Patents by Inventor Heui-keun Choh

Heui-keun Choh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060170940
    Abstract: Apparatuses and methods for performing gamut compression. A gamut mapping apparatus of the invention includes a gamut analyzing unit for analyzing the gamut of a source device and the gamut of a target device using a gamut information profile; a gamut compressing unit for mapping original images of the source device within the gamut of the target device by using the analytical information on the gamuts; and a gamut extending unit for increasing the chroma of predetermined images among the compressed original images on the basis of the analytical information on the gamuts and the performance result of the gamut compressing unit.
    Type: Application
    Filed: December 19, 2005
    Publication date: August 3, 2006
    Inventors: Byoung-ho Kang, Dae-won Kim, Heui-keun Choh, Min-ki Cho
  • Publication number: 20060145979
    Abstract: A liquid crystal display includes: a signal controller including a gamma converter outputting output image data have gamma characteristic adapted to a gamma 2.
    Type: Application
    Filed: November 12, 2003
    Publication date: July 6, 2006
    Inventors: Seung-Woo Lee, Yun-Ju Yu, Doo-Sik Park, Heui-Keun Choh, Chang-Yeong Kim, Yong-Koo Park
  • Publication number: 20060078365
    Abstract: A printing apparatus comprising an outer case having a cylindrical inner surface, an inner case inside the outer case and having a cylindrical outer surface facing and spaced by a predetermined distance from the cylindrical inner surface of the outer case; a paper path formed between the inner surface of the outer case and the outer surface of the inner case; a paper feed unit feeding a sheet of paper along the paper path; a printing unit rotatably mounted inside and about a central axis of the inner case; and a rotating unit rotating the printing unit. The length and width of the printing apparatus is less than the length and width of the sheet of paper, thereby providing true compactness and portability without sacrificing print quality. Continuous rotating printing unit provides significant increase in print speed without sacrificing print quality.
    Type: Application
    Filed: October 7, 2005
    Publication date: April 13, 2006
    Inventors: Heui-keun Choh, Gee-young Sung
  • Publication number: 20060061786
    Abstract: An apparatus to detect a color gamut boundary using a spherical coordinate system and an interpolation scheme, and a mapping apparatus and method using the same. The method for detecting a color gamut boundary includes converting color coordinate values of input color samples to spherical coordinate system values (?, ?, ?); performing interpolation by adding at least a color coordinate value by using adjacent color coordinate values when there is one having no color coordinate value of a given number of segments, the spherical coordinate system being uniformly divided into the given number of segments; detecting one having the largest radius r of color coordinate values positioned in the segment for each divided segment; and detecting one closest to a center of each segment of the detected color coordinate values having the largest radius for each segment to detect the color gamut boundary. Thus, it is possible to make an accurate color gamut boundary descriptor.
    Type: Application
    Filed: September 19, 2005
    Publication date: March 23, 2006
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Min-ki Cho, Heui-keun Choh
  • Publication number: 20050063582
    Abstract: An apparatus and method for image-based 3D photorealistic head modeling are provided. The method for creating a 3D photorealistic head model includes: detecting frontal and profile features in input frontal and profile images; generating a 3D head model by fitting a 3D genetic model using the detected facial features; generating a realistic texture from the input frontal and profile images; and mapping the texture onto the 3D head model. In the apparatus and method, data obtained using a relatively cheap device, such as a digital camera, can be processed in an automated manner, and satisfactory results can be obtained even from imperfect input data. In other words, facial features can be extracted in an automated manner, and a robust “human-quality” face analysis algorithm is used.
    Type: Application
    Filed: August 27, 2004
    Publication date: March 24, 2005
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: In-Kyu Park, Heui-Keun Choh, Vladimir Vezhnevets, Hui Zhang
  • Publication number: 20050057472
    Abstract: A liquid crystal display includes a signal controller having a luminance controller receiving image data from an external graphic source and controlling the luminance of the image data such that the luminance at the gray expressed by a specific data value of the image data is established to be 80 cd/m2, and a gamma converter outputting image data each having a gamma characteristic adapted to the gamma 2.2 curve. The liquid crystal display further includes a data driver receiving the image data from the signal controller and selecting and outputting gray voltages corresponding to the image data, and an inverter controlling a lamp such that the lamp emits light with a luminance of 80 cd/m2 or more. With the liquid crystal display, the luminance of a backlight is determined to be a specific value larger than 80 cd/m2, and the luminance of the input image data is controlled such that the luminance of the image data at the specific data value is established to be 80 cd/m2.
    Type: Application
    Filed: November 12, 2003
    Publication date: March 17, 2005
    Inventors: Seung-Woo Lee, Yun-Ju Yu, Doo-Sik Park, Jong-Seon Kim, Heui-Keun Choh, Chang-Yeong Kim
  • Publication number: 20050024538
    Abstract: A method of visually measuring the brightness of ambient lighting around a display device is disclosed. In this method, first, a reference brightness of the display device is determined according to a type of display device. Thereafter, information about locations where the display device is used is received from the user, and illuminance values of the display device corresponding to brightness stages are set based on the reference brightness and the location information. Then, a reference brightness is converted into each of the illuminance values corresponding to each of the brightness stages. The converted images with the illumination values corresponding to the brightness stages are displayed to the user, and an image that has a brightness value nearest to the brightness of ambient lighting is selected, and the brightness value of the selected image is determined as the brightness of ambient lighting.
    Type: Application
    Filed: June 30, 2004
    Publication date: February 3, 2005
    Applicant: Samsung Electronics, Co., Ltd.
    Inventors: Du-sik Park, Heui-keun Choh, Hyun-Jeong Koo, Chang-yeong Kim, Jin-ho Yim, Dong-sik Park, Hwan-young Kim
  • Patent number: 5870069
    Abstract: A method for displaying a color image under various illuminants is provided. In the color image displaying method, the chromaticity of an illuminant existing in a space in which a predetermined display device is located and the luminance ratio of a white paper on the display under the illuminant with respect to a luminance of the display device are measured. A shift ratio of a visual white of the display device using the chromaticity and the luminance ratio is determined. A new visual white of the display device in which the influence of the illuminant is removed using the shift ratio is obtained. A white of a displayed color image on the display device is shifted to the new visual white. Therefore, a visually consistent color image can be reproduced on the color display device under any illuminant.
    Type: Grant
    Filed: January 15, 1997
    Date of Patent: February 9, 1999
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Heui-keun Choh, Du-sik Park
  • Patent number: 5791781
    Abstract: In determining a color temperature in a color display device, the present invention comprises the steps of: producing a patch set I composed of a plurality of patches which appear gray under respective illuminant components and producing a patch set II composed of a plurality of patches to be a metameric pair with a neutral gray emitted from the respective illuminant components, under a specific illuminant; visually detecting peripheral illuminant components by selecting patch having identical color to that of patch having an equivalent energy spectral reflection degree in the patch set I; and determining a color temperature of the display device from the patch set II by using the detected illuminant component. Thus, the present invention provides color temperature information in producing a profile of the device required by a CMS by determining the color temperature of the display device considering the peripheral illuminant component without using a colorimeter.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: August 11, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Du-sik Park, Heui-keun Choh