Abstract: A method for estimating surface moisture content of wood chips for use in a pulp and paper production process comprises measuring chip surface moisture using an infrared surface moisture sensor, and adjusting a calibration of the surface moisture measured with a model using values of a set of optical parameters representing light reflection characteristics of the wood chips, to estimate their surface moisture content.

Abstract: A system (200) and method (800) for determining whether a sample object (203) has a color that is within a predetermined range is provided. The system (200) includes a light source (201) capable of projecting lights having different light wavelength spectrum upon the sample object (203). A controller (222) causes the light source (201) to project a first light wavelength spectrum upon the sample object (203), then another, then another, and so forth. While each light is projecting upon the object, a monochromatic image capture device (202) captures an image having luminous intensity information. The luminous intensity information, or a subset thereof selected by an image selection tool (232) is then compared to the statistical range, which is derived from a plurality of images taken of a reference object (403).

Abstract: A miniature readhead is provided for photometric color detection using ambient light. The readhead is hand-held, including a superposed plate and tray. The tray receives sample media configured to react and to change color according to an amount of analyte in a sample. The plate is optically transmissive, so that ambient light is transmissible therethrough to the sample media indexed within the tray. An array of light detectors is disposed along the plate, including sets of detectors configured to detect light of at least three mutually distinct wavelengths reflected from the test areas. Light shields superposed with each of the light detectors selectively permit ambient light to pass to the tray, while substantially preventing ambient light from reaching the light detectors prior to reflecting from the test areas. The readhead may be incorporated into a photometric diagnostic instrument configured to analyze the reflections and derive a diagnosis value.

Abstract: A two-dimensional colorimeter includes: an image sensing section, having an image sensor constituted of a number of pixels arranged in a two-dimensional manner, for sensing an object image to be measured to acquire a two-dimensional image; a discriminator for discriminating whether a targeted color with respect to the two-dimensional image acquired by the image sensing section is to be corrected in terms of a pixel or pixels; and a calculator for performing a calculation to apply predetermined correction information corresponding to the color to be corrected to the two-dimensional image in terms of a pixel or pixels, based on a discrimination result by the discriminator.

Abstract: A quantitative evaluation of a color filter (10) in accordance with the capacity of said filter to restore hues comprises the use of a numerical color appearance model. Values of a perceptive attribute are calculated for hue samples (20), by simulating the observation of each of the samples through the filter (10) and without a filter. The values of the perceptive attribute correspond to the visual perception of the samples by an observer (40), and a deviation between the values with and without filter constitutes the result of the evaluation of the filter. Such a method makes it possible to quantitatively rank several color filters, and the ranking obtained corresponds to that which would be established by real observers evaluating the filters.

Abstract: A color measurement device includes an error detection function for color printing control. The color measurement device includes an optical measurement head, the optical measurement head being moveable linearly along a color bar region of a printing sheet, and being configured for making color measurements with respect to the color bar, and for detecting color measurement errors by determining whether such color measurements are being made at least in part with respect to regions of the printing sheet other than the color bar region. The optical measurement head may further include a pixel array for tracking a center trajectory of the color bar for purposes of detecting the color measurement errors, and a color measurement engine for purposes of making the color measurements with respect to the color bar. The color measurement device may further include a motion control element and a mechanical track to guide the optical measurement head along the color bar region.

Abstract: Color reproducibility needs to be evaluated in consideration of the influence of homogeneity in page image. Hence, a first chart is formed from an image of a uniform density of a region to be evaluated, and data associated with the spectral reflectances of plural points on the first chart are input. Based on the data obtained from the first chart, color differences between a predetermined point and other points on the first chart are calculated. When the calculated color differences fall within a permissible range of heterogeneity of colors in the region, a second chart is formed from an image corresponding to a color target, and data associated with the spectral reflectances of plural points on the second chart are input. Color differences are calculated from the data obtained from the second chart and data associated with the spectral reflectance of the color target.

