JP2019106631A - Image monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently monitor a suspicious person who may have delivered with a high degree of suspicion in a monitoring area where an unspecified number of people gather and contact each other exclusively for welcoming. I will provide a. SOLUTION: A person tracking means 50 tracks a plurality of people appearing in a surveillance area based on surveillance images sequentially acquired by an image acquisition means 30 taking a picture of a predetermined monitoring area, and a plurality of group detection means 51. Among the persons in the above, a group of persons who maintain a close positional relationship in which the distance between persons is equal to or less than the predetermined proximity determination distance within a predetermined suspicious behavior determination time is detected. Then, the separate action determination means 53 determines that another action has occurred in the group when the person in the group has a separation position relationship longer than the proximity determination distance and exceeds the predetermined separation determination distance, and determines a suspicious person. The means 54 determines a person in the group for which the occurrence of this other action is determined to be a suspicious person. [Selection diagram] Fig. 2

Description

  The present invention relates to an image monitoring apparatus for detecting a suspicious person who may have performed an act of delivery or the like from an image obtained by imaging a monitoring area.

  Recently, there is an urgent need to strengthen surveillance against terrorism in a surveillance area where an unspecified number of people gather, such as an airport arrival lobby. One of the items to be monitored in such a surveillance area is the act of delivering dangerous goods.

  Conventionally, monitoring efficiency has been improved by automatically detecting passing behavior by imaging and analyzing a monitoring area in which a large number of unspecified persons gather.

  For example, in the image monitoring device described in Patent Document 1, when a different area having a size equal to or larger than a reference value is detected by comparing images of the same person photographed at different times, the person possessed by the person It is determined that a change has occurred in the presence or absence of an object, and the distance between the possessed object lost person who has changed from possessed state to not possessed state and the possessed object appearing person who changed from possessed state to possessed state is predetermined When it was within the distance range, it was judged that there was a delivery act.

  Also, for example, in the image monitoring system described in Patent Document 2, the article in which the person is registered is checked by collating the image of the photographed person with the image or article feature of the article such as a bag registered beforehand. It was judged whether or not it was possessed, and it was judged that there was a delivery act when the distance between the person whose possessed article disappeared and the person whose possessed article appeared was within a predetermined distance range. Alternatively, in the system, it is determined that the delivery act has occurred when the feature of the posture of the person in the middle of delivering the possessed article is detected from the photographed image.

Unexamined-Japanese-Patent No. 2017-016344 JP, 2017-028561, A

  However, in the monitoring area where an unspecified large number of people gather like an arrival lobby and contact between people occurs exclusively for meeting, the delivery with low degree of suspiciousness is frequently detected, resulting in the problem of a reduction in monitoring efficiency. there were.

  For example, in the arrival lobby, souvenirs may frequently be exchanged between the arriving person and the welcoming person. Also, in the arrival lobby, there may be frequent acts of carrying a bag of the person who has arrived, aiming for the labor of the person who has arrived.

  The present invention has been made in view of the above-mentioned problems, and it is possible that delivery with a high degree of suspiciousness is performed in a monitoring area in which an unspecified large number of people gather and contact between persons occurs exclusively for meeting. An object of the present invention is to provide an image monitoring apparatus capable of efficiently monitoring a suspicious person.

  In order to achieve the above object, according to the present invention, there is provided an image acquisition means for sequentially acquiring a surveillance image obtained by photographing a predetermined surveillance area, and a person tracking means for tracking a plurality of persons appearing in the surveillance area based on the surveillance image. And group detection means for detecting, from among the plurality of persons, a group of persons maintaining a proximity positional relationship whose inter-person distance is equal to or less than a predetermined proximity determination distance within a predetermined suspicious activity determination time period; When another person in the group is in the separated position relationship in which the distance determination distance is longer than the proximity determination distance, another action determination unit determines that another action has occurred in the group, and the occurrence of the other action is An image monitoring apparatus comprising: a suspicious person determination unit that determines a person of a determined group as a suspicious person.

  Furthermore, monitoring area information storage means storing in advance a plurality of entrance areas corresponding to different entrances in the monitoring area, the group detection means is characterized in that the entrances having different positions appear. It is preferable to detect the group including a person who is a region.

  In addition, the group detection means calculates, for a person who maintains the proximity position relationship within the range of the suspicious activity determination time, a movement direction difference immediately before becoming the proximity position relationship, and the movement direction difference is a predetermined difference. It is preferable to detect the group when the direction determination angle is exceeded.

  Further, the person image of the person maintaining the proximity position relationship in the monitoring image is compared with the image feature of the delivery posture obtained in advance to determine whether or not the posture of the person is the delivery posture. It is preferable to further include an attitude determination unit, wherein the group detection unit detects a group of persons for which the delivery attitude has been determined.

  Further, the group detection means calculates, for a person who maintains the proximity position relationship within the range of the suspicious activity determination time, a movement distance when the proximity position relationship is maintained, and the movement distance is a predetermined value. It is preferable to detect the group when it is equal to or less than the stationary determination distance.

  Further, the separate behavior determination means measures a separation time in which a person of the group continues the separation positional relationship, and the separate behavior occurs in the group when the separation time exceeds a predetermined separate behavior determination time. It is preferable to determine that the

  Further, it is preferable that the separate action determination unit determines that the separate action has occurred in the group when the person in the group disappears from the monitoring area while maintaining the separated positional relationship.

  Further, the separate behavior determining means calculates, for the group having the separated positional relationship, a movement direction difference of a person from the close positional relationship to the separated positional relationship, and the movement direction difference is a predetermined separate behavior. It is preferable to determine that the separate action has occurred when the determination angle is exceeded.

  Further, the suspicious person determination means measures the stay time of the person in the monitoring area, and the stay time of the person of the group whose occurrence of the another action is determined is equal to or less than a predetermined short stay determination time. It is preferable to determine the person as a suspicious person.

  According to the present invention, since it is possible to determine a suspicious person who may have made a suspicious delivery by distinguishing it from a person who has made a meeting or a mere translation, a large number of unspecified persons gather and contact between the persons exclusively for a meeting. In the monitoring area where a problem occurs, a suspicious person can be efficiently monitored.

It is a block diagram showing a schematic structure of image surveillance device 1 concerning an embodiment. It is a functional block diagram showing the function of image surveillance device 1 concerning an embodiment. It is a schematic diagram which illustrated the situation of surveillance field information and group detection. It is the schematic diagram which illustrated the mode of monitoring area | region information, another action determination, and a suspicious person determination. FIG. 6 is a diagram showing an example of person information in person information storage means 40. FIG. 6 is a diagram showing an example of group information of group information storage means 42. It is the figure which showed the example of the process which determines a delivery attitude | position. It is the flowchart which showed the operation of the graphics surveillance device which relates to the execution form. It is a flowchart of person tracking processing by the image monitoring device according to the embodiment. It is a flowchart of the group detection process by the image monitoring apparatus which concerns on embodiment. It is a flowchart of another behavior determination processing by the image monitoring device according to the embodiment. It is a flowchart of the suspicious person determination processing by the image monitoring device according to the embodiment.

