Methods and apparatus for pixel binning and readout

1. An imaging apparatus capable of identifying a predetermined feature and producing an output image, comprising:

a pixel array, comprising a plurality of pixels arranged to form a plurality of rows;

an image signal processor coupled to the pixel array and configured to:

receive pixel data from the plurality of pixels; and

determine:

a region of interest according to the predetermined feature, wherein the region of interest corresponds to a first group of consecutive rows from the plurality of rows; and

a region of non-interest comprising a plurality of remaining rows from the plurality of rows;

a readout circuit coupled to the pixel array and configured to:

facilitate combining portions of the pixel data from the region of non-interest to form a plurality of second groups;

readout each row of the first group according to a first readout rate; and

readout each of the second groups according to a second readout rate;

wherein the first readout rate is substantially equal to the second readout rate.

2. The imaging apparatus according to claim 1 , wherein the image signal processor determines the region of interest according to a location of the predetermined feature within the plurality of pixels.

3. The imaging apparatus according to claim 2 , wherein the region of interest comprises a predetermined number of rows above and below the location of the predetermined feature.

4. The imaging apparatus according to claim 1 , wherein:

the first group produces a high resolution region in the output image; and

the second groups produce a low resolution region in the output image.

5. The imaging apparatus according to claim 1 , further comprising a floating diffusion region coupled to a subset of pixels from the plurality of pixels and configured to sum charges from the subset of pixels.

6. The imaging apparatus according to claim 1 , further comprising a plurality of source follower devices coupling a subset of pixels from the plurality of pixels to a common readout path, wherein the plurality of source follower devices may be activated to facilitate summing charges from the subset of pixels.

7. A method for reducing frame rate while retaining relevant data, comprising:

capturing a first image, comprising first image data, with an image sensor comprising a plurality of pixels arranged to form a plurality of rows;

detecting a feature in the first image;

identifying a region of interest corresponding to a first group of consecutive rows from the plurality of rows according to a location of the detected feature within the first image;

capturing a second image, comprising second image data;

combining portions of the second image data that are outside the region of interest to form a plurality of second groups of combined image data;

reading out the plurality of second groups of combined image data; and

reading out the second image data that corresponds to the region of interest in a row-by-row manner;

wherein a duration for reading out each second group from the plurality of second groups is substantially equal to a duration for reading out one row from the second image data that corresponds to the region of interest.

8. The method according to claim 7 , wherein combining portions of the second image data comprises summing pixel data from selected rows at a floating diffusion region.

9. The method according to claim 7 , wherein combining portions of the second image data comprises summing pixel data from selected rows at a common readout path.

10. The method according to claim 7 , wherein detecting the feature in the first image comprises:

sequentially reading out each row of the first image data; and

analyzing the first image data.

11. The method according to claim 7 , further comprising detecting the feature in the second image.

12. The method according to claim 7 , further comprising monitoring changes in a characteristic of the feature from the first image to the second image.

13. A system capable of producing an output image with high and low resolution regions, comprising:

an imaging apparatus capable of capturing a series of image frames, comprising:

a pixel array, comprising a plurality of pixels arranged to form a plurality of rows;

an image signal processor coupled to the pixel array and configured to:

receive pixel data from the plurality of pixels;

detect and identify a predetermined feature in a first image frame;

determine:

a region of interest according to a location of the predetermined feature within the plurality of pixels, wherein the region of interest corresponds to a first group of consecutive rows from the plurality of rows; and

a region of non-interest comprising a plurality of remaining rows from the plurality of rows;

monitor a characteristic of the predetermined feature in a second image frame; and

transmit an output signal based on the characteristic of the predetermined feature; and

a readout circuit coupled to the pixel array and configured to:

facilitate combining pixel data from the region of non-interest to form a second group;

readout each row of the first group according to a first readout rate; and

readout the second group according to a second readout rate;

wherein the first readout rate is substantially equal to the second readout rate; and

a host processor coupled to the imaging apparatus and responsive to the output signal.

14. The system according to claim 13 , wherein the region of interest comprises a predetermined number of rows above and below the location of the predetermined feature.

15. The system according to claim 13 , wherein:

the first group produces a high resolution region in the output image; and

the second group produces a low resolution region in the output image.

16. The system according to claim 13 , further comprising a floating diffusion region coupled to a subset of pixels from the plurality of pixels and configured to sum charges from the subset of pixels.

17. The system according to claim 13 , further comprising a plurality of source follower devices coupling a subset of pixels from the plurality of pixels to a common readout path.

18. The system according to claim 13 , wherein the host processor engages a peripheral system based on the output signal.

19. The system according to claim 13 , wherein:

the first image frame produces only a high resolution image; and

the second image frame produces an image with a high resolution region and a low resolution region.