INTRUSION DETECTION PROCEDURE

Abstract

An intrusion detection method implemented by a verification device connected to at least two cameras, comprising the steps of: receiving information representative of a first motion detection from a first camera; recording information representative of a moment of the first motion detection in association with an identifier of the first camera; receiving information representative of a second motion detection from a second camera; recording information representative of a moment of the second motion detection in association with an identifier of the second camera; detecting an intrusion if the time interval between the moment of the first motion detection and the moment of the second motion detection is less than a predefined duration. Figure to be published with the abbreviation: Fig. 3

Description

Title of the invention: INTRUSION DETECTION METHOD technical field

[0001] The present invention relates to the field of surveillance and more particularly to an intrusion detection method aimed at avoiding false detections by surveillance camera. STATE OF PRIOR ART

[0002] The use of cameras allows for the surveillance of a site such as a house or property. By analyzing images, a camera can detect a change in the environment. For example, the camera identifies a change between two images acquired within a predefined time interval, such as a change in the light intensity of one or more pixels, and thus detects movement. Motion detection by a camera is then interpreted as an intrusion, which generates an alarm. However, it sometimes happens that movements in the environment, such as trees moving in the wind, generate intrusion detections even when no intruder is present.

[0003] It is therefore desirable to overcome these drawbacks of the state of the art.

[0004] In particular, it is desirable to provide a solution that prevents false intrusion detections. It is also desirable to provide a solution that allows the use of existing cameras without modifying their motion detection methods. Statement of the invention

[0005] An object of the present invention is to propose an intrusion detection method implemented by a verification device, connected to at least two cameras, and comprising the steps of: receiving information representative of a first motion detection from a first camera; recording information representative of a moment of the first motion detection in association with an identifier of the first camera which performed said first motion detection; receiving information representative of a second motion detection from a second camera; recording information representative of a moment of the second motion detection in association with an identifier of the second camera which performed said second motion detection.The process further includes a step to detect an intrusion if the time interval between the moment of the first motion detection and the moment of the second motion detection is less than a predefined duration.

[0006] Thus, it is possible to detect an intrusion using motion detection methods implemented by existing cameras while avoiding false detections.

[0007] According to a particular embodiment, the verification device implementing the intrusion detection method is located at a distance from the first and second cameras, and the intrusion detection step involves verifying that the first camera and the second camera are arranged on the same surveillance site.

[0008] Thus, it is possible to perform remote intrusion detection. Furthermore, it is possible to perform centralized intrusion detection from different monitoring sites.

[0009] According to a particular embodiment, the method further comprises a step of sending an alarm message to an alarm control center when an intrusion is detected.

[0010] Thus, it is possible to avoid a false intrusion detection and to generate an alarm when an intrusion is detected.

[0011] The invention also relates to a verification device, connected to two cameras and comprising: means for receiving information representative of a first motion detection from a first camera; means for recording information representative of a moment of the first motion detection in association with an identifier of the first camera which performed said first motion detection; means for receiving information representative of a second motion detection from a second camera; means for recording information representative of a moment of the second motion detection in association with an identifier of the second camera which performed said second motion detection;and means to detect an intrusion if the time interval between the first motion detection and the second motion detection is less than a predefined duration.

[0012] The invention also relates to an intrusion detection system comprising at least two cameras arranged on the same surveillance site, an alarm control panel and the verification device mentioned above.

[0013] According to a particular embodiment, each camera of the intrusion detection system is oriented in a different direction from another camera so that the field of vision of one camera is disjoint from the field of vision of another camera.

