Vehicle lighting control using image processing of changes in ambient light intensity

Patent metadata

Field	Value
Publication number	US-12020487-B2
Application number	US-202117797205-A
Country	US
Kind code	B2
Filing date	Jan 28, 2021
Priority date	Feb 3, 2020
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

Changes in ambient light intensity are detected by processing image data from an image capture device to determine, iteratively, a signal-to-noise ratio of the image data. The signal-to-noise ratio is a ratio of average to variance of pixel values for some of the pixels forming the image. A control output is generated, based on the signal-to-noise ratio, that is responsive to changes in ambient light intensity. The control output is used control a light source of a vehicle.

First claim

The invention claimed is:

1. An apparatus for detecting changes in ambient light intensity, comprising:
a controller configured to;
receive image data from at least one image capture device, the image data representing sequential images of at least a part of a field of view of the at least one image capture device and including for each image a pixel value for each of a plurality of pixels forming the respective image;
process the image data in accordance with an algorithm to define at least one region of the field of view based on a spatial distribution of different pixel values in the received images, wherein the at least one region defines at least some of the plurality of pixels and represents less than all of the field of view;
process the image data of the at least one region to determine iteratively a signal-to-noise ratio of the image data, wherein the signal-to-noise ratio is a ratio of average to variance of the pixel values of at least some of the plurality of pixels; and
generate a control output responsive to changes in ambient light intensity, wherein the control output is based on the signal-to-noise ratio.

2. The apparatus according to claim 1 , including at least one light source, wherein the control output is arranged to control the at least one light source responsive to changes in ambient light intensity.

3. The apparatus according to claim 1 , including a display configured to display images of the field of view, generated by the at least one image capture device.

4. The apparatus according to claim 1 , wherein at least one region is selected from the field of view to define said at least some of the plurality of pixels, the at least one region representing less than all of the field of view.

5. The apparatus according to claim 4 , wherein the at least one region includes a reference surface forming a constant element of the field of view.

6. The apparatus according to claim 4 , wherein the controller is configured to determine the signal-to-noise ratio in a temporal domain, as the ratio of average to variance of different pixel values for each pixel of said at least some of the plurality of pixels, over a plurality of sequential images of the selected at least one region, over a short reference time period.

7. The apparatus according to claim 1 , wherein the controller is configured to determine the signal-to-noise ratio in a spatial domain, as the ratio of average to variance across said at least some of the plurality of pixels, for each of the images.

8. The apparatus according to claim 7 , wherein at least one region is selected from the field of view to define said at least some of the plurality of pixels, the at least one region representing less than all of the field of view.

9. The apparatus according to claim 7 , wherein each image is an image of all of the field of view, and for each image, said at least some of the plurality of pixels include all of the plurality of pixels forming the respective image.

10. The apparatus according to claim 1 , wherein the controller is configured to determine the signal-to-noise ratio iteratively over a standard reference time period, and to generate the control output responsive to a change in the signal-to-noise ratio, only if the change persists over the standard reference time period.

11. A vehicle including an apparatus according to claim 1 , at least one image capture device mounted on the vehicle for generating the image data, and at least one light source mounted on the vehicle, wherein the control output is arranged to control the at least one light source responsive to changes in ambient light intensity.

12. The vehicle according to claim 11 , wherein the at least one image capture device includes a reversing camera, the field of view of the reversing camera being positioned behind the vehicle, the vehicle further including a display for displaying images of the field of view, generated by the reversing camera, to a driver of the vehicle.

13. The vehicle according to claim 11 , wherein the field of view of the at least one image capture device includes a part of the vehicle.

14. The vehicle according to claim 13 , wherein the at least one light source is arranged to illuminate said part of the vehicle.

Assignees

• Perkins Engines Co Ltd

Inventors

• Flatman Michael
• Roberts Samuel Alec
• Abel Thomas Henry
• Wise Raymond Alan
• Petrany Peter Joseph

Classifications

• B60R2300/80

  characterised by the intended use of the viewing arrangement · CPC title

• B60R2300/20

  characterised by the type of display used · CPC title

• B60R2300/10

  characterised by the type of camera system used · CPC title

• B60Q2300/30

  Indexing codes relating to the vehicle environment · CPC title

• B60Q1/30

  for indicating rear of vehicle, e.g. by means of reflecting surfaces · CPC title