142 results about "Chromatic contrast" patented technology

The embodiment of the invention discloses an image color correction method, apparatus and system. The method comprises the following steps: obtaining color card images of a standard color card at a plurality of different color temperatures, performing analysis to obtain standard reference values and original collection values of RGB three channels of color blocks in the standard color card at thecolor temperatures, and calculating a calibrated color correction matrix at each color temperature, wherein the color correction matrix is a 3*N-dimensional color correction matrix, N is a positive integer, and N is greater than or equal to 3; and obtaining an input pixel value of an image to be corrected, determining a target color temperature in a collection environment of the image to be corrected, matching a target color correction matrix corresponding to the target color temperature, and correcting the color of the image to be corrected according to the target color correction matrix andthe input pixel value of the image to be corrected. According to the image color correction method, apparatus and system disclosed by the invention, the color of the image is corrected by designing the color correction matrix with high dimensions and adding a medium gray block constraint item, so that the color rendition effect is better, and the chromatic aberration in the image color correctionis weakened.

The invention relates to a green component and color difference space-based Bayer format color interpolation method. Two main errors which are jaggies and pseudo colors respectively exist in the conventional color interpolation methods. In the method, in a full-color image recovery process, color recovery is realized by adopting a combined way of interpolating green components, red components and blue components in steps; and the method comprises the reconstruction of the full-resolution green components G, the calculation of pixel point color differences R-G or B-G comprising the red or blue components, the reconstruction of full-resolution color difference images R-G and B-G, and the recovery of the red components R and the blue components B by the addition of the reconstructed full-resolution green components and the reconstructed color difference images. The method of the invention has the advantages of effectively solving the problem that the images have blurry edges and unsharp detail textures, reducing the color distortion of the images, preventing color mutation and improving color smoothness.

The invention relates to the technical field of optical lenses, particularly to an achromatic metalens design method and an achromatic metalens thereof. The achromatic metalens design method comprisesperforming analog scanning on every degree of freedom geometrical parameter of every single nano unit through a numerical simulation method, performing numerical adding on phase shift produced by nano units with different geometrical parameter combinations, performing numerical multiplication on transmittance to acquire the total phase shift and the total transmittance of superposed multilayer nano units, performing superposition combination on the nano units with appropriate units, and arranging the superposed nano units according to the corresponding Fresnel hyperbolic-type laws corresponding to every target wavelength to obtain the achromatic metalens. By performing parameter design, superposition combination and arrangement on the nano units forming the achromatic metalens, the achromatic metalens can act on multiple target wavelengths and eliminate the influence of color difference brought about by traditional lenses, and the area of the achromatic metalens can be increase to thecentimeter scale or above.

An efficient demosaicing method includes reconstructing missing green pixels after estimating green-red color difference signals and green-blue color difference signals that are used in the reconstruction, and then constructing missing red and blue pixels using the color difference signals. This method creates a full resolution frame of red, green and blue pixels. The full resolution frame of pixels is sent to a display unit for display. In an efficient demosaicing process that includes local contrast enhancement, image contrast is enhanced to build and boost a brightness component from the green pixels, and to build chromatic components from all of the red, green, and blue pixels. Color difference signals are used in place of the red and blue pixels in building the chromatic components.

The invention relates to a color-spun yarn color matching method based on a least square support vector machine. The method is characterized by comprising the following steps that reference color fibers are determined, and the corresponding color data value is acquired; a part of or all reference color fibers are selected, combined in different ways and mixed in different mixing ratios for spinning and sample preparation, and the reflectance values of all samples are measured; the reflectance value of a standard sample and the corresponding proportional relation serve as training samples, and an LS-SVM function model is trained; a corresponding sample recipe C is calculated; according to the prediction recipe C, sample making is conducted, a simulated sample is obtained, and the reflectance value of simulated sample is measured; through the comparison, the chromatic aberration between a target sample and the simulated sample is obtained, if the chromatic aberration meets a preset value, the proportion is determined as an optimum recipe, otherwise, recipe modification is conducted; the optimum recipe is input in an LS-SVM training set for training. The types of the reference color fibers adopted by the method are less, after the recipe obtained by calculation is verified and modified, the accuracy of the optimum recipe is high, color matching is simple and reliable, and the efficiency and the practicability are high.

