Position Detection System, Position Detection Method, Program, Object Determination System and Object Determination Method

• US 20090252375A1
• Filed: 04/01/2009
• Published: 10/08/2009
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: REKIMOTO, Junichi
• Granted Patent: US 8,897,499 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• 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: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

There is provided a position detection system including an imaging unit to capture an image of a projection plane of an electromagnetic wave, an electromagnetic wave emission unit to emit the electromagnetic wave to the projection plane, a control unit to control emission of the electromagnetic wave by the electromagnetic wave emission unit, and a position detection unit including a projected image detection section to detect a projected image of an object existing between the electromagnetic wave emission unit and the projection plane based on a difference between an image of the projection plane captured during emission of the electromagnetic wave fay the electromagnetic wave emission unit and an image of the projection plane captured during no emission of the electromagnetic wave, and a position detection section to detect a position of the object based on a position of the projected image of the object.

Claims

1. A position detection system comprising:

an imaging unit to capture an image of a projection plane of an electromagnetic wave;

an electromagnetic wave emission unit to emit the electromagnetic wave to the projection plane;

a control unit to control emission of the electromagnetic wave by the electromagnetic wave emission unit; and

a position detection unit including a projected image detection section to detect a projected image of an object existing between the electromagnetic wave emission unit and the projection plane based on a difference between an image of the projection plane captured during emission of the electromagnetic wave by the electromagnetic wave emission unit and an image of the projection plane captured during no emission of the electromagnetic wave, and a position detection section to detect a position of the object based on a position of the projected image of the object.

2. The position detection system according to claim 1, wherein

the imaging unit captures a frame image in synchronization with a prescribed synchronizing signal, and

the control unit controls emission of the electromagnetic wave by the electromagnetic wave emission unit in synchronization with the prescribed synchronizing signal.

3. The position detection system according to claim 2, wherein

the electromagnetic wave emission unit includes a first electromagnetic wave emission unit and a second electromagnetic wave emission unit placed in a different position from the first electromagnetic wave emission unit,

the control unit switches among emission of the electromagnetic wave by the first electromagnetic wave emission unit, emission of the electromagnetic wave by the second electromagnetic wave emission unit, and no emission of the electromagnetic wave by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit,

the projected image detection section detects a projected image of the object from a first image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and detects a projected image of the object from a second image captured dining emission of the electromagnetic wave by the second electromagnetic wave emission unit, and

the position detection section detects a spatial position of the object based on positions of the projected images of the object detected from the first image and the second image.

4. The position detection system according to claim 3, wherein

the position detection unit further includes an estimation section to estimate a straight line connecting the first electromagnetic wave emission unit and the projected image of the object based on the position of the projected image of the object detected from the first image and estimate a straight line connecting the second electromagnetic wave emission unit and the projected image of the object based on the position of the projected image of the object detected from the second image, and

the position detection section detects an intersection of the straight lines estimated by the estimation section as the spatial position of the object.

5. The position detection system according to claim 3, wherein

the control unit periodically switches among emission of the electromagnetic wave by the first electromagnetic wave emission unit, emission of the electromagnetic wave by the second electromagnetic wave emission unit, and no emission of the electromagnetic wave by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit, and

the projected image detection section detects the projected image of the object based on a difference between the first image and an image captured during no emission of the electromagnetic wave by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit in the same cycle as the first image, and detects the projected image of the object based on a difference between the second image and an image captured during no emission of the electromagnetic wave by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit in the same cycle as the second image.

6. The position detection system according to one of claims 1 to 5, further comprising:

a filter to transmit a wavelength component of the electromagnetic wave emitted from the electromagnetic wave emission unit, wherein

the imaging unit captures an image of the projection plane through the filter.

7. The position detection system according to one of claims 1 to 5, wherein

the electromagnetic wave emission unit emits infrared rays or visible rays.

8. A position detection method comprising the steps of:

switching between emission and no emission of an imageable electromagnetic wave by an electromagnetic wave emission unit;

capturing an image of a projection plane of the electromagnetic wave emitted from the electromagnetic wave emission unit;

detecting a projected image of an object existing between the electromagnetic wave emission unit and the projection plane based on a difference between an image of the projection plane captured during emission of the electromagnetic wave by the electromagnetic wave emission unit and an image of the projection plane captured during no emission of the electromagnetic wave; and

detecting a position of the object, based on a position of the projected image of the object.

9. A program causing a computer to implement functions comprising:

a control section to switch between emission and no emission of an image able electromagnetic wave by an electromagnetic wave emission unit;

a projected image detection section to detect a projected image of an object existing between the electromagnetic wave emission unit and a projection plane based on a difference between an image of the projection plane captured during emission of the electromagnetic wave by the electromagnetic wave emission unit and an image of the projection plane captured during no emission of the electromagnetic wave, the images being captured by an imaging unit to capture an image of the projection plane of the electromagnetic wave emitted from the electromagnetic wave emission unit; and

a position detection section to detect a position of the object based on a position of the projected image of the object.

