Apparatus for vehicle surroundings monitoring

• US 8,289,391 B2
• Filed: 08/18/2010
• Issued: 10/16/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kiyohara, Masahiro, Yumiba, Ryo, Irie, Kota, Monji, Tatsuhiko
• Primary Examiner(s): Lazaro, David
• Assistant Examiner(s): Henry, Marie Georges
• Application Number:
  US12/859,020
• Publication Number:
  US 20110074957A1
• Time in Patent Office: 790 Days
• Field of Search: 348/148, 348/153
• US Class Current: 348/148
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images
• CPC Class Codes: G06V 10/267 by performing operations on regions, e.g. growing, shrinking or watersheds
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

There is provided apparatus for vehicle surroundings monitorings that assists so as to make it possible for a driver to check the periphery of the vehicle with ease. Plural images are obtained by capturing the periphery of the vehicle with mutually differing exposure. A process of image recognition is then performed for a target within the thus obtained images. The images are then compared, and images for which the accuracy of image recognition of the target is favorable are selected from among the images. The selected images are joined and composited to generate a host vehicle periphery composite image. Thus, an image with a wide dynamic range and high visibility is generated, thereby making it easier for the driver to check the periphery of the vehicle.

Claims

1. Apparatus for vehicle surroundings monitoring that assists checking of surroundings of a vehicle by a driver by displaying an image captured outside of the vehicle, the apparatus comprising:

an imaging unit that captures a predetermined range around the vehicle with mutually differing exposure amounts;

an image recognition unit that performs recognition of a predefined recognition target by image processing plural images with mutually differing exposure amounts that are captured by the imaging unit;

an image compositing unit that generates a composite image from the images based on a recognition result of the image recognition unit; and

a display unit that displays the composite image composited by the image compositing unit,

wherein the image compositing unit compares, with each or one another, plural images within which the recognition target has been recognized by the image recognition unit, extracts from each of the plural images an image area where accuracy of the recognition target is high, and generates the composite image using the extracted image areas, and

wherein the image compositing unit creates, in accordance with the accuracy of the recognition target and a distance from an area where the recognition target is detected, a weight map defining a proportion with which each of the image areas is to be used in the generation of the composite image, and generates the composite image in accordance with the weight map.

2. The apparatus for vehicle surroundings monitoring according to claim 1, wherein the image compositing unit generates the composite image by mixing a luminance value and color information of each pixel of the plural images in accordance with the weight map.

3. The apparatus for vehicle surroundings monitoring according to claim 1, further comprising a vehicle information providing unit that computes, based on predetermined vehicle information, a relative host vehicle position in each of the images captured by the imaging unit, wherein

the image compositing unit generates the composite image using information on the host vehicle position computed by the vehicle information providing unit.

4. The apparatus for vehicle surroundings monitoring according to claim 3, wherein the vehicle information includes at least one of:

vehicle speed;

wheel speed;

steering angle;

wheel angle;

stop lamp activation information;

headlamp activation information;

wiper activation information; and

host vehicle position information by a host vehicle positioning system.

5. The apparatus for vehicle surroundings monitoring according to claim 1, further comprising a shutter speed control unit that controls a shutter speed of the imaging unit based on the recognition result of the image recognition unit.

6. The apparatus for vehicle surroundings monitoring according to claim 5, further comprising an exposure amount information holding unit that stores information on exposure amount of each of the images captured by the imaging unit, wherein

the shutter speed control unit controls the shutter speed of the imaging unit based on the information on exposure amount that is stored in the exposure amount information holding unit and on the recognition result of the image recognition unit.

7. The apparatus for vehicle surroundings monitoring according to claim 1, comprising plural imaging units, wherein plural images of mutually differing exposure amounts are obtained at each of the imaging units.

8. The apparatus for vehicle surroundings monitoring according to claim 1, wherein the plural images with mutually differing exposure amounts are obtained by capturing with the same imaging unit plural times.

9. The apparatus for vehicle surroundings monitoring according to claim 1, further comprising a target tracking unit that tracks a moving body based on the recognition result by the image recognition unit, and estimates a moved position of the moving body even when recognition by the image recognition unit is unsuccessful.

10. The apparatus for vehicle surroundings monitoring according to claim 9, wherein the target tracking unit chronologically tracks the moving body recognized by the image recognition unit and estimates movement of the moving body.

11. The apparatus for vehicle surroundings monitoring according to claim 1, wherein the plural images with mutually differing exposure amounts are generated by capturing with the same imaging unit plural times, and accumulating the captured images.

12. The apparatus for vehicle surroundings monitoring according to claim 1, wherein the plural images with mutually differing exposure amounts are captured and generated by plural imaging units.