A method and a system have been developed to calibrate the total spectral radiance factor (TSRF) obtained from different instruments. A broad-band light source covering the whole visible range as well as the fluorescence excitation wavelengths is used to measure the TSRF, and one or more narrow-band light sources outside of the fluorescent band is used to measure fluorescent spectral radiance factor (FSRF) separately. After that, the TSRF is adjusted by the FSRF, and a calibrated TSRF can be obtained. This can be applied to characterize Optical Brightening Agents (OBAs) as well as other fluorescent materials without requiring any moving part of the instrument to do the calibration.
A method includes controlling an integrated camera of a mobile device to detect a plurality of fiducial markers displayed as part of a test pattern on a display surface of a color display device, wherein the test pattern is one of a plurality of test patterns, estimating a position of the integrated camera relative to the display surface, using the plurality of fiducial markers, augmenting a live image of the test pattern on a display of the mobile device with an overlay, controlling, in response to a position of the overlay being aligned on the display of the mobile device with the live image of the test pattern, the integrated camera to capture an image of the test pattern, and calculating an adjustment to a color setting of the color display device, wherein the adjustment is calculated using information extracted from the image.
G09G 3/20 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix
G06T 7/33 - Determination of transform parameters for the alignment of images, i.e. image registration using feature-based methods
G06T 7/73 - Determining position or orientation of objects or cameras using feature-based methods
G06T 7/90 - Determination of colour characteristics
In one or more implementations, an apparatus, system or method is provided to compensate for second-order diffraction error (SODE) in connection with color or light measurements of a sample. In one particular implementation, methods and systems have been developed to compensate for SODE in a spectrophotometer by using a set of wavelength-dependent compensation factors or called diffraction ratios. The compensation factors can be generated with a narrow-band light source that covers the lower part of the wavelength range of the spectrophotometer but not the higher part of the wavelength range where the second-order diffraction error occurs and can be applied to the raw data of the spectrophotometer to compensate for the second-order diffraction error.
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
When a light beam hits an opaque sample, the sample will reflect light towards various directions with various intensities back into the 2π hemisphere above the sample plane. Bidirectional Reflectance Distribution Function (BRDF) can be used to describe such a property of the sample. A hemi-spherical screen is used to collect the light in the 2π hemisphere, and a pin-hole imaging system can be used to map the intensity of light distributed in the 2π hemisphere into a 2-dimensional image. From this 2-dimensional image, the BRDF of the sample material can be obtained.
A method includes controlling an integrated camera of a mobile device to detect a plurality of fiducial markers displayed as part of a test pattern on a display surface of a color display device, wherein the test pattern is one of a plurality of test patterns, estimating a position of the integrated camera relative to the display surface, using the plurality of fiducial markers, augmenting a live image of the test pattern on a display of the mobile device with an overlay, controlling, in response to a position of the overlay being aligned on the display of the mobile device with the live image of the test pattern, the integrated camera to capture an image of the test pattern, and calculating an adjustment to a color setting of the color display device, wherein the adjustment is calculated using information extracted from the image.
G09G 3/20 - Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix
G06T 7/33 - Determination of transform parameters for the alignment of images, i.e. image registration using feature-based methods
G06T 7/73 - Determining position or orientation of objects or cameras using feature-based methods
G06T 7/90 - Determination of colour characteristics
In one example, a color reference chart for evaluating a chrominance signal of a video image includes a plurality of color samples arranged in an array, wherein the plurality of color samples comprises: a first color sample of a first known, non-neutral hue and saturation and a second color sample of a second known, non-neutral hue and saturation positioned so that at least a portion of the second color sample is directly adjacent to at least a portion of the first color sample, and a barrier of a known neutral color positioned directly adjacent to the plurality of color samples without separating the at least a portion of the second color sample from the at least a portion of the first color sample.
