Showing papers on "Colorimeter published in 2009"

Comparison of Minolta colorimeter and machine vision system in measuring colour of irradiated Atlantic salmon.

Abstract: BACKGROUND: Minolta and machine vision are two different instrumental techniques used for measuring the colour of muscle food products. Between these two techniques, machine vision has many advantages, such as its ability to determine L*, a*, b* values for each pixel of a sample's image and to analyse the entire surface of a food regardless of surface uniformity and colour variation. The objective of this study was to measure the colour of irradiated Atlantic salmon fillets using a hand-held Minolta colorimeter and a machine vision system and to compare their performance. RESULTS: The L*, a*, b* values of Atlantic salmon fillets subjected to different electron beam doses (0, 1, 1.5, 2 and 3 kGy) were measured using a Minolta CR-200 Chroma Meter and a machine vision system. For both Minolta and machine vision the L* value increased and the a* and b* values decreased with increasing irradiation dose. However, the machine vision system showed significantly higher readings for L*, a*, b* values than the Minolta colorimeter. Because of this difference, colours that were actually measured by the two instruments were illustrated for visual comparison. Minolta readings resulted in a purplish colour based on average L*, a*, b* values, while machine vision readings resulted in an orange colour, which was expected for Atlantic salmon fillets. CONCLUSION: The Minolta colorimeter and the machine vision system were very close in reading the standard red plate with known L*, a*, b* values. Hence some caution is recommended in reporting colour values measured by Minolta, even when the ‘reference’ tiles are measured correctly. The reason for this discrepancy in colour readings for salmon is not known and needs further investigation. Copyright © 2009 Society of Chemical Industry

Color calibration system

Abstract: A color calibration system in accordance with a preferred embodiment of the present invention comprises a display device provided with a color sensor for detecting a color temperature and illuminance of ambient light, a microcomputer, and a colorimeter for performing colorimetry on a display screen of the display device from the outside. The microcomputer calculates a target value by using a preset calculation equation and a detection result on the ambient light detected by the color sensor. Then, the microcomputer automatically performs color calibration of the display device so that a colorimetry result obtained by the colorimeter may agree with the target value.

Digital image color analysis compared to direct dental CIE colorimeter assessment under different ambient conditions.

Abstract: Purposes: To evaluate the concordance and repeatability of two in-vivo methods for dental color assessment and to clarify the influence of different ambient light conditions and subject´s head position on the assessed color variables. Methods: Color assessments were performed by two examiners on sixteen arbitrarily selected subjects under two different, standardized conditions of illumination and at two different standardized head angulations. CIE (L*a*b*) data for upper and lower central incisors were recorded in two different ways: (1) by an intra-oral contact dental colorimeter and (2) by processing digital images for performing color calculation using AdobePhotoshop™ software. The influence of the different ambient conditions on both methods, as well as the concordance of measurements were analyzed statistically using several mixed linear models. Results: Ambient light as a single factor had no significant influence on maxillary L*, a* and b* values, but it did have an effect on mandible assessments. Head angulation variation resulted in significant L* value differences using the photo method. The operator had a significant influence on values a* and b* for the photo method and on a* values for the colorimeter method. In fully lit ambient condition, the operator had a significant influence on the segregated L*, a*, and b* values. With dimmed lights, head angulation became significant, but not the operator. Evaluation of segregated L* values was error prone in both methods. Comparing both methods, ΔE values did not exceed 2.85 units, indicating that color differences between methods and recorded under varying ambient conditions are well below the sensitivity of the naked eye.

Cheap, handheld colorimeter to read paper-based diagnostic devices

Abstract: Investigators describe a point-of-care system, with a microfluidic paper device and a handheld optical colorimeter, for quantifying analyte concentrations in biological fluids.