Compensation of lateral-color chromatic-aberration effects in a digital color-graphics projection display is achieved by providing projection optics for the projection display which is nontelecentric to a certain degree to establish an angled geometry for gathering light off axis for projection by the projection optics and by providing a plurality of component-primary-color object planes for object digital graphics of different primary colors to be projectively displayed through the projection optics. At least two of the component-primary-color object planes are located at different effective axial distances from the projection optics. The effective axial distances of the object planes from the projection optics are respectively keyed to the angled nature of the off-axis light gathering of the projection optics and to the lateral-color chromatic-aberration differences in lateral magnification by the projection optics at different primary colors so that such color-dependent differences in lateral magnification tend to be compensated.

A system and method for defringing chromatic aberrations that occur in imaging devices such as scanners. The system comprises shift filters to shift lines in the various color planes together. In addition in each color plane, a spread filter is used to compensate for the unequal point spread functions of each color. Furthermore, the results can be enhanced by filtering in the luminance-chrominance space.

The invention relates to a method for classifying observer color matching functions. The method includes the steps that a color matching experimental device is set up and comprises a target color, a matching color and a standard observation box providing an illuminating light source, multiple colors are selected, the target color and the matching color are respectively composed of different primary color spectrums, and the illuminating light source is a sunlight source; observers are organized to perform a color matching experiment through adjusting the number of three channel primary colors of a displayer RGB; a PR650 spectral radiosity meter is used for measuring color stimulation spectrum data of the target color and the matching color on the displayer; CIE1931, CIE1964, CIE2006 and Sarkar1-8 are selected as the color matching functions of the experiment to calculate color difference of color matching of the observers, cone cell spectrum responses of the observers organized for the experiment are classified, and the observers are divided to the corresponding categories of color matching functions. The method is used for evaluating and dividing the cone cell spectrum responses of the different observers.

What is disclosed is an image processing method for enabling one to print color graphics and other recognizable objects on monochrome printers while retaining color differences. More specifically, the present method is for preserving color discriminability in a grayscale representation. The method involves first sorting colors according to at least one characteristic dimension of a color space such as lightnesses. The color space preferably is a luminance-chrominance color space, although others are envisioned. The sorted colors are adjusted by a metric appropriate to the color space such that the metric imparts a degree of distinction among the colors along the chosen characteristic dimension. The spacing between two adjacent sorted colors can be constant, or weighted by the total color difference between the two colors in the original color space. Color difference can be calculated using for example ΔE*ab, ΔE*LCh, ΔE*94, or DE2000 metrics. Once the colors have been adjusted, they are converted to the monochrome representation using straightforward techniques.

The invention relates to a multi-target optimization and color-matching method of special-color ink in offset printing. The traditional method can not realize accurate ink color matching. The method comprises the following steps of: firstly calibrating and coloring, and calculating a unit concentration value of each ink; secondly, measuring a spectral reflectivity value of a target sample and a substrate, and calculating a unit concentration value of the sample and the substrate; then establishing a constraint condition and a target function of a multi-target optimization color-matching model, and finally calculating and obtaining a corresponding formula by utilizing a Pareto disaggregation optimization method according to the target function of the multi-target optimization color-matching model. The multi-target optimization and color-matching method has the characteristics of simple and convenient calculation process; in the color matching process, the color-difference minimization between the formula and the sample is considered, simultaneously the spectrum isomerism between the formula and the sample is reduced, and the influence of different light sources on the color matching result is furthest eliminated.

