Apparatus for controlling exposure of multi-view camera, system including the same, and method for controlling exposure of multi-view camera

Patent metadata

Field	Value
Publication number	US-2018115694-A1
Application number	US-201615367041-A
Country	US
Kind code	A1
Filing date	Dec 1, 2016
Priority date	Oct 20, 2016
Publication date	Apr 26, 2018
Grant date	—

Abstract

A system for controlling exposure of a multi-view camera is disclosed. The system includes a plurality of cameras having different views, a single image-based camera parameter calculator calculating single image-based camera parameters for each of the plurality of cameras; an image intensity ratio calculator calculating an image intensity ratio corresponding to an image intensity difference in an overlapped region between image data obtained from the plurality of cameras; and a multi-image-based camera parameter calculator calculating multi-image-based camera parameters for correcting intensity differences between images of the plurality of cameras on the basis of the single image-based camera parameters and the image intensity ratio.

First claim

What is claimed is:

1 . A system for controlling exposure of a multi-view camera, comprising:
a plurality of cameras having different views; a single image-based camera parameter calculator configured to calculate single image-based camera parameters for each of the plurality of cameras; an image intensity ratio calculator configured to calculate an image intensity ratio corresponding to an image intensity difference in an overlapped region between image data obtained from the plurality of cameras; and a multi-image-based camera parameter calculator configured to calculate multi-image-based camera parameters for correcting intensity differences between the respective images of the plurality of cameras on the basis of the single image-based camera parameters and the image intensity ratio.

2 . The system for controlling exposure of a multi-view camera according to claim 1 , further comprising an exposure controller configured to control exposure values of the plurality of cameras on the basis of the multi-image-based camera parameters.

3 . The system for controlling exposure of a multi-view camera according to claim 1 , wherein the plurality of cameras include at least one from a group consisting of a first camera configured to photograph a front of a vehicle, a second camera configured to photograph a left of the vehicle, a third camera configured to photograph a right of the vehicle, and a fourth camera configured to photograph a rear of the vehicle.

4 . The system for controlling exposure of a multi-view camera according to claim 1 , wherein the single image-based camera parameter calculator includes:
a virtual image generator configured to change intensities of each of the image data photographed in the plurality of cameras to generate a plurality of virtual images for each of the image data; a feature value image generator configured to extract feature values of each of the plurality of virtual images to generate a plurality of feature value images; and a parameter calculator configured to calculate the single image-based camera parameters using a relationship between the feature values obtained from the plurality of feature value images and intensities.

5 . The system for controlling exposure of a multi-view camera according to claim 4 , wherein the parameter calculator configured to calculate the single image-based camera parameters so as to be exponentially increased or decreased.

6 . The system for controlling exposure of a multi-view camera according to claim 1 , wherein the image intensity ratio calculator configured to calculate the image intensity ratio on the basis of a median filtering algorithm and a mean filtering algorithm.

7 . The system for controlling exposure of a multi-view camera according to claim 1 , wherein the image intensity ratio calculator configured to calculate a median of a value obtained by dividing a pixel mean value of image patches defined in first image data photographed in a first camera of the plurality of cameras by a pixel mean value of image patches defined in second image data photographed in a second camera of the plurality of cameras as the image intensity ratio, in an overlapped region between the first image data and the second image data.

8 . The system for controlling exposure of a multi-view camera according to claim 7 , wherein the multi-image-based camera parameter calculator includes:
a cost function deriver configured to derive a first cost function in which values of the single image-based camera parameters are reflected on the basis of an exposure value of a next frame by the single image-based camera parameters and further configured to derive a second cost function in which values of the multi-image-based camera parameters are reflected on the basis of an exposure value of a current frame by the single image-based camera parameters and the image intensity ratio; and an optimal parameter calculator configured to calculate camera parameters so that the first cost function and the second cost function are minimized.

9 . The system for controlling exposure of a multi-view camera according to claim 8 , wherein the cost function deriver configured to derive the second cost function so that the intensity difference in the overlapped region is decreased by increasing the exposure value of the current frame, when the intensity difference in the overlapped region is large.

10 . The system for controlling exposure of a multi-view camera according to claim 8 , wherein the multi-image-based camera parameter calculator further includes a balance parameter adjuster configured to adjust a balance parameter using an exposure level ratio using a camera parameter of a current frame of a single image and a camera parameter of a next frame of the single image.

11 . The system for controlling exposure of a multi-view camera according to claim 10 , wherein the cost function deriver configured to derive the cost functions on the basis of the balance parameter.

12 . The system for controlling exposure of a multi-view camera according to claim 11 , wherein the optimal parameter calculator configured to calculate an exposure value at which values of the cost functions are minimized as an optimal camera parameter value.

13 . An apparatus for controlling exposure of a multi-view camera, comprising:
a cost function deriver configured to derive a first cost function in which values of single image-based camera parameters are reflected on the basis of an exposure value of a next frame by the single image-based camera parameters and configured to derive a second cost function in which values of multi-image-based camera parameters are reflected on the basis of an exposure value of a current frame by the single image-based camera parameters and an image intensity ratio; and an optimal parameter calculator configured to calculate camera parameters so that the first cost function and the second cost function are minimized.

14 . The apparatus for controlling exposure of a multi-view camera according to claim 13 , further comprising a balance parameter adjuster configured to adjust a balance parameter used to derive the cost functions, using an exposure level ratio using a camera parameter of a current frame of a single image and a camera parameter of a next frame of the single image.

15 . A method for controlling exposure of a multi-view camera, comprising:
calculating single image-based camera parameters for each of a plurality of cameras having different views; calculating an image intensity ratio in an overlapped region between images photographed from the plurality of cameras; and calculating multi-image-based camera parameters using the image intensity ratio and the single image-based camera parameters.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Korea Advanced Inst Sci & Tech

Inventors

• Choi Jin Wook
• Shim In Wook
• Oh Tae Hyun
• Kweon In So

Classifications

• H04N23/73 Primary

  by influencing the exposure time · CPC title

• H04N7/181 Primary

  for receiving images from a plurality of remote sources · CPC title

• B60R1/00

  Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles · CPC title

• G06T7/97

  Determining parameters from multiple pictures (depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85) · CPC title

• G06T2207/20024

  Filtering details · CPC title