Video surveillance method and system based on average image variance
First Claim
Patent Images
1. A video surveillance method, comprising:
- under control of a video camera module,capturing a subject image of a zone being monitored;
analyzing the subject image to detect an occurrence of a variation in the subject image compared to a previously captured image; and
outputting the subject image if the occurrence of the variation has been detected in the subject image, wherein;
analyzing the subject image includes dividing the subject image into image zones; and
the occurrence of a variation in the subject image compared to the previously captured image is detected if a condition is confirmed in at least one image zone of the subject image, the condition being;
|MR(t,i)−
MRF(t−
1,i)|≧
G(i)·
VRF(t−
1,i),in which MR(t,i) is the average value of pixels of the image zone i in the subject image t, MRF(t−
1,i) is an average value of pixels of the image zone i calculated on several previous images from a previous image t−
1, G(i) is a detection threshold value defined for the image zone i and VRF(t−
1,i) is an average variance value calculated on several previous images from the previous image t−
1.
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Accused Products
Abstract
The present disclosure relates to a video surveillance method comprising steps of a video camera periodically capturing an image of a zone to be monitored, analyzing the image to detect a presence therein, and of the video camera transmitting the image only if a presence has been detected in the image.
18 Citations
24 Claims
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1. A video surveillance method, comprising:
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under control of a video camera module, capturing a subject image of a zone being monitored; analyzing the subject image to detect an occurrence of a variation in the subject image compared to a previously captured image; and outputting the subject image if the occurrence of the variation has been detected in the subject image, wherein; analyzing the subject image includes dividing the subject image into image zones; and the occurrence of a variation in the subject image compared to the previously captured image is detected if a condition is confirmed in at least one image zone of the subject image, the condition being;
|MR(t,i)−
MRF(t−
1,i)|≧
G(i)·
VRF(t−
1,i),in which MR(t,i) is the average value of pixels of the image zone i in the subject image t, MRF(t−
1,i) is an average value of pixels of the image zone i calculated on several previous images from a previous image t−
1, G(i) is a detection threshold value defined for the image zone i and VRF(t−
1,i) is an average variance value calculated on several previous images from the previous image t−
1.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A video surveillance device, comprising:
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an image sensor configured to capture a subject image of a zone being monitored; and a detector coupled to the image sensor and configured analyze the subject image to detect an occurrence of a variation in the subject image compared to a previously captured image, and output the subject image if the occurrence of the variation has been detected in the subject image, wherein the detector is further configured to; divide the subject image into image zones; and detect an occurrence of a variation in the subject image if a condition is confirmed in at least one image zone of the subject image, the condition being;
|MR(t,i)−
MRF(t−
1,i)|≧
G(i)·
VRF(t−
1,i),in which MR(t,i) is the average value of pixels of the image zone i in the subject image t, MRF(t−
1,i) is an average value of pixels of the image zone i calculated on several previous images from a previous image t−
1, G(i) is a threshold value defined for the image zone i and VRF(t−
1,i) is an average variance value calculated on several previous images from the previous image t−
1.- View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A video surveillance system, comprising:
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one or more video camera modules, each video camera module configured to capture a subject image of a zone being monitored by the video camera, analyze the subject image to detect an occurrence of a variation in the subject image compared to a previously captured image, and transmit the subject image if the occurrence has been detected in the subject image; and a controller configured to select the subject image to be transmitted from a respective one of the one or more video cameras that captured the subject image, according to the occurrence of the variation in the subject image, wherein the video camera module is further configured to; divide the subject image into image zones; and detect an occurrence of a variation in the subject image if a condition is confirmed in at least one image zone of the subject image, the condition being;
|MR(t,i)−
MRF(t−
1,i)|≧
G(i)·
VRF(t−
1,i),in which MR(t,i) is the average value of pixels of the image zone i in the subject image t, MRF(t−
1,i) is an average value of pixels of the image zone i calculated on several previous images from a previous image t−
1, G(i) is a threshold value defined for the image zone i and VRF(t−
1,i) is an average variance value calculated on several previous images from the previous image t−
1.- View Dependent Claims (22, 23, 24)
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Specification