Method and system for efficient edge blending in high fidelity multichannel computer graphics displays

• US 6,545,685 B1
• Filed: 01/14/1999
• Issued: 04/08/2003
• Est. Priority Date: 01/14/1999
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Silicon Graphics Incorporated (Graphics Properties Holdings, Inc.)
• Inventors: Dorbie, Angus
• Primary Examiner(s): Zimmerman, Mark
• Assistant Examiner(s): Nguyen, Kimbinh T.
• Application Number:
  US09/231,405
• Time in Patent Office: 1,545 Days
• Field of Search: 345/419, 345/426, 345/629, 345/597, 345/582, 348/38, 348/383, 348/382, 463/42
• US Class Current: 345/582
• CPC Class Codes: G06F 3/1438 using more than one graphics controller
• CPC Class Codes: G06F 3/1446 display composed of modules, e.g. video walls
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2340/10 Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607

Abstract

A method for implementing edge blending between a first and second video frame to create a seamless multichannel display system. The method is implemented in a graphics computer system including a processor coupled to a memory via a bus. Within the computer system, a first video frame is rendered for display on a first video channel. A second video frame is rendered for display on a second channel. A first overlap region is rendered onto the first frame to obtain a first blended video frame. A second overlap region is blended onto the second frame to obtain a second blended video frame. The first blended video frame from the first channel and the second blended video frame from the second channel are then combined such that the first overlap region and the second overlap region correspond, thereby forming a seamless junction between the first blended frame and the second blended frame and implementing a high fidelity multichannel display.

Claims

1. In a multichannel display system, a method for implementing edge blending between a first and second video frame to create a seamless multichannel display system, comprising:

a) rendering a first video frame for display on a first channel;

b) rendering a second video frame for display on a second channel;

c) rendering a first overlap region onto the first video frame to obtain a first blended video frame;

d) rendering a second overlap region onto the second video frame to obtain a second blended video frame, wherein the first overlap region and the second overlap region are implemented by producing a first polygon to define the first overlap region and a second polygon to define the second overlap region, and mapping a first texture over the first polygon and a second texture over the second polygon such that the first and second textures modulate a brightness level within the first and second overlap regions; and

e) combining the first blended video frame from the first channel and the second blended video frame from the second channel such that the first overlap region and the second overlap region correspond, thereby forming a seamless junction between the first blended video frame and the second blended video frame.

2. The method of claim 1, wherein the first video frame is rendered using a first computer system coupled to provide video information to the first channel, and the second video frame is rendered using a second computer system coupled to provide video information to the second channel.

3. The method of claim 1, wherein the first overlap region modulates a brightness level of the first video frame and the second overlap region modulate a brightness level of the second video frame such that the first blended video frame and the second blended video frame combine to form the seamless junction there between.

4. The method of claim 1, wherein the first polygon is a first plurality of polygons and the second polygon is a second plurality of polygons.

5. The method of claim 4, wherein the plurality of polygons have respective transparency values operable for modulating the brightness level within the first and second overlap regions.

6. The method of claim 4, wherein the plurality of polygons have respective color values operable for modulating the brightness level within the first and second overlap regions.

7. The method of claim 1, wherein the first and second textures include a plurality of colored samples operable for modulating the brightness level within the first and second overlap regions.

8. The method of claim 1, wherein a first transparency mask is stored within a first frame buffer and a second transparency mask is stored within a second frame buffer, the first and second transparency masks operable to modulate the brightness level within the first and second overlap regions as the first and second video frames are respectively rendered into the first and second frame buffers.

