Microlensing for real-time sensing of stray light

1. A device comprising:

an image sensor comprising a plurality of light-sensitive pixels;

a first lens positioned over a first subset of light-sensitive pixels selected from the plurality of light-sensitive pixels; and

a controller configured to:

determine a first angle of incidence of a first light signal detected by the first subset of light-sensitive pixels;

based on the first determined angle of incidence, determine an amount of stray light incident on the image sensor; and

alter payload images captured using the image sensor based on the determined amount of stray light.

2. The device of claim 1 , wherein determining the amount of stray light incident on the image sensor comprises comparing the first determined angle of incidence to a threshold angle of incidence.

3. The device of claim 2 , wherein the threshold angle of incidence is 10°, and wherein the first determined angle of incidence and the threshold angle of incidence are measured relative to a vector that extends perpendicularly from a surface of the image sensor.

4. The device of claim 1 , further comprising a second lens positioned over a second subset of light-sensitive pixels selected from the plurality of light-sensitive pixels, wherein the controller is further configured to:

determine a second angle of incidence of a second light signal detected by the second subset of light-sensitive pixels; and

based on the second determined angle of incidence, determine the amount of stray light incident on the image sensor.

5. The device of claim 4 , wherein the controller is further configured to generate a stray-light map across the image sensor based on the first determined angle of incidence, the second determined angle of incidence, a location of the first subset of light-sensitive pixels on the image sensor, and a location of the second subset of light-sensitive pixels on the image sensor.

6. The device of claim 5 , wherein determining the stray-light map comprises generating a gamma-encoded histogram or a log-encoded histogram and interpolating values for light-sensitive pixel locations that are not within the first subset of light-sensitive pixels or the second subset of light-sensitive pixels.

7. The device of claim 4 , further comprising a third lens positioned over a third subset of light-sensitive pixels selected from the plurality of light-sensitive pixels, wherein the controller is also configured to:

determine a third angle of incidence of a third light signal detected by the third subset of light-sensitive pixels; and

based on the third determined angle of incidence, determine the amount of stray light incident on the image sensor.

8. The device of claim 7 , wherein the first subset of light-sensitive pixels corresponds to a first color channel of the image sensor, wherein the second subset of light-sensitive pixels corresponds to a second color channel of the image sensor, and wherein the third subset of light-sensitive pixels corresponds to a third color channel of the image sensor.

9. The device of claim 8 , wherein the controller is further configured to:

generate a first stray-light map across the image sensor corresponding to the first color channel;

generate a second stray-light map across the image sensor corresponding to the second color channel; and

generate a third stray-light map across the image sensor corresponding to the third color channel.

10. The device of claim 1 , wherein the first subset of light-sensitive pixels is oriented along a periphery of the image sensor.

11. The device of claim 10 , wherein the first subset of light-sensitive pixels is located in a corner of the image sensor.

12. The device of claim 1 , wherein the first angle of incidence is determined by comparing relative intensities detected by each light-sensitive pixel in the first subset of light-sensitive pixels.

13. The device of claim 1 , wherein determining the amount of stray light incident on the image sensor comprises comparing the first determined angle of incidence to a threshold angle of incidence, and wherein the threshold angle of incidence is based on:

a geometry of the image sensor;

materials of the image sensor;

a geometry of the first lens;

materials of the first lens;

environmental factors; or

a user setting.

14. The device of claim 1 , wherein the determined amount of stray light is stored in a memory as a look-up table.

15. The device of claim 1 , wherein the first subset of light-sensitive pixels comprises a 2×2 array of light-sensitive pixels, a 3×3 array of light-sensitive pixels, or a 4×4 array of light-sensitive pixels.

16. The device of claim 1 , wherein the controller is further configured to determine a true-black optical level based on the determined amount of stray light.

17. The device of claim 1 , wherein the image sensor is associated with a camera, and wherein the controller is further configured to adjust a pose of the camera, adjust a lens of the camera, or apply one or more filters to the camera based on the determined amount of stray light.

18. The device of claim 1 , wherein the device is used for object detection and avoidance within an autonomous vehicle.

19. A method comprising:

receiving, at a lens positioned over a first subset of light-sensitive pixels selected from a plurality of light-sensitive pixels that are part of an image sensor, a first light signal;

directing, using the lens, the first light signal toward the first subset of light-sensitive pixels;

detecting, by one or more light-sensitive pixels of the first subset, the first light signal;

determining a first angle of incidence of the detected first light signal;

determining, based on the first determined angle of incidence, an amount of stray light incident on the image sensor; and

altering payload images captured using the image sensor based on the determined amount of stray light.

20. A device comprising:

an image sensor comprising a plurality of light-sensitive pixels;

a plurality of subsets of light-sensitive pixels selected from the plurality of light-sensitive pixels positioned along an entire periphery of the image sensor;

a plurality of lenses, wherein each lens is positioned over a corresponding subset of light-sensitive pixels; and

a controller configured to:

determine an angle of incidence of light detected by each subset of light-sensitive pixels; and

based on the determined angles of incidence, determine a stray-light map across the image sensor; and

alter payload images captured using the image sensor based on the determined stray-light map.