Patent Publication Number: US-2022222472-A1

Title: Fraudulent act recognition device, control program therefor, and fraudulent act recognition method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-004304, filed on Jan. 14, 2021, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a fraudulent act recognition device, a control program therefor, and a fraudulent act recognition method. 
     BACKGROUND 
     In recent years, in a retail store such as a supermarket, a self-service point of sale (POS) terminal has attracted attention from the viewpoint of a reduction in personal expenses, infection prevention measures against infectious diseases, and the like. A self-service POS terminal is a settlement terminal adapted for self-service with which a customer performs operation from registration to settlement of purchased commodities by himself or herself. In order to prevent fraudulent acts of customers, weight meters are used in many self-service POS terminals. 
     A weight meter is provided, for example, in a table for bagging a commodity for which registration is finished. The customer bags the commodity registered in the self-service POS terminal. The self-service POS terminal calculates a net weight of the bagged commodity according to a change in weight at that time. If the net weight does not coincide with a set weight of the registered commodity, the self-service POS terminal emits a warning. Therefore, since a warning is emitted, for example, if the customer commits a fraudulent act of bagging the commodity pretending as if the customer registers the commodity in the self-service POS terminal, there is a suppression effect for the fraudulent act of this type. 
     However, even if the weight meter is provided, a fraudulent act of replacing the registered commodity with another commodity having the same weight cannot be identified. Therefore, there is a demand for development of a technique that can suppress such a fraudulent act by the customer. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a system configuration a store where a self-service POS terminal is introduced; 
         FIG. 2  is a perspective view illustrating a positional relation between the self-service POS terminal and a camera; 
         FIG. 3  is a schematic diagram illustrating an example of a monitoring image displayed on a display of an attendant terminal; 
         FIG. 4  is a block diagram illustrating a main part circuit configuration of a fraudulent act recognition device; 
         FIG. 5  is a schematic diagram illustrating an example of a message table; 
         FIG. 6  is a schematic diagram illustrating an example of a time-series buffer; 
         FIG. 7  is a flowchart for explaining a function of an action recognizing unit; 
         FIG. 8  is a flowchart for explaining a function of an operation recognizing unit; 
         FIG. 9  is a flowchart for explaining a function of a fraud detecting unit; 
         FIG. 10  is a flowchart for explaining the function of the fraud detecting unit; 
         FIG. 11  is a flowchart for explaining the function of the frau detecting unit; and 
         FIG. 12  is a flowchart for explaining a function of an informing unit. 
     
    
    
     DETAILED DESCRIPTION 
     An object of embodiments is to provide, in order to solve the problems described above, a fraudulent act recognition device, a control program therefor, and a fraudulent act recognition method that can suppress a fraudulent act of replacing a registered commodity with another commodity. 
     In general, according to one embodiment, a fraudulent act recognition device is configured to be operatively coupled to a camera that monitors operation of a settlement terminal by a purchaser. The fraudulent act recognition device includes a controller configured to recognize a commodity registration operation of the settlement terminal initiated by the purchaser. The controller is configured to review imaging data provided by the camera to recognize an action of the purchaser who performs the commodity registration operation. The controller is configured to determine whether the action of the purchaser is indicative of a fraudulent act. The controller is configured to provide a notification in response to an determination that the action of the purchaser is indicative of the fraudulent act. 
     An embodiment is explained below with reference to the drawings.  FIG. 1  is a system configuration diagram of a store where a self-service POS terminal  11  is introduced. This system (e.g., a store system, a checkout system, etc.) includes a self-service POS system  100  and a fraudulent act recognition system  200 . The self-service POS system  100  includes a plurality of self-service POS terminals  11 , a POS server  12 , a display control device  13 , an attendant terminal  14 , and a communication network  15 . The plurality of self-service POS terminals  11 , the POS server  12 , and the display control device  13  are connected to the communication network  15 . The attendant terminal  14  is connected to the display control device  13 . The communication network  15  is typically a local area network (LAN). The LAN may be a wired LAN or may be a wireless LAN. 
     The self-service POS terminal  11  (e.g., a user interface) is a settlement terminal adapted for self-service with which a customer performs operation from registration to settlement of purchased commodities by himself or herself. The customer is sometimes referred to as purchaser, consumer, client, and the like. The POS server  12  is a server computer for centrally controlling the operations of the self-service POS terminals  11 . The display control device  13  is a controller that generates, based on data signals output from the self-service POS terminals  11 , a monitoring image SC (see  FIG. 3 ) for each of the self-service POS terminals  11  and causes a display device of the attendant terminal  14  to display the monitoring image SC. The attendant terminal  14  is a terminal for a store clerk (e.g., an attendant) to monitor states of the self-service POS terminals  11 . The attendant terminal  14  includes a display (e.g., a user interface) such as a liquid crystal display or an organic EL display. The attendant terminal  14  divides a screen of the display into a plurality of screens and displays the monitoring image SC (e.g., a notification, a message, a visual indicator) associated with a different attendant terminal  14  for each of the divided screens. A well-known self-service POS system in the past can be directly applied to such a self-service POS system  100 . 