  Hereinafter, as an embodiment of the present invention, an example of the image monitoring device 1 will be described which detects a suspicious person from a monitoring image in which an arrival lobby in an airport is photographed and displays the detection result to a surveillance officer. That is, the monitoring area in this embodiment is an arrival lobby.

<Configuration of Image Monitoring Device 1>
FIG. 1 is a block diagram showing a schematic configuration of the image monitoring device 1. The image monitoring apparatus 1 includes an imaging unit 2, a communication unit 3, a storage unit 4, an image processing unit 5, and a display unit 6.

  The photographing unit 2 is a monitoring camera, is connected to the image processing unit 5 through the communication unit 3, and is a photographing unit that photographs a monitoring area at predetermined time intervals and sequentially outputs a monitoring image. For example, the imaging unit 2 is a plurality of surveillance cameras arranged in a chain with a shared view with the adjacent surveillance cameras. Each of these surveillance cameras is installed in a surveillance area or a ceiling, a pillar, a wall, a pole, etc. in the vicinity of the surveillance area while being fixed in a field of view over the surveillance area and calibrated in advance. The photographing unit 2 photographs the monitoring area at a frame cycle of 1 second to generate a visible color image. Hereinafter, the time to be engraved in the frame period is referred to as time. Note that the imaging unit 2 may be configured by a single camera, or a monochrome image may be generated instead of a color image.

  The communication unit 3 is a communication circuit, one end of which is connected to the image processing unit 5, and the other end of which is the photographing unit 2 and the display unit 6 via a coaxial cable or a communication network such as LAN (Local Area Network) or the Internet. Connected The communication unit 3 acquires a monitoring image from the imaging unit 2 and inputs the monitoring image to the image processing unit 5, and outputs the detection result input from the image processing unit 5 to the display unit 6.

  The storage unit 4 is a memory device such as a read only memory (ROM) or a random access memory (RAM), and stores various programs and various data. The storage unit 4 is connected to the image processing unit 5 to input and output such information with the image processing unit 5.

  The image processing unit 5 is configured by an arithmetic device such as a central processing unit (CPU), a digital signal processor (DSP), and a micro control unit (MCU). The image processing unit 5 is connected to the storage unit 4 and reads out and executes a program from the storage unit 4 to operate as various processing means / control means, store various data in the storage unit 4 and read it out. The image processing unit 5 is also connected to the imaging unit 2 and the display unit 6 via the communication unit 3 and detects and detects a suspicious person by analyzing the monitoring image acquired from the imaging unit 2 via the communication unit 3 The result is displayed on the display unit 6 via the communication unit 3.

  The display unit 6 is a display device such as a liquid crystal display or a CRT (Cathode Ray Tube) display, and is connected to the image processing unit 5 via the communication unit 3 and is a display unit that displays the detection result by the image processing unit 5 . The observer visually recognizes the displayed detection results to determine the necessity of coping with the suspicious person, and takes action such as rushing a cooperator as necessary.

<Function of Image Monitoring Device 1>
FIG. 2 is a functional block diagram showing the functions of the image monitoring device 1. The communication unit 3 functions as an image acquisition unit 30 and a suspicious person information output unit 31 and the like, and the storage unit 4 functions as a person information storage unit 40, a monitoring area information storage unit 41 and a group information storage unit 42 and the like. The image processing unit 5 functions as a person tracking unit 50, a group detection unit 51, a posture determination unit 52, another action determination unit 53, a suspicious person determination unit 54, and the like.

  The image acquisition unit 30 sequentially acquires a monitor image from the imaging unit 2 which is an imaging unit, and sequentially outputs the acquired monitor image to the person tracking unit 50, the posture determination unit 52, and the suspicious person information output unit 31.

  Each means will be described below with reference to FIGS.

  The personal information storage means 40 stores personal information which is information about each person shown in the monitoring image. Specifically, the person information storage means 40 enumerates, as person information of each person, a person image of the person extracted from the monitoring image by the person tracking means 50, and a position (person position) at which the person image is extracted. The stored person position history, person feature quantities such as a color histogram characterizing the person image of the person in the monitoring image, and the like are stored in association with the person ID of the person. The person position history includes at least the appearance position and the current position.

  Further, the personal information storage means 40 stores intermediate data of the group detection means 51, the separate action determination means 53 and the suspicious person determination means 54 related to the person as the personal information of each person in association with the person ID of each person. Do.

  FIG. 5 exemplifies the intermediate data of the person information, and FIG. 5 (a) shows intermediate data 200 of the persons A to E being tracked at a certain time t, and FIG. Subsequent intermediate data 201 are shown respectively.

  The appearance position is intermediate data generated by the group detection unit 51, and corresponds to the entrance in the monitoring area where each person has appeared. In the present embodiment, in the appearance position, any one of an initial value blank, "entry gate", and "entry / exit area" is set.

  The stay time is intermediate data generated by the suspicious person determination means 54, and represents the time during which each person is staying in the monitoring area.

  The stationary time is intermediate data generated by the group detection unit 51, and represents a time during which each person can be regarded as stationary.

  The latest movement direction is intermediate data generated by the separate action determination unit 53, and represents the latest movement direction of each person. In the present embodiment, the movement direction is represented by an angle that increases counterclockwise with the X-axis direction in the virtual three-dimensional space of the XYZ coordinate system that simulates the monitoring area as 0 degree.

  The person tracking unit 50 analyzes a monitoring image sequentially input from the image acquiring unit 30, thereby tracking a plurality of persons appearing in the monitoring area to generate person information of each person, and the generated person information is person information It is stored in the storage means 40.

  Specifically, the human tracking means 50 performs background subtraction processing on the input monitoring image to detect a human region, extracts an image within the human region from the monitoring image, and extracts a human image. Further, the person tracking means 50 extracts the feature amount from the person image and calculates the degree of similarity with the person feature amount stored in the person information storage means 40, and sets the representative point of the person image as the person position. calculate.

  The position of the person is, for example, the three-dimensional position of the lowermost end (foot) of each person. For example, when the imaging unit 2 is configured by a plurality of calibrated surveillance cameras, a head is obtained by applying a three-dimensional person model to a view volume obtained by back projecting a person image extracted from each surveillance camera onto a world coordinate system. The part center position can be determined. The position of the person can also be another representative point such as the center of gravity, the top end, or the center of the head of the person. The position of the person may be represented by a plane coordinate system of the monitoring image (that is, a representative point of the person image).

  When the person feature amount whose similarity with the feature amount extracted from the person image exceeds a predetermined identification threshold is not stored, the person tracking unit 50 issues a new person ID, and the feature amount extracted from the person image Is stored in the personal information storage unit 40 in association with the personal ID as the personal feature amount, and is stored in the personal information storage unit 40 in association with the personal ID and the personal image and the position of the human. In addition, what is necessary is just to memorize | store the person image extracted by the surveillance camera closest to a person, for example, when comprising the imaging | photography part 2 with several surveillance cameras.

  On the other hand, when a person feature whose similarity with the feature extracted from the person image exceeds the identification threshold is stored, the person tracking unit 50 identifies the person image as that of the person indicated by the person feature. . The person tracking means 50 stores the person image in the person information storage means 40 in association with the person ID and the person position of the identified person. Further, the person tracking means 50 updates the person feature amount of the identified person with the feature amount extracted from the person image.

