Patents by Inventor Chihiro Sakuwa

Chihiro Sakuwa 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).

  • Patent number: 8218083
    Abstract: A video noise reducer processes a frame difference signal equal to the difference between the video signal of the current frame and the video signal of the preceding frame or the difference between the video signal of the current frame and the noise-reduced video signal of the preceding frame to obtain a motion detection signal and a noise detection signal. The difference between the motion detection signal and the noise detection signal is then processed to obtain a recursion coefficient. The frame difference signal is multiplied by the recursion coefficient and the resulting product is additively combined with the video signal of the current frame to reduce noise without generating significant motion artifacts.
    Type: Grant
    Filed: March 16, 2007
    Date of Patent: July 10, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masako Asamura, Koji Minami, Chihiro Sakuwa, Toshihiro Gai
  • Patent number: 8218632
    Abstract: A frame interpolation apparatus generates a pixel value at an interpolation position by examining pairs of pixel blocks, one from a preceding reference frame and one from a following reference frame, located in positions that are point-symmetric or nearly point-symmetric with respect to the interpolation position. The pair of pixel blocks showing the greatest mutual similarity is selected, the central pixels in the selected pair of pixel blocks are taken as reference pixels, and the interpolated pixel value is generated from the reference pixel values. By routinely examining a large number of pairs of pixel blocks for each interpolation position, the frame interpolation apparatus can detect image motion accurately and generate accurate interpolated values.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: July 10, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koji Minami, Toshihiro Gai, Hironobu Yasui, Shuji Sotoda, Chihiro Sakuwa, Takashi Fujiwara
  • Patent number: 8174614
    Abstract: A video signal processing apparatus, which can prevent degradation of picture quality in converting an interlaced scan video signal to a progressive scan video signal, includes an interframe correlation detection means (11); an interfield correlation detection means (12); a field resolution determination means (13) which generates a signal (filhv) indicative of a degree of high frequency components existing in a field; a pull-down sequence detection means (14) which generates a telecine detection signal (tci) indicating whether or not an input video signal is any of 2-3 pull-down telecine video signal and 2-2 pull-down telecine video signal and also generates a mixing ratio signal (tcmix) indicative of a mixing ratio used at the time of interpolation processing; an interpolation signal generation means (110) which mixes a plurality of kinds of interpolation signals (Im, It) in accordance with the telecine detection signal (tci) and the mixing ratio signal (tcmix); and a rate doubling conversion means (9) whic
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: May 8, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masako Asamura, Koji Minami, Chihiro Sakuwa, Toshihiro Gai
  • Patent number: 7667721
    Abstract: A gray-scale conversion means (10) converts the gray scale of an input video signal (100) as necessary, and outputs the video signal with the converted gray scale. A statistical processing means (13) detects a statistical property of each field or frame of the input video signal; a scene change detection means (16) detects scene changes in the input video signal. A conversion characteristic determination means (22) determines the gray-scale conversion characteristic according to outputs of the statistical processing means (13) and the scene change detection means (16). The gray-scale correction increases contrast regardless of image content, and enables faster response to changes in image content.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: February 23, 2010
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koji Minami, Chihiro Sakuwa, Toshihiro Gai, Masako Asamura
  • Publication number: 20080151103
    Abstract: A video signal processing apparatus, which can prevent degradation of picture quality in converting an interlaced scan video signal to a progressive scan video signal, includes an interframe correlation detection means (11); an interfield correlation detection means (12); a field resolution determination means (13) which generates a signal (filhv) indicative of a degree of high frequency components existing in a field; a pull-down sequence detection means (14) which generates a telecine detection signal (tci) indicating whether or not an input video signal is any of 2-3 pull-down telecine video signal and 2-2 pull-down telecine video signal and also generates a mixing ratio signal (tcmix) indicative of a mixing ratio used at the time of interpolation processing; an interpolation signal generation means (110) which mixes a plurality of kinds of interpolation signals (Im, It) in accordance with the telecine detection signal (tci) and the mixing ratio signal (tcmix); and a rate doubling conversion means (9) whic
    Type: Application
    Filed: November 21, 2005
    Publication date: June 26, 2008
    Inventors: Masako Asamura, Koji Minami, Chihiro Sakuwa, Toshihiro Gai
  • Publication number: 20080069217
    Abstract: A frame interpolation apparatus generates a pixel value at an interpolation position by examining pairs of pixel blocks, one from a preceding reference frame and one from a following reference frame, located in positions that are point-symmetric or nearly point-symmetric with respect to the interpolation position. The pair of pixel blocks showing the greatest mutual similarity is selected, the central pixels in the selected pair of pixel blocks are taken as reference pixels, and the interpolated pixel value is generated from the reference pixel values. By routinely examining a large number of pairs of pixel blocks for each interpolation position, the frame interpolation apparatus can detect image motion accurately and generate accurate interpolated values.
