Abstract:
Multiple colors of light emitted by an assembled light emitting diode (LED) based illumination device is automatically tuned to within a predefined tolerance of multiple target color points by modifying portions of wavelength converting materials associated with each color. A first color of light emitted from the assembled LED based illumination device in response to a first current is measured and a second color of light emitted from the assembled LED based illumination device in response to a second current is measured. A material modification plan to modify wavelength converting materials is determined based at least in part on the measured colors of light and desired colors of light to be emitted. The wavelength converting materials may be selectively modified in accordance with the material modification plan so that the assembled LED based illumination device emits colors of light that are within a predetermined tolerance of target color points.
Abstract:
In a color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the samples to a spectrograph. A rendering device may also be a display having a member supporting a color measuring instrument for receiving light from an area of the screen. The color measuring instruments provide for non-contact measurements of color samples rendered on a display or a sheet, and are self-calibrating by the use of calibration references.
Abstract:
The color of light emitted by an assembled light emitting diode (LED) based illumination device with at least two different wavelength converting materials is automatically tuned to within a predefined tolerance of a target color point by modifying portions of the wavelength converting materials. The color of light emitted from the assembled LED based illumination device is measured and a material modification plan is determined based at least in part on the measured color of light and a desired color of light to be emitted. The material modification plan may further include the location of the wavelength converting materials to be modified. The wavelength converting materials are selectively modified in accordance with the material modification plan so that the assembled LED based illumination device emits a second color of light that is within a predetermined tolerance of a target color point.
Abstract:
The color uniformity of a light spot is measured by providing an image of the light spot by means of a camera or camera sensor with sensor elements, each of the sensor elements capturing a set of three or more color component values that together define a set of pixel values at such sensor element, wherein the image includes a plurality of sets of pixel values. The method also derives for each of the plurality of sets of pixel values at a corresponding sensor element a first ratio between a first pair of the pixel values or of values obtained therefrom in such set. Preferably a second ratio is also derived between a second pair of the pixel values or of values obtained therefrom in such set, where the second pair is different from the first pair. Where the sensor elements used each provides a single intensity value instead of multiple pixel values of different colors, light is projected onto a spot of the camera or camera sensor along an optical path with a different one of three or more different color filters sequentially in the path. For each sensor element a first ratio is derived between a first pair of the intensity values of different colors provided by such sensor element or of values obtained therefrom and preferably also a second ratio is derived between a second pair of the intensity values of different colors or of values obtained therefrom provided by such sensor element different from the first pair.
Abstract:
LED based illumination modules are realized that are visually color matched to light sources not based on LEDs based on visually matched color spaces. A visually matched color space is employed to both instrumentally and visually match an LED based light source with a light source not based on LEDs. In one aspect, an LED based illumination module is realized to achieve a target color point in a visually matched color space within a predetermined tolerance. In another aspect, an LED based illumination module is realized to visually match a light source not based on LEDs. A target color point in the CIE 1931 XYZ color space is derived based at least in part on the spectrum of the visually matched LED based illumination module. LED based illumination modules visually matched to light sources not based on LEDs are realized based on the derived target color point.
Abstract:
Multiple colors of light emitted by an assembled light emitting diode (LED) based illumination device is automatically tuned to within a predefined tolerance of multiple target color points by modifying portions of wavelength converting materials associated with each color. A first color of light emitted from the assembled LED based illumination device in response to a first current is measured and a second color of light emitted from the assembled LED based illumination device in response to a second current is measured. A material modification plan to modify wavelength converting materials is determined based at least in part on the measured colors of light and desired colors of light to be emitted. The wavelength converting materials may be selectively modified in accordance with the material modification plan so that the assembled LED based illumination device emits colors of light that are within a predetermined tolerance of target color points.
Abstract:
The color response of camera devices may be calibrated, using a correction factor that can account for differences in the spectra of light emitted by different light sources used during calibration. The correction factor may be calculated based on the expected spectral sensitivities of the camera devices, the power spectrum of an actual light source, and the power spectrum of a canonical light source. The correction factor is then applied to adjust a measured color response of a given camera device, so that the adjusted color response is effectively the response of the given camera device if it had been illuminated by the canonical light source. In this manner, any measured color response differences, which may be due to differences between the actual light source used and the canonical light source, can be effectively reduced (if not essentially eliminated.) Other embodiments are also described and claimed.
Abstract:
A system for generating a colored light comprises a set of illuminant types and a processor. The set of illuminant types is associated with a chromaticity gamut, and the set of illuminant types comprises at least five illuminant types that are each associated with an illuminant type hue angle. The processor is configured to determine, based at least in part on a mapping, a sequence of one or more output level sets that are associated with changing a first generated colored light associated with a first color coordinate to a second generated colored light associated with a second color coordinate. The mapping comprises associating each color coordinate with an output level set that uses a set of hue-adjacent illuminant types. Hue-adjacent illuminant types comprise a group of illuminant types that are determined to be adjacent in a circular ordered list of illuminant types which is circularly ordered according to the illuminant type hue angle.
Abstract:
A method for detecting a fire flame using fuzzy finite automata is provided. The fire-flame detection method comprises (1) acquiring an image required for the detection of fire-flame, (2) dividing the image into a number of blocks, (3) extracting a fire-flame candidate block using a brightness distortion of a pixel in the block, (4) detecting a fire-flame candidate region from the fire-flame block using a color probability model, and (5) determining whether the fire-flame candidate region corresponds to a fire-flame via fuzzy finite automata. The fire-flame detection method can detect fire-flames in a variety of fire images with relatively high precision, by establishing a probability model using the brightness distortion and wavelet energy in fire-flame regions with continuous and irregular fluctuation patterns and using the upward motion, and applying the model to fuzzy finite automata.
Abstract:
The invention discloses a method of constructing light-measuring look-up table, a light-measuring method, and a light-measuring system. The method of constructing light-measuring look-up table is to construct a look-up table by according to spectrum parameters relative to a light spectrum model, three actual color-matching functions relative to the light-measuring system and three standard color-matching functions, calculating both a look-up color coordinate and a reference color coordinate corresponding to each of the spectrum parameters. The light-measuring method includes: first, measuring a to-be-measured light by the light-measuring system to obtain actual stimulus values and calculating an actual color coordinate; then, comparing the actual color coordinate with the look-up color coordinates to determine both a to-be-measured light spectrum parameter and an estimated color coordinate relative to the to-be-measured light; furthermore, according to the to-be-measured light spectrum parameter, one of the standard color-matching functions and one of the actual stimulus values, calculating an estimated luminance.