  Also, the person tracking means 50 deletes the person feature amount that has not been identified as any person image from the person information storage means 40 as being of the person who has moved to the outside of the monitoring area and finished tracking.

  The monitoring area information storage means 41 stores in advance monitoring area information including a first entrance area and a second entrance area representing different entrances in the monitoring area. For example, in the present embodiment in which the arrival lobby is the surveillance area, the first entrance represented by the first entrance area is the entry gate, and the second entrance represented by the second entrance area is the other door, aisle, and the like. It is the entrance of the escalator. The surveillance area is a contact between the person to be met and the person to be met, and the person to be greeted is at least included among the persons emerging from the first entrance area, and the person to be met is at least among the persons emerging from the second entrance area. It can be estimated that it is included in

  For example, in the present embodiment in which the position of the person is represented by the three-dimensional position of the lowermost end of the person, each of the first entrance area and the second entrance area is on the reference plane in the virtual three-dimensional space Set as the area of the floor surface). FIG. 3 schematically shows a reference plane of a virtual three-dimensional space represented by an XYZ coordinate system, and the first entrance area 101 and the second entrance area 102 and 103 set on the reference plane are shown. It is illustrated.

  Note that when the position of the person is another representative point, it may be a three-dimensional area in the virtual three-dimensional space, and when the position of the person is a representative point of the plane coordinate system of the monitoring image, the two-dimensional area of the plane coordinate system can do.

  The group information storage means 42 stores information on a combination of persons. In the present embodiment, the group information storage means 42 relates to all the pairs of persons under tracking, other than the detection results and the judgment results by the group detection means 51, the posture judgment means 52, the another action judgment means 53 and the suspicious person judgment means 54. The intermediate data by these means are stored. Therefore, in addition to the information on the pair of persons detected as the group, the information on the person pair not yet detected as the group is included and stored, but these are referred to as group information for convenience.

  FIG. 6 illustrates the group information 300 corresponding to the person information of FIG.

  The person pair is a pair of persons being tracked, and is represented by a combination of person IDs.

  The proximity time is intermediate data generated by the group detection unit 51, and represents the time during which each person pair was in proximity.

  The posture flag is data of the determination result generated by the posture determination means 52, and is set to 1 when the posture of each person pair is determined to be the delivery posture, and 0 otherwise.

  The group flag is data of the detection result generated by the group detection unit 51, and is set to 1 when each person pair is detected as a group, and 0 otherwise.

  The separation time is intermediate data generated by the separate action determination means 53, and represents the time when each person pair is separated. The separation time is measured only for the person pair detected as a group.

  The separate action state is data of the determination result generated by the separate action determination means 53, and "Yes" when another action with high accuracy is determined for each person pair, and another action with low accuracy is determined Is set to "Warning", otherwise it is set to "None". Another behavioral state is determined only for the person pair detected as a group.

  The suspiciousness degree is data of the judgment result generated by the suspicious person judging means 54, and it is an integer of 1 or more when it is judged that there is a possibility of a person who constitutes each person pair being a suspicious person, 0 otherwise Is set. In the present embodiment, the range of the degree of suspiciousness is 0-2. When it is determined that there is a possibility of a suspicious person, the larger the certainty of being a suspicious person, the larger the value is set.

  The group detection means 51 can be a group of persons of the person who maintained the proximity position relationship between the plurality of persons whose distance between the persons is equal to or less than the predetermined proximity judgment distance D1 within the predetermined suspicious behavior judgment time period. The information is detected as a group having sex and the information of the detected group is stored in the group information storage means 42.

  Specifically, the group detection unit 51 refers to the person information stored in the person information storage unit 40 and the group information stored in the group information storage unit 42, and the person being tracked at each time The distance between the positions of the persons (the distance between the persons) is calculated for each combination (person pair) and is compared with D1 to determine whether or not it is the proximity position relationship, and it is determined to be the proximity position relationship. The time (proximity time) that has been determined to be in close proximity relation for each person pair is measured and compared with the group action determination time T1 and the short-term contact determination time T2, the proximity time exceeds T1 and is less than or equal to T2 Detect a group

  That is, it is assumed that the persons who continued to be close to the distance of D1 or less for a longer time than T1 are not simply the persons passing each other but the persons having the involvement in the other party such as conversation or delivery. Persons who continued to be close to the distance of D1 or less for a short time of T2 or less are those who have been in contact with each other, avoiding contact with the eyes for a long time, and these persons are groups that have the possibility of suspicious persons As detected. The group action determination time T1 is set, for example, in advance to a typical required time for the passing people to walk away from each other to a distance less than D1 and then to a distance exceeding D1 plus a margin. The short-term contact determination time T2 can be set in advance to, for example, the length of time required only for delivery plus a margin, and the proximity determination distance D1 is, for example, the length for two arms plus a margin The distance can be set in advance.

  Here, a group detected only by time and distance may include a person who is merely translating by chance. Therefore, the group detection unit 51 detects a group including persons having different entry areas corresponding to the appearing positions so as not to detect a person who is merely translating by chance as a group. Specifically, the group detection unit 51 refers to the personal information stored in the personal information storage unit 40 and the monitoring area information stored in the monitoring area information storage unit 41, and the appearance position of each person is By comparing the coordinates of the first entrance area and the second entrance area, it is determined whether the appearance position of the person is the first entrance area or the second entrance area. And group detection means 51 is a person whose appearance position is a first entrance area among combinations of persons maintaining proximity position relation whose distance between persons is equal to or less than proximity determination distance D1 within the range of suspicious activity determination time And a combination of persons whose occurrence positions are the second entrance area is detected as a group.

  In addition, in order to increase the certainty of being persons who have been involved in the other party, it is possible to set that both have stopped as a condition for group detection. That is, the group detection unit 51 calculates the movement distance when the proximity position relationship is maintained for the person maintaining the proximity position relationship within the range of the suspicious activity determination time, and the movement distance is determined to be a predetermined stationary. A group is detected when the distance is less than or equal to D0. In addition, it is not necessary to be the movement distance of D0 or less in all of the time when maintaining the close positional relationship, and it is the persons who have participated in each other if it is the movement distance of D0 or less for the predetermined stationary judgment time T3. You can check

  Specifically, the group detection unit 51 refers to the person information stored in the person information storage unit 40, and the proximity position relationship of the person is determined from the person position of the person determined to be the proximity position relationship. The movement distance during the period is calculated and compared with D0, and the time (resting time) in which the movement distance is D0 or less is measured and compared with T3. The stationary determination distance D0 can be set to, for example, a distance of about the width of an individual, and the stationary determination time T3 can be set in advance to, for example, approximately the same time as the group behavior determination time T1. Then, the group detection unit 51 maintains the proximity position relationship in which the inter-person distance is equal to or less than the proximity determination distance D1 within the range of the suspicious activity determination time, and sets T3 among combinations of persons who are entrance regions having different appearance positions. A combination including a person whose movement distance is less than or equal to D0 is detected as a group in a longer time.

  Then, the group detection means 51 sets 1 in the group flag of the person pair detected as a group in the group information and 0 in the group flag of the person pair not detected as a group. Further, the group detection unit 51 appropriately inputs and outputs the appearance position of each person in the person information and the still time as the intermediate result of the detection process with the person information storage unit 40, and the proximity time of each person pair in the group information Are input to and output from the group information storage means 42.