A new, low-cost, on-line rgb colorimeter for wine industry based on optical fibers

Abstract: This paper presents a new kind of colour sensor based in measurement the three channels of RGB colour space, using bifurcated optical fibres to conduct light from illuminant to liquid under test and from liquid to photo sensor. This kind of colorimeter can be applied to wine industry in despite of using different colour space in relation to traditional methods. This paper shows a brief description of colour measurement process, a prototype implementation and several experimental results to compare their results to colour data from commercial equipment, and to verify its applicability to wine industry.

System and method for liquid delivery evaluation using solutions with multiple light absorbance spectral features

Abstract: A system and related method for improved liquid delivery evaluation using a solution containing one or more dyes such that the solution exhibits multiple distinct detectable light absorbance spectral features for calibrating or testing over extended volume or dilution ranges are described. The system includes: a photometric instrument capable of measuring optical absorbance at multiple wavelengths; one or more sample solutions to be dispensed using the liquid delivery system whose performance is being tested or calibrated; and vessels optionally pre-filled, or filled by the user, with diluent solution. The sample solutions contain one or more dyes, chosen so that multiple distinct detectable light absorbance spectral features, such as peaks and/or valleys and/or plateaus of the solution can be distinguished for volume or dilution ranges of interest. The concentrations of the dyes may be chosen so that a large volume delivery device is calibrated using a spectral feature in the solution with a low absorbance per unit pathlength, while a small volume delivery device is calibrated with the same sample solution but using a different spectral feature with a high absorbance per unit pathlength.

Color high-fidelity camera automatic color measuring apparatus

Abstract: PROBLEM TO BE SOLVED: To provide a color high-fidelity camera automatic color measuring apparatus capable of measuring spectral sensitivity characteristics of a filter of a camera intended for obtaining accurate color information, and measuring a color and calculating a correction factor at high accuracy in color measurement for calculating the correction factor required for calibration of the filter. SOLUTION: Based on image outputs (S 1i , S 2i , S 3i ) of the camera 5 and color measurement data (X i , Y i , Z i ) of a spectroscopic colorimeter 6 obtained by emitting lights of different colors from a window 2 of a LED calibrator 1 in which a plurality of LEDs are incorporated, taking an image of the light emitted from the LED calibrator 1 by the camera 5 through a lens 7, reflecting the light passing through the lens 7 to the spectroscopic colorimeter 6 for color measurement by a turnable total reflection mirror 8 which can change an optical path from the lens 7 to the camera 5, a method of least squares is used to calculate a color difference E and the correction factor M. COPYRIGHT: (C)2010,JPO&INPIT

Instrument or method for measuring absorbance

Abstract: PROBLEM TO BE SOLVED: To find absorbance with errors in absorbance owing to large gas bubbles excluded therefrom SOLUTION: By a control part 7, a plurality of points in a reagent reaction chamber are determined as measurement candidates and a first light emitter 3 is moved to the plurality of measurement candidates while a light emission order is given to the light emitter 3 Further, a second light emitter 4 is relatively moved to the respective measurement candidates while the emission order is given to the light emitter 4 By an arithmetic means 8, measurement points are determined as out-of-object measurement points where the measured absorbance on light of a second wavelength is equal to or more than a threshold stored in a threshold storage means 9 The absorbance of inspecting-object liquid matter is found based on the measured absorbance on a first wavelength at object measurement points other than the out-of-object measurement points COPYRIGHT: (C)2011,JPO&INPIT

Application of color difference meter in the quality inspection of food

Abstract: The color difference related information and the colorimeter applied in the quality inspection of food were introduced in the paper.