A method includes controlling a gloss channel of a color measurement apparatus to measure a surface gloss of a color sample to generate a gloss value for the color sample. A color channel of the color measurement apparatus is controlled to measure a reflectance spectrum of the color sample to generate a first plurality of reflectance values for the color sample under a first measurement geometry. The first plurality of reflectance values are converted to a second plurality of reflectance values representing the reflectance spectrum of the color sample under a second measurement geometry, different from the first measurement geometry. The converting utilizes an adjustment that is a function of the gloss value.
In the disclosure provided herein, the described apparatus, systems and methods are directed to compensation of errors caused by the difference between the specular port and the sphere in a sphere-based color-measurement instrument, and improvement of the performance of the instrument. In one or more implementations, described approaches eliminate the need for hardware replacement, and therefore reduce costs associated with the operation of color measurement instruments.
A method has been developed to monitor the aging of an illuminator (such as a lamp) and the interior sphere wall in a sphere-based color measurement instrument. This monitoring process or method is configurable to independently monitor the aging of the illuminator as well as the aging of the interior surface of a color measurement device using standard calibration measurements already present in the color measurement device.
In one or more implementations, the apparatus, systems and methods disclosed herein are directed to calibrating a smart phone with an arbitrary phone case for color lookup applications, wherein the calibration process includes obtaining, with the smartphone without the case equipped, a first measurement data set that includes at least one measurement of each of a black, white and grey calibration target; obtaining, with the smartphone with the case equipped, at least three exposure measurements of a white calibration target at least three different exposure times; calculating an optimized exposure time using at least the at least three exposure measurements; obtaining, with the smartphone with the case equipped, a second measurement data set that includes at least one measurement of each of a black, white and grey calibration target at the optimized exposure time; generating fitting parameters from the first and second measurement datasets; and storing the generated fitting parameters and optimized exposure time in at least one of a local or remote data storage device.
Apparatus, systems and methods disclosed herein are directed to calibrating a smart phone with an arbitrary phone case for color lookup applications, wherein the calibration process includes obtaining, with the smartphone without the case equipped, a first measurement data set that includes at least one measurement of each of a black, white and grey calibration target; obtaining, with the smartphone with the case equipped, at least three exposure measurements; calculating an optimized exposure time; obtaining, with the smartphone with the case equipped, a second measurement data set that includes at least one measurement of each of a black, white and grey calibration target at the optimized exposure time; generating fitting parameters; and storing the generated fitting parameters and optimized exposure time in a data storage device.
In one or more implementations, the apparatus, systems and methods disclosed herein are directed to configuring a color measurement device to output color measurements that match the expected output of a different color measurement device. In a particular implementation, a method is provided for matching the color measurements made by a color measurement device to the color measurements made by a target color measurement device by implementing a single step color calibration and conversion process using an Artificial Neural Network (ANN). By way of non-limiting example, the raw counts from the color measurement device is converted to a specific color space, such as L*a*b, directly through an ANN. Such ANN is trained to ensure the output of the color measurement from the color measurement device will match with the output of the color measurement from a target color measurement device.
A method has been developed to improve the stability of a color measurement system that measures reflectances using matrix-transformation method. The transformation matrix can be obtained by training with a raw measurement matrix and a master reflectance matrix. The raw measurement matrix can be stacked with one or more of its variations, with each variation being some random noise added onto a part or the whole original raw signal matrix. The same number of master reflectance matrices are also stacked to match the size and sample ordering of the raw measurement matrix. The resulting transformation matrix will be more stable and less sensitive to the measurement noise.
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/25 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
A method has been developed to improve the stability of a color measurement system that measures reflectances using matrix-transformation method. The transformation matrix can be obtained by training with a raw measurement matrix and a master reflectance matrix. The raw measurement matrix can be stacked with one or more of its variations, with each variation being some random noise added onto a part or the whole original raw signal matrix. The same number of master reflectance matrices are also stacked to match the size and sample ordering of the raw measurement matrix. The resulting transformation matrix will be more stable and less sensitive to the measurement noise.
