Patent•
Color image processing apparatus
14 Nov 2005-
TL;DR: A color image processing apparatus reproduces color data of a subject at higher accuracy by estimating the spectral reflectance of the subject from the color chip basis function vn (λ).
Abstract: A color image processing apparatus reproduces color data of a subject at higher accuracy by estimating the spectral reflectance of the subject from the color chip basis function vn (λ) which can expand the spectral reflectances of all color chips of the reference chart and the expansion coefficients B of the color chips The color image processing apparatus uses an image processing device to which a subject shooting signal Q shot by the color image input device and a reference chart shooting signal G taken from a plurality of color chips each having a spectral reflectance, is known
Citations
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Patent•
30 Apr 1997TL;DR: An omnidirectional image projection apparatus for projecting an image of a substantially hemispherical scene as viewed from a single viewpoint, including a means for projecting a collimated beam of light modulated with the image, and a truncated convex substantially paraboloid-shaped reflector positioned to orthographically reflect the projected image as mentioned in this paper.
Abstract: An omnidirectional image apparatus (130) for sensing an image of a substantially hemispherical scene from a single viewpoint, including a truncated, convex, substantially paraboloid-shaped reflector (135) positioned to orthographically reflect an image of the substantially hemispherical scene, and an image sensor (110) positioned to receive the orthographically reflected image. An omnidirectional image projection apparatus for projecting an image of a substantially hemispherical scene as viewed from a single viewpoint, including a means for projecting a collimated beam of light modulated with the image, and a truncated convex substantially paraboloid-shaped reflector positioned to orthographically reflect the collimated beam of light modulated with the image to project the hemispherical scene.
310 citations
Patent•
31 Aug 2006
TL;DR: In this article, a dual-use camera is provided for a portable or laptop computer, or a cellular phone, handset, personal digital assistant or other handheld device with a digital camera, in which one of the camera or a display is movable with respect to the other to enable the camera in a first mode to capture images of the display for enabling calibration of display, and in a second mode for capturing image other than of display.
Abstract: Color calibration of color image rendering devices, such as large color displays, which operate by either projection or emission of images, utilize internal color measurement instrument or external color measurement modules locatable on a wall or speaker. A dual use camera is provided for a portable or laptop computer, or a cellular phone, handset, personal digital assistant or other handheld device with a digital camera, in which one of the camera or a display is movable with respect to the other to enable the camera in a first mode to capture images of the display for enabling calibration of the display, and in a second mode for capturing image other than of the display. The displays may represent rendering devices for enabling virtual proofing in a network, or may be part of stand-alone systems and apparatuses for color calibration. Improved calibration is also provided for sensing and correcting for non-uniformities of rendering devices, such as color displays, printer, presses, or other color image rendering device.
251 citations
Patent•
07 Jan 1999TL;DR: In this paper, a method and apparatus for improving the efficiency of color correcting subsampled luminance and chrominance based data is presented, which can be used to convert between various types of color spaces, and may be used in the processing of both device dependent and device independent data.
Abstract: The present invention is directed to a method and apparatus for improving the efficiency of color correcting subsampled luminance and chrominance based data. More specifically, the present invention is directed to a method of applying a full conversion between color spaces for one pixel in a selected pixel block. Chrominance values are assigned to the remaining pixels based upon their luminance values relative to the luminance value of the converted pixel. The invention may be used to convert between various types of color spaces, and may be used in the processing of both device dependent and device independent data.
154 citations
Patent•
26 May 2012
TL;DR: In this article, a driving transistor is used to drive current through a light emitting device according to programming information which is stored on a storage device, such as a capacitor, and a switching transistor is included to select the circuits for programming, monitoring, and emission.
Abstract: Circuits for programming, monitoring, and driving pixels in a display are provided. Circuits generally include a driving transistor to drive current through a light emitting device according to programming information which is stored on a storage device, such as a capacitor. One or more switching transistors are generally included to select the circuits for programming, monitoring, and/or emission. Circuits advantageously incorporate emission transistors to selectively couple the gate and source terminals of a driving transistor to allow programming information to be applied to the driving transistor independently of a resistance of a switching transistor.
153 citations
Patent•
15 Dec 2005
TL;DR: In this paper, a method and system for programming, calibrating and driving a light emitting device display is described, which may include extracting a time dependent parameter of a pixel for calibration.
Abstract: A method and system for programming, calibrating and driving a light emitting device display is provided. The system may include extracting a time dependent parameter of a pixel for calibration.
149 citations
References
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Patent•
14 Jun 2006
TL;DR: In this paper, the authors propose a data structure for controlling color reproduction of input color image data representing one or more pages or page constituents in a network having nodes (or sites), where each one of the nodes comprises at least one rendering device.
