to determine color of ambient light comprising a memory, a processor, and a light color sensor with a plurality of channels that detect light at different wavelengths. Wherein the memory comprises a calibration matrix determined by calibrating a test light color sensing device under at least one ambient lighting condition, and a normalized gain value for each channel determined by calibrating the ambient light color sensing device to an artificial light source. Wherein the processor receives the sensor readings from the light color sensor, normalizes each received sensor reading using the normalized gain value of a respective channel, determines at least one measured light color value that quantifies color of light from the normalized sensor readings, and determines at least one calibrated light color value by correlating the at least one measured light color value through the calibration matrix.

Automation of the comparison of the colors of small surfaces of products. In one embodiment, color differences are measured rather than an absolute color value. An apparatus is provided for capturing color images of a portion of a product or part to provide a sample product image. The sample image is compared to an image of a standard product obtained under the same conditions with the same apparatus. The color difference is measured to determine when it is in a predetermined range.

An ambient light color sensor adapted to determine color of ambient light and method for calibrating thereof. The ambient light color sensor comprises a sensor body having at least one diffuser and a light color sensing module disposed below the at least one diffuser. The light color sensing module comprises a plurality of channels adapted to detect light collected by the at least one diffuser at different wavelengths to produce sensor readings. The ambient color sensor is adapted to measure color of ambient light by storing a calibration matrix determined by calibrating a test light color sensor to a test ambient light source, receive the sensor readings from the light color sensing module, determine an interpolated spectral power distribution from the received sensor readings, convert the interpolated spectral power distribution to at least one measured light color value that quantifies color of light, and determine at least one calibrated light color value by correlating the at least one measured light color value through the calibration matrix. The sensor readings received from the ambient light color sensor and test sensor readings received from the test light color sensor during calibration thereof may be normalized by calibrating the ambient light color sensor and the test light color sensor to an artificial light source.

Embodiments of the present invention provide a computer-implemented method (200) of processing colour image data which comprises determining (220, 230) output colour information values based on first and second tristimulus colour spaces indicative of first and second cone spectral sensitivity functions, wherein the determining (220, 230) comprises determining a first one of the output colour information values based on a first tristimulus colour space and determining a second one of the output colour information values based on a second tristimulus colour space to be within a predetermined range of the first one of the output colour information values, and outputting (240) the output colour information values.

A device and a method for inspecting containers for impurities and three-dimensional container structures comprising a radiation source. The radiation source is designed to emit radiation that radiates through a container to be examined. The device also comprises a detection element designed to detect the radiation that has been emitted by the radiation source and has radiated through the container. The device further comprises an evaluation element designed to evaluate the radiation detected by the detection element in terms of dirt and damage to the container. The radiation source has a plurality of spatially separated radiation zones. The radiation zones of the radiation source are designed to emit radiation of different wavelength ranges or of a different intensity.

A method and device for determining the color homogeneity of hair is provided. In accordance with various exemplary embodiments, a method comprises providing a digital image in which hair is depicted and which is parameterized in a color space which is defined by employing a parameter set in which one of the parameters is a hue, defining at least one hair analysis region in the digital image, determining a hue distribution in at least one hair analysis region, and determining at least one color homogeneity value on the basis of the determined hue distribution.

A method may include supplying electric power to a first light source and a second light source of at least two light sources by at least one ballast so that the first light source and the second light source emit a first source light and a second source light with a first and second spectral light distribution, respectively. The method further includes superimposing the first and second source light using an optical unit such that the lighting device outputs light with a spectral superposition light distribution. The method further includes detecting the light outputted from the lighting device using a light distribution sensor that provides a sensor signal corresponding to a spectral light distribution of the detected light. The method further includes comparing the sensor signal to a predefined spectral light distribution and adjusting the electric power supplied to the respective light source by the ballast based on the comparison.

A method for adjusting uniformity of image color tones includes setting brightness of a darkest display region as target brightness and setting color temperature coordinates of a designated display region as target color temperature coordinates of at least one part of display regions of a display, comparing the brightness and the color temperature coordinates of each display region of the at least one part of display regions with the target brightness and the target color temperature coordinates for generating a first calibrated color tone, generating a second calibrated color tone of the each display region of the at least one part of display regions according to an Alpha channel parameter and the first calibrated color tone, generating a uniformity compensated image layer according to all second calibrated color tones, and virtually overlaying the uniformity compensated image layer on the at least one part of display regions.