Motion detection method and device, program and vehicle surveillance system

• US 7,346,188 B2
• Filed: 06/23/2005
• Issued: 03/18/2008
• Est. Priority Date: 08/23/2004
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Aichi, Isao
• Primary Examiner(s): Werner; Brian
• Assistant Examiner(s): Akhavannik; Hadi
• Application Number:
  US11/159,250
• Publication Number:
  US 20060039584A1
• Time in Patent Office: 999 Days
• Field of Search: 382/103, 382/154
• US Class Current: 382/103
• CPC Class Codes: G06T 7/254 involving subtraction of images

Abstract

Based on an input image from an imaging device and a preset background image, a digitized image is generated for each frame. The digitized images are compared. Then, an increased region, a decreased region, and an overlap region, which are adjacent to each other, are extracted as a single integrated region. Region parameters, which are a region area, a sum of X-coordinates and a sum of Y-coordinates, are obtained for each of the extracted integrated region, the increased region and the decreased region. Based on the region parameters, a motion of the object displayed on the integrated region is obtained for each of the integrated regions.

Claims

1. A motion detection method comprising the steps of:

digitizing a background differential image corresponding to a differential image between an input image sequentially input for each frame and a preset background image so as to generate a digitized image composed of a target region different from the background image and a background region with no difference from the background image for each frame;

determining an overlap region when a value of a common pixel in a current frame is equal to the value of the same pixel in a frame directly preceding the current frame;

determining an increased region when the value of a common pixel in the current frame is greater than the value of the same pixel in the frame directly preceding the current framed;

determining a decreased region when the value of a common pixel in the current frame is less than the value of the same pixel in the frame directly preceding the current frame;

comparing digitized images between frames to extract the overlap region remaining as the target region, the increased region changed from the background region to the target region, and the decreased region changed from the target region to the background region;

when the increased region and the decreased region are adjacent to the overlap region, obtaining an integrated region by grounding the increased region, the decreased region, and the overlap region;

for each of the integrated region, the increased region, and the decreased region, obtaining region parameters composed of the number of pixels contained in the region, a sum of X-coordinates obtained by adding X-coordinate values in two-dimensional coordinates indicating a position of a pixel for all the pixels contained in the region, and a sum of Y-coordinates obtained by adding Y-coordinate values for all the pixels contained in the region; and

detecting a motion of a moving object displayed on the integrated region for each of the integrated regions based on the region parameters.

2. A motion detection device comprising:

digitized image generating means for digitizing a background differential image corresponding to a differential image between an input image sequentially input for each frame and a preset background image so as to generate a digitized image composed of a target region different from the background image and a background region with no difference from the background image for each frame;

frame comparison means for determining an overlap region when a value of a common pixel in a current frame is equal to the value of the same pixel in a frame directly preceding the current frame, for determining an increased region when the value of a common pixel in the current frame is greater than the value of the same pixel in the frame directly preceding the current frame, and for determining a decreased region when the value of a common pixel in the current frame is less than the value of the same pixel in the frame directly preceding the current frame;

region extracting means for comparing digitized images generated in the digital image generating means between frames to extract the overlap region remaining as the target region, the increased region changed from the background region to the target region, and the decreased region changed from the target region to the background region and, when the increased region and the decreased region are adjacent to the overlap region, for obtaining an integrated region by grouping the increased region, the decreased region, and the overlap region;

region parameter calculating means for, for each of the integrated region, the increased region, and the decreased region, obtaining region parameters composed of the number of pixels contained in the region, a sum of X-coordinates obtained by adding X-coordinate values in two-dimensional coordinates indicating a position of a pixel for all the pixels contained in the region, and a sum of Y-coordinates obtained by adding Y-coordinate values for all the pixels contained in the region; and

motion detecting means for detecting a motion of a moving object displayed on the integrated region for each of the integrated regions based on the region parameters.

3. The motion detection device according to claim 2, wherein the motion detection means obtains a position of a center of gravity of the moving object before and after movement based on the region parameters so as to detect a motion of the moving object.

4. A vehicle surveillance system comprising:

digitized image generating means for digitizing a background differential image corresponding to a differential image between an input image sequentially input for each frame and a preset background image so as to generate a digitized image composed of a target region different from the background image and a background region with no difference from the background image for each frame;

frame comparison means for determining an overlap region when a value of a common pixel in a current frame is equal to the value of the same pixel in a frame directly preceding the current frame, for determining an increased region when the value of a common pixel in the current frame is greater than the value of the same pixel in the frame directly preceding the current frame, and for determining a decreased region when the value of a common pixel in the current frame is less than the value of the same pixel in the frame directly preceding the current frame;

region extracting means for comparing digitized images generated in the digital image generating means between frames to extract the overlap region remaining as the target region, the increased region changed from the background region to the target region, and the decreased region changed from the target region to the background region and, when the increased region and the decreased region are adjacent to the overlap region, for obtaining an integrated region by grouping the increased region, the decreased region, and the overlap region;

region parameter calculating means for, for each of the integrated region, the increased region, and the decreased region, obtaining region parameters composed of the number of pixels contained in the region, a sum of X-coordinates obtained by adding X-coordinate values in two-dimensional coordinates indicating a position of a pixel for all the pixels contained in the region, and a sum of Y-coordinates obtained by adding Y-coordinate values for all the pixels contained in the region;

motion detecting means for detecting a motion of a moving object displayed on the integrated region for each of the integrated regions based on the region parameters;

imaging means provided in a vehicle compartment so as to supply an image captured by taking the vehicle compartment or the vicinity of the vehicle through a window to the motion detection device as the input image;

determination means for determining a presence of any of an intruder and a suspicious individual based on a result of detection in the motion detection device; and

notification means for notifying a result of determination in the determination means.

5. The vehicle surveillance system according to claim 4, wherein the imaging means is provided on an interior roof of the vehicle.

6. The vehicle surveillance system according to claim 4, wherein the imaging means includes any one of a fisheye camera and an omnidirectional camera.

7. The vehicle surveillance system according to claim 4, wherein the imaging means includes an infrared camera.

8. The vehicle surveillance system according to claim 4, wherein the imaging means supplies a distance image having a pixel value in accordance with a distance to an imaged object to be measured as the input image.

9. A computer-readable medium comprising instructions being executed by a computer, the instructions including a computer-implemented method for detecting motion, the instructions for:

digitizing a background differential image corresponding to a differential image between an input image sequentially input for each frame and a preset background image so as to generate a digitized image composed of a target region different from the background image and a background region with no difference from the background image for each frame;

determining an overlap region when a value of a common pixel in a current frame is equal to the value of the same pixel in the frame directly preceding the current frame;

determining an increased region when the value of a common pixel in the current frame is greater than the value of the same pixel in the frame directly preceding the current frame;

determining a decreased region when the value of a common pixel in the current frame is less than the value of the same pixel in the frame directly preceding the current frame;

comparing digitized images between frames to extract the overlap region remaining as the target region, the increased region changed from the background region to the target region, and the decreased region changed from the target region to the background region;

when the increased region and decreased region are adjacent to the overlap region, obtaining an integrated region by grouping the increased region, the decreased region, and the overlap region;

for each of the integrated region, the increased region, and the decreased region, obtaining region parameters composed of the number of pixels contained in the region, a sum of X-coordinates obtained by adding X-coordinate values in two-dimensional coordinates indicating a position of a pixel for all the pixels contained in the region, and a sum of Y-coordinates obtained by adding Y-coordinate values for all the pixels contained in the region; and

detecting a motion of a moving object displayed on the integrated region for each of the integrated regions based on the region parameters.