     The fraudulent act recognition system  200  includes a plurality of cameras  21  and a fraudulent act recognition device  22 . The plurality of cameras  21  respectively correspond to the plurality of self-service POS terminals  11  in a one to one relation. The cameras  21  are cameras for photographing customers who operate the self-service POS terminals  11  corresponding to the cameras  21 . 
     The fraudulent act recognition device  22  includes functions of an action recognizing unit  221 , an operation recognizing unit  222 , a fraud detecting unit  223 , and an informing unit  224  (e.g., includes processing circuitry or control circuitry, such as at least one controller, that performs the functions of the action recognizing unit  221 , the operation recognizing unit  222 , the fraud detecting unit  223 , and the informing unit  224 ). The action recognizing unit  221  performs a function of recognizing, based on imaging data (e.g., video data) output from the cameras  21 , an action of a customer who performs commodity registration operation in the self-service POS terminal  11 . The commodity registration operation is clarified in the following explanation. The action recognizing unit  221  can be referred to as action recognizing means as well. The operation recognizing unit  222  performs a function of recognizing, based on data of the monitoring image SC output from the display control device  13  to the attendant terminal  14 , the commodity registration operation in the self-service POS terminal  11  by the customer. The operation recognizing unit  222  can be referred to as operation recognizing means as well. The fraud detecting unit  223  performs a function of detecting, based on a recognition result by the action recognizing unit  221  and a recognition result by the operation recognizing unit  222 , a fraudulent act of the customer from an action of the customer to a commodity for which the commodity registration operation is recognized. The fraud detecting unit  223  can be referred to as fraud detecting means as well. The informing unit  224  performs a function of informing the fraudulent act of the customer if the fraudulent act is detected by the fraud detecting unit  223 . The informing is performed, for example, from the attendant terminal  14  to the attendant. The informing unit  224  can be referred to as informing means as well. 
       FIG. 2  is a diagram for explaining a positional relation between the self-service POS terminal  11  and the camera  21 . First, an exterior configuration of the self-service POS terminal  11  is explained. 
     The self-service POS terminal  11  includes a main body  40  set on a floor surface and a bagging table  50  set besides the main body  40 . A touch panel  41  (e.g., a user interface) is attached to an upper part of the main body  40 . The touch panel  41  is configured by a display and a touch sensor. The display is a device for displaying various screens to an operator who operates the self-service POS terminal  11 . The touch sensor is a device for detecting a touch input to a screen by the operator. In the self-service POS terminal  11 , the operator is usually a customer. 
     In the main body  40 , a basket table  60  is provided in a side surface center portion on the opposite side of a side where the bagging table  50  is set. The basket table  60  is a table for a customer coming from a selling floor to place, for example, a basket storing purchased commodities. The customer stands on the near side of the main body  40  in  FIG. 2  where the customer is able to see a screen of the touch panel  41 . Therefore, when viewed from the customer, the basket table  60  is present on the right side across the main body  40  and the bagging table  50  is present on the left side across the main body  40 . In the following explanation, the side where the customer stands is represented as the front of the main body  40 , the side where the bagging table  50  is set is represented as the left side of the main body  40 , and the side where the basket table  60  is provided is represented as the right side of the main body  40 . 
     In the front of the main body  40 , a reading window  42  of a scanner, a card insertion port  43 , a receipt dispensing port  44 , a coin depositing port  45 , a coin dispensing port  46 , a bill depositing port  47 , and a bill dispensing port  48  are formed. A communication cable  61  extends from the right side surface of the main body  40  to the outside. A reader/writer  62  for electronic money media is connected to the distal end of the communication cable  61 . The reader/writer  62  is placed on a placing table  63  provided in a right side surface upper part of the main body  40 . 
     A display pole  64  is attached to the upper surface of the main body  40 . The display pole  64  includes, at the distal end portion thereof, a light emitting unit  65  (e.g., a light, a visual indicator, etc.) that selectively emits, for example, blue and red light. The display pole  64  displays (e.g., indicates) the current state of the self-service POS terminal  11 , for example, a standby state, an operating state, a calling state, and an error state, each corresponding to certain light emission colors of the light emitting unit  65 . 
