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. The method further includes calculating X, Y, Z values for the first pixel in the image measurement, and then repeating the steps of the method beginning with calculating an R, G, B gray value for each subsequent pixel in the image measurement.
Abstract:
The invention provides a spectrometer (10) which includes a filter arrangement (16,18), in addition to any option filters (20) for limiting an operational wavelength range of the spectrometer, the filter arrangement (16,18) comprising a plurality of broadband optical filters or broadband optical filter areas each of known transmission and being located or selectively locatable in a path of collected incident spectral radiation (44). The spectrometer further includes at least one detector (24) arranged to measure the spectral radiation passing through at least one of the broadband filters located in the path of collected incident spectral radiation, and signal-processing means (34) for recovering the spectrum of the collected spectral radiation from measurements by the detector (24).
Abstract:
Systems and methods for providing spectral measurements are described. In one embodiment, a spectral measuring device comprises at least one radiation source configured to provide N (N≧2) linearly independent illuxninant sources characterized by M (M≧N) wavelength channels in a predetermined wavelength range; a sensor unit including at least one sensor, configured to be in optical communication with the radiation sources and an object; a memory storing an illuminant characterization matrix including spectral characteristics of the N illuminant sources in the M wavelength channels; and a processor configured to provide spectral responses of the object in the M wavelength channels, based at least in part on the illuminant characterization matrix. The embodiments of the invention can be used to construct a new class of compact spectral measuring devices, such as handheld color measuring devices.
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:
Embodiments of the present invention recite a method of compiling color analysis parameters. In one embodiment of the present invention, a corrected color description of at least one test subject is constructed. The corrected color description of at least one test subject is then accessed. The at least one test subject is assigned to a classification color according the accessed corrected color description. The said classification color is then correlated with a prescriptive recommendation.
Abstract:
Spectrophotometer color measurement with a target illumination system and a reflected illumination sensing system where the target surface is variably spaced from said spectrophotometer. Color correction calibration information corresponding to color measurements for known different spacings of a test target surface from the spectrophotometer are obtained and stored. In use, the spacing of the actual target surface from the spectrophotometer is measured to provide a target spacing information signal. That signal is automatically combined with the stored color correction calibration information for the corresponding distances to provide at least partial correction of color measurement errors of the spectrophotometer for variable spacing of the target surface relative to the spectrophotometer even with low cost fixed focus optics. The spectrophotometer output can be so corrected by changing the target illumination, such as by LED pulse width changes, and/or by corrective adjustment of the measured reflectances.
Abstract:
In one embodiment, apparatus for characterizing a target is provided with a plurality of light sources that are positioned to illuminate a target. The light sources emit different wavelengths of light. A color sensor is positioned to receive and sense different wavelengths of light reflected from the target. A control system is operably associated with the plurality of light sources and the color sensor to A) in a calibration mode, operate the light sources and separately regulate drive signals of light sources emitting different wavelengths of light, in response to outputs of the color sensor, and B) in an operational mode, i) operate the light sources using the regulated drive signals, and ii) characterize the target in response to data output from the color sensor. A textile characterization system is also disclosed.
Abstract:
A method for adjusting a color measurement of a secondary color measurement instrument. The method includes generating a profile for the secondary color measurement instrument based on color measurements of a master color measurement instrument, and applying the profile to adjust the color measurement of the secondary color measurement instrument.
Abstract:
Optical characteristic measuring systems and methods such as for determining the color or other optical characteristics of teeth are disclosed. Perimeter receiver fiber optics are spaced apart from a source fiber optic and receive light from the surface of the object/tooth 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/tooth being measured. Under processor control, the optical characteristics measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence, gloss 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. A method of producing dental prostheses based on measured data also is disclosed. Measured data also may be stored and/or organized as part of a patient data base.
Abstract:
In optical filter systems and optical transmission systems, an optical filter compresses data into and/or derives data from a light signal. The filter way weight an incident light signal by wavelength over a predetermined wavelength range according to a predetermined function so that the filter performs the dot product of the light signal and the function.