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
As described herein, a method has been developed to estimate the gloss of a black or dark sample using a color measurement system. In such a system, when measuring a higher gloss sample, more illumination light reflected from the sample surface will be directed away from the receiving sensor, and thus less signal will be detected. Using a derived sensor-signal to surface-gloss relationship, the surface gloss of a sample can be calculated by applying the measurements of the sample to the signal to gloss relationship to obtain a more accurate gloss measurement of a sample under analysis.
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.
A system including a processor and a memory configured to store code executed by the processor is provided. In one or more implementations, the processor is configured by the code to calibrate measurements made by color measurement devices. In one particular implementation, the processor receives a measurement dataset of one or more color values, for a sample obtained by a color measurement device. The processor is configured to convert the measurement dataset to a standard space measurement dataset using a standard space measurement model and calculate a color dataset based on the standard space measurement dataset using a color conversion model. The processor is further configured to output the calculated color dataset to at least one of a display, database or local memory store.
A processing system of a mobile device acquires an image of an object of a target color, wherein the image was captured by an integrated digital camera of the mobile device, calculates a first plurality of values that describes the target color, and wherein the calculating is based on an analysis of a pixel of the image, and identifies a first candidate color from among a plurality of candidate colors, wherein each candidate color in the plurality of candidate colors is associated with a second set of values that describes the each candidate color, and wherein the second set of values describing the first candidate color matches the first set of values more closely than any second set of values associated with another candidate color of the plurality of candidate colors.
A processing system of a mobile device acquires an image of an object of a target color, wherein the image was captured by an integrated digital camera of the mobile device, calculates a first plurality of values that describes the target color, and wherein the calculating is based on an analysis of a pixel of the image, and identifies a first candidate color from among a plurality of candidate colors, wherein each candidate color in the plurality of candidate colors is associated with a second set of values that describes the each candidate color, and wherein the second set of values describing the first candidate color matches the first set of values more closely than any second set of values associated with another candidate color of the plurality of candidate colors.
By way of overview and introduction, various embodiments of the apparatus, systems and methods described herein are directed improved approaches to aligning and standardizing different total spectral radiance factor shapes measured with different instruments. Furthermore, in one or more configurations and approaches, the disclosure presented herein is directed to obtaining a whiteness calibration value for use in sample measurements without the need of UV filter adjustments.
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
A method includes determining a fielded color measurement instrument is not calibrated to measure light emitted by a fielded light emitting device, assembling a calibration matrix, such that a product of the calibration matrix multiplied by a response of the fielded color measurement instrument to the light emitted by the fielded light emitting device is a triplet that corresponds to a Commission Internationale de L'éclairage XYZ color space, wherein the calibration matrix contains measurements made by the fielded color measurement instrument of a first plurality of lights emitted by the fielded light emitting device and measurements made by a spectroradiometer of a second plurality of lights emitted by a reference light emitting device of a same make and model as the fielded light emitting device, wherein the spectroradiometer is located remotely from the fielded color measurement instrument, and storing the calibration matrix on the fielded color measurement instrument.
Embodiments of the present invention are directed towards systems, methods and computer program products for correcting inter-instrumentation variation among color measurement devices. In one particular implementation, a method for correcting inter-instrument variation among color measurement devices includes obtaining a set of color measurements of an item under analysis. The described approach also includes accessing a conversion model, wherein the conversion module has been generated using one or more ANN back propagated over a collection of data points, where the data points correspond to measurements of a color standard using devices from a control device batch and a test device batch. Using the conversion module, a processor is configured to transform the set of color measurements into a calibrated color measurement set. The calibrated color measurement set is then output to at least one display, memory or remote computing device.
