Variable exposure for color image sensor

1. A method of capturing an image of a scene using an image capture device having an array of pixels, wherein the array of pixels includes pixels of different colors, the method comprising:

for a first duration, capturing the scene with a first plurality of the pixels of a first color; and

for a second duration, capturing the scene with a second plurality of the pixels of a second color;

wherein the first plurality of pixels and second plurality of pixels are different pixels, the first plurality of pixels are associated with only the first color, the second plurality of pixels are associated with only the second color, the first and second durations are different, the first and second durations are chosen, at least in part, to improve the signal to noise ratio of the image capture device, and the first and second durations are chosen separately for the first plurality of pixels and the second plurality of pixels, respectively, according to respective colors of the first and second pluralities of pixels, and

wherein capturing the scene for the first duration includes sending a first reset pulse to a first reset transistor and concurrently sending a first transfer pulse to a first transfer transistor, capturing the scene for the second duration includes sending a second reset pulse to the first reset transistor and concurrently sending a second transfer pulse to a second transfer transistor, timing of the first reset and transfer pulses are different from timing of the second reset and transfer pulses, timing of the first reset and transfer pulses correspond to the first color, and timing of the second reset and transfer pulses correspond to the second color, the first reset transistor being shared by at least two adjacent pixels from among the array of pixels, the first and second transfer transistor each corresponding to a different one of the at least two adjacent pixels, the at least two adjacent pixels including both a pixel from among the first plurality of pixels of the first color and a pixel from among the second plurality of pixels of the second color.

2. The method of claim 1 , further comprising:

for a third duration, capturing a third portion of the scene with a third plurality of the pixels of a third color, the third duration being chosen for the third plurality of pixels according to a color of the third plurality of pixels,

wherein the capturing a third portion of the scene the scene includes sending a third reset pulse to a second reset transistor and concurrently sending the second transfer pulse to a third transfer transistor in addition to the second transfer transistor such that the second reset pulse, the third reset pulse and the second transfer pulse are all sent concurrently, the third transfer transistor corresponding to a pixel from among the third plurality of pixels of the third color, the third duration being the same as the second duration.

3. The method of claim 2 , wherein the first, second, and third colors include red, green, and blue.

4. The method of claim 2 , wherein the first, second, and third durations are different.

5. The method of claim 2 , wherein the array of pixels are arranged as a Bayer grid.

6. The method of claim 2 , wherein the image capture device includes a CMOS image sensor.

7. The method of claim 1 , wherein the first duration is defined as beginning when a reset signal received by the first plurality of pixels changes state and ending when data representing the captured image is read from the first plurality of pixels, and

the second duration is defined as beginning when a reset signal received by the second plurality of pixels changes state and ending when data representing the captured image is read from the first plurality of pixels.

8. An image capture device, comprising:

an array of pixels having pixels of different colors;

a plurality of transfer transistors each corresponding to a pixel from among the array of pixels;

a plurality of reset transistors each shared by at least two adjacent pixels from among the array of pixels; and

circuitry configured to control the operation of the pixels to thereby capture an image of a scene by

capturing the scene with a first plurality of the pixels of a first color for a first duration; and

capturing the scene with a second plurality of the pixels of a second color for a second duration;

wherein the first plurality of pixels and second plurality of pixels are different pixels, the first plurality of pixels are associated with only the first color, the second plurality of pixels are associated with only the second color, the first and second durations are different, and the first and second durations are chosen separately for the first plurality of pixels and the second plurality of pixels, respectively, according to respective colors of the first and second pluralities of pixels, and

wherein the circuitry is further configured to control the operation of the pixels to thereby capture the image of the scene by concurrently sending a first reset pulse to a first reset transistor and a first transfer pulse to a first transfer transistor, and concurrently sending a second reset pulse to the first reset transistor and a second transfer pulse to a second transfer transistor, timing of the first reset and transfer pulses being different from timing of the second reset and transfer pulses timing of the first reset and transfer pulses corresponding to the first color, timing of the second transfer and reset pulses corresponding to the second color, the first reset transistor being shared by at least two adjacent pixels from among the pixel array, the first and second transfer transistors each corresponding to a different one of the at least two adjacent pixels, the at least two adjacent pixels including both a pixel from among the first plurality of pixels of the first color and a pixel from among the second plurality of pixels of the second color.

