Patents by Inventor Yoshinobu Ebisawa

Yoshinobu Ebisawa 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: 20170278269
    Abstract: A corneal reflection position estimation system according to an embodiment includes: an image acquisition unit configured to continuously acquire an image of an eye of a subject by controlling a camera equipped with a light source, the image acquisition unit being configured to acquire a plurality of pupil images taken by using light from the light source and then acquire one unilluminated image taken without using light from the light source; and an estimation unit configured to calculate positions of corneal reflection or corneal sphere centers, which correspond to the plurality of pupil images, as reference positions, calculate a movement vector of the corneal reflection or the corneal sphere center based on a plurality of the reference positions, and estimate the corneal reflection position in the unilluminated image based on at least the movement vector.
    Type: Application
    Filed: July 27, 2015
    Publication date: September 28, 2017
    Inventor: Yoshinobu EBISAWA
  • Publication number: 20170105619
    Abstract: A pupil detection system according to an embodiment includes a vector calculation unit configured to calculate a plurality of candidate vectors each connecting a corneal sphere center and a pupil center by a stereo method based on a first pupil image of a subject which is picked up by a first camera and a second pupil image of the subject which is picked up by a second camera, and a determination unit configured to select, from among the plurality of candidate vectors, a candidate vector satisfying a vector condition in which an angle between the pupil center and a reference line is equal to or less than a predetermined threshold and determine that a pupil is located at a pupil center corresponding to the selected candidate vector.
    Type: Application
    Filed: May 12, 2015
    Publication date: April 20, 2017
    Inventor: Yoshinobu EBISAWA
  • Patent number: 9514538
    Abstract: A pupil detection method includes a step of acquiring images by taking a facial image of a subject using each of a left camera and a right camera, a step of extracting one or more image candidate points serving as candidates for pupils from the images, a step of extracting points corresponding to a combination of image candidate points corresponding to the same point in a three-dimensional space as space candidate points, a step of selecting a pair of two space candidate points from the extracted space candidate points and calculating a distance between the selected pair, a step of excluding a pair of space candidate points where the calculated distance is not within a specified range, and a step of determining one or more pairs of space candidate points from the pairs not excluded and determining that a pair of pupils of the subject exist at the positions.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: December 6, 2016
    Assignee: NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20160125241
    Abstract: A pupil detection light source device includes an aperture disposed to face a subject to allow light from a pupil of the subject to pass therethrough, an illumination light for obtaining a light pupil image toward the subject from the inside or the vicinity of the aperture when seen from the subject, and an illumination light for forming a reflection image with glasses obtained by canceling a reflection image with glasses of the light pupil image using an image difference toward the subject from the inside or the vicinity of the aperture when seen from the subject.
    Type: Application
    Filed: May 2, 2014
    Publication date: May 5, 2016
    Applicant: NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventor: Yoshinobu EBISAWA
  • Patent number: 9329683
    Abstract: A gaze point detection device 1 has four cameras 2a, 2b, 2c, 2d, light sources 3a, 3b, 3c, 3d, control circuits 4, 5, 6, and an image processor 7. The image processor 7 calculates vectors r, each of which is from a corneal reflection point to the center of a pupil, on a plane that is vertical to base lines. The image processor 7 also calculates angles ? of the line of sight on the basis of the vectors r and by using a function f including M parameters. Moreover, the image processor 7 determines the M parameters based on the angles ?, and detects a point of gaze Q based on the line of sight direction calculated using the determined parameters. The number of cameras is set at M×½ or higher.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: May 3, 2016
    Assignee: NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20150287206
    Abstract: A pupil detection method includes a step of acquiring images by taking a facial image of a subject using each of a left camera and a right camera, a step of extracting one or more image candidate points serving as candidates for pupils from the images, a step of extracting points corresponding to a combination of image candidate points corresponding to the same point in a three-dimensional space as space candidate points, a step of selecting a pair of two space candidate points from the extracted space candidate points and calculating a distance between the selected pair, a step of excluding a pair of space candidate points where the calculated distance is not within a specified range, and a step of determining one or more pairs of space candidate points from the pairs not excluded and determining that a pair of pupils of the subject exist at the positions.
    Type: Application
    Filed: May 24, 2013
    Publication date: October 8, 2015
    Inventor: Yoshinobu Ebisawa
  • Patent number: 9135708
    Abstract: A gaze point detection device 1 comprises two stereo cameras 2a, 2b for acquiring a face image of a subject A, light sources 3a, 3b disposed on the outside of apertures 9a, 9b, a control circuit 4, 5, 6, and an image processor 7. The image processor 7 calculates a vector r from a corneal reflection point to a pupil on a plane perpendicular to reference lines of the stereo cameras 2a, 2b, computes an angle ? of lines of sight of the subject A with respect to the respective reference lines by using a function f1, corrects the function f1 such that directions of lines of sight are closer to each other, and calculates the line of sight directions to detect a gaze point Q on a display screen.