  In addition, in order to increase the certainty of the persons who had the delivery, in addition to the two having stopped, or in place of the two having stopped, taking the posture of the delivery as a condition of the group detection It is also good.

  Therefore, the posture determination means 52 compares the monitoring image when the person in the group in the monitoring image maintains the close positional relationship with the image feature of the delivery posture acquired in advance, and the posture of the person is It is determined whether or not it is a delivery attitude, and the determination result is stored in the group information storage unit 42. The group detection unit 51 detects a group with reference to the determination result.

  Specifically, first, the posture determination means 52 detects a plurality of parts from the person image of the person determined to be in the close positional relationship, with reference to the person information stored in the person information storage means 40. That is, the posture determination means 52 has images of the head, right shoulder, right elbow, right wrist, left shoulder, left elbow, left wrist, right hip, right knee, right ankle, left hip, left knee, left ankle and each image in advance. A human body image of a person determined to be in a close positional relationship is input to a part classifier that is a part classifier that has learned the positional relationship between images and stored in the storage unit 4, and a part in the human image Identify the placement of

  Next, the posture determination means 52 detects the positions of the right-hand and left-hand part shape models in the specified arrangement. The detected position is a local position in the person area of each person. The posture determination means 52 adds the position of the person who is the representative position of the person image of the person to the positions of the right hand and left hand in the person image of each person to calculate the position of the global right hand and left hand in the monitoring area. The position of each part may be detected by shape matching between a person area in a person image and a shape model of a plurality of parts.

  Subsequently, the posture determination means 52 calculates the distance of the combination of the position of the right hand and the left hand in the monitoring area among the persons determined to be in the close positional relationship, and selects the minimum distance from among the calculated distances. Calculated as the distance between hands.

  Then, the posture determination means 52 determines that the posture of the combination of persons is the delivery posture when the distance of the hand between the persons is less than or equal to a predetermined threshold D3 for the combination of the persons determined to be in the close positional relationship. The posture flag of the group information storage unit 42 is updated to one. The initial value of the posture flag is 0, and the posture flag of the combination of persons not updated to 1 is maintained at 0. The threshold value D3 can be set in advance to a length of about the width of the bag.

  FIG. 7 shows an example of the posture determination process for person images 510 and 520 of persons A and C who are delivering bags. The circle in the figure indicates the position of the detected site. In this example, the right wrist 511 and the left wrist 512 are detected from the person image 510 of the left person A by the posture determination means 52, and the right wrist 521 and the left wrist 522 are detected from the person image 520 of the right person C. There is. And the posture determination means 52 calculates the distance between the left wrist 512 and the right wrist 521 among them as the distance of the hand between persons, and since the distance is D3 or less, the postures of the persons A and C are It is determined that the posture is the delivery posture, and the value of the posture flag of the person pair “A, C” in the group information of FIG.

  The groups detected by the group detection means 51 include not only suspicious person groups but also simple pick-up groups. The separate action determination means 53 determines whether or not the persons who make up the detected group have taken another action after that, and thus a suspicious group taking another action and a group of a meeting who often does not take another action. To distinguish between

  Therefore, the separate action determination unit 53 determines that the separate action has occurred in the group when at least a person in the group has a separated positional relationship in which the separation determination distance D2 longer than the close determination distance D1 is determined. The group information storage unit 42 stores the determination result. Specifically, the separate action determination means 53 refers to the person information stored in the person information storage means 40 and the group information stored in the group information storage means 42, and adds 1 to the group flag at each time. It is determined whether or not the person pair is in a separated positional relationship by calculating the inter-person distance for each person pair for which is set and comparing with D2. For example, the separation determination distance D2 may be about three times as long as the proximity determination distance D1.

  FIG. 5 illustrates intermediate data 200 of person information at a certain time t. Further, FIG. 3 schematically shows movement trajectories 110 to 114 in which the positions of the persons obtained by tracking the persons A to E are connected by the time t shown in FIG. 5. Further, FIG. 6 illustrates the group information 300 after 30 hours from time t.

  An example of group detection by the group detection unit 51 will be described based on these.

  As shown in the intermediate data 200 of FIG. 5 and the movement trajectories 110 and 112 of FIG. 3, the appearance position of the person A is the entry gate 101, and the appearance position of the person C is the entry / exit area 102, which are different from each other. The persons A and C are close to a distance equal to or less than D1 at time t, and the close positional relationship is maintained for 10 hours thereafter as shown in the close time of the group information 300 in FIG. Also, as shown in the stationary time of the intermediate data 200, at least the persons A and C were stationary for five times while the close positional relationship was maintained. Furthermore, as shown in the group information 300, it is determined that the person pair "A, C" has taken the delivery attitude, and 1 is set to the attitude flag of the pair. From these data, the person pair “A, C” is determined to satisfy the detection condition and is detected as a group.

  Further, as shown in the intermediate data 200 and the movement locus 111, the appearance position of the person B is the entry gate 101, which is different from the appearance position of the person C. People B and C were close to a distance of D1 or less at time t, and as shown in the proximity time of group information 300, the proximity positional relationship was maintained for 10 hours thereafter. Also, as shown in the stationary time of the intermediate data 200, at least the persons B and C have been stationary for 5 hours while the close positional relationship is maintained. Furthermore, as shown in the group information 300, it is determined that the person pair "B, C" has taken delivery posture, and 1 is set to the posture flag of the pair. From these data, the person pair "B, C" is considered to satisfy the detection condition and is detected as a group.

  Further, as shown in the intermediate data 200 and the movement trajectories 113 and 114, the appearance position of the person D is the entry gate 101, and the appearance position of the person E is the entry / exit area 103, which are different from each other. The persons D and E were close to a distance equal to or less than D1 at time t, and as shown in the proximity time of the group information 300, the proximity positional relationship was maintained for 10 hours thereafter. Also, as shown in the stationary time of the intermediate data 200, at least the persons B and C have been stationary for 5 hours while the close positional relationship is maintained. Furthermore, as shown in the group information 300, it is determined that the person pair "D, E" has taken delivery attitude, and 1 is set to the attitude flag of the pair. From these data, the person pair "D, E" is considered to satisfy the detection condition and is detected as a group.

  Here, even if it is a group that is not a suspicious person, it may happen that one step in the group is delayed and another one in the group moves ahead for a short time without noticing it. In order to prevent a false alarm in such a case, it is preferable that the separate behavior judging means 53 confirm the moving direction and / or the separation time at the time of separation.

  That is, the separate action determination means 53 calculates the movement direction difference of the person from the proximity position relation to the separation position relation for the group having the separation position relation, and the movement direction difference is a predetermined another action determination angle If it exceeds r, it is determined that another action has occurred.

  Further, the separate action determination means 53 measures the separation time in which a person in the group continues the separation positional relationship, and determines that the separate action has occurred in the group when the separation time exceeds the predetermined separate action determination time T4. Do.

  Specifically, the separate action determination means 53 refers to the person information and the group information, and the distance between persons exceeds D2 for each person pair whose group flag is set to 1 at each time. The difference between the most recent movement direction of the two is calculated as the movement direction difference at the time of separation and compared with another behavior determination angle r, and the time when the distance between persons exceeds D2 is measured as the separation time and compared with T4. When the movement direction difference exceeds r and the separation time exceeds T4, it is determined that another action has occurred in the person pair. The separate action determination angle r may be, for example, 90 degrees, and the separation time may be, for example, several seconds.

