Blending multiple display layers

• US 20070285439A1
• Filed: 06/08/2006
• Published: 12/13/2007
• Est. Priority Date: 06/08/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jalil, Suhail, King, Scott Howard, Liang, Yi
• Granted Patent: US 8,018,472 B2
• Time in Patent Office: Days
• US Class Current: 345/638
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 2360/122 Tiling
• CPC Class Codes: G09G 5/397 Arrangements specially adapted for transferring the contents of two or more bit-mapped memories to the screen simultaneously, e.g. for mixing or overlay G09G5/02 takes precedence

Abstract

Image processing techniques are described that reduce the amount of bandwidth required to read an image from memory for display. According to the techniques, a processor stores low change rate display layers in a memory such that a processor can read the display layers from the memory using a reduced amount of processing resources. An overlay module blends low change rate display layers into a combined overlay layer. A processor reads the overlay layer from the memory and selectively processes the overlay layer based on processing information for the overlay layer recorded in memory. The processor then blends the overlay layer and a high change rate video display layer to update a single image for display according to a high change rate. In addition, the overlay module updates the overlay layer based on the low change rate display layers according to a low change rate.

Claims

1. A method comprising:

combining two or more display layers to form an overlay layer;

selectively processing the overlay layer based on processing information for the overlay layer recorded in memory;

combining the overlay layer with a video layer to form an image for presentation on a display device;

updating the image at a first change rate corresponding to a change rate associated with the video layer; and

updating the overlay layer at a second change rate lower than the first change rate.

2. The method of claim 1, wherein updating the image comprises:

reading the overlay layer from the memory;

selectively processing the overlay layer based on the processing information for the overlay layer recoded in the memory; and

recombining the overlay layer with the video layer according to the first change rate.

3. The method of claim 1, wherein updating the overlay layer comprises:

reading the two or more display layers from the memory; and

recombining the display layers according to the second change rate.

4. The method of claim 1, further comprising:

storing the overlay layer in a memory as a plurality of tiles including headers; and

recording processing information for each of the plurality of tiles in headers of the respective tiles, and

wherein selectively processing the overlay layer comprises selectively processing the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

5. The method of claim 4, wherein recording processing information in headers comprises recording one or more of a current tile status that indicates whether the current tile is substantially transparent, an adjacent tile status that indicates a number of adjacent tiles in the overlay layer that are substantially transparent, a compression type for the current tile, and a burst length for a next tile in the overlay layer in the headers of the plurality of tiles.

6. The method of claim 4, further comprising:

reading the overlay layer from the memory on a tile-by-tile basis; and

reading the processing information recorded in the headers of the plurality of tiles.

7. The method of claim 4, wherein selectively processing the plurality of tiles comprises skipping processing at least a portion of the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

8. The method of claim 4, wherein selectively processing the plurality of tiles comprises:

determining whether a current tile in the overlay layer is substantially transparent based on a current tile status recorded in the header of the current tile; and

skipping processing the current tile when the current tile is determined to be substantially transparent.

9. The method of claim 8, wherein selectively processing the plurality of tiles comprises:

determining a number of adjacent tiles to the current tile in the overlay layer that are substantially transparent based on an adjacent tile status recorded in the header of the current tile; and

skipping processing the number of adjacent tiles in the overlay layer.

10. The method of claim 4, wherein storing the overlay layer comprises:

compressing at least a portion of the plurality of tiles in the overlay layer according to a compression type for each of the tiles; and

recording the compression type for each of the tiles in the headers of the respective tiles.

11. The method of claim 10, wherein compressing at least a portion of the plurality of tiles comprises performing run-length encoding on the plurality of tiles, and wherein the compression types include pixel basis compression, component basis compression, or no compression.

12. The method of claim 10, wherein selectively processing the overlay layer comprises:

reading a compression type for a current tile recorded in a header of the current tile; and

decompressing the current tile according to the compression type for the current tile.

13. The method of claim 4, wherein storing the overlay layer comprises storing pixel strips of each of the plurality of tiles in successive memory locations not separated by line strides in the memory.

14. The method of claim 13, wherein storing the overlay layer comprises performing run-length encoding on at least a portion of the plurality of tiles in the overlay layer with unlimited pixel strip run lengths for each of the plurality of tiles.

