Method of sharing a desktop with attendees of a real-time collaboration

• US 20040179036A1
• Filed: 03/13/2003
• Published: 09/16/2004
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle Corporation
• Inventors: Teplov, Ilya, Huck, Paul, Skurikhin, Aleksey, Fedotov, Alex
• Granted Patent: US 7,222,305 B2
• Time in Patent Office: Days
• US Class Current: 345/751
• CPC Class Codes: G06F 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay
• CPC Class Codes: H04L 65/4015 where at least one of the additional parallel sessions is real time or time sensitive, e.g. white board sharing, collaboration or spawning of a subconference
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15

Abstract

A method of facilitating the reproduction of a presenter'"'"'s desktop for attendees of a real-time collaboration. A bound portion of the desktop (the portion shared with the attendees) is logically divided into clusters. When the content of a cluster changes, the cluster is analyzed and one or more objects describing the content may be identified. Each object that is not already cached is cached and assigned a cache ID. Each object in the cluster is described in an object primitive to be sent to the attendees. Actions for reproducing the object on the attendees'"'"' clients are sent as action primitives. The object and action primitives allow the content of the presenter'"'"'s desktop to be sent incrementally instead of sending the entire desktop.

Claims

1. In a real-time collaboration, a method of sharing a presenter'"'"'s desktop with collaboration attendees, the method comprising:

at a presenter'"'"'s client computer system having a desktop, selecting a bound portion of the client desktop to share with one or more attendees of a collaboration;

identifying an area of the bound portion in which the appearance of the desktop changed;

identifying one or more objects included in the area;

for any object in said objects that is not already cached and assigned a cache ID;

caching said object; and

assigning said object a cache ID;

for each of said objects, constructing an object block describing the object;

for each of said objects, constructing an action block to facilitate reproduction of the object, wherein said action block identifies said object by said cache ID; and

forwarding said object blocks and said action blocks toward the attendees.

2. The method of claim 1, wherein each of said one or more objects is of one of the following types:

a character, a cursor, an image, a palette and a region.

3. The method of claim 2, wherein:

said character type comprises a pattern of pixels of a single color;

said cursor type comprises a cursor;

said image type comprises a multi-color image;

said palette type comprises identifiers of one or more colors; and

said region type comprises a description of a region within the bound portion.

4. The method of claim 1, wherein said action block comprises one or more actions, each said action being of one of the following types:

character update, image update, source blit and tile.

5. The method of claim 4, wherein:

said character update type is configured to generate one or more graphical objects in one color;

said image update type is configured to generate a multi-color image;

said source blit type is configured to move content within the bound portion from one location to another location; and

said tile type is configured to reproduce a background pattern of the bound portion.

6. The method of claim 1, wherein said identifying an area of the bound portion in which the appearance of the desktop changed comprises:

logically dividing the bound portion into multiple clusters; and

in each cluster;

computing a checksum on the values of pixels in the cluster; and

comparing the computed checksum to a checksum previously computed for the cluster.

7. The method of claim 1, further comprising:

receiving a notification from a display driver that contents of the bound area changed.

8. The method of claim 1, further comprising:

maintaining a timer to determine when to examine the bound portion for changes to the desktop.

9. The method of claim 1, further comprising:

delaying examining the bound portion of the desktop to control the rate of flow of collaboration data from the presenter'"'"'s client computer system.

10. A computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of sharing a presenter'"'"'s desktop with collaboration attendees, the method comprising:

at a presenter'"'"'s client computer system having a desktop, selecting a bound portion of the client desktop to share with one or more attendees of a collaboration;

identifying an area of the bound portion in which the appearance of the desktop changed;

identifying one or more objects included in the area;

for any object in said objects that is not already cached and assigned a cache ID;

caching said object; and

assigning said object a cache ID;

for each of said objects, constructing an object block describing the object;

for each of said objects, constructing an action block to facilitate reproduction of the object, wherein said action block identifies said object by said cache ID; and

forwarding said object blocks and said action blocks toward the attendees.

11. A method of sharing a presenter'"'"'s desktop with a collaboration attendee, comprising:

logically dividing the presenter'"'"'s desktop into a plurality of clusters;

for each cluster, periodically computing a checksum on pixel values in the cluster;

if a checksum for a first cluster differs from a previously computed checksum for the first cluster;

associating one or more attributes with the first cluster, wherein a first of said attributes comprises a number of colors of pixels in the first cluster;

identifying a graphical object in the first cluster;

constructing an object primitive block describing the graphical object; and

constructing an action primitive block configured to reproduce the graphical object; and

transmitting said object primitive block and said action primitive block to the collaboration attendee to facilitate reproduction of the graphical object on a client of the attendee.

12. The method of claim 11, wherein the graphical object is one of the following types:

a character, a cursor and an image.

