Surveillance apparatus and recording medium recorded surveillance program
First Claim
1. A recording medium having recorded thereon a surveillance program executed by a computer including input/output means, a CPU and a memory, said program comprising the steps of:
- inputting images in a time series from said input/output means;
registering a plurality of different background images from said images into said memory;
calculating a minimum value of a difference between each of said plurality of different background images and an image inputted afresh for each pixel, and storing said minimum value in said memory; and
judging an existence/absence of an invading object on the basis of said difference.
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Accused Products
Abstract
An economical surveillance apparatus robust to an environmental change includes an input unit for inputting images in a time series, a background image memory unit for storing a plurality of input images, a difference image memory unit for calculating and storing difference degree between a plurality of background images of the background image memory unit and an image inputted afresh, and a judging unit for judging an existence/absence of an invading object by utilizing the value of the difference degree of the difference image memory unit. This surveillance apparatus can automatically register a plurality of background images from a camera image. Since the background images that are no longer used are automatically erased, the drop of detection speed and detection sensitivity can be prevented.
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Citations
10 Claims
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1. A recording medium having recorded thereon a surveillance program executed by a computer including input/output means, a CPU and a memory, said program comprising the steps of:
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inputting images in a time series from said input/output means;
registering a plurality of different background images from said images into said memory;
calculating a minimum value of a difference between each of said plurality of different background images and an image inputted afresh for each pixel, and storing said minimum value in said memory; and
judging an existence/absence of an invading object on the basis of said difference. - View Dependent Claims (2, 3, 4, 5)
said surveillance program includes a step of erasing said background image;
in said erasing step, a pixel to be erased is decided on the basis of a period from a registration time of each of said pixel values to a time at which said pixel is last looked up, and a period from the time at which said pixel is last looked up to a present time; and
when registration is made, new pixel value is written to an empty region if said empty region exists in said memory, and if said empty region does not exist, a degree of importance for each pixel value of a corresponding pixel is calculated and is overwritten to a pixel value having the lowest degree of importance.
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4. A recording medium according to claim 1, wherein said surveillance program further includes a step of recording said image inputted afresh when said invading object is judged to exist.
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5. A recording medium according to claim 1, wherein said surveillance program further includes the steps of:
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storing a minimum value image comprising an absolute value of a difference for each pixel; and
dividing said minimum value image into blocks, calculating and storing a mean value of an absolute value for a difference for each of said blocks;
wherein an existence/absence of an invading object is judged on the basis of a time series change of said mean value.
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6. A computer readable medium having embodied thereon a surveillance program which, when executed by a computer system, performs the method comprising:
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receiving images in time series from one or more input devices;
registering a plurality of different background images from the images;
detecting a presence absence of an invading object from the images of one or more input devices, by;
determining an absolute value of a difference between an input image and each of said plurality of different background images for each pixel, determining a minimum value image among all the background images at which the difference between the input image and each of said plurality of different background images is minimal, determining a mean value of a difference for each discrete block within the minimum value image, and determining the presence/absence of an invading object on the basis of a time series change of said mean value. - View Dependent Claims (7, 8, 9, 10)
each background image is registered or erased for each pixel;
erasing is determined on the basis of a period from a registration time of said pixel to a time at which said pixel is last looked up, and a period from a time at which said pixel is last looked up to a current time;
when registration is made, a new pixel value is written to an empty region if said empty region exists in a background image memory section of said memory device, and if said empty region does not exist, importance of each pixel value of a corresponding pixel is calculated and is overwritten to an image value having the lowest degree of importance.
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9. A computer readable medium according to claim 6, wherein said input image is recorded afresh for each pixel, when the invading object is present.
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10. A computer readable medium according to claim 6, further comprising:
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an input image storage section for storing an input image afresh for each pixel;
a background image storage section for registering a plurality of different background images; and
a difference image storage section for storing the minimum value image in discrete blocks, and for storing the mean value of the difference for each block.
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Specification