The invention belongs to the technical field of printing, and particularly relates to a high-fidelity spot color number hard proofing method. The method comprises the following steps: step 1: a spot color hard proofing color block guide table parameter control database is established; step 2: a spot color is proofed by a hard proofing device and a spot color effect evaluation is performed; step 3: a spot color hard proofing color block guide table test chart is generated; step 4: the test chart is printed and data-analyzed; and step 5: an original drive value of an optimal color block is applied to substitute the original drive value of the spot color block in a GMG color management system so that spot color proofing with the minimum chromatic aberration is realized. The neighborhood color block guide table is established for the spot colors via a programming method, and the guide table is utilized to perform proofing. Then the chromatic aberration of each color block value in the guide table is measured, and the minimum value of the chromatic aberration is defined as a proofing drive value of the spot color in color management software. Problems that conventional spot color proofing is slow in speed and low in accuracy are compensated by the method and cycle correction is not needed so that a requirement of spot color proofing can be realized via one time of correction.

High-contrast, high-density cell-sized microparticles are introduced into a cell-containing solution prior to the solution being spread onto a planar substrate for imaging. The microparticles facilitate both the process of imager autofocusing and the subsequent registration of multiple images taken of regions of the substrate. The microparticles can further facilitate the correction of chromatic aberration.

A shade selection program is disclosed that predicts the shade choice with the smallest CIEDE2000 color difference for dental composite resin restorations when given a backing and target shade. By utilizing generated regression models, a database of spectral reflectance information, and principles of Kubelka-Munk layering, a highly accurate shade selection program was designed. Additionally, a blending model for quantification of color adjustment potential was developed. Systems and methods for correlating RGB data from the VITA Linearguide 3D Master and VITA Bleached Guide 3D Master shade guides with their spectroradiometric correlates through a regression model while indicating a methodology for validation of accuracy of digital imaging systems are disclosed.

The invention discloses a four-field-sequential-color-LCD-based color display method. Local primary desaturation processing is carried out on a color range included by each local backlight region; on the premise that the original image color is reproduced completely, four-field primary colors with minimum chromatic aberration are searched reasonably to carry out color mixing, so that a color breakup phenomenon of the traditional red-green-blue primary color sequential LCD can be suppressed effectively and thus the image quality of the sequential LCD can be improved. Meanwhile, because of full utilization of divided region backlight of the LCD during local primary desaturation processing, the primary color range is reduced and local dimming is realized, so that power consumption of the LCD can be reduced.

In a flow cytometer, an objective lens for focusing an input laser-radiation beam including at least four different laser-radiation wavelengths in a common plane includes only three singlet lens-elements. Two of the elements are cylindrical elements arranged as a cylindrical telescope for shaping and reducing the size of the input laser-beam. The third element is a spherical element arranged to focus the reduced size beam in the common plane. In one example, all three elements are made from the same optical material.

The invention provides a ternary exposure technology-based achromatic system and an implementation method thereof. The system comprises a micro display, a collimating lens, a first grating and a second grating, wherein colored light emitted by the micro display irradiates to the first grating through the collimating lens; RGB (Red Green Blue) three-color light wave is reflected in the same direction to enter a light waveguide through modulation of the first grating; at the second grating, the light wave is modulated and reflected back to enter human eyes, so colorful images can be seen by human eyes. According to the ternary exposure technology-based achromatic method, a same holographic material is subjected to exposure for three times by changing the recording angle respectively to obtain a grating structure for modulating the lights of red, green and blue colors respectively. Laser of 532 nm is used as a recording light source, a silver halide plate (a silver halide emulsion material) is selectively used as a holographic recording material; the method is simple, effective and practical and particularly has great economic significance to large-scale industrial production.

The invention relates to a solar cell color difference sorting method and system based on machine vision. The solar cell color difference sorting method comprises the steps of collecting images of to-be-sorted cells; dividing the images into a plurality of subimages which are crossed vertically and horizontally, calculating an LAB three-component average value of each subimage and color difference values between the subimages, and finding out the maximal color difference value of the subimages; judging whether the maximal color difference value is greater than a set threshold, if the maximal color difference value is greater than a set threshold, cell colors are not uniform, a detection result is directly output and is sent to a sorting control module for the next operation, and image processing is finished; if the maximal color difference value is not greater than the set threshold, the cell colors are uniform, and the color difference between a to-be-tested image and each standard image is calculated according to the LAB three-component average values of the to-be-sorted images and different colors of standard images so as to judge the color type of the cells. According to the solar cell color difference sorting method, the automatic solar cell color difference sorting is realized, and the sorting quality and efficiency are increased.