  In the above description, although the moving direction difference exceeds r and the separation time exceeds T4, another action occurs when the moving direction difference exceeds r on condition that only one of the moving conditions is satisfied. It may be determined that the other action has occurred when the separation time exceeds T4. Further, two or more conditions may be managed and ranked according to the satisfied conditions.

  In this embodiment, it is determined that another action has occurred when the movement direction difference exceeds r and the separation time exceeds T4, and when the separation time exceeds T4, the former has higher confidence than the latter. Manage as a state.

  Then, the separate behavior determining means 53 determines that the moving direction difference exceeds r and the separation time exceeds T4 in the group information in the separate behavior state of the pair of persons, the separation time exceeds T4, and the movement direction difference is Set “Warning” to another behavior state of the person pair whose r has not yet exceeded r, and “none” to the other behavior state of the other person pair. Further, the separate action determination means 53 appropriately inputs / outputs the separation time of each person in the person information to / from the person information storage means 40 as an intermediate result of the determination process, and calculates the latest movement direction of each person pair in group information. Input / output with the group information storage means 42.

  The suspicious person determination means 54 determines that the person in the group in which the occurrence of another action is determined is a suspicious person with reference to at least the determination result by the separate action determination means 53, and generates information (suspicious person information) of the suspicious person Then, the information is output to the suspicious person information output means 31.

  Specifically, the suspicious person determination means 54 refers to the group information stored in the group information storage means 42, and sets a person who constitutes a pair of persons whose other action state is "Yes" or "Warning" with the suspicious person. It determines and sets one or more values to the suspiciousness degree of the said person pair in the group information of the group information storage means 42. At this time, the suspicious person determination means 54 determines that the degree of suspiciousness is “warning”, assuming that the likelihood of being a suspicious person is higher when the other behavior state is “yes” than when the other action state is “warning”. 1. Set the suspiciousness degree when it is "Available" to 2.

  Here, it is considered that the suspicious person performing the delivery tends to shorten the stay time of the monitoring area in order to avoid the eyes. Therefore, the suspicious person determination means 54 measures the stay time of the person in the monitoring area, and the stay time of the person of the group whose occurrence of another action is determined is the predetermined short stay determination time T5 or less. Can also be determined as a suspicious person. The short-term stay determination time T5 is preset to a time shorter than the average stay time of the monitoring area obtained through, for example, prior experiments.

  Alternatively, it is also preferable to increase the certainty of being a suspicious person according to the short stay time. In this case, for example, the suspicious person determination means 54 sets the suspiciousness degree of the pair to 3 when the stay time of any of the persons who make up the person pair whose separate action state is “A” is equal to or less than T5. The suspiciousness degree of the pair is set to 2 when the stay time of the person who constitutes the person pair whose other action state is "yes" exceeds T5. Further, for example, the suspicious person determination means 54 sets the suspiciousness degree of the pair to 2 when the stay time of any of the persons constituting the person pair whose another action state is “warning” is T5 or less. The suspiciousness degree of the pair is set to 1 when the stay time of the persons constituting the person pair whose other action state is "warning" exceeds T5 in any case.

  In addition, the suspicious person determination means 54 generates suspicious person information in which the monitoring person can visually recognize the action of the person based on the person information of the persons constituting the person group having a degree of suspiciousness of 1 or more. It is outputted to the person information output means 31. For example, the suspicious person information can be an image obtained by combining the monitoring image, the suspiciousness degree of the corresponding person pair, and the person image of the corresponding person.

  The suspicious person information output unit 31 transmits the suspicious person information input from the suspicious person determination unit 54 to the display unit 6 via the communication network. Then, the suspicious person information is displayed by the display unit 6 and is visually recognized by the surveillance staff.

  FIG. 5 exemplifies the intermediate data 201 of the personal information 30 hours after a certain time t. Further, FIG. 4 schematically shows movement trajectories 210 to 214 connecting person positions obtained by tracking the persons A to E from time t to 30 hours later. Further, FIG. 6 illustrates the group information 300 after 30 hours from time t.

  Based on these, an example of another behavior determination processing by the other behavior determination means 53 and a suspicious person determination by the suspicious person determination means 54 will be described.

  As shown in the group information 300, person pairs "A, C", "B, C" and "D, E" for which 1 is set in the group flag are detected as a group.

  Among them, the person pair “A, C” has a large movement direction difference at the time of separation as shown by the movement trajectories 210 and 211, and as shown at the separation time of the group information 300, continuing. From these data, it is determined that another action has occurred for the person pair "A, C", and "A" is set as the other action state. Then, the suspiciousness degree of the person pair "A, C" is set to 2 in response to the other behavior state being set to "present".

  The person pair “B, C” has a large movement direction difference at the time of separation as seen from the movement trajectories 211 and 212, but as shown in the group information 300, the separation time is still five times. From these data, it is determined that another action has occurred for the person pair "B, C", and "warning" is set to the other action state because the separation time is still short. Then, the suspiciousness degree of the person pair "B, C" is set to 1 in response to the other behavior state being set to "Warning".

  Since the movement direction difference at the time of separation is small as the person pair “D, E” can be seen from the movement trajectories 213 and 214, the occurrence of another action is not determined. Therefore, the another behavior state of the person pair "D, E" remains "none", and the suspiciousness degree of the person pair "B, C" remains zero.

  The operation of the image monitoring device 1 will be described with reference to the flowcharts of FIGS.

  The administrator of the image monitoring device 1 confirms that the monitoring area is unmanned and starts the image monitoring device 1. After activation, the imaging unit 2 captures the monitoring area at predetermined time intervals and sequentially outputs monitoring images. The communication unit 3 operates as the image acquisition unit 30, and the monitoring image is sequentially input to the image processing unit 5 via the image acquisition unit 30.

  The image processing unit 5 repeats the processing of steps S1 to S5 of FIG. 8 each time a monitoring image is acquired.

  When a surveillance image is acquired via the image acquisition unit 30 (S1), the image processing unit 5 operates as a person tracking unit 50 etc. and the storage unit 4 operates as a person information storage unit 40 etc. Track each person (S2).

  The person tracking process of step S2 will be described with reference to FIG. In the process of person tracking processing, the image processing unit 5 also operates as a group detection unit 51, a posture determination unit 52, another action determination unit 53, and a suspicious person determination unit 54, and the storage unit 4 is a monitoring area information storage unit 40. Also, it operates as the group information storage unit 42, and information generation for group detection, another action determination, and a suspicious person determination is appropriately performed.

  First, the person tracking means 50 extracts a person image from the surveillance image by differential processing between the surveillance image and the background image, and identifies the person position (current position) (S211). In addition, in step S211, the person tracking unit 50 appropriately updates the background image. It should be noted that the person tracking means 50 generates a background image by averaging the input monitor image or the like in step S211 and stores the image in the storage unit 4 until the predetermined time elapses from immediately after the activation. The processing of steps S212 to S226 is omitted.

