Pointer light tracking method, program, and recording medium thereof

• US 8,049,721 B2
• Filed: 02/09/2006
• Issued: 11/01/2011
• Est. Priority Date: 02/10/2005
• Status: Expired due to Fees

• Current Assignee: Lunascape Corporation (MEDIA DO Co., Ltd.)
• Original Assignee: Lunascape Corporation (MEDIA DO Co., Ltd.)
• Inventors: Tagawa, Kinya
• Primary Examiner(s): Lao; Lun-Yi
• Assistant Examiner(s): MERKOULOVA, OLGA VLADIMIROVNA
• Application Number:
  US11/816,033
• Publication Number:
  US 20090021480A1
• Time in Patent Office: 2,091 Days
• Field of Search: 345/158, 345/157, 345/179, 702/145, 702/95, 178/19.05
• US Class Current: 345/158
• CPC Class Codes: G03B 17/54 with projector
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A pointer light tracking method wherein all black image and white square images located at four corners of the all black image are projected on the display, the display on which the all black image and the white square images are displayed is shot by a camera, a domain corresponding to the white square image is extracted from the obtained image data, central coordinates (x, y) of the extracted domain are computed, and a parameter necessary in performing distortion correction by use of projection conversion for coordinate expressing the position of the pointer light on the display is computed from the computed central coordinates (x, y) and central coordinates (X, Y) of the white square image.

Claims

1. A pointer light tracking method of shooting pointer light projected on a display with a camera to obtain image data and tracking the pointer light projected on the display with a computer based on the obtained image data, the method comprising the steps of:

projecting an all black image and white square images located at four corners of the all black image on the display;

storing central coordinates (X1, Y1)-(X4, Y4) of the four white square images;

shooting with the camera the display where the all black image and the four white square images are displayed;

extracting four domains corresponding to the four white square images from image data obtained from the camera;

computing central coordinates (x1, y1)-(x4, y4) of the extracted four domains;

computing parameters for performing distortion correction using projection conversion for a coordinate expressing a position of the pointer light on the display based on the computed central coordinates (x1, y1)-(x4, y4) and the central coordinates (X1, Y1)-(X4, Y4) of the four white square images;

shooting the display that displays only the pointer light and a presentation image;

adjusting at least one of a shutter speed, exposure, or gamma value of the camera shooting the display displaying both the pointer light and the presentation image to obtain pointer light image data where only the pointer light is strongly displayed.

2. The pointer light tracking method according to claim 1, further comprising the step of performing gradation processing for the obtained pointer light image data to enlarge a domain of light spot of the pointer light contained in the obtained pointer light image data.

3. A non-transitory computer-readable storage medium storing a pointer light tracking program executable by a computer for tracking pointer light projected on a display where an all black image and white square images located at four corners of the all black image are projected based on an image data obtained by shooting with a camera the pointer light projected on the display, the program comprising computer instructions for:

storing central coordinates (X1, Y1)-(X4, Y4) of the four white square images;

shooting with camera the display where the all black image and the four white square images located with the projected pointer light are displayed;

extracting four domains corresponding to the four white square images from the image data obtained from the camera;

computing central coordinates (x1, y1)-(x4, y4) of the extracted four domains;

computing a parameters for performing distortion correction using projection conversion for a coordinate expressing a position of the pointer light on the display based on the computed central coordinates (x1, y1)-(x4, y4) and the central coordinates (X1, Y1)-(X4, Y4) of the four white square images;

shooting the display that displays only the pointer light and a presentation image;

adjusting at least one of a shutter speed, exposure, or gamma value of the camera shooting the display displaying both the pointer light and the presentation image to obtain pointer light image data where only the pointer light is strongly displayed.

4. The non-transitory computer-readable storage medium according to claim 3, wherein the program further comprises computer instructions for performing gradation processing for the obtained pointer light image data to enlarge a domain of light spot of the pointer light contained in the obtained pointer light image data.