13. The method of claim 11, wherein:

the graphical object comprises a connected pattern of pixels of one color.

14. The method of claim 11, wherein the graphical object comprises a cursor.

15. The method of claim 11, wherein the graphical object comprises multiple colors.

16. The method of claim 11, wherein the graphical object comprises multiple, discontinuous, regions of the presenter'"'"'s desktop.

17. The method of claim 11, wherein said action primitive block identifies an action primitive for reproducing the graphical object.

18. The method of claim 17, wherein said action primitive comprises a character update configured to reproduce a series of objects of one color.

19. The method of claim 17, wherein said action primitive comprises an image update configured to reproduce a multi-color object.

20. The method of claim 17, wherein said action primitive comprises a source blit comprising a portion of the presenter'"'"'s desktop that was moved from one location on the desktop to another location on the desktop.

21. The method of claim 17, wherein said action primitive comprises a tile configured to reproduce the content of a first cluster.

22. The method of claim 11, wherein the one or more attributes further include a ratio between a number of pixels in the first cluster that are of a first color and a number of pixels in the first cluster that are of a second color.

23. The method of claim 11, wherein the one or more attributes further include an identifier of a palette identifying the colors of all pixels in the first cluster.

24. The method of claim 11, further comprising, if the checksum for the first cluster differs from said previously computed checksum:

determining whether the one or more attributes associated with the first cluster are substantially similar to attributes associated with a second cluster.

25. The method of claim 24, further comprising, if the checksum for the first cluster differs from said previously computed checksum:

merging the first cluster and the second cluster into a first region of clusters having substantially similar attributes.

26. The method of claim 11, further comprising, if the checksum for the first cluster differs from said previously computed checksum:

caching the graphical object if the graphical object is not already cached.

27. A computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of sharing a presenter'"'"'s desktop with a collaboration attendee, the method comprising:

logically dividing the presenter'"'"'s desktop into a plurality of clusters;

for each cluster, periodically computing a checksum on pixel values in the cluster;

if a checksum for a first cluster differs from a previously computed checksum for the first cluster;

associating one or more attributes with the first cluster, wherein a first of said attributes comprises a number of colors of pixels in the first cluster;

identifying a graphical object in the first cluster;

constructing an object primitive block describing the graphical object; and

constructing an action primitive block configured to reproduce the graphical object; and

transmitting said object primitive block and said action primitive block to the collaboration attendee to facilitate reproduction of the graphical object on a client of the attendee.

28. A method of sharing a presenter'"'"'s desktop with real-time collaborators, comprising:

logically dividing a presenter'"'"'s desktop into a plurality of clusters, wherein a portion of the presenter'"'"'s desktop is shared with one or more collaborators in a real-time collaboration;

for each cluster;

computing a checksum on content of the presenter'"'"'s desktop displayed in said cluster; and

comparing said checksum to a stored checksum calculated on previous content of the presenter'"'"'s desktop displayed in said cluster;

for each cluster in which said computed checksum differs from said stored checksum, scanning said cluster for changes between said previous contents of the presenter'"'"'s desktop and said contents of the presenter'"'"'s desktop; and

transmitting said changes toward the collaborators as incremental updates to the presenter'"'"'s desktop.

29. The method of claim 28, wherein said computing a checksum comprises computing a checksum on the values of all pixels in said cluster.

30. The method of claim 28, wherein said scanning a cluster comprises:

identifying one or more graphical objects in said cluster; and

defining said one or more graphical objects as a set of object primitives; and

defining a set of action primitives configured to facilitate reproduction of said one or more graphical objects.

31. The method of claim 28, further comprising:

for each cluster in which said computed checksum differs from said stored checksum, assigning a set of attributes describing said cluster.

32. The method of claim 31, wherein a first attribute comprises a number of colors displayed in said cluster.

33. The method of claim 31, further comprising:

merging a plurality of said clusters in which said computed checksum differs from said stored checksum, wherein said merged clusters have one or more identical assigned attributes.

34. A computer readable storage medium storing instructions that, when executed by a computer, cause the computer to perform a method of sharing a presenter'"'"'s desktop with real-time collaborators, the method comprising:

logically dividing a presenter'"'"'s desktop into a plurality of clusters, wherein a portion of the presenter'"'"'s desktop is shared with one or more collaborators in a real-time collaboration;

for each cluster;

computing a checksum on content of the presenter'"'"'s desktop displayed in said cluster; and

comparing said checksum to a stored checksum calculated on previous content of the presenter'"'"'s desktop displayed in said cluster;

for each cluster in which said computed checksum differs from said stored checksum, scanning said cluster for changes between said previous contents of the presenter'"'"'s desktop and said contents of the presenter'"'"'s desktop; and

transmitting said changes toward the collaborators as incremental updates to the presenter'"'"'s desktop.