  Next, the person tracking means 50 extracts the feature amount from each of the person images, and compares it with the person feature amount of the person (tracking person) being tracked stored in the person information storage means 40 By specifying the person ID, the person is associated (S212). At this time, the person tracking unit 50 assigns a new person ID to a person image that does not correspond to any of the persons being tracked.

  Subsequently, the person tracking unit 50 sequentially sets the tracking person including the new person (new person) as the target person and executes the loop process of steps S213 to S226.

  In the loop process of the tracking person, first, the human tracking means 50 checks whether the noted person is a new person (S214). If there is no record in the person information storage means 40, it is a new person. If the focused person is a new person (yes in step S214), the process proceeds to step S215.

  In step S215, the addition of the person information of the new person and the group information is performed. That is, the person tracking means 50 causes the person information storage means 40 to additionally store the person ID of the notable person given in step S212, the person image extracted in step S211, and the person information having the person feature amount extracted in step S212. Further, the group detection unit 51 causes the group information storage unit 42 to additionally store group information of a new person pair in which the person ID of the person of interest and the person ID of the other tracking person are combined.

  In the subsequent step S216, personal information and group information of the new person are initialized. That is, the group detection unit 51 updates the appearance position in the personal information added at step S215 as a blank, and updates the stillness time to zero. Further, the group detection unit 51 updates the proximity time in the group information additionally written in step S215 to 0 and the group flag to 0. Further, the posture determination means 52 updates the posture determination flag in the group information to zero. Further, the separate action determination means 53 updates the latest movement direction in the person information to blanks, and updates the separation time in the group information to 0, and the separate action state to "none". Also, the suspicious person determination means 54 updates the stay time in the personal information to 0, and updates the suspiciousness degree in the group information to 0.

  In the subsequent step S217, the group detection unit 51 compares the current position of the person of interest with the monitoring area information stored in the monitoring area information storage unit 41, and determines whether the appearance position of the person of interest is the first entry area It is determined whether it is the second entrance area and the determination result is stored in the person information storage unit 40. In the present embodiment, a character string “entry gate” is stored in the first entrance area, and a character string “entry / exit area” is stored in the second entrance area.

  When the determination in step S217 is finished, the process proceeds to step S226.

  On the other hand, if the noted person is not a new person (NO in step S214), the process proceeds to step S218.

  In step S218, the person tracking unit 50 and the group detection unit 51 confirm whether or not the person of interest has disappeared (ie, moved out of the monitoring area). When it disappears (yes in step S218), the person tracking means 50 deletes the person information of the noted person from the person information storage means 40, and the group detection means 51 stores the group information of the person pair including the noted person in the group information After deleting from the means 42 (S225), the process proceeds to step S226.

  On the other hand, if the noted person has not disappeared (NO in step S218), the process proceeds to step S219.

  In step S219, the group detection unit 51 determines the stillness by calculating the movement distance from the person position one time before the noted person stored in the person information storage unit 40 and the current position of the noted person identified in step S211. Compare with distance D0. If the movement distance is D0 or less (yes in step S219), the group detection unit 51 increments the stillness time of the noted person stored in the person information storage unit 40 by one time (S220). On the other hand, when the movement distance exceeds D0 (No in step S219), the group detection unit 51 resets the stillness time of the noted person stored in the person information storage unit 40 to 0 (S221). Proceed to step S222.

  In the subsequent step S222, the suspicious person determination means 54 increments the stay time of the noted person stored in the person information storage means 40 by one time.

  In the following step S223, the separate action determination means 53 calculates the movement direction from the person position one time before the attention person stored in the person information storage means 40 and the current position of the attention person specified in step S211. The calculated moving direction is overwritten and stored in the nearest moving direction of the noted person in the person information storage unit 40.

  In the following step S224, the person tracking means 50 overwrites and stores the current position of the noted person specified in step S211 in the current position of the noted person in the person information storage means 40.

  In the subsequent step S226, the person tracking means 50 confirms whether or not all of the chase persons including the new person have been processed as the target person. If there is an unprocessed chase person (No in step S226), the process returns to step S213, and the process of the next chase person is performed. On the other hand, if all the tracking persons have been processed (YES in step S226), the process proceeds to step S3 in FIG.

  In step S3, a group detection process is performed based on the person information and the group information updated by the person tracking process.

  The group detection process of step S3 will be described with reference to FIG. In the process of group detection processing, the image processing unit 5 operates as the group detection unit 51 and the posture determination unit 52, and the storage unit 4 operates as the person information storage unit 40 and the group information storage unit 42.

  The group detection unit 51 reads group information from the group information storage unit 42, sequentially sets a person pair included in the group information as a target pair, and executes the loop process of steps S311 to S323.

  In the loop processing of a person pair, first, the group detection unit 51 confirms whether or not the group flag of the target pair is 0 (S312). If the group flag is 0, it is not determined whether or not there is a possibility of the group of suspicious individuals for the pair of attentions (yes in step S312), and the process proceeds to step S313. On the other hand, when the group flag is 1 (no in step S312), steps S313 to S322 are omitted, and the process proceeds to step S323.

  In step S313, the group detection unit 51 reads the personal information of each of the persons who form the target pair from the personal information storage unit 40, and compares the appearance positions of the two. If the two entrances are different (yes in step S313), the group detection unit 51 determines that there is a possibility of a group of suspicious individuals and advances the process to step S314. On the other hand, if the appeared entrances are the same (NO in step S313), steps S314 to S322 are omitted, and the process proceeds to step S323.

  In step S314, the group detection unit 51 compares the stillness time of each of the persons constituting the noted pair with the stillness judgment time T3. If both stationary times exceed T3 (yes in step S314), the group detection unit 51 advances the process to step S315 on the assumption that there is a possibility of a group of suspicious persons. On the other hand, if one of the stationary times is T3 or less (NO in step S314), steps S315 to S322 are omitted, and the process proceeds to step S323.

  In step S315, the group detection unit 51 calculates the inter-person distance from the current position of the persons constituting the target pair, and compares the inter-person distance with the proximity determination distance D1. When the inter-person distance is equal to or less than D1 (yes in step S315), the group detection unit 51 increases the proximity time of the target pair stored in the group information storage unit 42 by one time (S316). Proceed to step S317. On the other hand, when the inter-person distance exceeds D1 (NO in step S315), steps S316 to S322 are omitted, and the process proceeds to step S323.

  In step S317, the posture determination means 52 reads out the personal information of each of the persons constituting the attention pair from the person information storage means 40, and determines whether the posture of the attention pair is the delivery attitude from the current position of both and the person image. judge. If the posture of the attention pair is the delivery posture (yes in step S317), the posture determination means 52 updates the posture flag of the attention pair stored in the group information storage means 42 to 1 (S318). On the other hand, when the posture of the attention pair is not the delivery posture (NO in step S317), the process of step S318 is omitted.

  In steps S319 to S321, the group detection unit 51 newly reads out the group information of the noted pair from the group information storage unit 42, and reads again the person information of each of the persons constituting the noted pair from the person information storage unit 40. Based on the information in, it is determined whether or not the focused pair is a possibility of a group of suspicious persons.

  In step S319, the group detection unit 51 confirms whether the posture flag of the target pair is one. If the posture flag is 1 (yes in step S319), the group detection unit 51 advances the process to step S320 on the assumption that there is the possibility of a group of suspicious persons. On the other hand, when the posture flag is 0 (no in step S319), steps S320 to S322 are omitted, and the process proceeds to step S323.