Correction unit for color measurement unit mounted in printing apparatus equipped with the color measurement unit, and correction lut for color measurement unit

Abstract: PROBLEM TO BE SOLVED: To perform color correction for which dispersion for each measurement unit is added. SOLUTION: When generating an LUT for correction, wherein a correction value equivalent to the difference between a color-measurement value in a spectroreflectometer of a colorimeter to be a reference and a color measurement value in a spectroreflectometer of a colorimeter to be a correction object is data, the LUT for correction includes a wavelength, a reflectance and a change in reflectivity relative to the wavelength of the reflectance as elements of the argument; the correction value is obtained, on the basis of the color measurement result of a patch corresponding to a predetermined color; and the correction value is obtained, by deducing it on the basis of the color measurement result for a lattice point where the correction value lacks. COPYRIGHT: (C)2011,JPO&INPIT

Colorimeter optical system

Abstract: The invention relates to a colorimeter optical system, which comprises a lighting source, an integrating sphere, an optical path system, a positioning lens, and a main sampling sensor array, wherein the positioning lens is arranged at the bottom of the integrating sphere; a testing opening which loads measured substance is arranged on the positioning lens; the optical path system is arranged between the lighting source and the integrating sphere; light rays emitted by the lighting source are irradiated to the measured substance of the testing opening by the optical path system; after the light rays reflected by the measured substance are integrated by the integrating sphere, a path of light rays are irradiated to the main sampling sensor array for being used during sampling; the colorimeter optical system is characterized in that the colorimeter optical system also comprises an auxiliary light path and an auxiliary sampling sensor array; a spectroscope faces toward the lower port of the auxiliary light path; after the light rays reflected by the measured substance is integrated by the integrating sphere, the other path of light rays pass through the spectroscope, enter into the auxiliary light path, and are irradiated to the auxiliary sampling sensor array for being used during sampling. When the colorimeter optical system is disturbed by external environment during measurement, two-path measurement guarantees the accuracy and stability of chromatic measurement.

Display arrangement i.e. TV-display arrangement, has control and evaluation unit producing evaluating measured values of display colorimeter, where values are converted into correction values to calibrate LCD display

Abstract: The arrangement has a processor-based control and evaluation unit for a LCD display (2). A calibration device has a display colorimeter (7) i.e. red blue green colorimeter, for color measurement in a measurement-display section (8). The evaluation unit initiates color and/or brightness calibration of the display. The evaluation unit produces a reference color diagram on the section, where the diagram is measured by the display colorimeter. The evaluation unit evaluates measured values of the display colorimeter, where the values are converted into correction values to calibrate the display. An independent claim is also included for a method for calibrating a display using a display arrangement.

Portable ozone colorimeter

Abstract: The utility model discloses a portable ozone colorimeter, relating to the field of a water quality analysis instrument; the portable ozone colorimeter includes a sealed shell, the surface of which is provided with keys, a power switch, a data output screen and a removable cover, wherein, the shell is fixed with a colorimetric pool at the corresponding position of the removable cover; the colorimetric pool is provided with a colorimetric pool channel, a light source mono-chromator and a photoelectric detector in a matching way, wherein the colorimetric pool channel is internally provided with a colorimetric bottle while the photoelectric detector, micro-processor and the data output screen are connected in sequence. Besides, the shell is provided with a cell which is connected with the power switch, the photoelectric detector, the micro-processor and the data output screen respectively. The portable ozone colorimeter is applicable to the fast test of the ozone concentration in drinking water, mineral water, purified water and natural purified drinking water, thereby avoiding the defects of the prior ozone concentration test method and the device in the water. The portable ozone colorimeter has the advantages of simple operation, correct result and easy storage and transportation, thus being suitable for on-site fast test.

Efficient measurement of large light source near-field color and luminance distributions for optical design and simulation

Abstract: The color and luminance distributions of large light sources are difficult to measure because of the size of the source and the physical space required for the measurement. We describe a method for the measurement of large light sources in a limited space that efficiently overcomes the physical limitations of traditional far-field measurement techniques. This method uses a calibrated, high dynamic range imaging colorimeter and a goniometric system to move the light source through an automated measurement sequence in the imaging colorimeter's field-of-view. The measurement is performed from within the near-field of the light source, enabling a compact measurement set-up. This method generates a detailed near-field color and luminance distribution model that can be directly converted to ray sets for optical design and that can be extrapolated to far-field distributions for illumination design. The measurements obtained show excellent correlation to traditional imaging colorimeter and photogoniometer measurement methods. The near-field goniometer approach that we describe is broadly applicable to general lighting systems, can be deployed in a compact laboratory space, and provides full near-field data for optical design and simulation.

