Image sensor with scaled filter array and in-pixel binning

1. An apparatus comprising:

a pixel array including a plurality of individual pixels grouped into pixel kernels having two or more individual pixels, wherein each pixel kernel includes a floating diffusion that is electrically coupled to all individual pixels in the kernel;

a color filter array positioned over and optically coupled to the pixel array, the color filter array comprising a plurality of tiled minimal repeating units, each minimal repeating unit including a plurality of scaled filters, each scaled filter having a photoresponse selected from among two or more different photoresponses, wherein the individual pixels within each pixel kernel are optically coupled to a corresponding scaled filter; and

circuitry and logic coupled to the pixel array to cause the apparatus to operate in multiple image-capture modes, including:

a first mode wherein signals from individual pixels within the pixel array are individually transferred to their floating diffusion and read, resulting in a high-resolution, low-sensitivity image, and

a second mode wherein signals from all individual pixels in a pixel kernel are binned into the floating diffusion of the kernel and read, resulting in a low-resolution, high-sensitivity image;

wherein the circuitry and logic further operate the first mode and the second mode in a first sequence or a second sequence, the first sequence comprising:

using the first mode to capture the high-resolution, low-sensitivity image,

identifying a feature of interest in the high-resolution, low-sensitivity image,

processing only a subset of pixels from the high-resolution, low-sensitivity image that include at least the feature of interest to create a high-resolution, low-sensitivity sub-image, and

using the second mode to capture a low-resolution, high-sensitivity sub-image of the subset of pixels that include at least the feature of interest.

2. The apparatus of claim 1 wherein each pixel kernel includes M×N pixels and wherein M, N, or both, are greater than 1.

3. The apparatus of claim 2 wherein M equals N or wherein M does not equal N.

4. The apparatus of claim 2 wherein each scaled filter is optically coupled to M×N pixels.

5. The apparatus of claim 1 wherein the minimal repeating unit is:

G

R

B

G

wherein

G represents a scaled filter with a green photoresponse,

B represents a scaled filter with a blue photoresponse, and

R represents a scaled filter with a red photoresponse.

6. The apparatus of claim 1 wherein the minimal repeating unit is:

C

R

G

C

wherein

G represents a scaled filter with a green photoresponse,

C represents a scaled filter with a colorless photoresponse, and

R represents a scaled filter with a red photoresponse.

7. The apparatus of claim 1 wherein the minimal repeating unit is:

G

R

B

C

wherein

G represents a scaled filter with a green photoresponse,

B represents a scaled filter with a blue photoresponse,

R represents a scaled filter with a red photoresponse, and

C represents a scaled filter with a colorless photoresponse.

8. The apparatus of claim 1 wherein the minimal repeating unit is:

C

Y

Y

M

wherein

G represents a scaled filter with a green photoresponse,

C represents a scaled filter with a colorless photoresponse, and

R represents a scaled filter with a red photoresponse.

9. The apparatus of claim 1 wherein the pixel array has a first dimension and a second dimension, and wherein the subset pixels comprises a strip of pixels extending the entire first dimension of the pixel array but less than the entire second dimension.

10. The apparatus of claim 1 wherein each scaled filter is a contiguous filter optically coupled to the pixels in a corresponding pixel kernel.

11. The apparatus of claim 1 wherein the first mode is executed before the second mode.

12. The apparatus of claim 1 wherein only one of the first mode and the second mode is executed.

13. A process comprising:

in an image sensor including:

a pixel array including a plurality of individual pixels grouped into pixel kernels having two or more individual pixels, wherein each pixel kernel includes a floating diffusion that is electrically coupled to all individual pixels in the kernel, and

a color filter array positioned over and optically coupled to the pixel array, the color filter array comprising a plurality of tiled minimal repeating units, each minimal repeating unit including scaled filters, each scaled filter having a photoresponse selected from among two or more photoresponses, wherein the individual pixels within each pixel kernel are optically coupled to a corresponding scaled filter,

programming circuitry and logic coupled to the pixel array to cause the image sensor, when operated, to include multiple image-capture modes, including:

a first mode wherein signals from individual pixels within the pixel array are individually transferred to their floating diffusion and read, resulting in a high-resolution, low-sensitivity image, and

a second mode wherein signals from all individual pixels in every pixel kernel are binned into the floating diffusion of the kernel and read, resulting in a low-resolution, high-sensitivity image;

wherein the circuitry and logic are further programmed to operate the first mode and the second mode in a first sequence or a second sequence, the first sequence comprising:

using the first mode to capture the high-resolution, low-sensitivity image,

identifying a feature of interest in the high-resolution, low-sensitivity image,

processing only a subset of pixels from the high-resolution, low-sensitivity image that include at least the feature of interest to create a high-resolution, low-sensitivity sub-image, and

using the second mode to capture a low-resolution, high-sensitivity sub-image of the subset of pixels that include at least the feature of interest.

14. The process of claim 13 wherein each pixel kernel includes M×N pixels and wherein M, N, or both, are greater than 1.

15. The process of claim 14 wherein M equals N or wherein M does not equal N.

16. The process of claim 14 wherein each scaled filter is optically coupled to M×N pixels.

17. The process of claim 13 wherein the minimal repeating unit is:

G

R

B

G

wherein

G represents a scaled filter with a green photoresponse,

B represents a scaled filter with a blue photoresponse, and

R represents a scaled filter with a red photoresponse.

18. The process of claim 13 wherein the minimal repeating unit is:

C

R

G

C

wherein

G represents a scaled filter with a green photoresponse,

C represents a scaled filter with a colorless photoresponse, and

R represents a scaled filter with a red photoresponse.

19. The process of claim 13 wherein the minimal repeating unit is:

G

R

B

C

wherein

G represents a scaled filter with a green photoresponse,

B represents a scaled filter with a blue photoresponse,

R represents a scaled filter with a red photoresponse, and

C represents a scaled filter with a colorless photoresponse.

20. The process of claim 13 wherein the minimal repeating unit is:

C

Y

Y

M

wherein

G represents a scaled filter with a green photoresponse,

C represents a scaled filter with a colorless photoresponse, and

R represents a scaled filter with a red photoresponse.

21. The process of claim 13 wherein the pixel array has a first dimension and a second dimension, and wherein the subset pixels comprises a strip of pixels extending the entire first dimension of the pixel array but less than the entire second dimension.

22. The process of claim 13 wherein each scaled filter is a contiguous filter optically coupled to the pixels in a corresponding pixel kernel.

23. The process of claim 13 wherein the first mode is executed before the second mode.

24. The process of claim 13 wherein only one of the first mode and the second mode is executed.

25. The apparatus of claim 1 wherein second sequence comprises:

using the second mode to capture the low-resolution, high-sensitivity image,

processing the low-resolution, high-sensitivity image to identify a feature of interest in the low-resolution, high-sensitivity image, and

invoking the first sequence if the feature of interest requires a high-resolution image.

26. The process of claim 13 wherein second sequence comprises:

using the second mode to capture the low-resolution, high-sensitivity image,

processing the low-resolution, high-sensitivity image to identify a feature of interest in the low-resolution, high-sensitivity image, and

invoking the first sequence if the feature of interest requires a high-resolution image.