Vehicle environment monitoring apparatus

• US 7,925,050 B2
• Filed: 10/16/2007
• Issued: 04/12/2011
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Arriver Software AB (Qualcomm, Inc.)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Nagaoka, Nobuharu, Hashimoto, Hideki
• Primary Examiner(s): Do; Anh Hong
• Application Number:
  US11/974,819
• Publication Number:
  US 20080260207A1
• Time in Patent Office: 1,274 Days
• Field of Search: 382/100, 382/103, 382/104, 382/286, 340/630, 340/5, 340/61, 356/438, 250/221
• US Class Current: 382/104
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/32 using correlation-based methods
• 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

Abstract

A vehicle environment monitoring apparatus capable of extracting an image of a monitored object in an environment around a vehicle by separating the same from the background image with a simple configuration having a single camera mounted on the vehicle is provided. The apparatus includes a first image portion extracting processing unit to extract first image portions (A1, A2) considered to be the head of a pedestrian from a currently picked up image and a previously picked up image by an infrared camera, a mask area setting processing unit to set mask areas (M1(0,0), M1(1,0), . . . , M1(5,8)) around the first image portion (A1) in the currently picked up image, and an object extracting processing unit to carry out pattern matching for the previously picked up image by a comparison pattern obtained through affine transformation of each mask area at a change rate (Rate) between the first image portions (A1, A2), and to set an area (Ar1) including the first image portion (A2) and a second image portion (M2(1,3), M2(2,3), . . . , M2(3,6)) where a displacement amount between the position (black point) corresponding to the centroid of the mask area and the matching position is smaller than a predetermined threshold value to be an image area of the monitored object.

Claims

1. A vehicle environment monitoring apparatus detecting a monitored object in an environment around a vehicle from an image picked up by a single imaging unit mounted on the vehicle, comprising:

a first image portion extracting unit to extract a first image portion having a predetermined feature value from each of a first picked-up image and a second picked-up image picked up by the imaging unit at different time points;

a change rate calculating unit to calculate a change rate in size of the first image portion extracted from the second picked-up image in respect to the first image portion extracted from the first picked-up image;

a second image portion extracting unit to extract, from each of the first and second picked-up images, a second image portion having a change rate of not greater than a predetermined level in relative positional relation with the first image portion between the first and second picked-up images;

an object detecting unit to detect an area including the first and second image portions in the first or second picked-up image as an image area of the same monitored object in the environment around the vehicle; and

an object reaching time estimating unit to calculate a time until the vehicle reaches the monitored object based on the change rate in size.

2. The vehicle environment monitoring apparatus according to claim 1, further comprising:

a real space distance grasping unit to grasp a distance between the vehicle and a position in a real space corresponding to the image area including the first and second image portions; and

an object type determining unit to calculate a size of the object in the real space corresponding to the image area including the first and second image portions using the distance grasped by the real space distance grasping unit, and to determine a type of the object based on the size.

3. The vehicle environment monitoring apparatus according to claim 2, wherein the object type determining unit calculates at least one of a height and a width of the object in the real space as a size of the object in the real space corresponding to the image area including the first and second image portions.

4. A vehicle environment monitoring apparatus detecting a monitored object in an environment around a vehicle from an image picked up by a single imaging unit mounted on the vehicle, comprising:

a first image portion extracting unit to extract a first image portion having a predetermined feature value from each of a first picked-up image and a second picked-up image picked up by the imaging unit at different time points;

a change rate calculating unit to calculate a change rate in size of the first image portion extracted from the second picked-up image in respect to the first image portion extracted from the first picked-up image;

a mask area setting unit to set a mask area in the first picked-up image in a predetermined position around the first image portion;

a second image portion extracting unit to set a comparison pattern obtained by reducing or enlarging the mask area by the change rate in size, to extract an area having a highest degree of correlation in shape with the comparison pattern from the second picked-up image, and to extract the extracted area as a second image portion of the second picked-up image and also to extract the mask area as a second image portion of the first picked-up image, when a displacement amount between a relative position of a centroid of the extracted area in respect to the first image portion of the second picked-up image and a relative position of a centroid of the mask area in respect to the first image portion in which an area including the first image portion and the mask area in the first picked-up image is reduced or enlarged by the change rate in size, is not greater than a predetermined threshold value; and

an object detecting unit to detect an area including the first and second image portions in the first or second picked-up image as an image area of the same monitored object in the environment around the vehicle.

5. The vehicle environment monitoring apparatus according to claim 4, wherein at least one of an area upward of the first image portion and an area downward of the first image portion is defined as the mask area.

6. The vehicle environment monitoring apparatus according to claim 4, wherein at least one of an area leftward of the first image portion and an area rightward of the first image portion is defined as the mask area.

7. The vehicle environment monitoring apparatus according to claim 4, wherein

the imaging unit is an infrared camera,

the first image portion extracting unit extracts the first image portion from an infrared gray scale image picked up by the imaging unit, and

the second image portion extracting unit extracts the second image portion by correlation processing with the mask area in the gray scale image.