    Type: Grant
    Filed: August 9, 2011
    Date of Patent: September 15, 2015
    Assignee: NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20130329957
    Abstract: A gaze point detection device 1 has four cameras 2a, 2b, 2c, 2d, light sources 3a, 3b, 3c, 3d, control circuits 4, 5, 6, and an image processor 7. The image processor 7 calculates vectors r, each of which is from a corneal reflection point to the center of a pupil, on a plane that is vertical to base lines. The image processor 7 also calculates angles ? of the line of sight on the basis of the vectors r and by using a function f including M parameters. Moreover, the image processor 7 determines the M parameters based on the angles ?, and detects a point of gaze Q based on the line of sight direction calculated using the determined parameters. The number of cameras is set at M×1/2 or higher.
    Type: Application
    Filed: December 7, 2011
    Publication date: December 12, 2013
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20130188834
    Abstract: A gaze point detection device 1 comprises two stereo cameras 2a, 2b for acquiring a face image of a subject A, light sources 3a, 3b disposed on the outside of apertures 9a, 9b, a control circuit 4, 5, 6, and an image processor 7. The image processor 7 calculates a vector r from a corneal reflection point to a pupil on a plane perpendicular to reference lines of the stereo cameras 2a, 2b, computes an angle ? of lines of sight of the subject A with respect to the respective reference lines by using a function f1, corrects the function f1 such that directions of lines of sight are closer to each other, and calculates the line of sight directions to detect a gaze point Q on a display screen.
    Type: Application
    Filed: August 9, 2011
    Publication date: July 25, 2013
    Inventor: Yoshinobu Ebisawa
  • Patent number: 8371693
    Abstract: An autism diagnosis support apparatus 1 according to the present invention is an autism diagnosis support apparatus that detects a symptom of autism based on a state of a subject looking at a target, including: an eye-gaze point detection unit 2 that detects a line-of-sight direction of the subject looking at the target; a color camera 3 that takes an image of the target; a pupil position detection unit 4 that measures a pupil coordinate of the target; and a data analysis unit 7 that calculates a relationship between the line-of-sight direction of the subject and a pupil position of the target using the line-of-sight direction and the pupil coordinate and outputs the relationship along with the image of the target.
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: February 12, 2013
    Assignee: National University Corporation Shizuoka University
    Inventor: Yoshinobu Ebisawa
  • Patent number: 8358337
    Abstract: A pupil detection device includes a camera, a light source disposed at the camera, an optical system, and an image processing system, which are disposed so that the examinee's face is irradiated with the light from the light source from the camera, and a face image including a pupil is formed in the camera. The light source includes a first light source, having a first wavelength that makes a bright pupil image by reflection in the examinee's pupil, and a second light source having a second wavelength that makes a dark pupil image by reflection in the examinee's pupil, but otherwise exhibiting the same illumination effect as the first light source. The camera includes a first image data acquisition system using the first illumination light source, and a second image data acquisition system using the second illumination light source.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: January 22, 2013
    Assignee: National University Corporation Shizuoka University
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20110242486
    Abstract: An autism diagnosis support apparatus 1 according to the present invention is an autism diagnosis support apparatus that detects a symptom of autism based on a state of a subject looking at a target, including: an eye-gaze point detection unit 2 that detects a line-of-sight direction of the subject looking at the target; a color camera 3 that takes an image of the target; a pupil position detection unit 4 that measures a pupil coordinate of the target; and a data analysis unit 7 that calculates a relationship between the line-of-sight direction of the subject and a pupil position of the target using the line-of-sight direction and the pupil coordinate and outputs the relationship along with the image of the target.
    Type: Application
    Filed: March 29, 2011
    Publication date: October 6, 2011
    Inventor: Yoshinobu EBISAWA
  • Patent number: 7766479
    Abstract: A gaze point detecting device 1 detects a gaze point of an object person by projecting a display image displayed by an LCD 8 to outside via a finder 4 and capturing an eye image of the object person by a CCD 11 in response to illumination light irradiated toward outside from the finder 4, and the device comprises an optical system 5 arranged spaced only a focal length apart from a display surface 8a on an optical path of an image displaying optical system between the LCD 8 and the finder 4; the optical system 5 being arranged on an optical path of an imaging optical system between the finder 4 and the CCD 11; a telecentric optical system including a diaphragm 9 arranged spaced only a focal length apart from the optical system 5 on the optical path; and a controller 3 that detects a position of the gaze point of the object person based on the eye image captured by the CCD 11.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: August 3, 2010
    Assignee: National University Corporation Shizuoka University
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20090219386
    Abstract: The pupil detection device according to the present invention includes a camera means C, a light source L, an optical path forming means, and a calculation means, which are disposed in a manner to retain the relation by means of the optical path forming means, such that the examinee's face is irradiated with the light from the light source from an aperture of the camera means, and that a face image including a pupil EB is formed in the above camera means. The formed image data is calculated to detect the pupil. The above light source L includes a first illumination light source, having a first wavelength light component to make a bright pupil by reflection in the examinee's pupil, and a second illumination light source having a second wavelength light component to make a dark pupil by reflection in the examinee's pupil and exhibiting the same illumination effect as the first illumination light source except for the pupil.
