Automatic display update of still frame images for videoconferencing

• US 5,990,931 A
• Filed: 04/09/1997
• Issued: 11/23/1999
• Est. Priority Date: 04/10/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Vtel Corporation
• Inventors: Kenoyer, Michael Lee, Nimri, Alain
• Primary Examiner(s): Tung, Bryan
• Assistant Examiner(s): PHILIPPE, GIMS S
• Application Number:
  US08/826,900
• Time in Patent Office: 958 Days
• Field of Search: 348/96, 348/700, 348/701, 348/143, 348/97, 348/15, 348/100, 348/154, 348/409, 348/421, 348/13, 348/14, 353/122, 353/121, 353/112, 353/113, 209/3.3, 40/361, 395/114, 364/189, 345/330, 345/331, 345/332, 709/200.07, 709/200.1
• US Class Current: 348/14.08
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q

Abstract

A method and apparatus to be used for videoconferencing when the presentation is to include displays of documents or other visuals. A camera is focused on the document and detects when the document is being handled by the presenter. It automatically determines when to initially display the document, as well as when to update frames of data representing the document.

Claims

1. A computer-implemented method of using a processor to automatically present graphics slides as still displays on a videoconferencing system, said videoconferencing system having a processor that receives frames of graphics data, comprising the steps of:

detecting a change between a current frame and a previous frame;

comparing any said change to at least one significance criterium to determine whether said current frame should be displayed as a new slide;

repeating the above steps for a next frame without displaying said frame as a new slide, if said significance criterium is not met;

transmitting said frame to be displayed as a new slide, if said significance criterium is met; and

generating a control signal to said videoconferencing system indicating whether said frame is to be displayed as said still image.

2. The method of claim 1, wherein said detecting step is performed with a motion detection algorithm.

3. The method of claim 1, wherein said detecting step is performed such that said change is not a change resulting from a change in overall intensity of said frames.

4. The method of claim 1, wherein said frames represent displays on a computer screen and wherein said significance criterium is based on a change to a predetermined object in said displays.

5. The method of claim 1, further comprising the step of repeating said detecting step for a number of frames, to determine that said change has continued for a predetermined number of frames, and wherein said determining step is further based on the results of said repeating step.

6. The method of claim 1, wherein said significance criterium is based on a noise factor.

7. The method of claim 1, further comprising the step of evaluating the intensity level of said current frame to determine whether said current frame is blank, and wherein said determining step is further based on the results of said evaluating step.

8. The method of claim 1, further comprising the step of comparing said current frame to a frame previously presented, and wherein said determining step is further based on the results of said comparing step.

23. The method of claim 1, wherein said comparing step is accomplished by evaluating said change such that said still display is not affected by changes that are quantitized by said at least one significance criterium and that have a level not indicated during said comparing step.

9. A computer-implemented method of using a processor to automatically preview and present graphics slides as still displays on a videoconferencing system, said videoconferencing system having a processor that receives frames of graphics data, comprising the steps of:

detecting a change between a current frame and a previous frame;

comparing any said change to at least one significance criterium to determine whether said current frame should be displayed as a preview;

repeating the above steps for a next frame without displaying said frame as a preview, if said significance criterium is not met; and

transmitting said frame to be displayed as a preview, if said significance criterium is met;

generating a control signal to said videoconferencing system indicating whether said frame is to be displayed as a preview; and

determining whether to present a new slide, based on movement in said preview.

10. The method of claim 9, wherein said detecting step is performed with a motion detection algorithm.

11. The method of claim 9, wherein said detecting step is performed such that said change is not a change resulting from a change in overall intensity of said frames.

12. The method of claim 9, wherein said frames represent displays on a computer screen and wherein said significance criterium is based on a change to a predetermined object in said displays.

13. The method of claim 9, further comprising the step of repeating said detecting step for a number of frames, to determine that said change has continued for a predetermined number of frames, and wherein said determining step is based on the results of said repeating step.

14. The method of claim 9, said significance criterium is based on a noise factor.

15. The method of claim 9, further comprising the step of repeating said detecting step for a number of frames, to determine when said change is stable, and wherein said step of determining whether to present a new slide is based on the results of said repeating step.

16. The method of claim 9, further comprising the step of evaluating the intensity level of said current frame to determine whether said current frame is blank, and wherein said step of determining whether to present a new slide is based on the results of said evaluating step.

17. The method of claim 9, further comprising the step of comparing said current frame to a frame previously presented, and wherein said step of determining whether to present a new slide is based on the results of said comparing step.

24. The method of claim 9, wherein said comparing step is accomplished by evaluating said change such that said still display is not affected by changes that are quantitized by said at least one significance criterium and that have a level not indicated during said comparing step.

18. An improved processor-implemented videoconferencing system that automatically presents graphics slides as still displays, the improvement comprising:

a processor that receives frames of graphics data, said processor being programmed to detect a change between a current frame and a previous frame, to compare any said change to at least one significance criterium to determine whether said current frame should be displayed as a new slide;

to repeat the above steps for a next frame without displaying said frame as a new slide if said significance criterium is not met;

to transmit said frame to be displayed as a new slide if said significance criterium is met; and

to generate a control signal to said videoconferencing system indicating whether said slide is to be presented as said still image.

19. The system of claim 18, wherein said processor is further programmed such to detect said change when said change is not the result of a change in overall intensity of said frames.

20. The method of claim 18, wherein said processor is further programmed to repeatedly detect change such that it determines whether a new slide should be presented only after said change has continued for a predetermined number of frames.

21. The method of claim 18, wherein said processor is further programmed to repeatedly detect change such that it determines when said change is stable.

22. The method of claim 18, wherein said processor is further programmed to evaluate the intensity level of said current frame to determine whether said current frame is blank.

25. The system of claim 18, wherein said processor evaluates any said change such that said still display is not affected by changes that are quantitized by said at least one significance criterium and that have a level not indicated during said comparing step.