Abstract: Methods and apparatuses for determining a color calibration for different spectral light inputs in an imaging apparatus measurement are disclosed herein. In one embodiment, for example, a method for determining a color calibration for different spectral light inputs in an imaging apparatus measurement can include creating a reference color calibration and a reference luminance scaling calibration for each of a plurality of colors. The method can also include measuring a reference gray value R, G, B for each color in an image measurement of the light source. The method can further include calculating an R, G, B gray value for a first pixel in each of three filtered image measurements. The method can then include calculating pixel ratio values from each of the three first pixel gray values and comparing the reference gray values to the pixel ratio values to determine which one or more reference gray values are closest to the pixel ratio values.

Abstract: A method for providing an intensity or brightness measurement using a digital image-capturing device comprising: selecting a target area within a field of view of the image-capturing device, the target area containing pixels; measuring the intensity or brightness of pixels in a target area; accumulating the intensity or brightness values of the pixels in the target area; and determining a pixel value representative of the intensity or brightness of the pixels in the target area. A device for making color measurements comprising an image-capture device, a processor or logic device, and a memory location for accumulating color data, and the processor or logic device is programmed to perform color measurements by accumulating the data for pixels located in the target area in memory, and determining a representative color value.

Abstract: A beam splitter array includes first and second beam splitters and a reflector to reflect part of a beam from the second splitter. The first splitter outputs a first beam having a power spectral density comprising a substantial portion of a white light spectrum from a first output port, and a second beam of optical radiation having a power spectral density comprising a substantial portion of a first non-white spectrum and a substantial portion of a second non-white spectrum from a second output port, from an input beam received at a first angle of incidence. The second splitter receives the second beam at a second incidence angle, and reflects a substantial portion of the second beam having a power spectral density comprising the first non-white light spectrum, and transmits a substantial portion of the second beam having a power spectral density comprising the second non-white light spectrum.

Abstract: A method includes receiving light from a material at a digital imaging device. The method also includes filtering the light into at least three spectral bands using a filter, where different regions of the filter pass different spectral bands. The method further includes measuring the light in each of the spectral bands and determining at least one color associated with the material using the measured light in the spectral bands. The different regions of the filter could include multiple masks (where each mask passes one of the spectral bands), different areas of a linear variable filter, and/or individual filters (where each individual filter passes one of the spectral bands). The digital imaging device could include a digital camera. The filter could be formed on a detector in the digital camera, and/or a component of the digital camera could be replaced with the filter.

Abstract: An apparatus may include an interface to allow a scanning beam device to be coupled. The apparatus may include at least four lasers optically coupled with the interface. Each of the at least four lasers may provide a different wavelength visible spectrum light to the scanning beam device through the interface. An actuator driver of the apparatus may be electrically coupled with the interface. The actuator driver may provide actuator drive signals to the scanning beam device through the interface. The actuator drive signals may be operable to cause the scanning beam device to scan a beam of the different wavelength lights over a surface. An image generation unit of the apparatus may generate an image of the surface. The image may be generated based, at least in part, on light from the beam that has been reflected from the surface and detected by at least one photodetector.

Abstract: An optical system comprising an optical instrument and a processing unit. The optical instrument may comprise an illumination source and a sensor. The processing unit may comprise a data storage having stored thereon a characterization of the illumination source and a characterization of the sensor. The processing unit may also comprise a computer configured to calculate a system response of the illumination source and the receiving element considering the characterization of the illumination source and the characterization of the receiving element.

Abstract: An optical assembly is disclosed that includes an illumination source, a detection sensor, a monitor sensor, and an optical piece having a first side adapted to face a sample. The optical piece defines an illumination channel extending from the illumination source toward the first side, a detection channel extending from the first side toward the detection sensor, and a monitor channel extending from the illumination channel toward the monitor sensor. A spectrophotometer is also disclosed that includes a circuit board, illumination source and one or more sensors. The circuit board includes an optically transparent region, wherein the illumination source is mounted and situated relative to a first surface of the circuit board, so as to direct light through the optically transparent region. Each sensor is mounted and situated relative to a second surface of the circuit board opposite the first surface.

Abstract: A lead edge and/or trail edge sheet curl sensing and constraint method and system. First and second light emitters and detector pairs are aligned such that the light beams from the first light emitter and second light emitter cross at the transport media sheet substrate path, which constitutes the path of a media sheet substrate with zero curl. A media sheet substrate with either positive or negative curl on the lead edge of the sheet substrate interrupts light beams from the first and second light emitters, as detected by first and second light detectors. A similar approach can be used to detect the trail edge curl. The time delay between the light beam interruptions is proportional to the sheet substrate curl, and the order of interruptions indicates whether the sheet substrate curl is positive or negative. A first pair and a second pair of substrate constraint rollers can also be provided in the paper path upstream and downstream of the sensing system.