    Type: Application
    Filed: September 19, 2007
    Publication date: March 20, 2008
    Inventors: Koji Minami, Toshihiro Gai, Hironobu Yasui, Shuji Sotoda, Chihiro Sakuwa, Takashi Fujiwara
  • Publication number: 20080062101
    Abstract: A gray-scale conversion means (10) converts the gray scale of an input video signal (100) as necessary, and outputs the video signal with the converted gray scale. A statistical processing means (13) detects a statistical property of each field or frame of the input video signal; a scene change detection means (16) detects scene changes in the input video signal. A conversion characteristic determination means (22) determines the gray-scale conversion characteristic according to outputs of the statistical processing means (13) and the scene change detection means (16). The gray-scale correction increases contrast regardless of image content, and enables faster response to changes in image content.
    Type: Application
    Filed: February 16, 2005
    Publication date: March 13, 2008
    Inventors: Koji Minami, Chihiro Sakuwa, Toshihiro Gai, Masako Asamura
  • Patent number: 7280709
    Abstract: In the conversion of a video signal from interlaced to progressive scanning, the value of each pixel on an interpolated scan line is calculated by a procedure that includes calculating similarity values for pairs of pixel blocks located in point-symmetrical positions on opposite sides of the interpolated pixel; deciding whether similar edges are present in corresponding positions in the two pixel blocks constituting each pixel block pair; selecting an interpolation direction corresponding to the most similar pixel block pair among the pixel block pairs in which the similar edges are present; and using the pixels disposed at or closest to the centers of the two pixel blocks in this pixel block pair as reference pixels. Restricting diagonal interpolation directions to pixel block pairs in which similar edges are present improves the accuracy of the interpolation direction.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: October 9, 2007
    Assignee: Mitsubishi Electric Corporation
    Inventors: Koji Minami, Masako Asamura, Chihiro Sakuwa, Toshihiro Gai
  • Publication number: 20070229709
    Abstract: A video noise reducer processes a frame difference signal equal to the difference between the video signal of the current frame and the video signal of the preceding frame or the difference between the video signal of the current frame and the noise-reduced video signal of the preceding frame to obtain a motion detection signal and a noise detection signal. The difference between the motion detection signal and the noise detection signal is then processed to obtain a recursion coefficient. The frame difference signal is multiplied by the recursion coefficient and the resulting product is additively combined with the video signal of the current frame to reduce noise without generating significant motion artifacts.
    Type: Application
    Filed: March 16, 2007
    Publication date: October 4, 2007
    Inventors: Masako Asamura, Koji Minami, Chihiro Sakuwa, Toshihiro Gai
  • Publication number: 20040246546
    Abstract: In the conversion of a video signal from interlaced to progressive scanning, the value of each pixel on an interpolated scan line is calculated by a procedure that includes calculating similarity values for pairs of pixel blocks located in point-symmetrical positions on opposite sides of the interpolated pixel; deciding whether similar edges are present in corresponding positions in the two pixel blocks constituting each pixel block pair; selecting an interpolation direction corresponding to the most similar pixel block pair among the pixel block pairs in which the similar edges are present; and using the pixels disposed at or closest to the centers of the two pixel blocks in this pixel block pair as reference pixels. Restricting diagonal interpolation directions to pixel block pairs in which similar edges are present improves the accuracy of the interpolation direction.
    Type: Application
    Filed: December 23, 2003
    Publication date: December 9, 2004
    Inventors: Koji Minami, Masako Asamura, Chihiro Sakuwa, Toshihiro Gai