ENHANCED INPUT USING FLASHING ELECTROMAGNETIC RADIATION

• US 20080205701A1
• Filed: 02/15/2008
• Published: 08/28/2008
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: GestureTek Incorporated (Winning Brands Corp.)
• Inventors: MacDougall, Francis, Shamaie, Atid
• Granted Patent: US 8,116,518 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 3/042 by opto-electronic means
• 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: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 40/28 Recognition of hand or arm movements, e.g. recognition of deaf sign language static hand signs G06V40/113

Abstract

Enhanced input using flashing electromagnetic radiation, in which first and second images, captured on a first side of a screen, of an object and an ambient electromagnetic radiation emitter disposed on a second side of the screen, are accessed. The first image being captured while the object is illuminated with projected electromagnetic radiation, and the second image being captured while the projected electromagnetic radiation is extinguished. A position of the object relative to the screen based on coniparing the first and second images is determined. An application is controlled based on the determined position.

Claims

1. A computer-implemented method comprising:

accessing first and second images, captured on a first side of a screen, of an object and an ambient electromagnetic radiation emitter disposed on a second side of the screen, the first image being captured while the object is illuminated with projected electromagnetic radiation, and the second image being captured while the projected electromagnetic radiation is extinguished;

determining a position of the object relative to the screen based on comparing the first and second images; and

controlling an application based on the determined position.

2. The method of claim 1, further comprising projecting electromagnetic radiation as a first light curtain along and parallel to the second side of the screen.

3. The method of claim 2, further comprising:

projecting electromagnetic radiation as a second light curtain adjacent and parallel to the second side of the screen, the first light curtain and the second light curtain being parallel to each other and disposed at a first location and a second location with respect to the second side of the screen.

4. The method of claim 1, wherein the object comprises a portion of a body of a person.

5. The method of claim 1, further comprising determining a second position, and wherein the application is controlled based on the determined position and the second position.

6. The method of claim 1, wherein determining a position of the object relative to the screen based on comparing the first and second images comprises subtracting the first and second images to create a difference image.

7. The method of claim 6, wherein determining a position of the object relative to the screen comprises determining the location of the object in the difference image.

8. The method of claim 1, wherein controlling an application based on the determined position comprises controlling a cursor.

9. The method of claim 1, wherein the projected electromagnetic radiation comprises infrared radiation.

10. The method of claim 1, wherein a visible image is projected onto the screen, the object is in motion, and controlling an application based on the determined position comprises controlling a cursor on the visible image such that motion of the cursor corresponds to the motion of the object.

11. The method of claim 10 wherein the motion of the object comprises a gesture made by a person.

12. The method of claim 1, wherein accessing first and second images comprises accessing first and second images of an object and a second object, the object and the second object disposed on the same side of the screen, and further comprising determining a position of a second object relative to the screen.

13. The method of claim 1, further comprising modeling a shadow cast on the screen, the shadow cast by the object while the object is illuminated with the projected electromagnetic radiation.

14. The method of claim 13, further comprising determining, based on the model, that the shadow obscures a second object and wherein determining a position of the second object relative to the screen comprises accounting for the shadow.

15. A system comprising:

a translucent screen comprising a first side and a second side;

a source of electromagnetic radiation, the source configured to alternate between emitting the electromagnetic radiation and extinguishing the electromagnetic radiation at a rate of flashing;

a sensor positioned on a first side of the screen and configured to sense electromagnetic radiation at the rate of flashing, the electromagnetic radiation reflected from an object disposed in the vicinity of the screen on the second side of the screen; and

a processor configured to;

determine a position of the object based on the sensed electromagnetic radiation, and

control an application based on the determined position of the object.

16. The system of claim 15, wherein:

the screen comprises edges, and

the source of electromagnetic radiation comprises a linear array of emitters positioned along one or more of the edges of the screen such that electromagnetic radiation is projected on the, and parallel to, the second side of the screen.

17. The system of claim 16, wherein the screen comprises a parallelogram.

18. The system of claim 15, wherein the source of electromagnetic radiation comprises a series of linear arrays of emitters, each of the linear arrays positioned on the second side of the screen at a distance from a surface of the screen.

19. The system of claim 15, wherein the source of electromagnetic energy emits diverging electromagnetic energy, and further comprising a channel adjacent to the source, the channel configured to collimate the emitted electromagnetic energy.

20. The system of claim 19, wherein the channel comprises a block of material with a passageway extending through the block from an entry to an exit, the diverging electromagnetic energy impinging on the entry and a portion of the diverging electromagnetic energy emerging from the exit as collimated electromagnetic energy.

21. The system of claim 19, wherein the channel comprises a lens.

22. The system of claim 15, wherein the source of electromagnetic radiation comprises an emitter positioned on the first side of the screen and the electromagnetic radiation passes through the screen and interacts with the object.

23. The system of claim 15, wherein the source of electromagnetic radiation comprises a light emitting diode.

24. The system of claim 23, wherein the light emitting diode emits infrared radiation.

25. The system of claim 15, wherein the sensor comprises an array of pixels.

26. The system of claim 15, wherein the processor is further configured to model a shadow cast by the object and determine a position of a second object disposed on the second side of the screen based on the modeled shadow.

27. A computer program product, tangibly embodied in a machine-readable medium, the computer program product comprising instructions that, when read by a machine, operate to cause a data processing apparatus to:

access first and second images, captured on a first side of a screen, of an object and an ambient electromagnetic radiation emitter disposed on a second side of the screen, the first image being captured while the object is illuminated with projected electromagnetic radiation, and the second image being captured while the projected electromagnetic radiation is extinguished;

determine a position of the object relative to the screen based on comparing the first and second images; and

control an application based on the determined position.