9. The image capture device of claim 8 , wherein the circuitry is further configured to control the operation of the pixels to capture an image of a scene by capturing the scene with a third plurality of the pixels of a third color for a third duration, the third duration being chosen for the third plurality of pixels according to a color of the third plurality of pixels, wherein capturing the scene for the third duration includes sending a third reset pulse to a second reset transistor and concurrently sending the second transfer pulse to a third transfer transistor in addition to the second transfer transistor such that the second reset pulse, the third reset pulse and the second transfer pulse are all sent concurrently, the third transfer transistor corresponding to a pixel from among the third plurality of pixels of the third color, the third duration being the same as the second duration.

10. The image capture device of claim 9 , wherein the first, second, and third colors include red, green, and blue.

11. The image capture device of claim 9 , wherein the first, second, and third durations are different.

12. The image capture device of claim 9 , wherein the array of pixels are arranged as a Bayer grid.

13. The image capture device of claim 9 , wherein the image capture device includes a CMOS image sensor.

14. The image capture device of claim 9 , wherein the first, second, and third durations are chosen, at least in part, to improve the signal to noise ratio of the image capture device.

15. An image capture device, comprising:

an array of pixels having pixels of different colors;

a plurality of transfer transistors each corresponding to a pixel from among the array of pixels;

a plurality of reset transistors each shared by at least two adjacent pixels from among the array of pixels; and

circuitry configured to control the operation of the pixels to thereby capture an image of a scene, wherein the circuitry includes

means for capturing the scene for a first duration with a first plurality of the pixels of a first color;

means for capturing the scene for a second duration with a second plurality of the pixels of a second color;

means for capturing the scene for a third duration with a third plurality of the pixels of a third color;

wherein the first plurality of pixels and second plurality of pixels are different pixels, the first plurality of pixels are associated with only the first color, the second plurality of pixels are associated with only the second color, the first and second durations are different, and the first and second durations are chosen separately for the first plurality of pixels and the second plurality of pixels, respectively, according to respective colors of the first and second pluralities of pixels, and

wherein the means for capturing the scene for a first duration is further configured to send a first reset pulse to a first reset transistor and a first transfer pulse to a first transfer transistor, concurrently, and the means for capturing the scene for a second duration is further configured to send second reset pulse to the first reset transistor and a second transfer pulse to a second transfer transistor, concurrently, liming of the first transfer and reset pulses being different from timing of the second transfer and reset pulses, timing of the first reset and transfer pulses corresponding to the first color, timing of the second reset and transfer pulses corresponding to the second color, the first reset transistor being shared by at least two adjacent pixels from among the pixel array, the first and second transfer transistors each corresponding to a different one of the at least two adjacent pixels, the at least two adjacent pixels including both a pixel from among the first plurality of pixels of the first color and a pixel from among the second plurality of pixels of the second color.

16. The image capture device of claim 15 , wherein the first, second, and third colors include red, green, and blue.

17. The image capture device of claim 15 , wherein the first, second, and third durations are different.

18. The image capture device of claim 15 , wherein the array of pixels are arranged as a Bayer grid.

19. The image capture device of claim 15 , wherein the image capture device includes a CMOS image sensor.

20. The image capture device of claim 15 , wherein the means for capturing the scene for the third duration is further configured to send a third reset pulse to a second reset transistor and concurrently send the second transfer pulse to a third transfer transistor in addition to the second transfer transistor such that the second reset pulse, the third reset pulse and the second transfer pulse are all sent concurrently, the third transfer transistor corresponding to a pixel from among the third plurality of pixels of the third color, the third duration being the same as the second duration.