Embodiments of the present invention are directed towards systems, methods and computer program products for correcting inter-instrumentation variation among color measurement devices. In one particular implementation, a method for correcting inter-instrument variation among color measurement devices includes obtaining a set of color measurements of an item under analysis. The described approach also includes accessing a conversion model, wherein the conversion module has been generated using one or more ANN back propagated over a collection of data points, where the data points correspond to measurements of a color standard using devices from a control device batch and a test device batch. Using the conversion module, a processor is configured to transform the set of color measurements into a calibrated color measurement set. The calibrated color measurement set is then output to at least one display, memory or remote computing device.
A color measurement system is provided that includes an integrating sphere having at least one specular component included (SCI) sensor configured to output a signal in response to light incident thereupon and at least one specular component excluded (SCE) sensor configured to output a signal in response to light incident thereupon, a sample port, a SCE port, a light source configured to direct a beam of light into the sphere and provide illumination at the sample port and a specular component excluded port. The system also includes a processor having a memory and configured by code to activate the light source so as to cause a beam of light to be directed into the sphere and provide illumination to the sample port. The processor is also configured to receive a signal output by the SCI sensor and a signal output by the SCE sensor. Furthermore, the processor is configured to obtain at least one measurement coefficient value and generate a corrected SCE measurement value using at least the SCI sensor value, the SCE sensor value and the obtained measurement coefficient. The processor is configured to output at least the corrected SCE measurement value and the SCI measurement value.
In one example, an initial transform is stored for converting wavelength channel responses of a color measurement instrument to color readings. The initial transform is set in-factory by a manufacturer of the color measurement device. A color selection of a sample is subsequently retrieved from a database, where the color selection was made by an end user in response to a color reading by the color measurement instrument using the initial transform. An adjustment to the initial transform is calculated using the color selection. The adjustment is then sent to the color measurement instrument for use in making future color measurements.
A method and a system are provided for obtaining improved spectra recovery results of a measurement of a sample through the use of a calibration matrix obtained from calibration measurement values using at least one illumination source. By calculating the reflectance spectrum of a collection of calibration samples across several rounds of measurements and cascading the results, an improved calibration matrix can be used to convert the sample measurement values to more accurate results.
G01J 3/46 - Measurement of colourColour measuring devices, e.g. colorimeters
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/25 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
Embodiments of the present invention are directed towards systems, methods and computer program products for correcting inter-instrumentation variation among color measurement devices. In one particular implementation, a method for correcting inter-instrument variation among color measurement devices includes obtaining a set of color measurements of an item under analysis. The described approach also includes accessing a conversion model, wherein the conversion module has been generated using one or more ANN back propagated over a collection of data points, where the data points correspond to measurements of a color standard using devices from a control device batch and a test device batch. Using the conversion module, a processor is configured to transform the set of color measurements into a calibrated color measurement set. The calibrated color measurement set is then output to at least one display, memory or remote computing device.
In accordance with particular implementations of the invention described herein, a sample for analysis is illuminated under each of one or more narrow-band light sources. The light incident upon this sample is received by a sensor that generates measurement data in response thereto. One or more processors are configured to receive the measurement data and derive an excitation response curve and a fluorescent response curve from the measurement data. The processor is further configured to generate a fluorescent profile value using measurements from the fluorescent response curve for each of the captured narrow band measurement data and an excitation profile value corresponding to the area under the fluorescence curve divided by the area under the excitation curve. The generated fluorescent profile and excitation profile are both output as a dataset providing improved measurement values over similar approaches in the art.
A method and a system are provided to measure transmittance or reflectance of a color specimen by using a transformation matrix obtained from the measurement values of a series of known transmittance or reflectance calibration color standards and multiple flashes from different illumination sources. A color spectrum can be determined with reduced error by calculating the reflectance spectra of an object using measurement matrices obtained under at least two illuminants and the transformation matrix.
Various embodiments of the systems and methods described herein are directed towards training an artificial neural network to identify color values of a sample by providing image data obtained through multiple image capture devices under a plurality of lighting conditions. The present invention also includes using a pre-trained neural network to identify the color values of a sample having an unknown color value by capturing an image of an unknown color sample and known color reference samples under any illumination or hardware configuration.