[0014] The invention also relates to a computer program, which can be stored on a medium and / or downloaded from a communication network, in order to be read by a processor. This computer program includes instructions for implementing the method mentioned above in any one of its embodiments. when said program is executed by the processor. The invention also relates to an information storage medium storing such a computer program. Brief description of the drawings

[0015] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of at least one exemplary embodiment, said description being made in relation to the accompanying drawings, among which:

[0016] [Fig-1] schematically illustrates an intrusion detection system comprising cameras, a verification device and an alarm system;

[0017] [Fig.2] schematically illustrates a material architecture of the verification device fiction implementing an intrusion detection process;

[0018] [Fig.3] schematically illustrates the intrusion detection process implemented by the verification device; and

[0019] [Fig.4] schematically illustrates an example of the device's hardware architecture verification.

[0020] DETAILED DESCRIPTION OF IMPROVEMENTS

[0021] Fig. 1 schematically illustrates an intrusion detection system 100. The intrusion detection system comprises at least two cameras 110a and 110b, arranged on the same surveillance site, a verification device 120 and an alarm control unit 130.

[0022] Each camera 110a, 110b continuously acquires images of the environment and detects movement by analyzing these images. To detect movement, the camera 110a, 110b can, for example, identify whether a change is observed between two images acquired within a first predefined time interval, for one or more areas of the image. Each image acquired by the camera 110a, 110b is subdivided into areas such as pixels or sets of pixels. A change in an area between two images can be, for example, a change in the light intensity or a change in the color of said area. In addition, the camera 110a, 110b can count a number of areas for which a change is identified within a second predefined time interval. The camera 110a, 110b detects movement if this number of areas exceeds a predefined quantity.

[0023] When a camera 110a, 110b detects movement, the camera 110a, 110b in question transmits a message representing a motion detection to the verification device 120.

[0024] Cameras 110a, 110b of the intrusion detection system 100 can be arranged at different monitoring sites. Cameras 110a, 110b of the intrusion detection system 100 can thus belong to different monitoring sites different. In this embodiment, the surveillance site to which each camera 110a, 110b belongs is known to the verification device 120.

[0025] Each time motion is detected by a camera 110a, 110b, the monitoring device 120 receives a message indicating motion detection from said camera 110a, 110b. The monitoring device 120 determines that there is an intrusion at a monitored site when at least two separate cameras 110a, 110b located at said monitored site transmit a message indicating motion detection within a time interval shorter than a predefined duration. When this occurs, the monitoring device 120 transmits an alarm message to the alarm control panel 130.

[0026] According to a particular embodiment, the verification device 120 includes a video platform that receives and centralizes representative motion detection information transmitted by cameras 110a and 110b. The verification device 120 further includes a rule engine that receives representative motion detection information from the video platform, determines whether an intrusion has occurred, and identifies the relevant monitoring site. The verification device 120 also includes a centralized home automation application for each monitoring site. When an intrusion has been detected at a monitoring site by the rule engine, the centralized home automation application for that monitoring site receives representative intrusion detection information and then transmits an alarm message to the alarm control panel 130.The video platform and the rule engine can be implemented using software solutions hosted on internet-accessible servers. This allows intrusion detection to be performed on different monitoring sites using a single set of software solutions, common to all monitoring sites, and located remotely from said sites.

[0027] Fig. 2 schematically illustrates an example of the orientation of two cameras 110a, 110b arranged on the same surveillance site.

[0028] Each camera 110a is oriented in a different direction from another camera 110b at the same surveillance site, so that the field of view of a camera 110a is different from and separate from a distinct camera 110b. Thus, the same fixed element in the environment, but capable of generating motion detection, such as a tree or a plant, cannot be imaged by two separate cameras 110a and 110b, thereby preventing false detection.

[0029] Alternatively, when part of the field of view of a camera 110a partially or totally overlaps the field of view of another camera 110b, for example due to installation constraints, an exclusion zone can be configured on said camera 110a. The exclusion zone is an area of ​​the image acquired by said Camera 110a corresponds to the portion of its field of view that overlaps the field of view of the other camera 110b. The exclusion zone is therefore considered invisible by camera 110a. Consequently, camera 110a cannot detect movement within this exclusion zone and cannot take into account any changes within it when performing motion detection. Thus, the field of view of camera 110a analyzed during motion detection does not overlap the field of view of a separate camera 110b. Figure 3 schematically illustrates an intrusion detection method implemented by the verification device 120.

