Interactive video display system using strobed light

• US 20080062123A1
• Filed: 10/31/2007
• Published: 03/13/2008
• Est. Priority Date: 06/05/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Reactrix Systems Incorporated
• Inventors: Bell, Matthew
• Granted Patent: US 8,300,042 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• 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 23/20 for generating image signals from infrared radiation only
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

An interactive video display system uses strobing light to allow easy and unencumbered interaction between a person and projected video images. A camera may be synchronized to the strobing light and the strobing light may be in an infrared spectral range. A processing system detects images of a human in the field of view of the camera and controls the display so that the projected video images are changed based on an interaction between the human and the projected video images. The system may project the video images on a surface around the person and may move the projected video images on the surface based on a movement of the person. The projected video images may include computer-generated characters and/or virtual objects that react to the movement of a person.

Claims

1. An interactive video display system comprising:

a display configured to project video images onto a surface;

a strobing lamp configured to illuminate the surface using strobed light;

a camera having exposures synchronized to the strobed light, the camera configured to have a field of view that includes the surface; and

a processing system configured to detect images of a human in the field of view using the camera, and to control the display so that the projected video images are changed based on an interaction between the human and the projected video images.

2. The system of claim 1 wherein the strobed light illuminates the surface during every second camera exposure.

3. The system of claim 1 wherein an output power of the strobing lamp is controlled by the processing system, such that the brightness of the strobing lamp is greater than a continuous-duty brightness limitation of the strobing lamp.

4. The system of claim 1 wherein the strobed light is not visible to the human eye.

5. The system of claim 1 wherein the strobed light is in an infrared spectral range.

6. The system of claim 1 wherein the processing system is further configured to determine the interaction in part by subtracting each pixel in a first camera image provided when the strobing light is on from a corresponding pixel in a second camera image provided when the strobing light is off.

7. The system of claim 1 wherein the camera is an interlaced charged-coupled display camera and the strobing lamp is configured to illuminate the surface during an exposure of a first field of the interlaced charged-coupled display camera and not illuminate the surface during an exposure of a second field of the interlaced charged-coupled display camera.

8. The system of claim 7 wherein the processing system is further configured to determine the interaction in part by subtracting each pixel in the first field from a corresponding pixel in the second field.

9. The system of claim 1 further comprising a bandpass filter disposed in front of the camera, the bandpass filter configured to pass the light of the strobing lamp and to attenuate ambient light.

10. The system of claim 1 wherein the processing system is further configured to generate the projected video images using an adaptive model of a background that analyzes changes in images from the camera over time.

11. The system of claim 10 wherein the processing system is further configured to generate the adaptive model of the background by generating a model image from the images from the camera, the pixels in the model image belonging to either a foreground or the background.

12. The system of claim 1 wherein the surface is a substantially horizontal surface configured to support the human while standing.

13. A method for displaying an interactive video image comprising:

projecting video images onto a surface;

illuminating the surface using strobed light;

synchronizing camera exposures to the strobed light, the camera configured to have a field of view that includes the surface;

detecting images of a human in the field of view using the camera; and

changing the projected video images based on an interaction between the human and the projected video images.

14. The method of claim 13 wherein the projected video images have a physical location on the surface that is around the human.

15. The method of claim 14 wherein changing the projected video images includes moving the projected video images on the surface based on a movement of the human.

16. The method of claim 13 wherein the projected video images include virtual objects that react to the movements of the human.

17. The method of claim 13 wherein the strobed light is in an infrared spectral range.

18. The method of claim 13 wherein changing the projected video images includes using an adaptive model of a background that analyzes changes in images from the camera over time.

19. The method of claim 18 further comprising generating the adaptive model of the background by generating a model image from the images from the camera, the pixels in the model image belonging to either a foreground or the background.

20. The method of claim 13 further comprising determining the interaction in part by subtracting each pixel in a first camera image provided when the strobing light is on from a corresponding pixel in a second camera image provided when the strobing light is off.

21. The method of claim 13 further comprising:

illuminating the surface during an exposure of a first field of the camera; and

not illuminating the surface during an exposure of a second field of the camera.

22. The method of claim 21 further comprising subtracting each pixel in the first field from a corresponding pixel in the second field.

23. An interactive video display system comprising:

means for projecting video images onto a surface;

means for illuminating the surface using strobed light;

means for capturing images in a field of view including the surface, the means for capturing images having exposures synchronized to the strobed light;

means for detecting images of a human in the captured images; and

means for changing the projected video images based on an interaction between the human and the projected video images.

24. The system of claim 23 wherein the strobed light in an infrared spectral range.

25. The system of claim 23 wherein the surface is a substantially horizontal surface configured to support the human while standing.