  In step S320, the group detection unit 51 compares the proximity time of the target pair with the group behavior determination time T1. If the proximity time exceeds T1 (yes in step S320), the group detection unit 51 determines that there is a possibility of a group of suspicious individuals, and advances the process to step S321. On the other hand, if the proximity time is equal to or less than T1 (NO in step S320), steps S321 and S322 are omitted, and the process proceeds to step S323.

  In step S321, the group detection unit 51 compares the proximity time of the target pair with the short-term contact determination time T2. When the proximity time is equal to or less than T2 (yes in step S321), the group detection unit 51 determines that there is a possibility of the group of the suspicious person, and the group flag of the attention pair stored in the group information storage unit 42 is 1 To (S322). On the other hand, if the proximity time exceeds T2 (NO in step S321), step S322 is omitted because there is no possibility that the group is a suspicious person, and the process proceeds to step S323.

  In step S323, the group detection unit 51 confirms whether all the person pairs included in the group information have been processed as the target pair. If there is an unprocessed person pair (No in step S323), the process returns to step S311 to perform the process of the next person pair. On the other hand, if all of the person pairs have been processed (YES in step S323), the process proceeds to step S4 in FIG.

  In step S4, another action determination process is performed to determine whether another action has occurred for the person in the group detected by the group detection process.

  Another action determination process of step S4 will be described with reference to FIG. In the process of the separate action determination process, the image processing unit 5 operates as the separate action determination unit 53, and the storage unit 4 operates as the person information storage unit 40 and the group information storage unit 42.

  The separate action determination unit 53 reads out the group information from the group information storage unit 42, sequentially sets the person pair included in the group information as a target pair, and executes the loop process of steps S411 to S422.

  In the loop processing of the person pair, the separate behavior determination means 53 first confirms whether the group flag of the attention pair is 1 (S412). If the group flag is 1 (yes in step S412), the process proceeds to step S413. On the other hand, if the group flag is 0, it is not determined (No in step S412), and the process proceeds to step S422.

  Further, the other-action determining means 53 confirms whether the another-action state of the attention pair is “none” or “warning” (S413). If another behavior state is "none" or "warning", the process proceeds to step S414 as a determination target (yes in step S413). On the other hand, if it is determined that the other behavior state is "YES" (NO in step S413), the process proceeds to step S422.

  In step S414, the separate action determination means 53 reads out the personal information of each of the persons constituting the pair of interest from the personal information storage means 40, calculates the inter-person distance from the current position of both, and determines the inter-person distance as the separation determination distance D2. Compare with. When the inter-person distance exceeds D2 (yes in step S414), the separate action determination unit 53 increases the separation time of the target pair stored in the group information storage unit 42 by one time (S417), The process then proceeds to step S418. On the other hand, when the inter-person distance is equal to or less than D2, it is determined that another action has not occurred (No in step S414), and the other action determination unit 53 resets the separation time of the target pair in the group information storage unit 42 to 0. At the same time (S415), "none" is set to the other behavior state of the same pair (S416), and the process proceeds to step S422.

  In step S418, the another behavior determination means 53 compares the separation time of the attention pair updated in step S417 with the other behavior determination time T4. If the separation time exceeds T4, another process is generated (YES in step S418), and the process proceeds to step S419. On the other hand, if the separation time is equal to or less than T4, another action is not generated (NO in step S418), steps S419 to S421 are omitted, and the process proceeds to step S422.

  In step S419, the another action determination unit 53 calculates a moving direction difference which is a difference between the closest moving directions among the persons constituting the pair of interest, and compares the moving direction difference with the other direction determination angle r. If the movement direction difference exceeds r, it is determined that the certainty factor of occurrence of another action is high (yes in step S419), the another action determination means 53 changes the other action state of the noted pair in the group information storage means 42 “Avail” is set (S421), and the process proceeds to step S422. On the other hand, if the movement direction difference is equal to or less than r, it is assumed that the state where there is a possibility of occurrence of another action continues (No in step S419). "Warning" is set in the action state (S420), and the process proceeds to step S422.

  In step S422, the other-action determination means 53 confirms whether all the person pairs included in the group information have been processed as a target pair. If there is an unprocessed person pair (No in step S422), the process returns to step S411 to process the next person pair. On the other hand, if all the pairs of persons have been processed (YES in step S422), the process proceeds to step S5 in FIG.

  In step S5, a suspicious person determination process of determining a suspicious person based on the result of the separate action determination process is performed.

  The suspicious person determination process of step S5 will be described with reference to FIG. In the process of the suspicious person determination process, the image processing unit 5 operates as the suspicious person determination unit 54, and the storage unit 4 operates as the personal information storage unit 40 and the group information storage unit 42.

  The suspicious person determination unit 54 reads out the group information from the group information storage unit 42, sequentially sets the person pair contained in the group information as a target pair, and executes the loop process of steps S511 to S518.

  In the loop processing of the person pair, the suspicious person determination means 54 confirms another behavior state of the noted pair in the group information (S512, S515).

  When the another behavior state of the noted pair is "present" (yes in step S512), the suspicious person determination means 54 updates the suspiciousness degree of the noted pair in the group information storage means 42 of the noted pair to 2 (S514) .

  Then, if the separate action state is “warning” or “none” (NO in step S512), the suspicious person determination means 54 advances the process to step S515.

  On the other hand, when the stay time of the persons constituting the noted pair exceeds T5 in any case (no in step S513), the suspicious person judging means 54 determines the suspiciousness degree of the noted pair in the group information storage means 42 of the noted pair. It is updated to 0 (S517), and the process proceeds to step S518.

  In step S515, the suspicious person determination means 54 again confirms another behavior state of the noted pair. When the another behavior state of the noted pair is "warning" (yes in step S515), the suspicious person determination means 54 updates the suspiciousness degree of the noted pair in the group information storage means 42 of the noted pair to 1 (S516) The process then proceeds to step S518.

  On the other hand, when the another behavior state of the noticed pair is "none" (No in step S515), the suspicious person judging means 54 updates the suspiciousness degree of the noticed pair in the group information storage means 42 of the noticed pair to 0 ( S517), the process proceeds to step S518.

  In step S518, the suspicious person determination means 54 confirms whether or not all the pairs of persons included in the group information have been processed as a target pair. If there is an unprocessed person pair (No in step S518), the process returns to step S511 to process the next person pair. On the other hand, if all of the person pairs have been processed (YES in step S518), the process proceeds to step S6 in FIG.

  In step S6, the suspicious person determination means 54 refers again to the group information in the group information storage means 42, and confirms the presence or absence of a group whose suspiciousness degree is 1 or more.

  If there is a group whose suspiciousness degree is 1 or more (yes in step S6), generation and output of suspicious person information are performed (S7).

  In step S7, the suspicious person determination means 54 reads out, from the person information storage means 40, the person information of the person who constitutes the person pair whose degree of suspiciousness is one or more. Then, the suspicious person determination means 54 generates a suspicious person image in which a character string indicating the degree of suspiciousness of the person pair to which each person belongs belongs for each person and the person image of each person. Further, the suspicious person determination means 54 generates an image obtained by arranging and combining the one or a plurality of suspicious person images in the monitoring image as suspicious person information, and outputs the image to the communication unit 3.