[0030] In a step 301, the verification device 120 is waiting for motion detection.

[0031] In a step 302a, the verification device 120 receives, from a first camera 110a, information representative of a first motion detection and identifies said first camera 110a having made said first motion detection.

[0032] In a subsequent step 303a, the verification device 120 records in a table, in association with an identifier of the first camera 110a, information representing the time ti of the first motion detection. The time of a motion detection corresponds, for example, to the time at which the motion detection was performed or to the time at which the verification device 120 received the information representing the motion detection. The verification device 120 then performs a step 304.

[0033] In a step 302b, the verification device 120 receives, from a second camera 110b, information representative of a second motion detection and identifies said first camera 110a having made said second motion detection.

[0034] In step 303b, the verification device 120 records in a table, in association with an identifier of the second camera 110b, information representative of the time t2 of the second motion detection. The verification device 120 then performs step 304.

[0035] In step 303a (respectively 303b), according to a first embodiment, where information representing a previous motion detection instant is already recorded following a previous motion detection performed by the first camera 110a (respectively the second camera 110b), the verification device 120 replaces said information representing a previous motion detection instant with information representing the instant ti of the first most recent motion detection (respectively the instant t2 of the second motion detection). The information representing an instant of The previous motion detection is then erased by the verification device 120.

[0036] According to a second embodiment, the verification device 120 replaces information representing a previous motion detection instant with information representing a new motion detection instant (for example, the instant ti of the first motion detection) only when a predefined time has elapsed between the previous motion detection instant and the instant of the new motion detection. The verification device 120 then erases the information representing the previous motion detection instant so as to retain only a single piece of information representing a motion detection instant performed by a camera 110a, 110b.Otherwise, if motion detection is carried out by a camera 110a, 110b before the predefined time has elapsed since a previous motion detection time carried out by said camera 110a, 110b, then the verification device 120 does not record anything.

[0037] According to a third embodiment, the verification device 120 successively records in the table, in association with an identifier of the first camera 110a (respectively of the second camera 110b), each piece of information representing a moment of motion detection. In step 304, the verification device 120 checks in the table whether two motion detections made by two distinct cameras 110a, 110b are recorded. In other words, the verification device 120 checks whether a first motion detection made by a first camera 110a is recorded and whether a second motion detection made by a second camera 110b, distinct from the first camera 110a, is recorded. If so, the verification device 120 performs step 305. Otherwise, the verification device 120 performs step 301 again.

[0038] In the optional step 305, the verification device 120 further checks whether the second camera 110b belongs to the same surveillance site as the first camera 110a. If so, the verification device 120 performs step 306. Otherwise, the verification device 120 performs step 301 again.

[0039] In step 306, the verification device 120 calculates a time interval between the time t1 of the first motion detection and the time t2 of the second motion detection. In the case where several second motion detections are made by different second cameras 110b, distinct from the first camera 110a, the verification device 120 selects the time t2 of the most recent second motion detection.

[0040] According to the first and second embodiments described above, a single instant ti (respectively t2) of motion detection performed by the same camera 110a (respectively 110b) is recorded at a given time and is therefore taken into account to calculate said time interval.

[0041] According to the third embodiment described above, if several instants ti (respectively t2) of motion detections made by the same camera 110a (respectively 110b) are recorded successively in association with an identifier of said camera 110a (respectively 110b), the verification device chooses the instant ti of the first motion detection (respectively t2 of the second motion detection) most recent.

[0042] The verification device 120 then compares an absolute value of said time interval to a predefined duration. If the absolute value of said time interval is less than the predefined duration, the verification device 120 determines that there is an intrusion on the monitored site and performs step 307. Otherwise, the verification device 120 performs step 301 again.

[0043] At step 307, the verification device 120 erases the information representing the times ti and t2 of the first and second motion detections and then performs a step 308.