The invention discloses a white balance processing method and device based on an RGB space. The method comprises the following steps: after obtaining an original value of each pixel point in a to-be-processed image respectively in an R color channel, a G color channel and a B color channel, calculating red-blue color differences of the pixel points; determining neutral grey pixel points via the red-blue color differences and neutral grey pixel point judgment conditions, wherein the neutral grey pixel point judgment conditions are iterated and updated with a current color temperature change; after that, according to a proportion of the number of the neutral grey pixel points to the total number of the pixel points in the to-be-processed image, calculating to obtain gain values of the pixel points respectively in the R color channel, the G color channel and the B color channel, obtaining corrected values of the pixel points according to the gain values, and then adjusting the original values of each pixel point in the to-be-processed image respectively in the R color channel, the G color channel and the B color channel to the corrected values, thereby realizing white balance processing of the to-be-processed image. Through the scheme disclosed by the invention, the white balance processing on the image can be realized; and thus, the color differences in the image are reduced, and the image quality is improved.

The invention provides an achromatic method based on a three-time exposure technology. The method relates to a miniature display screen, a collimating lens, a first optical grating and a second optical grating. Colored light emitted from the miniature display screen irradiates to the first optical grating after passing through the collimating lens, through modulation of the first optical grating, RGB three-color light waves can be reflected in the same direction to enter an optical waveguide, the light waves are modulated and reflected out at the second optical grating to enter human eyes, and thus colored images can be seen by the human eyes. According to the achromatic method based on the three-time exposure technology, the angle change is recorded, exposure can be conducted on the same holographic material for three times, and accordingly a grating structure capable of modulating the RGB three-color light can be obtained. A laser of 532 nm is used as a recording light source, a silver salt plate (a silver halides latex material) is selected to be used as the holographic recording material, the method is simple, effective and practical, and the method is of great economic significance to large-scale industrial production particularly.

The invention relates to a segmentation and localization method for two mutually overlapped fruits in picking the fruits, and is particularly suitable for the quasi-circular fruits of which the fruit color and the background color have large chromatic aberration. The segmentation and localization method for the two overlapped fruits based on chromatic aberration comprises the steps that an original image Io of only two fruits are mutually overlapped is inputted and binarization is performed so that a binary image IS with the fruit area acting as a target area is obtained, then the minimum external affine rectangle of the target area, a target rectangle and two ROI subareas are successively selected on the binary image IS, a segmentation line dividing the target rectangle into two quadrilateral areas is obtained by connecting the central points of the two ROI subareas, and then the positions of the two fruits are determined by determining the centers of gravity of the two quadrilateral areas; and finally a circle is drawn with the centers of gravity of the two quadrilateral areas acting as the centers of circle and the distance from the two centers of gravity to any one intersection point of the segmentation line and the target rectangle acting as the radius, and the two circular areas are judged as the areas of the two fruits.

Disclosed is an energy compensation and chromatic aberration removal method for total-reflection optical splicing cameras. The method comprise the processing steps of calculating an effective gray average of laboratory calibrated images and a column average of detectors in energy loss areas, and fitting first energy compensation coefficients of the detectors; selecting a great many on-orbit image data, calculating histograms of adjacent normal areas of the energy loss areas and histograms of each column of images after the first compensation in the energy loss areas respectively, and creating histogram lookup tables of the detectors in the energy loss areas; and removing chromatic aberration among splicing sheets based on adaptive gray information of image data overlapping areas. By means of the technical scheme of the energy compensation and chromatic aberration removal method for total-reflection optical splicing cameras, the energy loss problem of splicing areas of total-reflection optical splicing cameras can be solved, laboratory calibrated data of cameras before satellite launching and a great many on-orbit image data after satellite launching are fully used, and energy of the optical splicing areas is guaranteed to be compensated effectively.

