Application of video to graphics weighting factor to video image YUV to RGB color code conversion

• US 5,852,444 A
• Filed: 11/25/1996
• Issued: 12/22/1998
• Est. Priority Date: 12/07/1992
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Lippincott, Louis A.
• Primary Examiner(s): FETTING, ANTON W
• Application Number:
  US08/755,714
• Time in Patent Office: 757 Days
• Field of Search: 395/131, 358/448, 358/492, 345/199, 345/113-115, 345/138, 345/150-154, 345/431
• US Class Current: 345/603
• CPC Class Codes: G09G 2340/125 wherein one of the images is motion video
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables

Abstract

In the system of the present invention an individual displayed pixel is a weighted combination of a video pixel and a graphics pixel. For example, a pixel displayed on a monitor may be three-quarters graphics and one-quarter video. In this system a color lookup table providing a red, a green and a blue lookup table output value is extended to provide a further lookup table output value. The further lookup table output value is a weight value representative of the relative weights of a video pixel and a corresponding graphics pixel. The weight value is applied to a matrix multiplier which also receives video pixel information and graphics pixel information. The matrix multiplier determines a weighted combination of the video and graphics pixel information according to the weight value to provide a blended pixel. A YUV standard to RGB standard conversion matrix is provided within in order to receive video signals in a YUV format and apply the video signals to the matrix multiplier in an RGB format.

Claims

1. A video processing system for combining first and second input signals to provide a combined output signal, wherein the first input signal is representative of a first pixel and the second input signal is representative of a second pixel and a combining factor index, the system comprising:

(a) lookup table means for determining a combining factor in accordance with a table location accessed by the combining factor index of the second input signal;

(b) means for applying the first and second pixels and the combining factor to a blending circuit;

(c) the blending circuit, wherein the blending circuit is for combining the first and second pixels in accordance with the combining factor to provide the combined output signal; and

(d) means for converting the first pixel from a YUV type pixel to an RGB type pixel before the first pixel is applied to the blending circuit, wherein the lookup table means (a) comprises;

(a)(1) a plurality of lookup tables for converting the second pixel from a YUV type pixel to an RGB type pixel before the second pixel is applied to the blending circuit; and

(a)(2) a lookup table for determining the combining factor in accordance with the table location accessed by the combining factor index of the second input signal.

2. The video processing system of claim 1, wherein the blending circuit is a pixel blending matrix multiplier circuit.

3. The video processing system of claim 1, wherein the blending circuit comprises means for providing a weighted sum of the first and second pixels in accordance with said combining factor.

4. The video processing system of claim 1, wherein the first pixel is a video pixel and the second pixel is a graphics pixel.

5. The video processing system of claim 1, wherein:

means (d) comprises a conversion matrix circuit for converting the first pixel from a YUV type pixel to an RGB type pixel; and

the plurality of lookup tables comprises three lookup tables.

6. The video processing system of claim 5, wherein the conversion matrix circuit comprises a second plurality of three lookup tables.

7. The video processing system of claim 5, wherein:

the blending circuit is a pixel blending matrix multiplier circuit; and

the first pixel is a video pixel and the second pixel is a graphics pixel.

8. A video processing method for combining first and second input signals to provide a combined output signal, wherein the first input signal is representative of a first pixel and the second input signal is representative of a second pixel and a combining factor index, the method comprising the steps of:

(a) determining with a lookup table means a combining factor in accordance with a table location accessed by the combining factor index of the second input signal;

(b) applying the first and second input signals and the combining factor to a blending circuit;

(c) combining with the blending circuit the first and second input signals in accordance with the combining factor to provide a combined output signal; and

(d) converting the first pixel from a YUV type pixel to an RGB type pixel before the first pixel is applied to the blending circuit, wherein the lookup table means comprises;

(1) a plurality of lookup tables for converting the second pixel from a YUV type pixel to an RGB type pixel before the second pixel is applied to the blending circuit; and

(2) a lookup table for determining the combining factor in accordance with the table location accessed by the combining factor index of the second input signal.

9. The video processing method of claim 8, wherein the blending circuit is a pixel blending matrix multiplier circuit.

10. The video processing method of claim 8, wherein the blending circuit comprises means for providing a weighted sum of the first and second pixels in accordance with said combining factor.

11. The video processing method of claim 8, wherein the first pixel is a video pixel and the second pixel is a graphics pixel.

12. The video processing method of claim 8, wherein:

the converting of step (d) utilizes a conversion matrix circuit for converting the first pixel from a YUV type pixel to an RGB type pixel; and

the plurality of lookup tables comprises three lookup tables.

13. The video processing method of claim 12, wherein the conversion matrix circuit comprises a second plurality of three lookup tables.

14. The video processing method of claim 12, wherein:

the blending circuit is a pixel blending matrix multiplier circuit; and

the first pixel is a video pixel and the second pixel is a graphics pixel.

15. A video processing system for combining first and second input signals to provide a combined output signal, wherein the first input signal is representative of a first pixel and the second input signal is representative of a second pixel and a combining factor index, the system comprising:

(a) a lookup table coupled to the second input signal, the lookup table having a plurality of table locations;

(b) a blending circuit coupled to the first and second input signals and to the lookup table, the blending circuit generating the combined output signal; and

(c) a YUV to RGB converter circuit coupled between the first input signal and the blending circuit;

wherein;

the lookup table determines a combining factor in accordance with a table location accessed by the combining factor index of the second input signal;

the blending circuit combines the first and second pixels in accordance with the combining factor to provide the combined output signal; and

the lookup table comprises;

(a)(1) a second YUV to RGB converter circuit coupled between the second input signal and the blending circuit, the second YUV to RGB converter circuit comprising a plurality of lookup tables; and

(a)(2) a combing factor lookup table coupled between the second input signal and the blending circuit, wherein the combining factor lookup table outputs the combining factor in accordance with the table location accessed by the second input signal.

16. The video processing system of claim 15, wherein the blending circuit is a pixel blending matrix multiplier circuit.

17. The video processing system of claim 15, wherein the blending circuit provides a weighted sum of the first and second pixels in accordance with said combining factor.

18. The video processing system of claim 15, wherein the first pixel is a video pixel and the second pixel is a graphics pixel.

19. The video processing system of claim 15, wherein:

the YUV to RGB converter circuit comprises a conversion matrix circuit; and

the second YUV to RGB converter circuit comprising three lookup tables.

20. The video processing system of claim 19, wherein the conversion matrix circuit comprises three lookup tables.

21. The video processing system of claim 19, wherein:

the blending circuit is a pixel blending matrix multiplier circuit; and

the first pixel is a video pixel and the second pixel is a graphics pixel.

22. A video processing system for combining first and second input signals to provide a combined output signal, the video processing system comprising:

(a) lookup table means, wherein the first input signal is representative of a first pixel and the second input signal is representative of a second pixel and a combining factor index, wherein the lookup table means is for determining a combining factor in accordance with a table location accessed by the combining factor index of the second input signal;

(b) a blending circuit for combining the first and second pixels in accordance with the combining factor to provide the combined output signal;

(c) means for applying the first and second pixels and the combining factor to the blending circuit; and

(d) means for converting the first pixel from a YUV type pixel to an RGB type pixel before the first pixel is applied to the blending circuit, wherein the lookup table means (a) comprises;

(a)(1) a plurality of lookup tables for converting the second pixel from a YUV type pixel to an RGB type pixel before the second pixel is applied to the blending circuit; and

(a)(2) a lookup table for determining the combining factor in accordance with the table location accessed by the combining factor index of the second input signal.