[0044] At step 308, the verification device 120 transmits an alarm message to the alarm control unit 130. Alternatively, the rule engine of the verification device 120 transmits information representative of an intrusion detection to a centralized home automation application, which transmits an alarm message to the alarm control unit 130.

[0045] Figure 4 schematically illustrates an example of the hardware architecture of the verification device 120. The verification device 120 then comprises, connected by a communication bus 210; a processor or CPU (Central Processing Unit) 401; a RAM (Random Access Memory) 402; a ROM (Read Only Memory) 403; a storage unit 404, such as a HDD (Hard Disk Drive), or a storage media reader, such as an SD (Secure Digital) card reader; and a COM interface 405 allowing communication with the cameras 110a, 110b, and the alarm control panel 130.

[0046] The CPU 401 is capable of executing instructions loaded into RAM 402 from ROM 403, external memory (such as an SD card), storage media, or a communication network. When the verification device 120 is powered on, the CPU 401 can read instructions from RAM 402 and execute them. These instructions form a computer program that causes the CPU 401 to implement all or part of the steps described herein in relation to the verification device 120.

[0047] All or part of said steps can thus be implemented in software form by executing a set of instructions by a programmable machine, such as a A DSP (Digital Signal Processor) or a microcontroller, or it can be implemented in hardware by a dedicated machine or component, such as an FPGA (Field-Programmable Gate Array) or an ASIC. (Application-Specific Integrated Circuit). In general, the verification device 120 thus includes electronic circuitry configured to implement all or part of the steps described here in relation to the verification device 120.

Claims

Claims

1. Intrusion detection method implemented by a verification device (120), connected to at least two cameras (110a, 110b), and characterized in that the method comprises the steps of: - receiving (302a) information representative of a first motion detection from a first camera (110a), - recording (303a) information representative of an instant of the first motion detection in association with an identifier of the first camera (110a) having carried out said first motion detection, - receiving (302b) information representative of a second motion detection from a second camera (110b), - recording (303b) information representative of an instant of the second motion detection in association with an identifier of the second camera (110b) having carried out said second motion detection,- detecting an intrusion (306) if a time interval between the instant of the first motion detection and the instant of the second motion detection is less than a predefined duration and if the second camera is distinct from the first camera.,

2. Method according to claim 1, characterized in that the verification device (120) is located at a distance from the first and second cameras, and in that the step of detecting an intrusion comprises verifying that the first camera and the second camera belong to the same surveillance site.

3. Method according to one of claims 1 or 2, characterized in that it further comprises a step of sending (308) an alarm message to an alarm center (130) when an intrusion is detected.

4. Verification device (120), connected to two cameras (110a, 110b) and characterized in that it comprises: - means for receiving (302a) information representative of a first motion detection from a first camera (110a), - means for recording (303a) information representative of an instant of the first motion detection in association with an identifier of the first camera (110a) having carried out said first motion detection, - means for receiving (302b) information representative of a second motion detection from a second camera (110b), - means for recording (303b) information representative of an instant of the second motion detection in association with an identifier of the second camera (110b) having carried out said second motion detection, - means for detecting an intrusion (306) if a time interval between the instant of the first motion detection and the instant of the second motion detection is less than a predefined duration and if the second camera is distinct from the first camera.

5. Intrusion detection system (100), characterized in that it comprises at least two cameras (110a, 110b) arranged on the same surveillance site, an alarm center (130) and a verification device (120) according to claim 4.

6. Intrusion detection system (100) according to the preceding claim, characterized in that each camera is oriented in a different direction from another camera so that the field of vision of one camera is separate from the field of vision of another camera.

7. A computer program that can be stored on a medium and / or downloaded from a communication network, in order to be read by a processor, and comprising instructions for implementing the method according to one of claims 1 to 3, when said program is executed by the processor.

8. An information storage medium storing a computer program according to the preceding claim.

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