15. The method of claim 4, wherein selectively processing the plurality of tiles comprises reading a burst length for a next tile in the overlay layer in a header of a current tile, further comprising reading the next tile from the memory according to the burst length for the next tile.

16. The method of claim 4, wherein storing the overlay layer comprises storing each of the plurality of tiles in fixed size records including fixed size headers in the memory.

17. The method of claim 16, wherein updating the overlay layer comprises:

determining which of the plurality of tiles in the overlay layer include changing display items;

locating the changing tiles in the memory based on the fixed size records; and

updating only the changing tiles in the overlay layer.

18. A computer-readable medium comprising instructions that cause a programmable processor to:

combine two or more display layers to form an overlay layer;

selectively process the overlay layer based on processing information for the overlay layer recorded in memory;

combine the overlay layer with a video layer to form an image for presentation on a display device;

update the image at a first change rate corresponding to a change rate associated with the video layer; and

update the overlay layer at a second change rate lower than the first change rate.

19. The computer-readable medium of claim 18, wherein the instructions cause the programmable processor to:

read the overlay layer from the memory;

selectively process the overlay layer based on the processing information for the overlay layer recoded in the memory; and

recombine the overlay layer with the video layer to update the image according to the first change rate.

20. The computer-readable medium of claim 18, wherein the instructions cause the programmable processor to:

read the two or more display layers from the memory; and

recombine the display layers to update the overlay layer according to the second change rate.

21. The computer-readable medium of claim 18, further comprising instructions that cause the programmable processor to:

store the overlay layer in a memory as a plurality of tiles including headers; and

record processing information for each of the plurality of tiles in headers of the respective tiles, and

wherein the instructions cause the programmable processor to selectively process the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

22. The computer-readable medium of claim 21, further comprising instructions that cause the programmable processor to:

read the overlay layer from the memory on a tile-by-tile basis; and

read the processing information recorded in the headers of the plurality of tiles.

23. The computer-readable medium of claim 21, wherein the instructions cause the programmable processor to skip processing at least a portion of the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

24. The computer-readable medium of claim 21, wherein the instructions cause the programmable processor to:

determine whether a current tile in the overlay layer is substantially transparent based on a current tile status recorded in the header of the current tile;

skip processing the current tile when the current tile is determined to be substantially transparent;

determine a number of adjacent tiles to the current tile in the overlay layer that are substantially transparent based on an adjacent tile status recorded in the header of the current tile; and

skip processing the number of adjacent tiles in the overlay layer.

25. The computer-readable medium of claim 21, wherein the instructions cause the programmable processor to:

compress at least a portion of the plurality of tiles in the overlay layer according to a compression type for each of the tiles;

record the compression type for each of the tiles in the headers of the respective tiles;

read a compression type for a current tile recorded in a header of the current tile; and

decompress the current tile according to the compression type for the current tile.

26. The computer-readable medium of claim 21, wherein the instructions cause the programmable processor to:

store pixel strips of each of the plurality of tiles in successive memory locations not separated by line strides in the memory; and

perform run-length encoding on at least a portion of the plurality of tiles in the overlay layer with unlimited pixel strip run lengths for each of the plurality of tiles.

27. The computer-readable medium of claim 21, wherein the instructions cause the programmable processor to read a burst length for a next tile in the overlay layer in a header of a current tile, further comprising instructions that cause the programmable processor to read the next tile from the memory according to the burst length for the next tile.

28. The computer-readable medium of claim 21, further comprising instructions that cause the programmable processor to update the overlay layer, wherein the instructions cause the programmable processor to:

store each of the plurality of tiles in fixed size records including fixed size headers in the memory;

determine which of the plurality of tiles in the overlay layer include changing display items;

locate the changing tiles in the memory based on the fixed size records; and

update only the changing tiles in the overlay layer.

29. A system comprising:

an overlay module that combines two or more display layers to form an overlay layer; and

a processor that selectively processes the overlay layer based on the processing information for the overlay layer recorded in a memory, combines the overlay layer with a video layer to form an image for presentation on a display device, and updates the image at a first change rate corresponding to a change rate associated with the video layer, wherein the overlay module updates the overlay layer at a second change rate lower than the first change rate.

30. The system of claim 29, wherein the processor reads the overlay layer from the memory, selectively processes the overlay layer based on the processing information for the overlay layer recoded in the memory, and recombines the overlay layer with the video, layer to update the image according to the first change rate.