Abstract: A semiconductor opto device is disclosed. One embodiment provides an optodiode. The optodiode has a relative spectral sensitivity that is adapted to the relative spectral sensitivity of an eye, wherein, correspondingly adapted to the spectral sensitivity of the eye, a switch-on or switch-off process of the optothyristor or optotriac is triggered.

Abstract: A sensing system can include one or more particles having one or more plasmon resonances. The particles can be positioned adjacent to the active region of a sensor to enhance the sensitivity of the sensor to electromagnetic radiation having frequencies corresponding to the plasmon resonances. An array of sensors such as used for color imaging can employ different types of particles adjacent to different sensors, so that different sensors sense different colors. During fabrication of such sensors, the particles can be applied mechanically or using a process such as inkjet printing.

Abstract: A method for measuring chroma value by colorimeter to solve the drawbacks of conventional technologies, such as an inaccurate illuminant and the filter of color-matching function is difficult to be deposited and manufactured within an filter mod colorimeter, and an expensive spectrometer used within an spectrum mode calorimeter. The present invention does not need the spectrometer and the filter of color-matching function, and can measure an accurate chroma value of an object by using a multi-band illuminant illuminating the object and a power meter. Besides, the multi-band illuminant can be adjusted the illumination condition of standard illuminator under different color temperature, and measure the chroma value of the object under different color temperature. The accuracy of the measured chroma value is up to the level of the spectrum mode colorimeter, and the price is cheaper than the spectrum mode calorimeter.

Abstract: A system (200) and method (800) for determining whether a sample object (203) has a color that is within a predetermined range is provided. The system (200) includes a light source (201) capable of projecting lights having different light wavelength spectrum upon the sample object (203). A controller (222) causes the light source (201) to project a first light wavelength spectrum upon the sample object (203), then another, then another, and so forth. While each light is projecting upon the object, a monochromatic image capture device (202) captures an image having luminous intensity information. The luminous intensity information, or a subset thereof selected by an image selection tool (232) is then compared to the statistical range, which is derived from a plurality of images taken of a reference object (403).

Abstract: A hand-held colorimetric device (101) suitable for use by blind or color-blind individuals to determine the color of a surface-under-test (SUT), for example of a fabric, has an aperture (110) which, in use, is covered by the SUT (113) whose color is to be determined. Six LEDs (115A, 115B, 116B, 117A and 117B) arranged in pairs (115A/115B, 116A/116 B, 117a/117B) emitting red/orange, green, and blue light illuminate the SUT and diffuse reflections therefrom containing red/orange, green, and blue spectrum sample values are used to determine the luminous reflectivity and chromaticity values for the color of the SUT. The measured values are compared with colorimetric values of reference surfaces to determine the color of the SUT. The colorimetric device may output the name of the color aurally.

Abstract: A tristimulus colorimeter for measuring reflective or transmissive materials is provided. The colorimeter measures a sample under a calibrated light source, receives inputs to detectors, and determines CIE tristimulus values of the same sample as they would occur under a reference light source. The colorimeter includes a calibrated light source and a single silicon chip that includes three or more detectors. Each detector is permanently coated by a different mix of dyes or other colorants that form a wavelength-selective filter. A single silicon chip embodies all the detectors and electronics, with each detector coated over by deposited filter layers.

Abstract: Embodiments including color filter arrays are disclosed.

Abstract: A spectrophotometric scanner suitable for producing spectral reflectance images of surfaces of samples for a plurality of wavelength bands is disclosed. The spectrophotometric scanner comprises a scanner head for collecting spectral reflectance data, a positioning mechanism for positioning the scanner head in relation to a surface, and a computing device for controlling the mechanism and recording and analyzing the spectral reflectance data. The computing device directs the positioning mechanism to position the scanner head on a row of locations in a grid of locations of the surface; directs the scanner head to measure spectral reflectance data for each location in the row of locations; records and analyzes the spectral reflectance data; and produces spectral reflectance images from the spectral reflectance data. A light source in the scanner head comprises a plurality of sequentially controllable LEDs, each producing light in a different wavelength band.

