Method for detecting moving objects by comparing video images
First Claim
1. A method for detecting activity within a fixed view by using a monitor system, the monitor system comprising a camera for filming the fixed view at a predetermined camera speed and a calculator for detecting the activity within the fixed view according to a first image and a second image generated by the camera, the second image being generated within a predetermined time interval after the first image is generated, each of the images generated by the camera comprising a plurality of blocks, each of the blocks comprising a plurality of pixels, the method comprising:
- calculating an average value A for each block of the second image, each of the average values A is equal to an average of differences between pixels of one of the blocks of the second image and pixels of a corresponding block of the first image;
calculating a mean difference B between an average value of pixels of the first image and an average value of pixels of the second image;
calculating a difference V between the average value A and the mean difference B for each block of the second image, and selecting blocks of the second image that have corresponding differences V greater than a threshold value; and
determining whether there is any object moving within the fixed view according to the selected blocks.
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Accused Products
Abstract
A method detects activity within a fixed view by comparing first and second images. The first and second images respectively include a plurality of blocks, and each of the blocks having a plurality of pixels. The method including: calculating an average value A for each block of the second image, each of the average values A is equal to an average of differences between pixels of one of the blocks of the second image and pixels of a corresponding block of the first image; calculating a mean difference B between average pixel values of the first and second images; calculating a difference V between average value A and mean difference B for each block of the second image, and selecting blocks of the second image that have corresponding differences V greater than a threshold value; and determining whether there is any object moving within the fixed view according to the selected blocks.
26 Citations
20 Claims
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1. A method for detecting activity within a fixed view by using a monitor system, the monitor system comprising a camera for filming the fixed view at a predetermined camera speed and a calculator for detecting the activity within the fixed view according to a first image and a second image generated by the camera, the second image being generated within a predetermined time interval after the first image is generated, each of the images generated by the camera comprising a plurality of blocks, each of the blocks comprising a plurality of pixels, the method comprising:
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calculating an average value A for each block of the second image, each of the average values A is equal to an average of differences between pixels of one of the blocks of the second image and pixels of a corresponding block of the first image;
calculating a mean difference B between an average value of pixels of the first image and an average value of pixels of the second image;
calculating a difference V between the average value A and the mean difference B for each block of the second image, and selecting blocks of the second image that have corresponding differences V greater than a threshold value; and
determining whether there is any object moving within the fixed view according to the selected blocks. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for detecting activity within a fixed view by using a monitor system, the monitor system comprising a camera for filming the fixed view at a predetermined camera speed and a calculator for detecting the activity within the fixed view according to a first image and a second image generated by the camera, the second image being generated within a predetermined time interval after the first image is generated, each of the images generated by the camera comprising a plurality of blocks, each of the blocks comprising a plurality of pixels, the method comprising:
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selecting a detection area within the second image;
calculating an average value A for each block within the detection area, each of the average values A is equal to an average of differences between pixels of one of the blocks of the second image within the detection area and pixels of a corresponding block of the first image;
calculating a mean difference B between the average value of pixels of the second image within the detection area and the average value of corresponding pixels of the first image;
calculating a difference V between the average value A and the mean difference B for each block of the second image within the detection area, and selecting blocks of the second image within the detection area that have corresponding differences V greater than a threshold value; and
determining whether there is any object moving within a field of the fixed view that corresponds to the detection area according to the selected blocks. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification