Method and apparatus for chroma key production

1. A method for producing a chroma key comprising:

determining an area of interest for a composite scene by overlaying a foreground key on a background scene and by identifying pixels in the background scene that are within the foreground key;

generating a chroma key based on at least a luminance of the pixels identified within the area of interest and by adapting luma in the foreground key to luma in the area of interest;

calculating an average luminance of the pixels within the area of interest; and

calculating an average luminance of a sampled area in the foreground key, wherein the luma in the foreground key are adapted to luma in the area of interest by applying a difference between the average luminance of the pixels in the area of interest and the average luminance of the foreground key and applying the difference to the foreground scene for every field.

2. The method of claim 1 , wherein said generating further comprises generating the aroma key based on a chrominance signal of each pixel within the area of interest, and wherein the physical property of chrominance is based on the chrominance signal.

3. The method of claim 2 , wherein said generating further comprises:

determining whether a constant vector based on the chrominance signal is applied to all pixels in the area of interest; and

when a constant vector is applied to all pixels, applying a percentage of the same constant vector to a resulting foreground scene.

4. The method of claim 2 , wherein said generating further comprises:

determining whether a constant vector based on the chrominance signal is applied to all pixels in the area of interest; and

when a constant vector is not applied to all pixels, making no change to a resulting foreground scene.

5. The method of claim 3 , wherein said percentage comprises 5-10% of the constant vector.

6. An apparatus for producing a chroma key, the apparatus comprising:

means for determining an area of interest for a composite scene by overlaying a foreground key on a background scene and by identifying pixels in the background scene that are within the foreground key;

means for generating a chroma key based on at least luminance of the pixels identified within the area of interest and by adapting luma in the foreground key to luma in the area of interest

means for calculating an average luminance of the pixels within the area of interest; and

means for calculating an average luminance of a sampled area in the foreground key, wherein the luma in the foreground key are adapted to luma in the area of interest by applying a difference between the average luminance of the pixels in the area of interest and the average luminance of the foreground key and applying the difference to the foreground scene for every field.

7. The apparatus of 6 , wherein said generating means further comprises means for generating the chroma key based on a chrominance signal of each pixel within the area of interest, and wherein the physical property of chrominance is based on the chrominance signal.

8. The apparatus of 7 , wherein said generating means comprises:

means for determining whether a constant vector based on the chrominance signal is applied to all pixels in the area of interest; and

means for applying a percentage of the same constant vector to a resulting foreground scene when it is determined a constant vector is applied to all pixels.

9. The apparatus of 7 , wherein said generating means comprises;

means for determining whether a constant vector based on the chrominance signal is applied to all pixels in the area of interest; and

means for making no change to a resulting foreground scene when a constant vector is not applied to all pixels.

10. The apparatus of 7 , wherein said percentage comprises 5-10% of the constant vector.

11. An apparatus for producing a chroma key, comprising:

a source selection device configured to:

determine an area of interest for a composite scene by overlaying a foreground key on a background scene and by identifying pixels in the background scene that are within the foreground key; and

generate a chroma key based on at least luminance of the pixels identified within the area of interest and by adapting luma in the foreground key to luma in the area of interest, wherein the luma in the foreground key are adapted to luma in the area of interest by applying a difference between the average luminance of the pixels in the area of interest and the average luminance of the foreground key and applying the difference to the foreground scene for every field.

12. The apparatus of claim 11 , wherein said source selection device comprises:

a plurality of input sources;

a processor;

switching logic in communication with the processor; and

an adaptive chroma key sub-system connected to the processor and switching logic, said adaptive chroma key sub-system operating under the control of the processor to selectively combine two or more of the input sources for the composite scene.

13. The apparatus of claim 11 , wherein the physical properties of the pixels comprise luminance and chrominance signals.

14. The apparatus of claim 13 , wherein said source selection device is further configured to:

calculate an average luminance of pixels in the area of interest and a sampled area in the foreground key; and

generate the chroma key by providing link data for linking the luma in the foreground key to the luma in the area of interest.

15. The apparatus of claim 13 , wherein said source selection device is further configured to determine whether a constant vector based on the chrominance signal is applied to all pixels in the area of interest, and when a constant vector is applied to all pixels in the area of interest, to apply a percentage of the same constant vector to a resulting foregoing scene in the composite scene.

16. The method of claim 2 , wherein the chroma key adapts objects in the foreground scene within the area of interest to hue changes in the background scene within the area of interest.

17. The apparatus of claim 7 , wherein the chroma key adapts objects in the foreground scene within the area of interest to hue changes in the background scene within the area of interest.

18. The apparatus of claim 11 , wherein the source selection device is further configured to generate the chroma key based on a chrominance signal of each pixel within the area of interest, and wherein the physical property of chrominance is based on the chrominance signal.

19. The apparatus of claim 11 , wherein the chroma key adapts objects in the foreground scene within the area of interest to hue changes in the background scene within the area of interest.