Abstract: The present invention provides an apparatus for reading a color symbol, which comprises a matrix of color filters arranged in front of a detector. Light received from the filters of some colors is used to locate the color symbol, while light received from all the filters is used to read and decode the located symbol. Preferably, the filters used for locating the symbol are of the colors to which the detector is most sensitive. Preferably, the filters for locating the symbol are dominant in number.

Abstract: A light source estimating device includes a light receiving section for receiving visible light and invisible light radiated from a light source, and a light source estimating section for estimating a type of the light source on the basis of an intensity of the received visible light and an intensity of the received invisible light.

Abstract: A photodetector and method for making the same is disclosed. The photodetector includes a substrate having first, second, and third photodiodes and first and second pigment filter layers. The first, second, and third photodiodes generate first, second, and third photodiode output signals, respectively, each photodiode output signal being indicative of a light intensity incident on that photodiode and a dark current that is independent of the light intensity. The first and second pigment filter layers overlie the first and second photodiodes while a layer having both the first and second pigment filter layers overlie the third photodiode. An output circuit combines the first and third photodiode output signals to provide a first corrected output signal and combines the second and third photodiode output signals to provide a second corrected output signal.

Abstract: The invention relates to a system and a method for capturing images in a prober. According to the invention, the surface of a test object is illuminated in succession with light of a first, second and third color; and an image capturing device records a gray scale image of the surface; and a composite image is produced from the three gray scale images by means of an image evaluating device. The object of the invention is to qualitatively improve the image capturing, in order to raise the positioning accuracy by means of an improved display, as a result of which, finely structured test objects can be used. This object of the invention is achieved in that the lighting device is designed as a unit, which can be controlled by the image evaluating unit and which produces at least three colors and which exhibits at least one light emitting diode (LED) as the lighting means.

Abstract: A method for determining the optimal colorant thicknesses for integral CIE color-matching filters is provided. According to a computational study, a four band filter of the present invention provides a best approximation to the CIE XYZ color-matching functions with the least cost.

Abstract: Disclosed herein are systems and methods for measuring color and contrast in specular reflective devices such as interferometric modulators. To make color and contrast determinations, light reflected from a specular reflective device may be measured in-line with illumination of the device. The measurements may include measuring the spectra of light reflected from the device being tested as well as from specular bright and dark standards. The spectra may be used to determine a reflectance spectrum and color parameters for the specular reflective device.

Abstract: A device and method for controlling a plurality of individual light sources with varying spectra, wherein a desired resulting light spectrum with three manipulated variables representing a color standard is selected to serve as the basis along with an detected light spectrum to control the plurality of light sources with varying spectra in such a way that at least a part of the plurality of controllable light sources emits a resulting light spectrum that correspond to the desired light spectrum to at least a selectable level of accuracy.

Abstract: A color luminance meter 1 is provided with a polychrometer 4 as a spectral optical system including a light receiving sensor array 43, a signal processing circuit 5 and an operation control unit 6. The operation control unit 6 carries out calculations to obtain characteristics of a measurement light based on a specified spectral responsitivity, using light reception signals and specified weighting coefficients. The spectral responsitivities of light receiving sensors constructing the light receiving sensor array 43 are selected such that B?5 nm and A/B lies within a range of 1.5 to 4.0 when A, B denote the half power band width of the spectral responsitivities and a center wavelength interval of the spectral responsitivities. Accordingly, there can be provided a light measuring apparatus capable of maximally suppressing errors to highly precisely measure color luminance values and the like even in a measurement of a light lying in a narrow band such as a monochromatic light.

Abstract: A tooth shade scan system is provided that identifies tooth shades for a patient's tooth. An electronic database of tooth shade information for a shade guide may be stored. The database may include shade information based on tooth regions (e.g., the incisal, central, and cervical). A system operator may be shown an image of a patient's tooth on display equipment such as a computer monitor. An application running on the system may display dividers that the operator can manipulate to divide the image of the patient's tooth into regions. The regions may correspond to regions for which specific tooth shade information is available in the database. Values representative of a limited number of color characteristics for a region as a whole may be determined from the image. Corresponding categories of color characteristics may exist in the database, which is then used to identify tooth shades by region for the patient's tooth.