A method is provided for identifying colors across illuminants using a processor configured by code executing therein, the method comprising capturing a sample image with an image recording device, the image including pixels resenting a color sample under analysis and a color reference chart. The processor is also configured to execute comparing the color values of pixels representing the color reference chart of the sample image to the pixel values corresponding to a plurality of entries within a plurality of color reference datasets to determine the color reference having the closest match of sample captured in the image. The reference identifier of the color that is the closest match to the sample is then output for further use.
G06F 16/583 - Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually using metadata automatically derived from the content
A method is provided for identifying colors across illuminants using a processor configured by code executing therein, the method comprising capturing a sample image with an image recording device, the image including pixels representing a color sample under analysis and a color reference chart. The processor is also configured to execute comparing the color values of pixels representing the color reference chart of the sample image to the pixel values corresponding to a plurality of entries within a plurality of color reference datasets to determine the dataset representing the closest match of the illumination present at the time the sample image was captured. Using the identified illuminant, the color reference dataset having the closest illuminant is searched for the color under analysis.
Systems, methods and computer program products for segmenting colors in a sample image comprised of pixels using a processor configured by code executing for selecting at least one color value present within the sample image and for each color selected from the sample image comparing the color values of each pixel of the sample image to the selected color value and averaging the color values of each pixels of the sample image having a color value difference below a pre-determined threshold. The method also includes outputting the average color value as a color value data object; and associating each averaged color value with sample image.
In one example, an electronic signal is received from a target color measurement instrument that includes a plurality of color channels. A response of the target color measurement instrument to a light emitted by a target light emitting device is extracted from the signal. The response is calibrated to minimize a difference between the response and an output of a color matching function of a standard observer. Calibrating includes multiplying the response by a calibration matrix. The calibration matrix combines measurements of a first plurality of lights from a tunable light source and measurements of a second plurality of lights from the target light emitting device. A first subset of the measurements of the first plurality and second plurality of lights are made by the target color measurement instrument and a second subset of the measurements of the first plurality and second plurality of lights are made by a reference spectroradiometer.
Various embodiments of the systems and methods described herein are directed towards training an artificial neural network to identify color values of a sample by providing image data obtained through multiple image capture devices under a plurality of lighting conditions. The present invention also includes using a pre-trained neural network to identify the color values of a sample having an unknown color value by capturing an image of an unknown color sample and known color reference samples under any illumination or hardware configuration.
In one embodiment, an apparatus for measuring a color of a non-solid colored sample includes an integrating sphere having a sensor port, a sample port, and a plurality of registration marks affixed to an interior surface of the integrating sphere, outside a periphery of the sample port, a camera positioned near the sensor port, and a plurality of filters positioned between the integrating sphere and camera. An optical axis of the camera extends from the camera, through at least one of the plurality of filters, through the sensor port, to the sample port.
The present invention concerns a system and method for calibration and adjustment of the pixel color values represented within a digital image of a sample by a transmission microscope. Furthermore the present invention is directed to providing sufficient color information in order to generate a color mapping matrix that allows for the creation of a synthetic image to depict the sample under a desired illumination. The system and method provides a solution that generates a destination-device independent image that is configurable to any calibrated display device.
A system and apparatus for the color calibration of images recorded through a microscope. An integrated color calibration target microscope slide device and specimen are recorded with an imaging device that acquires both the color values of the specimen and the color values of the color calibration target under a plurality of illuminations and trans-illuminations. A composite image is formed to provide a spectral estimation of the relevant color values of the image. The image is converted into multi-stimulus values governed by a plurality of illuminating conditions. The multi-stimulus values are used to provide image calibration data so that color values of the image, when displayed on a display devices, are faithfully reproduced.
G09G 5/06 - Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the way in which colour is displayed using colour palettes, e.g. look-up tables
