COORDINATE DETECTION SYSTEM, INFORMATION PROCESSING APPARATUS, METHOD OF DETECTING COORDINATE, AND PROGRAM

• US 20150241997A1
• Filed: 02/17/2015
• Published: 08/27/2015
• Est. Priority Date: 02/25/2014
• Status: Abandoned Application

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: ONO, Yasuhiro
• Application Number:
  US14/623,910
• Publication Number:
  US 20150241997A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0308 comprising a plurality of distinctive and separately oriented light emitters or reflectors associated to the pointing device, e.g. remote cursor controller with distinct and separately oriented LEDs at the tip whose radiations are captured by a photo-detector associated to the screen
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A coordinate detection system for detecting a coordinate pointed by a pointer with which a pointing operation is performed on a board face includes a first calculation unit that extracts a plurality of areas respectively indicative of a plurality of annular members provided in the pointer from a picked-up image picked by an image pick-up unit arranged at a predetermined position of the board face and calculates center positions of the extracted areas; and a second calculation unit that calculates a position of a tip portion of the pointer on the board face based on the center positions of the areas calculated by the first calculation unit and a position of a principal point of the image pick-up unit.

Claims

1. A coordinate detection system for detecting a coordinate pointed by a pointer with which a pointing operation is performed on a board face, the coordinate detection system comprising:

a first calculation unit that extracts a plurality of areas respectively indicative of a plurality of annular members provided in the pointer from a picked-up image picked by an image pick-up unit arranged at a predetermined position of the board face and calculates center positions of the extracted areas; and

a second calculation unit that calculates a position of a tip portion of the pointer on the board face based on the center positions of the areas calculated by the first calculation unit and a position of a principal point of the image pick-up unit.

2. The coordinate detection system according to claim 1, further comprising:

a correction unit that corrects the center positions of the areas calculated by the first calculation unit based on a lens distortional property of the image pick-up unit.

3. The coordinate detection system according to claim 1,

wherein the first calculation unit calculates a barycentric positions in the areas as the center positions.

4. The coordinate detection system according to claim 2,

wherein the second calculation unit calculates a plane including a coordinate of a pixel on a sensor of the image pick-up unit specified in a three-dimensional coordinate space based on the center positions of the areas corrected by the correction unit and a coordinate of the principal point of the image pick-up unit in the three-dimensional coordinate space, and calculates a position of the tip portion of the pointer based on the calculated plane.

5. The coordinate detection system according to claim 1,

wherein the annular members of the pointer are arranged in perpendicular to a predetermined axis,

wherein the predetermined axis is arranged so as to conform with the center points of the annular members.

6. An information processing apparatus for controlling a coordinate input apparatus having a board face, on which a pointing operation is performed by a pointer, the information processing apparatus comprising:

a first calculation unit that extracts a plurality of areas respectively indicative of a plurality of annular members provided in the pointer from a picked-up image picked by an image pick-up unit arranged at a predetermined position of the board face and calculates center positions of the extracted areas; and

a second calculation unit that calculates a position of a tip portion of the pointer on the board face based on the center positions of the areas calculated by the first calculation unit and a position of a principal point of the image pick-up unit.

7. The information processing apparatus according to claim 6, further comprising:

a correction unit that corrects the center positions of the areas calculated by the first calculation unit based on a lens distortional property of the image pick-up unit.

8. The information processing apparatus according to claim 6,

wherein the first calculation unit calculates a barycentric positions in the areas as the center positions.

9. The information processing apparatus according to claim 7,

wherein the second calculation unit calculates a plane including a coordinate of a pixel on a sensor of the image pick-up unit specified in a three-dimensional coordinate space based on the center positions of the areas corrected by the correction unit and a coordinate of the principal point of the image pick-up unit in the three-dimensional coordinate space, and calculates a position of the tip portion of the pointer based on the calculated plane.

10. A computer-readable recording medium with a program recorded thereon, the program being executed by a processor in an information processing apparatus for controlling a coordinate input apparatus having a board face, on which a pointing operation is performed by a pointer, wherein the program is executed by the processor to cause the information processing apparatus to implement:

a first calculation unit that extracts a plurality of areas respectively indicative of a plurality of annular members provided in the pointer from a picked-up image picked by an image pick-up unit arranged at a predetermined position of the board face and calculates center positions of the extracted areas; and

a second calculation unit that calculates a position of a tip portion of the pointer on the board face based on the center positions of the areas calculated by the first calculation unit and a position of a principal point of the image pick-up unit.