Abstract: A miniature readhead for a photometric diagnostic instrument includes a housing of hand-held form factor, configured for receiving reagent sample media therein. The sample media has a plurality of test areas configured to react with, and change color, according to an amount of an analyte in a sample. The holder is sized and shaped for forming an indexed fit with the sample media and includes an array of light sources coupled to the housing, each of the light sources configured to emit light onto a respective one of the test areas. An array of chambers respectively containing an array of light detectors, is configured to enable each of the light detectors to receive diffuse, non-specular reflections of the light from the test areas, while substantially preventing the light detectors from receiving specular reflections of the light.

Abstract: A photoelectric color measuring head for measuring color properties of a measurement object includes an illumination device for exposing the measurement object to illuminating light and a wavelength-range-selective photoelectric receiver device (40) which intercepts measurement light remitted by the illuminated measurement object and converts it into corresponding electrical measurement signals. The illumination device includes an essentially white light-emitting diode (30) and means (60) for defining the angle of incidence range, so that the measurement object receives light only within an angle of incidence range, standardized for color measurement applications, of preferably 45°+/?5-10°. The receiver device includes a sensor field consisting of a multitude of photoelectric sensor pixels arranged in a line and the sensor pixels are made sensitive to different wavelength ranges through previously arranged color filters (420).

Abstract: An output current from each pixel sensor can be extracted at an arbitrary ratio by a current divider. An arithmetic control unit sets the dividing ratio in correspondence to a color matching function. The current components are added together by a summing amplifier so that a signal corresponding to a tristimulus value is composed and then converted into a digital signal. That is, weighting by weight factors corresponding to color matching functions of CIE 2-degree observer is performed in a stage of analog signal processing.

Abstract: Methods are provided for detecting compression wood, blue stain, or pitch in lumber. A light beam is projected towards the wood sample. Line or area cameras acquire images of light that is reflected from the wood sample. Based on the intensity of the reflected light at one or more locations on the wood sample, compression wood, blue stain, or pitch may be detected.

Abstract: Method and apparatus for estimating surface moisture content of wood chips employing a surface moisture measurement obtained from a non-contact surface moisture sensor, which measurement is calibrated with values of a set of optical parameters, such as HSL color camera signals, representing light reflection characteristics of the wood chips in order to estimate the surface moisture content thereof.

Abstract: Systems and method provide compensation for temperature induced peak wavelength shift of LEDs is color parameter measuring systems that use a model to reconstruct target color parameter values from the reflectance values measured when the target is illuminated by LEDs. Several models may be constructed, with each model being trained at a unique temperature, resulting in a set of models that span the temperature range of interest. In real-time, the LED based color parameter measuring system measures the temperature and interpolates between the models to estimate the appropriate model to use at the temperature of interest. The estimated model is then used to perform the color parameter value estimation.

Abstract: A device comprising an illumination means and a light sensing means, that can examine and memorize a discrete color of an object based on the magnitude of the reflected light bouncing off of the colored surface in at least three areas of the electromagnetic spectrum. The device also provides output as a visually and/or audibly perceptible signal for deciphering the color. The color range identified by the device is not limited to the visible spectrum and may include infra-red and ultra-violet light. A storage means for memorizing colors may also be included in the device. Applications of ColorStick technology may include children's toys, aids for the visually handicapped (e.g. blind or color blind individuals), designers, internet shoppers, gardeners, etc.

Abstract: A photoelectric sensor includes a light-emitting element and a light-receiving element and detects a mark on an object. Prior to the detection of the mark, a reference received light quantity level is sampled for the surface of an object not including the mark, for every color of light. A mark received light quantity level is then sampled for every color of light. The difference is obtained between the reference received light quantity level and the corresponding mark received light quantity level for each color of light. A ratio of the obtained difference to the reference received light quantity level is obtained. For the colors of light where the difference equals or exceeds a predetermined value, the color of light having the largest ratio is selected for emission from the light-emitting element in the detection of the mark.

