Abstract:
A dedicated base vector based on a known spectral characteristic of a subject as an identification target having the known spectral characteristic and a spectral characteristic of an imaging system, which includes a spectral characteristic concerning a color imaging system used for image acquisition of subjects including the subject as the identification target and a spectral characteristic concerning illumination light used when image acquisition of the subjects by the color imaging system, are acquired. A weighting factor concerning the dedicated base vector is calculated based on an image signal obtained by image acquisition of the subject by the color imaging system, the dedicated has vector, and the spectral characteristic of the imaging system. An identification result of the subject which is the identification target having the known spectral characteristic is calculated based on the weighting factor concerning the dedicated base vector to output as an output signal.
Abstract:
A miniaturized spectrometer/spectrophotometer system and methods are disclosed. A probe tip including one or more light sources and a plurality of light receivers is provided. A first spectrometer system receives light from a first set of the plurality of light receivers. A second spectrometer system receives light from a second set of the plurality of light receivers. A processor, wherein the processor receives data generated by the first spectrometer system and the second spectrometer system, wherein an optical measurement of a sample under test is produced based on the data generated by the first and second spectrometer systems.
Abstract:
A method includes generating at least one first light beam and generating at least one second light beam and at least one third light beam using the at least one first light beam. The at least one first light beam has a plurality of first regions, the at least one second light beam has a plurality of second regions, and the at least one third light beam has a plurality of third regions. Each of the first, second, and third light beams has at least two regions that are spectrally different. The method also includes measuring a spectrum in each of a plurality of first wavelength bands for each of the second regions. The method further includes illuminating at least part of an object with the at least one third light beam to produce at least one fourth light beam. The at least one fourth light beam has a plurality of fourth regions, where at least two of the fourth regions are spectrally different. In addition, the method includes measuring a spectrum in each of a plurality of second wavelength bands for each of the fourth regions and identifying a radiance transfer factor of the object using at least some of the measured spectra.
Abstract:
To determine spectra, integrated multiple illuminant measurements from a non-fully illuminant populated color sensor may be converted into a fully populated spectral curve using a reference database. The reference database is partitioned into a plurality of clusters, and an appropriate centroid is determined for each cluster by, for example, vector quantization. Training samples that form the reference database may be assigned to the clusters by comparing the Euclidean distance between the centroids and the sample under consideration, and assigning each sample to the cluster having the centroid with the shortest Euclidean distance. When all training samples have been assigned, the resulting structure is stored as the reference database. When reconstructing the spectra for new measurements from the sensor, the Euclidean distances between actual color samples under measurement and each cluster centroid are measured. The spectra are then reconstructed using only the training samples from the cluster corresponding to the shortest Euclidean distance, resulting in improved speed and accuracy.
Abstract:
A correction algorithm may be applied for correcting misalignment of a radially-aligned array of sensors. Due to the tilt, signals from sensors that are further away from the media, may become slightly attenuated, while signals from sensors that are closer to the media are slightly increased. The error appears periodic and largely sinusoidal in nature around the array given the circular nature of the array of sensor elements. The algorithm determines the magnitude and phase of a sinusoidal function that best fits the wavelength data. In one embodiment, a discrete Fourier transform may be performed at the ‘frequency’ equivalent to one period around the array to determine the magnitude and phase estimate thereof. Then, a sinusoidal correction function may be generated using the magnitude and the phase in order to correct the reflectance data.
Abstract:
An image processing apparatus for use with a printed image on a moving substrate is provided. The image processing apparatus includes a first imaging device configured to process spatial data which indicates a position of color patches printed along an edge portion of the printed image on the moving substrate. The image processing apparatus further includes a second imaging device configured to process at least one of densitometric data and colorimetric data of the color patches of the printed image. The first imaging device and second imaging device acquire image data from substantially the same position on the substrate at substantially the same time. The image processing apparatus further includes a processor configured to monitor a color of the printed image on the moving substrate based on the spatial data and the at least one of densitometric data and colorimetric data.
Abstract:
In a reflection characteristic measuring apparatus 10 and a method for calibrating the reflection characteristic measuring apparatus, multiple standard spectral characteristics, or multiple calibration data based on the multiple standard spectral characteristics are obtained in advance with corresponding reference values relating to an emission characteristic of a light source 21. An optimum standard spectral characteristic or an optimum calibration data is selected from the multiple standard spectral characteristics or the multiple calibration data obtained. A spectral reflection characteristic of a sample is calculated using the selected standard spectral characteristic or the selected calibration data.
Abstract:
This application generally relates to methods and systems for detecting spectrophotometer misalignment. In particular, the application may characterize the noise of a spectral measurement relative to a reference substrate known to exhibit a generally linear (flat) spectral output over a known spectrum. From the spectral measurement, a linear regression may be performed on a portion of the spectral output to determine a best fit line and a correlation of determination (“R-squared value”) may be determined correlated the measured data to the best fit line. Finally, the R squared value may be compared to a predetermined threshold R squared value to determine if the sensor is misaligned beyond an acceptable amount. If so, an alert may be generated.
Abstract:
Devices, systems, and methods for measuring the color of a sample are disclosed. The exemplary device may have one or more light emitting diodes for directing a beam of ultraviolet light onto the sample and may also have one or more light emitting diodes for directing a beam of visible light onto the sample. The exemplary device may have a component for controlling the timing and power of operation of each light emitting diode. The exemplary device may also have at least one light detector for receiving the beam of light reflected from or transmitted through the sample and measuring at least one wavelength band of the received light. The exemplary device may further have a measurement analyzer for determining the color of the sample based on the measured light. The color may be determined for a specified illuminator incorporating effects of fluorescence.
Abstract:
Disclosed herein is a point-of-purchase (POP) spectrophotometer for open-viewing of a color sample. The POP spectrophotometer includes a housing assembly containing an illumination optical system and an imaging optical system in desired orientation. Also provided is at least one of a second illumination optical system, a sheen detection system, and a camera system. The housing assembly includes a chassis in secure arrangement with a plurality of supports that define a target plane having a target location and that space the chassis therefrom. The chassis is configured to position the illumination, imaging, sheen detection, and/or camera systems in desired orientations relative to the target location and each other. The POP spectrophotometer can include an alignment device and/or targeting optics for facilitating user-identification of the target location, and means can be provided to enhance insensitivity to ambient light and/or depth variation of the color sample.