9. In a multichannel display system including at least a first computer system for generating video information for a first channel and a second computer system for generating video information for a second channel, a method for implementing edge blending between the first and second channels to create a seamless multichannel display, the method comprising the computer implemented steps of:

a) using the first computer system, rendering a first video frame for display on the first channel;

b) using the second computer system, rendering a second video frame for display on the second channel;

c) rendering a first overlap region onto the first video frame to obtain a first blended video frame within a frame buffer of the first computer system;

d) rendering a second overlap region onto the second video frame to obtain a second blended video frame within a frame buffer of the second computer system, wherein the first overlap region and the second overlap region are implemented by producing a first polygon to define the first overlap region and a second polygon to define the second overlap region, and mapping a first texture having a first color sample over the first polygon and a second texture having a second color sample over the second polygon such that the first and second textures modulate a brightness level within the first and second overlap regions;

e) projecting the first blended video frame from the first channel onto a first screen; and

f) projecting the second blended video frame from the second channel onto a second screen, the first and second screens being directly adjacent, such that the first overlap region and the second overlap region correspond to form a seamless junction between the first blended video frame and the second blended video frame whereby the use of dedicated blending hardware external to one or more of the first computer system and the second computer system is not required.

10. The method of claim 9, wherein the first overlap region modulates a brightness level of the first video frame and the second overlap region modulates a brightness level of the second video frame such that the first blended video frame and the second blended video frame combine to form the seamless junction there between.

11. The method of claim 9, wherein the first polygon is a first plurality of polygons and the second polygon is a second plurality of polygons.

12. The method of claim 11, wherein the plurality of polygons have respective transparency values operable for modulating the brightness level within the first and second overlap regions.

13. The method of claim 11, wherein the plurality of polygons have respective color values operable for modulating the brightness level within the first and second overlap regions.

14. The method of claim 9, wherein the first colored sample is a first plurality of colored samples and the second colored sample is a second plurality of colored samples.

15. The method of claim 9, wherein a first transparency mask is stored within the frame buffer of the first computer system and a second transparency mask is stored within the frame buffer of the second computer system, the first and second transparency masks operable to modulate the brightness level within the first and second overlap regions as the first and second video frames are respectively rendered into the first and second frame buffers.

16. A multichannel display system, comprising:

a first computer system for generating video information coupled to a first channel; and

a second computer system for generating video information coupled to a second channel, the first and second computer systems including respective processors coupled to respective memories, wherein the first and second computer systems execute software causing the first and second computer systems to implement a method for edge blending between the first and second channels to create a seamless multichannel display, the method comprising the computer implemented steps of;

a) using the first computer system, rendering a first frame for display on the first channel;

b) using the second computer system, rendering a second frame for display on the second channel;

c) rendering a first overlap region onto the first frame to obtain a first blended frame within a frame buffer of the first computer system;

d) rendering a second overlap region onto the second frame to obtain a second blended frame within a frame buffer of the second computer system, wherein the first overlap region and the second overlap region are implemented by producing a first polygon to define the first overlap region and a second polygon to define the second overlap region, and mapping a first texture having a first color sample over the first polygon and a second texture having a second color sample over the second polygon such that the first and second textures modulate a brightness level within the first and second overlap regions;

e) outputting the first blended frame from the first channel to a first projector for projection onto a first screen; and

f) outputting the second blended frame from the second channel to a second projector for projection onto a second screen, the first and second screens being directly adjacent, such that the first overlap region and the second overlap region correspond to form a seamless junction between the first blended video frame and the second blended video frame whereby the use of dedicated blending hardware external to one or more of the first computer system and the second computer system is not required.

17. The system of claim 16, wherein the first overlap region modulates a brightness level of the first frame and the second overlap region modulates a brightness level of the second frame such that the first blended video frame and the second blended video frame combine to form the seamless junction there between.

18. The system of claim 16, wherein the first polygon is a first plurality of polygons and the second polygon is a second plurality of polygons.

19. The system of claim 18, wherein the plurality of polygons have respective transparency values operable for modulating the brightness level within the first and second overlap regions.

20. The system of claim 18, wherein the plurality of polygons have respective color values operable for modulating the brightness level within the first and second overlap regions.

21. The system of claim 16, wherein the first colored sample is a first plurality of colored samples and the second colored sample is a second plurality of colored samples.

22. The system of claim 16, wherein a first transparency mask is stored within the frame buffer of the first computer system and a second transparency mask is stored within the frame buffer of the second computer system, the first and second transparency masks operable to modulate the brightness level within the first and second overlap regions as the first and second frames are respectively rendered into the first and second frame buffers.