10. An object determination system comprising;

a first electromagnetic wave emission unit to emit an electromagnetic wave in a prescribed direction;

a second electromagnetic wave emission unit to emit an electromagnetic wave in a direction to intersect the electromagnetic wave emitted from the first electromagnetic wave emission unit;

an imaging unit to capture an image of an object existing in an intersection range of the electromagnetic wave emitted from the first electromagnetic wave emission unit and the electromagnetic wave emitted from the second electromagnetic wave emission unit, the imaging unit capable of imaging the electromagnetic waves emitted from the first electromagnetic wave emission unit and the second electromagnetic wave emission unit;

a control unit to switch emission of the electromagnetic waves by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit; and

a determination unit including a wave receiving portion detection section to detect a wave receiving portion of the object receiving the electromagnetic wave emitted from the first electromagnetic wave emission unit from a first image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and detect a wave receiving portion of the object receiving the electromagnetic wave emitted from the second electromagnetic wave emission unit from a second image captured during emission of the electromagnetic wave by the second electromagnetic wave emission unit, and a determination section to make a determination about a physical shape of the object according to proximity between the wave receiving portions detected from the first image and the second image.

11. An object determination method comprising the steps of:

switching emission of electromagnetic waves by a first electromagnetic wave emission unit to emit an imageable electromagnetic wave in a prescribed direction and a second electromagnetic wave emission unit to emit an electromagnetic wave in a direction to intersect the electromagnetic wave emitted from the first electromagnetic wave emission unit;

capturing an image of an object existing in an intersection range of the electromagnetic wave emitted from the first electromagnetic wave emission unit and the electromagnetic wave emitted from the second electromagnetic wave emission unit;

detecting a wave receiving portion of the object receiving the electromagnetic wave emitted from the first electromagnetic wave emission unit from a first image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and detecting a wave receiving portion of the object receiving the electromagnetic wave emitted from the second electromagnetic wave emission unit from a second image captured during emission of the electromagnetic wave by the second electromagnetic wave emission unit; and

making a determination about a physical shape of the object according to proximity between the wave receiving portions detected from the first image and the second image.

12. A program causing a computer to implement functions comprising:

a control section to switch emission of electromagnetic waves by a first electromagnetic wave emission unit to emit an imageable electromagnetic wave in a prescribed direction and a second electromagnetic wave emission unit to emit an electromagnetic wave in a direction to intersect the electromagnetic wave emitted from the first electromagnetic wave emission unit;

a wave receiving portion detection section to detect a wave receiving portion of the object receiving the electromagnetic wave emitted from the first electromagnetic wave emission unit from a first image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and detect a wave receiving portion of the object receiving the electromagnetic wave emitted from the second electromagnetic wave emission unit from a second image captured during emission of the electromagnetic wave by the second electromagnetic wave emission unit, the first image and the second image being captured by an imaging unit to capture an image of an object existing in an intersection range of the electromagnetic wave emitted from the first electromagnetic wave emission unit and the electromagnetic wave emitted from the second electromagnetic wave emission unit; and

a determination section to make a determination about a physical shape of the object according to proximity between the wave receiving portions detected from the first image and the second image.

13. A position detection system comprising:

an imaging unit to capture an image of a projection plane of an electromagnetic wave;

a first electromagnetic wave emission unit to emit an electromagnetic wave imageable by the imaging unit to the projection plane;

a second electromagnetic wave emission unit placed in a different position from the first electromagnetic wave emission unit;

a control unit to switch emission of electromagnetic waves by the first electromagnetic wave emission unit and the second electromagnetic wave emission unit; and

a position detection unit including a projected image detection section to detect a projected image of an object existing between the first electromagnetic wave emission unit and the projection plane from a first image captured during emission of the electromagnetic wave by the first electromagnetic wave emission unit and detect a projected image of the object from a second image captured during emission of the electromagnetic wave by the second electromagnetic wave emission unit, and a position detection section to detect a spatial position of the object based on positions of the projected images of the object detected from, the first image and the second image.

14. The position detection system according to claim 13, wherein

the position detection unit further includes an estimation section to estimate a straight line connecting the first electromagnetic wave emission unit and the projected image of the object based on the position of the projected image of the object detected from the first image and estimate a straight line connecting the second electromagnetic wave emission unit and the projected image of the object based on the position of the projected image of the object detected from the second image, and

the position detection section detects an intersection of the straight lines estimated by the estimation section as the spatial position of the object.