31. The system of claim 29, wherein the overlay module reads the two or more display layers from the memory, and recombines the display layers to update the overlay layer according to the second change rate.

32. The system of claim 29, wherein the display layers comprise two or more of a video control layer that includes video control buttons and a video counter, a system status layer that includes a signal strength indicator and a time clock, and a border layer that includes a decorative border.

33. The system of claim 29, wherein the display layers comprise slowly changing display layers and static display layers.

34. The system of claim 29, wherein the system is included within a wireless communication device (WCD).

35. The system of claim 34, wherein the system receives the two or more display layers from at least one of a video application controller and a system controller within the WCD.

36. The system of claim 34, wherein the high change rate display layer comprises a video layer, and wherein the system receives the video layer from a video application controller within the WCD.

37. The system of claim 29,

wherein the overlay module stores the overlay layer in a memory as a plurality of tiles including headers, and records processing information for each of the plurality of tiles in headers of the respective tiles;

and

wherein the processor selectively processes the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

38. The system of claim 37, wherein the overlay module records one or more of a current tile status that indicates whether the current tile is substantially transparent, an adjacent tile status that indicates a number of adjacent tiles in the overlay layer that are substantially transparent, a compression type for the current tile, and a burst length for a next tile in the overlay layer in the headers of the plurality of tiles.

39. The system of claim 37, wherein the processor reads the overlay layer from the memory on a tile-by-tile basis, and reads the processing information recorded in the headers of the plurality of tiles.

40. The system of claim 37, wherein the processor skips processing at least a portion of the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles.

41. The system of claim 37, wherein the processor determines whether a current tile in the overlay layer is substantially transparent based on a current tile status recorded in the header of the current tile, and skips processing the current tile when the current tile is determined to be substantially transparent.

42. The system of claim 41, wherein the processor determines a number of adjacent tiles to the current tile in the overlay layer that are substantially transparent based on an adjacent tile status recorded in the header of the current tile, and skips processing the number of adjacent tiles in the overlay layer.

43. The system of claim 37, wherein the overlay module compresses at least a portion of the plurality of tiles in the overlay layer according to a compression type for each of the tiles, and records the compression type for each of the tiles in the headers of the respective tiles.

44. The system of claim 43, wherein the overlay layer performs run-length encoding on the plurality of tiles to compress the portion of the plurality of tiles, and wherein the compression types include pixel basis compression, component basis compression, or no compression.

45. The system of claim 43, wherein the processor reads a compression type for a current tile recorded in a header of the current tile, and decompresses the current tile according to the compression type for the current tile.

46. The system of claim 37, wherein the overlay module stores pixel strips of each of the plurality of tiles in successive memory locations not separated by line strides in the memory.

47. The system of claim 46, wherein the overlay module performs run-length encoding on at least a portion of the plurality of tiles in the overlay layer with unlimited pixel strip run lengths for each of the plurality of tiles.

48. The system of claim 37, wherein the processor reads a burst length for a next tile in the overlay layer in a header of a current tile, and reads the next tile from the memory according to the burst length for the next tile.

49. The system of claim 37, wherein the overlay module stores each of the plurality of tiles in fixed size records including fixed size headers in the memory.

50. The system of claim 49, wherein the overlay module determines which of the plurality of tiles in the overlay layer include changing display items, locates the changing tiles in the memory based on the fixed size records, and updates only the changing tiles in the overlay layer.

51. A method comprising:

combining two or more display layers to form an overlay layer;

storing the overlay layer in a memory as a plurality of tiles including headers;

recording processing information for each of the plurality of tiles in headers of the respective tiles;

selectively processing the plurality of tiles in the overlay layer based on the processing information recorded in the headers of the plurality of tiles;

combining the overlay layer with a video layer to form an image for presentation on a display device;

updating the image at a first change rate corresponding to a change rate associated with the video layer, wherein updating the image comprises reading the overlay layer from the memory, selectively processing the plurality of tiles in the overlay layer based on the processing information recoded in the headers of the plurality of tiles, and recombining the overlay layer with the video layer according to the first change rate; and

updating the overlay layer at a second change rate lower then the first change rate, wherein updating the overlay layer comprises reading the two or more display layers from the memory and recombining the display layers according to the second change rate.