The invention discloses a fruit branch and leaf region obtaining method of red apple images in a garden. The method comprises steps of 1: acquiring apple RGB images; 2: obtaining fruit images: extracting R-G chromatic aberration images from the RGB images, successively carrying out corrosion operation, hole filling, small region removing and open operation on the R-G chromatic aberration images and finally carrying out threshold segmentation; 3: obtaining leaf images: subtracting the fruit images from the RGB images, extracting 2G-R-B chromatic aberration images from the subtracted images and carrying out small region removing and threshold segmentation; and 4: obtaining branch images: carrying out dynamic threshold segmentation on the R-G chromatic aberration images, adding the segmented images into the obtained fruit images to obtain fruit addition images, then subtracting the fruit addition images and the leaf images from the RGB images, extracting R-G chromatic aberration images from the subtracted images and then carrying out open operation, small region removing and threshold segmentation. According to the invention, the method lays a foundation for precise fruit identification and positioning, effective obstacle avoidance and successful picking for following picking robots.

The invention relates to a display device and a color temperature adjusting method. The color temperature adjusting method comprises: the phase to converting the input image signal into the illumination and aberration signal; the phase to detect the illumination gray scale signal of the gray part near the UV field origin in the converting aberration signal; the phase to increase the color signal Cb, Cr plus control value of the detected illumination gray scale according to the degree of the converting illumination signal; and the phase by adopting the increased Cb, Cr plus control value, to convert and output the illumination and aberration signal whose color temperature has been changed, into R, G and B signal by adopting the chromaticity space converting algorithm. The invention considers the repeatability of the color, setting the color temperature to be the lowest. The white field only detects the illumination gray scale ingredient of the colorless gray part, improving the color temperature, thereby satisfying the illumination of the outputted image and the light dark ratio, and the repeatability of colors on the sight of people.

A method is described for overcoming the adverse visual effect of misregistered ink planes in multiple ink color prints. Color separations are initially made in a normal fashion. The separation carrying the greatest object detail is then chosen as a luminance or achromatic channel. This may be used as is or preferably it is sharpened using a high pass filter. Normally this separation will be black. However, it may be a surrogate color for black, particularly if only two or three separations are made. Object detail in all other separations (chrominance separations) is degraded, usually by a low pass filter such as a Gaussian blur. The printed image formed when the separations are recombined in a conventional manner is remarkably visually tolerant of misregistration of the various ink planes in the image.

The invention relates to a method for preparing a color holographic polymer dispersed liquid crystal grating. According to the method, a multi-band exposure light path is set up, a reflection type liquid crystal spatial light modulator is adopted, different pictures with black and white strips are loaded on the reflection type liquid crystal spatial light modulator, and different sub-gratings are prepared; in this way, the devices of the light path do not need to be moved at all during exposure, convenience and fastness are realized, and repeatability is high; besides, due to the fact that exposure is conducted by means of RGB laser light and exposure angle remains unchanged, red light, green light and blue light on a displayer can be emitted at the same emergent angle based on the holographic recording and reconstruction principle, and chromatism-free stereo display image beam splitting is achieved; the polymer dispersed liquid crystal material adopted is a multi-light initiator and assisted initiator concurrent material, and the polymer dispersed liquid crystal material obtained finally can achieve exposure at multiple bands including red light 632.8 nm, green light 532 nm and blue light 441.6 nm. The left eye and right eye image beam splitting function is achieved in stereo display. The method has the advantages that image beam splitting effect is good and chromatism is completely avoided.

Provided in the invention is a CMYK four-color printing chromatic aberration positioning method. An RGB color value and a CMYK color value of a color card are collected to establish a mapping relation between an RGB value and a CMYK value; an RGB color value of a reference printed matter image and an RGB color value of a to-be-detected printed matter image are converted into corresponding CMYK values; and an average chromatic aberration of two pictures in CMYK color space is calculated, thereby completing chromatic aberration positioning of four CMYK color plates. According to the method provided by the invention, the printed matter chromatic aberration is localized to a concrete printing color plate, so that a chromatic aberration source of the printed matter can be analyzed specifically. Therefore, the method plays a role in guiding a feedback guiding printing control process; and a problem that the existing chromatic aberration analyzing method can not reflect a chromatic aberration value of each color plate can be solved.