Color processing method and color processing device

Abstract: PROBLEM TO BE SOLVED: To overcome disadvantages in the conventional art, in which colorimetric values differ under different observation conditions dependent on backing materials of a colorimeter etc. and it is necessary to measure color samples for preparing a color conversion table for each of the observation conditions. SOLUTION: First measurement data and first observation condition data are acquired by measuring color samples using a colorimeter under a first observation condition (at S201). Then, a second observation condition is designated by UI (at S202) to acquire second observation data (at S203). Using the first measurement data and the first and second observation condition data, second measurement data as a colorimetric value of the color sample under the second observation condition is generated (at S204). Thus, the second measurement data under the second observation condition can be acquired without actual color measurement by the colorimeter. COPYRIGHT: (C)2009,JPO&INPIT

Evaluation of Photoshop software potential for food colorimetry: color changes of Mazafati dates during accelerated ripening

Abstract: Color and appearance are among the first parameters perceived by consumers to judge the quality of foods. L*a*b* are used to report foods’ colors quantitatively. In this study the use of digital imaging and Photoshop software was evaluated for measurement of L*, a* and b* color parameters. The results showed that L*, a*, and b* values from Hunter colorimeter and the digital imaging method had a good correlation with R2 more than 0.95, but the values from digital imaging method can be used only to monitor the trend of color changes and the actual numbers of digital imaging L*, a* and b* obtained by digital imaging do not have the same value as the L*, a* and b* given by a Hunter colorimeter. Using two equations for the three parameters the values obtained from digital imaging method can be successfully converted to Hunter Lab color corresponding parameters. The color change of Mazafati date during accelerated ripening using acetic acid solutions was monitored by the proposed method. L*, a*, and b* of the samples all decreased over the ripening. Key words: Colorimetry, Photoshop software, Digital imaging, Mazafati date

Colourimeter and method for calibrating same

Abstract: The method involves clearly reading color monitor or color projector identifications and an initial set of color rendering characteristic values from a storage device of a color monitor or a color projector using a colorimeter. A reference set of color rendering characteristic values is compared with the initial set of color rendering characteristic values on the monitor. A set of calibration correction parameters is determined for the colorimeter and is stored in a colorimeter storage device. The identifications are stored in the storage device of the monitor or the projector. Independent claims are also included for the following: (1) a computer program product with a set of instructions for performing a method for calibrating a colorimeter (2) a data carrier with the computer program product for performing the method for calibrating the colorimeter (3) a colorimeter with an interface for connecting a color monitor and a color projector.

P‐73: Objective Evaluations of Manipulating Algorithms on FPD by a 2D‐Colorimeter

Abstract: Comparisons of CIE-Lab histograms of tested images on FPDs were performed by measurements with a 2D-colorimeter The images were generated by manipulating original images according to FPD characteristics, correlated color temperature, lightness, and saturation Experiments show that this method provides quantitative and intuitional data for assessments of the manipulating algorithms

Image display apparatus, driving method thereof, and program

Abstract: PROBLEM TO BE SOLVED: To make display colors of a display panel adapt to environment light. SOLUTION: Image display apparatus includes a processing circuit 40 which is configured to receive input of information regulated by the prescribed display system and to output four or more color components based on the information for a display panel 100, and a colorimeter 130 configured to measure the color of light of an environment surrounding the display panel. When colors of environment light at the first point of time measured by the colorimeter and the second point of time after that are changed, the processing circuit outputs four or more adapted color components so that colors regulated by the information are adapted to colors of environment light at the second point of time. COPYRIGHT: (C)2011,JPO&INPIT