23. The system of claim 22, wherein the first and second transparency masks are configured to implement irregularly shaped first and second overlap regions, thereby rendering the junction between the first and second blended frames less noticeable.

24. The system of claim 16, wherein the first overlap region and the second overlap region are implemented by storing the first frame into a texture memory of the first computer system and the second frame into a texture memory of the second computer system, the first frame and the second frame subsequently texture mapped onto a first polygon mesh, including the first polygon, in the frame buffer of the first computer system and a second polygon mesh, including the second polygon, in the frame buffer of the second computer system.

25. The system of claim 24, wherein the first polygon mesh and the second polygon mesh include a plurality of polygons having a respective color such that the first overlap region and the second overlap region are implemented when the first frame and the second frame are texture mapped onto the first polygon mesh and the second polygon mesh.

26. The system of claim 24, wherein the first polygon mesh and the second polygon mesh are subdivided within the first overlap region and the second overlap region to implement the edge blending.

27. In a multichannel display system, a method for implementing edge blending between a first and second video frame to create a seamless multichannel display system, comprising:

storing a first transparency mask, having a first color sample, within a first frame buffer;

rendering a first video frame into the first frame buffer for display on a first channel, the first transparency mask operable to modulate the brightness level to implement a first overlap region;

storing a second transparency mask, having a second color sample, within a second frame buffer;

rendering a second video frame into the second frame buffer for display on a second channel, the second transparency mask operable to modulate the brightness level to implement a second overlap region; and

projecting the first channel and the second channel such that the first overlap region and the second overlap region correspond, thereby forming a seamless junction between the first blended video frame and the second blended video frame.

28. The method of claim 27 further comprising:

implementing the first transparency mask using a first texture map; and

implementing the second transparency mask using a second texture map.

29. The method of claim 28, wherein the first and second transparency masks are configured to implement irregularly shaped first and second overlap regions, thereby reducing visibility of a junction between the first and second channels.

30. The method of claim 29 further comprising:

rendering the first video frame into the first frame with the first transparency mask using a texture mapping unit of a graphics subsystem; and

rendering the second video frame into the second frame with the second transparency mask using the texture mapping unit of the graphics subsystem.

31. In a multichannel display system, a method for implementing edge blending between a first and second video frame to create a seamless multichannel display system, comprising:

a) rendering a first video frame for display on a first channel;

b) rendering a second video frame for display on a second channel;

c) rendering a first overlap region onto the first video frame to obtain a first blended video frame;

d) rendering a second overlap region onto the second video frame to obtain a second blended video frame, wherein the first overlap region and the second overlap region are implemented by producing a first polygon to define the first overlap region and a second polygon to define the second overlap region, and mapping a first texture having a first color sample over the first polygon and a second texture having a second color sample over the second polygon such that the first and second textures modulate a brightness level within the first and second overlap regions; and

e) combining the first blended video frame from the first channel and the second blended video frame from the second channel such that the first overlap region and the second overlap region correspond, thereby forming a seamless junction between the first blended video frame and the second blended video frame.

32. A multichannel display system, comprising:

a first computer system capable of rendering a first frame and a first overlap region onto the first frame to obtain a first blended frame within a first frame buffer for generating video information coupled to a first channel;

a second computer system capable of rendering a second frame and a second overlap region onto the second frame to obtain a second blended frame within a second frame buffer for generating video information coupled to a second channel for projection by a second projector onto a second screen;

a first projector capable of projecting the first blended frame onto a first screen; and

a second projector capable of projecting the second blended frame onto a second screen;

wherein;

the first and second screens are directly adjacent, such that the first overlap region and the second overlap region correspond to form a seamless junction between the first blended video frame and the second blended video frame whereby the use of dedicated blending hardware external to one or more of the first computer system and the second computer system is not required; and

the first overlap region and the second overlap region are implemented by producing a first polygon to define the first overlap region and a second polygon to define the second overlap region, and mapping a first texture having a first color sample over the first polygon and a second texture having a second color sample over the second polygon such that the first and second textures modulate a brightness level within the first and second overlap regions.