Device using a camera and light polarization for the remote displacement of a cursor on a display

• US 20060023111A1
• Filed: 07/26/2005
• Published: 02/02/2006
• Est. Priority Date: 07/28/2004
• Status: Active Grant

• Current Assignee: University of Maryland
• Original Assignee: University of Maryland
• Inventors: DeMenthon, Daniel
• Granted Patent: US 7,542,072 B2
• Time in Patent Office: Days
• US Class Current: 348/360
• 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 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors

Abstract

A system and method is provided for imaging a screen of a display device, including filtering light emitted or reflected from the screen and a background region in proximity to the screen using first and second polarizing angles; sensing the filtered light; and generating at least one image set corresponding to the sensed filtered light. Each image set includes at least one image having a first plurality of pixels corresponding to the sensed filtered light using the first polarizing angle and a second plurality of pixels corresponding to the sensed filtered light using the second polarizing angle.

Claims

1. A system for imaging a screen of a display device comprising:

a photo sensor array sensing incident light emitted or reflected from the screen and a background region near the screen and generating at least one image set corresponding to the sensing; and

at least one polarizing filter including at least first and second polarizing regions for filtering light incident on the photo sensor array, wherein the first and second polarizing regions have first and second polarizing angles, respectively;

wherein each image set of the at least one image set includes at least one image having a first plurality of pixels corresponding to the sensing of incident light filtered by the first polarizing region and a second plurality of pixels corresponding to the sensing of incident light filtered by the second polarizing region.

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

at least one processor; and

at least one storage device storing a series of programmable instructions accessible and executable by the at least one processor for;

processing an image set of the at least one image set for computing intensity differentials between first and second pixels of respective pixel pairs of the image set, wherein for each pixel pair the first pixel corresponds to incident light filtered by the first polarizing region and the second pixel corresponds to incident light filtered by the second polarizing region.

3. The system according to claim 2, wherein the execution of the series of programmable instructions further provides for:

determining intensity differentials of the computed intensity differentials for the processed image set that satisfy a condition;

detecting at least one feature of the screen in the processed image set by detecting a pattern established by at least a portion of the pixel pairs that correspond to the determined intensity differentials, wherein the pattern corresponds to at least one feature of the screen in the processed image set; and

determining a location of the at least one detected feature of the screen in the processed image set.

4. The system according to claim 3, wherein the at least one feature includes at least a portion of respective edges of the screen.

5. The system according to claim 3, wherein the execution of the series of programmable instructions further provides for determining a region of the processed image set that corresponds to the screen in accordance with the determined location of the at least one detected feature of the screen.

6. The system according to claim 5, wherein the execution of the series of programmable instructions further provides for:

recognizing characters in the determined region of the processed image set that corresponds to the screen; and

generating corresponding digital representations of the recognized characters.

7. The system according to claim 3, wherein the execution of the series of programmable instructions further provides for tracking movement of the at least one detected feature in the at least one image set;

and

further comprising a communication device for providing tracking information indicative of the tracked movement to a processing device associated with the display device for controlling the position of a position indicator provided on a graphical user interface (GUI) displayed on the screen of the display device in accordance with the tracked movement of the at least one detected feature.

8. The system according to claim 1, wherein:

respective image sets of the at least one image set include first and second consecutively acquired images, wherein the first acquired image includes the first plurality of pixels and the second acquired image includes the second plurality of pixels; and

the at least one filter includes a first filter including the first polarizing region and a second filter including the second polarizing region.

9. The system according to claim 1, wherein:

respective image sets of the at least one image set include one image; and

the at least one filter includes a single filter, with the first and second polarizing regions arranged in a pattern on the single filter.

10. The system according to claim 2, wherein:

the at least one filter include a single filter, with the at least first and second polarizing regions arranged in a pattern on the single filter, the pattern including a plurality of boundaries between the first and second polarizing regions; and

respective image sets of the at least one image set include one image;

the first and second pixels of the respective pixel pairs are proximate to one another in the image, wherein the first pixel corresponds to light filtered by the first polarizing region on a first side of a boundary of the plurality of boundaries and the second pixel corresponds to light filtered by the second polarizing region on a second side of the boundary of the plurality of boundaries.

11. The system according to claim 10, wherein the first and second pixels of the respective pixel pairs are nearly adjacent to one another in the image.

12. The system according to claim 1, wherein the difference between the first and second polarizing angles is 90 degrees.

13. The system according to claim 10, wherein the single filter further comprises third and fourth polarizing regions having third and fourth polarization angles, wherein the pattern on the single filter includes a plurality of boundaries between the third and fourth polarizing regions.