  The communication unit 3 into which the suspicious person information is input operates as the suspicious person information output unit 31 and transmits the suspicious person information to the display unit 6. The display unit 6 displays the suspicious information so that the supervisor can view it.

  On the other hand, when there is no group whose degree of suspiciousness is 1 or more (No in step S6), step S7 is omitted. At this time, the image processing unit 5 may output the monitor image as it is to the communication unit 3 and transmit the monitor image to the display unit 6 and cause the display unit 6 to display the monitor image.

  When the above process is completed, the process returns to step S1.

<Modification>
(1) In the above embodiment, an example is shown in which the arrival lobby in the airport is used as a monitoring area. However, people and people are exclusively from different directions, such as the arrival lobby of the bus, the station before the ticket gate, and the junction of the passage. It is applicable to the area which arrives and joins.

  (2) In the above embodiment and its modification, an example in which two types of entrance areas are set is shown, but three or more types of entrance areas may be set, such as setting entrance areas on each passage of the trifurcation. It may be set.

  (3) In the above embodiment and each variation, the group detection unit 51 sets the proximity position relationship within the range of suspicious activity determination time with the group behavior determination time T1 as the lower limit and the short-term contact determination time T2 as the upper limit. Although the example which detects the group of the person who maintained was shown, the upper limit may be omitted and the range where the proximity time exceeds the group behavior determination time T1 may be the range of the suspicious behavior determination time.

(4) In the above-described embodiment and each of the modifications, an example is shown in which the group detection unit 51 detects a group of persons arriving from different directions based on the appearance position. The direction of movement can also be used.
In that case, the group detection means 51, similar to the separate action determination means 53 described above, for the person whose proximity position relationship is maintained within the range of the suspicious activity determination time, the movement direction difference immediately before the proximity position relationship The group is calculated when the movement direction difference exceeds a predetermined other direction determination angle.

(5) In the above-described embodiment and each of the modifications, an example is shown in which the separate action determination unit 53 detects the occurrence of another action based on the movement direction difference of the person from the close position relation to the separated position relation. However, it is also possible to use the disappearance from the monitoring area as a detection index instead of the movement direction difference.
In that case, the separate behavior determining means 53 determines that another group of behaviors has occurred when the group person disappears from the monitoring area while maintaining the separated positional relationship.

  (6) In the above embodiment and each of the modifications, the person tracking unit 50 records the appearance position and the latest position as the person position history, and the group detection unit 51, the separate action determination unit 53, and the suspicious person determination unit 54 sequentially In the example, various processes are performed with reference to the person position history. In a further modification, the photographing means adds the photographing time and outputs the monitoring image, and the person tracking means 50 records a set of the person position and the photographing time from the appearance position to the latest position as the person position history, The detection unit 51, the separate action determination unit 53, and the suspicious person determination unit 54 may perform various processing by tracing back the person position history as appropriate. In this case, for example, the immediately preceding movement direction can be an average of movement directions of three or more times. Further, in this case, for example, the suspicious person determination means 54 can add the movement locus of a person whose suspiciousness degree is one or more to the suspicious person information and output it.

(7) In the above-described embodiment and each of the modifications, the group detection unit 51 satisfies the condition of the appearance position or the movement direction difference, the condition of the delivery posture, and the condition of the stationary time in addition to the maintenance of the close positional relationship. Although an example of detecting a group of persons is shown, the group detection unit 51 may detect the condition of the appearance position, the condition of the moving direction difference, the condition of the delivery posture, and the condition of the stationary time. It may be detected using one of the condition of position, the condition of movement direction difference, the condition of delivery posture and the condition of stationary time, or the range where the condition of appearance position and the condition of movement direction difference are not used simultaneously Two or more conditions among the condition of appearance position, the condition of movement direction difference, the condition of delivery posture, and the condition of stationary time may be combined and detected.

1 ... image monitoring device 2 ... imaging unit 3 ... communication unit 30 ... image acquisition unit 31 ... suspicious person information output unit 4 ... storage unit 40 ... person information storage unit 41 ... monitoring area information storage means 42 ... group information storage means 5 ... image processing unit 50 ... person tracking means 51 ... group detection means 52 ... posture determination means 53 ... another action Judgment means 54 ・ ・ ・ Suspicious person judgment means 6 ・ ・ ・ Display part

Claims (9)

An image acquisition unit that sequentially acquires surveillance images obtained by imaging a predetermined surveillance area;
Person tracking means for tracking a plurality of persons appearing in the monitoring area based on the monitoring image;
Group detection means for detecting, from among the plurality of persons, a group of persons maintaining a proximity positional relationship whose inter-person distance is equal to or less than a predetermined proximity determination distance within a predetermined suspicious activity determination time range;
Another action determination means for determining that another action has occurred in the group when the separated position relationship in which the person in the group exceeds the separation determination distance longer than the proximity determination distance;
A suspicious person judging means for judging a person in a group, for which the occurrence of the another action is judged to be a suspicious person,
An image monitoring apparatus comprising: And monitoring area information storage means for storing in advance a plurality of entrance areas corresponding to different entrances in the monitoring area.
The image monitoring apparatus according to claim 1, wherein the group detection unit detects the group including a person who is the entrance area different in the appearing position.   The group detection means calculates, for a person who maintains the proximity position relationship within the range of the suspicious activity determination time, a movement direction difference immediately before becoming the proximity position relationship, and the movement direction difference is determined to be another predetermined direction. The image monitoring device according to claim 1, wherein the group is detected when an angle is exceeded. Posture determination that determines whether the posture of the person is the delivery posture by comparing the person image of the person who maintained the proximity position relationship in the monitoring image with the image feature of the delivery posture obtained in advance Means, and
The image monitoring apparatus according to any one of claims 1 to 3, wherein the group detection unit detects a group of persons whose transfer posture has been determined.   The group detection means calculates, for a person who maintains the proximity position relationship within the range of the suspicious activity determination time, a movement distance when the proximity position relationship is maintained, and the movement distance is determined to be a predetermined stationary The image monitoring device according to any one of claims 1 to 4, wherein the group is detected when the distance is equal to or less than a distance.   The separate action determination means measures a separation time in which a person of the group continues the separation positional relationship, and the separation action is generated when the separation time exceeds a predetermined separate action determination time. The image monitoring apparatus according to any one of claims 1 to 5, which determines.   The said another action determination means determines that the said another action generate | occur | produced to the said group, when the person of the said group lose | disappears from the said monitoring area | region, maintaining the said spaced apart positional relationship. The image monitoring device according to any one of the preceding claims.   The separate action determination means calculates, for the group in the separated position relationship, the movement direction difference of the person from the close position relationship to the separated position relationship, and the movement direction difference is a predetermined separate action determination angle. The image monitoring device according to any one of claims 1 to 6, wherein it is determined that the other action has occurred when the value of d. The suspicious person determination means measures a stay time of the person in the monitoring area, and the stay time of the person of the group whose occurrence of the another action is determined is equal to or less than a predetermined short stay determination time The image monitoring device according to any one of claims 1 to 8, wherein it is determined that the person is a suspicious person.

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