Abstract: The system provides for controlling color reproduction of input color image data representing one or more pages or page constituents in a network having nodes (or sites). Each one of the nodes comprises at least one rendering device. The system distributes the input color image data from one of the nodes to other nodes, and provides a data structure (virtual proof) in the network. This data structure has components shared by the nodes and other components present only at each node. Next, the system has means for providing color calibration data at each node characterizing output colors (colorants) of the rendering device of the node, and means for producing at each node, responsive to the color calibration data of the rendering device of the node, information for transforming the input color image data into output color image data at the rendering device of the node. The information is then stored in the data structure in different ones of the shared and other components. Means are provided in the system for transforming at each node the input color image data into output color image data for the rendering device of the node responsive to the information in the data structure. The rendering device of each node renders a color reproduction of the page constituents responsive to the output color image data, wherein colors displayed in the reproduction at the rendering device of each node appear substantially the same within the output colors attainable by the rendering devices. The system further has means for verifying at each node that the information for the rendering device of the node properly transformed the input color image data into the output color image data, and means for revising the information stored in the data structure at the node responsive to results of the verifying means. Shared components of the data structure may also store color preferences selected by a user. The information producing means of the system may further operate responsive to both the color calibration data and the color preferences. The rendering devices in the system can provide color reproductions having three or four colorants, and may provide more than four output colors (color inks).
345 citations
Patent•
08 Dec 1995TL;DR: In this article, the scene illuminant is determined and an optimum color-correction transformation is determined to minimize color errors between an original scene and a reproduced image by adjusting three or more parameters.
Abstract: Multi-channel color image signals from a digital camera having multi-channel image sensors are corrected to account for variations in scene illuminant. This is accomplished by determining the scene illuminant and determining an optimum color-correction transformation in response to the scene illuminant which transform minimizes color errors between an original scene and a reproduced image by adjusting three or more parameters.
168 citations
TL;DR: The algorithm requires extra information, over and above the usual three values mapping human cone responses, from the optical system, and with this additional information, a sampling across the visible range of the reflected, color-signal spectrum impinging on the optical sensor, the authors are able to separate the illumination spectrum from the surface reflectance spectrum.
Abstract: A separation algorithm for achieving color constancy and theorems concerning its accuracy are presented. The algorithm requires extra information, over and above the usual three values mapping human cone responses, from the optical system. However, with this additional information-specifically, a sampling across the visible range of the reflected, color-signal spectrum impinging on the optical sensor-the authors are able to separate the illumination spectrum from the surface reflectance spectrum contained in the color-signal spectrum which is, of course, the product of these two spectra. At the heart of the separation algorithm is a general statistical method for finding the best illumination and reflectance spectra, within a space represented by finite-dimensional linear models of statistically typical spectra, whose product closely corresponds to the spectrum of the actual color signal. Using this method, the authors are able to increase the dimensionality of the finite-dimensional linear model for surfaces to a realistic value. One method of generating the spectral samples required for the separation algorithm is to use the chromatic aberration effects of a lens. An example of this is given. The accuracy achieved in a large range of tests is detailed, and it is shown that agreement with actual surface reflectance is excellent. >
132 citations
Patent•
21 Aug 2002
TL;DR: In this paper, an input profile that is referenced in converting an input image from an image input device into a device independent color image is created based on image input devices information, shooting- and observation-time lighting data, and subject data, allowing accurate conversion of the input image to the device-independent color image.
Abstract: In a color reproduction device, an input profile that is referenced in converting an input image from an image input device into a device-independent color image is created based on image input device information, shooting- and observation-time lighting data, and subject data, allowing accurate conversion of the input image to the device-independent color image. In reproducing the image by an image output device, the spectral reflectance of the subject itself is calculated from image input device information and shooting-time lighting data, thereby reducing the effect of the shooting-time lighting. The colors of the subject under observation lighting are calculated from observation-time lighting data. A color reproduced image is estimated accurately on the basis of the subject data even if the input image has little information.
106 citations
Patent•
12 Aug 1994TL;DR: In this paper, a color correction system including an imaging apparatus which inputs or outputs an image signal from a signal processor into or from an image device, such as an input device such as a scanner or a camera or an output devices such as display device or a print device, is presented.
Abstract: The present invention is a color correction system including an imaging apparatus which inputs or outputs an image signal from a signal processor into or from an image device such as an input device such as a scanner or a camera or an output device such as a display device or a print device and which is constituted so as to correct colors by inputting or outputting image signals via a color converter, the conversion characteristic of which can be controlled according to a variation in the setting status or use environment of the imaging apparatus and faithful color reproduction can be realized between a plurality of imaging apparatuses having different characteristics.
85 citations