14. The system according to claim 13, wherein the difference between the third and fourth polarizing angles is 90 degrees.

15. The system according to claim 13, wherein the difference between the first and third polarizing angles is 45 degrees.

16. The system according to claim 10, wherein the pattern includes a plurality of sectors, with respective adjacent sectors of the plurality of sectors corresponding to different regions of the at least first and second polarizing regions.

17. The system according to claim 16, wherein the plurality of sectors are arranged concentrically.

18. The system according to claim 10, wherein the pattern includes a checkerboard arrangement of a plurality of shapes, with respective adjacent shapes corresponding to different regions of the at least first and second polarizing regions.

19. A method for imaging a screen of a display device comprising the steps of:

filtering light emitted or reflected from the screen and a background region in proximity to the screen using first and second polarizing angles;

sensing the filtered light; and

generating at least one image set corresponding to the sensed filtered light;

wherein each image set includes at least one image having a first plurality of pixels corresponding to the sensed filtered light using the first polarizing angle and a second plurality of pixels corresponding to the sensed filtered light using the second polarizing angle.

20. The method according to claim 19, further comprising processing an image set of the at least one image set for computing respective intensity differentials between first and second pixels of respective pixel pairs of the image set, wherein for each pair of pixels the first pixel corresponds to incident light filtered using the first polarizing angle and the second pixel corresponds to incident light filtered using the second polarizing angle.

21. The method according to claim 20, further comprising the steps of:

determining intensity differentials of the computed intensity differentials for the processed image set that satisfy a condition;

detecting at least one feature of the screen in the processed image set including detecting a pattern established by at least a portion of the pixel pairs that correspond to the determined intensity differentials, wherein the pattern corresponds to at least one feature of the screen in the processed image set; and

determining a location of the at least one feature of the screen in the processed image set.

22. The method according to claim 21, wherein the at least one feature includes at least a portion of respective edges of the screen.

23. The method according to claim 21, further comprising the step of determining a region of the processed image set that corresponds to the screen in accordance with the determined location of the at least one feature of the screen.

24. The method according to claim 23, further comprising the steps of:

recognizing characters in the determined region of the image set that corresponds to the screen; and

generating corresponding digital representations of the recognized characters.

25. The method according to claim 21, further comprising the steps of:

tracking movement of the at least one detected feature in the at least one image set; and

transmitting tracking information indicative of the tracked movement to a processing device associated with the display device for controlling the position of a position indicator provided on a graphical user interface (GUI) displayed on the screen of the display device in accordance with the tracked movement of the at least one detected feature.

26. A system for remotely controlling a cursor displayed on a graphical user interface (GUI) displayed on a screen of a display device, said system comprising:

a polarizing filter including at least first and second polarizing regions arranged in an arrangement for filtering light, wherein the first and second polarizing regions have first and second polarizing angles, respectively;

a photo sensor array sensing incident light emitted or reflected from the screen and a background region in proximity to the screen, said incident light being filtered by the first and second polarizing regions, said photo sensor array generating at least one image corresponding to the sensed incident light;

at least one processor;

at least one storage device accessible by the at least one processor and storing a series of programmable instructions executable by the at least one processor for;

comparing intensities between first and second pixels of respective pixel pairs of an image of the at least one image, wherein the first pixel corresponds to incident light filtered by the first polarizing region and the second pixel corresponds to incident light filtered by the second polarizing region;

determining a location of at least one feature of the screen in the image based on the intensity comparisons of the respective pixel pairs; and

tracking movement of the location of the at least one feature in at least two images of the at least one image; and

a communication device for transmitting tracking information indicative of the tracked movement to a processing device associated with the display device for controlling the position of a position indicator provided on a GUI displayed on the screen of the display device in accordance with the tracked movement of the location of the at least one feature.

27. The system according to claim 26, wherein the comparing step comprises computing a difference between the intensities of the first and second pixels.

28. The system according to claim 27, wherein the determining step comprises:

determining intensity differentials of the computed intensity differentials that satisfy a condition; and

detecting a pattern formed by at least a portion of the pixel pairs that correspond to the determined intensity differentials, wherein the pattern corresponds to at least one feature of the screen in the image.

29. The system according to claim 26, wherein the arrangement includes a plurality of boundaries between the at least first and second polarizing regions, and the first and second pixels of the respective pixel pairs are proximate to one another in the image and are located on opposite sides of a respective boundary of the plurality of boundaries.

30. The system according to claim 29, wherein the proximate first and second pixels of the respective pixel pairs are nearly adjacent to one another.

31. The system according to claim 26, wherein the difference between the first and second polarizing angles is 90 degrees.