    Type: Application
    Filed: August 22, 2006
    Publication date: September 3, 2009
    Applicant: NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20090219484
    Abstract: A gaze point detecting device 1 detects a gaze point of an object person by projecting a display image displayed by an LCD 8 to outside via a finder 4 and capturing an eye image of the object person by a CCD 11 in response to illumination light irradiated toward outside from the finder 4, and the device comprises an optical system 5 arranged spaced only a focal length apart from a display surface 8a on an optical path of an image displaying optical system between the LCD 8 and the finder 4; the optical system 5 being arranged on an optical path of an imaging optical system between the finder 4 and the CCD 11; a telecentric optical system including a diaphragm 9 arranged spaced only a focal length apart from the optical system 5 on the optical path; and a controller 3 that detects a position of the gaze point of the object person based on the eye image captured by the CCD 11.
    Type: Application
    Filed: March 7, 2007
    Publication date: September 3, 2009
    Inventor: Yoshinobu Ebisawa
  • Patent number: 7533989
    Abstract: Method and device for detecting a line-of-sight of a subject and a three-dimensional view-point measurement device. The method uses a first camera, that measures the position of a pupil relative to a coordinate system, a second camera having a light source arranged at a known position in the coordinate system, and forming a corneal reflection center to obtain data of a size of vector r from the corneal reflection center to the pupil center and an angle ? of the vector r relative to a coordinate axis of the coordinate system, and a calculation means for calculating a line-of-sight direction based on information from each camera. In determining a relational formula, a subject is made to gaze at a known point to perform measurement and a relational formula is determined. In a line-of-sight determining stage, the subject is measured again using the relational formula.
    Type: Grant
    Filed: December 24, 2004
    Date of Patent: May 19, 2009
    Assignee: National University Corporation Shizuoka University
    Inventor: Yoshinobu Ebisawa
  • Patent number: 7533988
    Abstract: An object of the present invention is, when determining a line-of-sight vector of a subject, to identify a three-dimensional position of a pupil center or corneal reflection center thereof. The line-of-sight vector is determined by measuring a distance from a camera to the pupil center or corneal reflection center of the subject using a two-dimensional CMOS distance image sensor by a light time-of-flight method and obtaining position information of the pupil center and corneal reflection center of the subject using the distance image sensor. If a position and a direction of the camera are identified, a camera-pupil center vector is determined from image information of the pupil center of the subject. Since the camera-pupil center distance has been measured, a pupil center position in a three-dimensional space is determined from the above information. Combining this with two line-of-sight vectors determines a position where line-of-sight vectors intersect, or a view-point.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: May 19, 2009
    Assignee: National University Corporation Shizuoka University
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20070279590
    Abstract: A method and device for detecting a line-of-sight of a subject and a three-dimensional view-point measurement device are provided. The method for detecting a line-of-sight uses a first camera 10, 11 that measure the position of a pupil relative to a coordinate system, a second camera 12 having a light source arranged at a known position in the coordinate system and forming a corneal reflection center to obtain data of a size of vector r from the corneal reflection center to the pupil center and an angle ? of the vector r relative to a coordinate axis of the coordinate system, and a calculation means for calculating a line-of-sight direction based on information from each of the cameras. In a stage of determining a relational formula, a subject is made to gaze at a known point to perform measurement and a relational formula is determined. In a stage of determining a line-of-sight, the subject is measured again to determine the line-of-sight using the relational formula.
    Type: Application
    Filed: December 24, 2004
    Publication date: December 6, 2007
    Inventor: Yoshinobu Ebisawa
  • Publication number: 20070014552
    Abstract: An object of the present invention is, when determining a line-of-sight vector of a subject, to identify a three-dimensional position of a pupil center or corneal reflection center thereof. The line-of-sight vector is determined by measuring a distance from a camera to the pupil center or corneal reflection center of the subject using a two-dimensional CMOS distance image sensor by a light time-of-flight method and obtaining position information of the pupil center and corneal reflection center of the subject using the distance image sensor. If a position and a direction of the camera are identified, a camera-pupil center vector is determined from image information of the pupil center of the subject. Since the camera-pupil center distance has been measured, a pupil center position in a three-dimensional space is determined from the above information. Combining this with two line-of-sight vectors determines a position where line-of-sight vectors intersect, or a view-point.
    Type: Application
    Filed: August 15, 2006
    Publication date: January 18, 2007
    Inventor: Yoshinobu Ebisawa