Abstract: The discriminating method utilizes first to third sensors respectively having spectral sensitivities corresponding to three primary colors and a fourth sensor having a spectral sensitivity that does not overlap the spectral sensitivities corresponding to the three primary colors as sensors constituting an image pickup system, and discriminates a light source type of a photographic light source by using information obtained by the first to fourth sensors. The image forming method corrects image data of an input image using the light source type discriminated by the above light source type discriminating method.

Abstract: In one embodiment, a plurality of color filters arranged in an N×N array. The color filters comprise equal numbers of color filters for each of three or more different colors. The color filters are arranged symmetrically in both an X and a Y direction. The center of gravity for each set of like-colored filters is the center of the array.

Abstract: A method for determining the properties of surfaces wherein a first process step specified radiation emits from at least one radiation source to a measuring surface, in further process steps the radiation reflected and/or scattered off the measuring surface is detected by a plurality of image-capturing components, and a signal is generated which specifies at least one parameter of the radiation detected by the image-capturing components. In further process steps the first signals are grouped based on predetermined criteria to form group signals, and at least one group-specific evaluation figure is computed, and a dependent statistical parameter correlating with at least one measuring surface remission characteristic. Finally at least one statistical parameter is read out in dependence on the predetermined criterion for grouping said first signals. The properties of the surface are specified by a relation between at least two statistical parameters.

Abstract: The invention is directed to a photosensor for color measurement based on three spectral components, particularly for highly accurate color measurement for testing and guaranteeing color constancy in engineered surfaces and consumer articles of any kind.

Abstract: A device for verifying and reading color, particularly used in reading the color of a liquid, the device comprising: a) a guide tube (10); and (b) at least one pair of liquid detection sensors (20), associated to the guide tube (10), the device comprising pairs of spectral-frequency emitting sensors (30, 31, 32) and spectral-frequency receiving sensors (30?, 31?, 32?), associated to the guide tube (10) and oppositely aligned, the spectral-frequency emitting sensors (30, 31, 32) being activated by detection of the liquid by the detection sensors (20).

Abstract: Color measuring systems and methods are disclosed. Perimeter receiver fiber optics are spaced apart from a central source fiber optic and receive light reflected from the surface of the object being measured. Light from the perimeter fiber optics pass to a variety of filters. The system utilizes the perimeter receiver fiber optics to determine information regarding the height and angle of the probe with respect to the object being measured. Under processor control, the color measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence and/or surface texture data also may be obtained. Audio feedback may be provided to guide operator use of the system. The probe may have a removable or shielded tip for contamination prevention.

Abstract: Method and apparatus for detecting the presence of a color dye in a water sample are described. Light is generated and passed through a water sample. A color sensor is utilized to measure the light that passes through the water sample. Based on the measured light, it is determined whether a dye color is present in the water sample.

Abstract: A test module used to verify the correct placement of light-emitting devices on electronic assemblies, by performing color and luminous intensity tests on these devices. The module includes one or a number of color sensitive photodiodes, which when exposed to light coupled from the emitter under test, will accurately measure the intensity, as well as the true color emitted by the device. The test module outputs analog signals, one directly proportional to the intensity, a second voltage proportional to the spectral wavelength of the device under test.

Abstract: A method for measuring degree and homogeneity of calcination of alumina utilizing an image analysis device equipped with a sensitive camera in a spectral analysis window corresponding to a wavelength range equal to or in the vicinity of visible light. The method includes the steps of mixing alumina under analysis in a liquid wherein the refractive index is, in the wavelength range, between the refractive index of a lightly calcined alumina and the refractive index of a strongly calcined alumina, preparing a slide for observation of the mixture in the image analysis device, the mixture being illuminated by stable polychromatic radiation compatible with the spectral analysis window, receiving an image by the camera and processing a signal resulting in the definition of an image composed of a given number of pixels with three calorimetric components, and statistically processing the pixels using their calorimetric components and determining the calcination degree and the homogeneity of the calcination.

Abstract: Method for defining the color group of an LED which emits mixed-color, in particular white, light. The CIE color space is divided by means of a network with two sets of intersecting network lines, one set being provided by a set of Judd straight lines and the other set by the line for the color loci of a Planckian radiator and also the associated lines of constant threshold value deviation, so that the network has a plurality of network cells bounded by network lines. The color locus of the LED is determined, and the network cell is determined in which the color locus of the LED is located. The LED is assigned to the color group of the network cell.