Method for activating and deactivating an image correction function, camera system and motor vehicle

Patent metadata

Field	Value
Publication number	US-9762810-B2
Application number	US-201414449187-A
Country	US
Kind code	B2
Filing date	Aug 1, 2014
Priority date	Aug 1, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A method for operating a camera system of a motor vehicle, in which images of an environmental region of the motor vehicle are captured by means of an image sensor of the camera system via an optic device and an image correction function is activated by means of a control unit of the camera system, in which a light fall-off in a boundary region of the images caused by the optic device is compensated for, wherein a current brightness level of the environmental region is captured by means of the control unit and the activation and deactivation of the image correction function are effected depending on the current brightness level.

First claim

The invention claimed is:

1. A method for operating a camera system of a motor vehicle, comprising:
capturing images of an environmental region of the motor vehicle by means of an image sensor of the camera system via an optic device and an image correction function is activated by means of a control unit of the camera system, in which a light fall-off in a boundary region of the images caused by the optic device with a wide opening angle is compensated for, wherein
a current brightness level of the environmental region is captured by means of the control unit and the activation and deactivation of the image correction function are effected depending on the current brightness level and depending on the current brightness level the camera system is switched from a normal light mode (NLM) to a low light mode (LLM), in which a gain factor and/or an exposure time are increased with respect to the normal light mode (NLM) and/or a frame rate (FR) of the image sensor is reduced, wherein the image correction function is deactivated upon switching to the low light mode (LLM) and is again activated upon switching again to the normal light mode (NLM);
detecting a temperature of the image sensor; and
effecting the switching based on a current value of the temperature by comparing a current value of an operating parameter of the image sensor, which is correlated with the brightness level and a gain factor, to at least one threshold, which is adjusted depending on the current value of the temperature.

2. The method according to claim 1 ,
wherein an operating parameter of the image sensor is captured by means of the control unit, which is correlated with the brightness level of the environmental region, and the activation and deactivation of the image correction function are effected depending on a current value of the operating parameter.

3. The method according to claim 2 , wherein a gain factor and/or an exposure time are used as operating parameter.

4. The method according to claim 1 , wherein at a higher temperature, the at least one threshold is adjusted to a lower threshold value than at a lower temperature.

5. The method according to claim 1 , wherein the image sensor is an HDR image sensor, by means of which HDR images of the environmental region are provided, wherein for providing an HDR image, at least two exposure time values of the HDR image sensor are adjusted, and wherein the image correction function is applied exclusively to pixels, which have been generated with a higher one of the exposure time values.

6. A camera system for a motor vehicle comprising:
an optic device having a wide opening angle with an image sensor for providing images of an environmental region of the motor vehicle via the optic device; and
a control unit for activating and deactivating an image correction function, in which a light fall-off in a boundary region of the images caused by the optic device is compensated for, wherein
the control unit is adapted to capture a current brightness level of the environmental region and to activate and deactivate the image correction function depending on the current brightness level and depending on the current brightness level the camera system is switched from a normal light mode (NLM) to a low light mode (LLM), in which a gain factor and/or an exposure time are increased with respect to the normal light mode (NLM) and/or a frame rate (FR) of the image sensor is reduced, wherein the image correction function is deactivated upon switching to the low light mode (LLM) and is again activated upon switching again to the normal light mode (NLM),
wherein a temperature of the image sensor is detected and the switching is effected based on a current value of the temperature, dependent on a comparison of the current value of an operating parameter of the image sensor, which is correlated with the brightness level and a gain factor, to at least one threshold, which is adjusted depending on the current value of the temperature.

7. A motor vehicle with a camera system according to claim 6 .

Assignees

• Connaught Electronics Ltd

Inventors

• Conneely Peadar
• Denny Patrick Eoghan

Classifications

• H04N25/583

  with different integration times · CPC title

• H04N25/61 Primary

  the noise originating only from the lens unit, e.g. flare, shading, vignetting or "cos4" · CPC title

• H04N23/667

  Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes · CPC title

• H04N23/88

  for colour balance, e.g. white-balance circuits or colour temperature control · CPC title

• H04N23/60

  Control of cameras or camera modules · CPC title