Abstract:
A method for matching colors including comparing the appearance of a first white color associated with a first color imaging system and a second white color associated with a second color imaging system, wherein the tristimulus values of the first and second white color are similar; determining a fixed correction to the tristimulus values of the second white color to achieve a visual match to the first white color; measuring a first set of spectral values for a first color associated with the first color imaging system; determining a first set of tristimulus values from the first set of spectral values; measuring a second set of spectral values for a second color associated with the second color imaging system; determining a second set of tristimulus values from the second set of spectral values; applying a correction to the tristimulus values of the second color; determining a difference between the tristimulus value of the first color and the corrected tristimulus value of the second color; and adjusting the second color to reduce the difference.
Abstract:
A method for characterizing a color in terms of tristimulus values, the method includes providing a source of a color; measuring a set of spectral values for color stimulus associated with the color using a spectral measurement device controlled by a digital processing system; calculating a first set of tristimulus values from the set of spectral values; defining a set of human observer color matching functions, the set of human observer color matching functions being functions of the tristimulus values; and determining a second set of tristimulus values from the set of spectral values using set of human observer color matching functions.
Abstract:
A color control apparatus includes an image-capture-data-obtaining unit that obtains image-capture data for a predetermined target by subjecting the predetermined target to image capturing; a colorimetric-data-obtaining unit that obtains colorimetric data for the predetermined target by subjecting the predetermined target to colorimetry; a first conversion unit that performs a first conversion including gradation conversion on the image-capture data and obtains first color data of a predetermined color space; a second conversion unit that performs a second conversion including gradation conversion on the colorimetric data and obtains second color data of a predetermined color space; and a modifying unit that, on the basis of color differences between the first color data and the second color data, performs optimization of the first conversion performed by the first conversion unit.
Abstract:
A goniophotometer includes two independent towers: a main support tower and an upright mirror tower. A swing arm is connected to the main support tower and can be rotated around a main horizontal axis. An elliptic flat rotation mirror, a first detector and a second detector are fixed to the swing arm. A test light source that is also connected to the main support tower can be rotated around a vertical axis. An upright round mirror is connected to the upright mirror tower. A far-field measurement can be achieved when a light beam from the test light source travels into the rotation mirror then is reflected to the upright mirror, and then is reflected by the upright mirror to the first detector. A near field measurement is achieved when the second detector receives a test light beam directly form the test light source.
Abstract:
According to one example embodiment described herein is a method of notating a color that includes determining, using predetermined mathematical equations and in dependence on numerical color attributes that identify a color, a plurality of numerical color emotion values each representative of a different human emotional response to the color; and assigning an identifying notation to the color, the identifying notation comprising a color emotion notation that includes the color emotion values.
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 reflectance of a color shifted painting color is also measured conveniently.A first reflectance R(αa) of a first reflected light Va inside an incident plane A is measured, and a first locus l of termini of first bisection vectors Ha(|Ha|=|R(αa)|), which displaces two-dimensionally inside the incident plane A, is determined. A second reflectance R(αb) of a second reflected light Vb outside the incident plane A is measured, and a second locus m of termini of second bisection vectors Hb (|Hb|=|R(αb)|), which displaces three-dimensionally outside the incident plane A, is measured. A locus n (x, y, zi) of a terminus of a bisection vector Hi on a plane z=z that is parallel to a plane under measurement is approximately modeled with a numerical equation showing an ellipse from the first locus l and the second locus m, thereby determining an approximation model equation, and an overall locus n′(x, y, z) of the overall termini of bisection vectors H′ of reflected lights V′ other than the first reflected light Va and the second reflected light Vb is approximately determined.
Abstract:
Color deviations of images are analyzed using a sensor. The received image sensor signal is analyzed pixel by pixel. An image sensor signal is produced for each color channel from a plurality of color channels. An image sensor signal from a first channel, and one from a second channel, are combined. An output signal of a first color contrast channel is generated. Now an image sensor signal from a third channel is combined with the ones from the first and second image sensors. An output signal of a second color contrast channel is generated. The outputs of these color contrast channels are classified.
Abstract:
A method and system for accurate and precise representation of color for still and moving images, particularly sequences of digitized color images. Spectral and/or extended dynamic range information is retained as images are captured, processed, and presented during color adjustment. Using this extra spectral information, various methodologies for further presenting or processing the color within these images can be optimized. Presentation-device independence is achieved not by attempting to discover a device-independent intermediate representation, but rather by deferring the binding and mapping of color representation onto a presentation device until its actual use.
Abstract:
The invention provides methods, systems and apparatus for assigning color names to individual image pixels, and generating verbal description of color composition in images, suitable for a wide variety of information processing applications. For an isolated image pixel (individual color sample or color value) an illustrative embodiment of this invention uses a predetermined vocabulary of color names, and then generates a distance measure describing the best color match and corresponding color name for the given pixel. For the input image, an illustrative embodiment of this invention computes the simplified representation of the scene, consistent with human perception, and uses the predetermined vocabulary, syntax rules and metric to assign color names to all perceptually significant objects and regions and obtain the verbal description of the overall color composition. The invention is also applicable to other types of information signals, such as sequences of video frames, web pages, etc.