     The bagging table  50  has a structure in which a bag holding tool  52  is attached to an upper part of a housing  51 . The bag holding tool  52  includes a pair of holding arms  53 . The holding arms  53  hold a register bag prepared in a store or a shopping bag, a so-called “my bag” carried by a customer, or the like. 
     A positional relation between the self-service POS terminal  11  and the camera  21  is explained. As illustrated in  FIG. 2 , the camera  21  is set in a position where the camera  21  is capable of photographing, from above, a customer who stands in the front of the self-service POS terminal  11  and faces components such as the main body  40 , the bagging table  50 , and the basket table  60 . 
     First, the customer standing in the front of the self-service POS terminal  11  places a basket or the like storing purchased commodities on the basket table  60  on the right side and causes the holding arms  53  on the left side to hold a register bag, a “may bag,” (e.g., a bag brought into the store by the customer) or the like. Subsequently, the customer operates the touch panel  41  according to guidance displayed on the touch panel  41  and declares a use start of the self-service POS terminal  11 . 
     Thereafter, the customer picks up the purchased commodities from the bag placed on the basket table  60  one by one. If a barcode is attached to the purchased commodity, the customer performs commodity registration by holding the barcode over the reading window  42  and causing the scanner to read the barcode. If a barcode is not attached to the purchased commodity, the customer performs the commodity registration by operating the touch panel  41  to select the purchased commodity from a list of commodities without barcodes. The customer puts the purchased commodity, for which registration is finished, in the register bag, the “my bag,” or the like. 
     The customer finishes registering all of the purchased commodities and subsequently operates the touch panel  41  to select a settlement method. For example, if selecting cash settlement, the customer deposits bills or coins in the bill depositing port  47  or the coin depositing port  45  and takes out change dispensed from the bill dispensing port  48  or the coin dispensing port  46 . For example, if selecting electronic money settlement, the customer holds an electronic money medium over the reader/writer  62 . For example, if selecting credit card settlement, the customer inserts a credit card into the card insertion port  43 . If ending the settlement in this way, the customer receives a receipt dispensed from the receipt dispensing port  44 , carries the register bag or the “my bag” removed from the holding arms  53 , and leaves the store. 
     That is, the camera  21  is set in a position where the camera  21  is capable of photographing a movement of a hand of the customer who acts as explained above in the front of the self-service POS terminal  11 . 
       FIG. 3  is a schematic diagram illustrating an example of the monitoring image SC displayed on the display of the attendant terminal  14 . As explained above, the monitoring images SC respectively corresponding to the plurality of self-service POS terminals  11  are divided and displayed on the display of the attendant terminal  14 .  FIG. 3  is an example of the monitoring image SC corresponding to one self-service POS terminal  11  among the plurality of self-service POS terminals  11 . The configuration of the monitoring images SC corresponding to the other self-service POS terminals  11  is the same as the monitoring image SC illustrated in  FIG. 3 . Therefore, explanation of the configuration is omitted. 
     As illustrated in  FIG. 3 , the monitoring image SC includes a register number field  71 , a terminal state field  72 , an error information field  73 , a declaration information field  74 , a details field  75 , and a total field  76 . 
     The register number field  71  is a field for displaying a register number. Register numbers are unique serial numbers allocated to the self-service POS terminals  11  that individually identify the self-service POS terminals  11 . The register numbers are identification information for identifying the self-service POS terminals  11 . 
     The terminal state field  72  is a field for displaying an operation state of the self-service POS terminal  11 . In this embodiment, any one of “standby,” “use start,” “being registered,” “settlement start,” and “being settled” is displayed in the terminal state field  72  as the operation state. 
     The “standby” is a state from when the preceding customer ends settlement until when a use start of the next customer is declared. An initial image is displayed on the touch panel  41  of the self-service POS terminal  11  in the state of “standby.” The initial image is an image including a touch button for causing the customer to select, for example, whether to use a register bag prepared in the store or use a “my bag.” 
     The “use start” is a state in which the customer standing in the front of the self-service POS terminal  11  declares a use start for settlement. The customer performs, on the initial image, selection operation for selecting whether to use the register bag or the “my bag.” The selection operation is declaration of the use start. In response to the selection operation, the operation state of the self-service POS terminal  11  changes to the “use start.” 
     The “being registered” is a state in which registration operation for a purchased commodity by the customer himself or herself is received. If a first purchased commodity is registered, the operation state of the self-service POS terminal  11  changes to “being registered.” Thereafter, the operation state of the self-service POS terminal  11  maintains the “being registered” until a shift to settlement is declared. 
     The “settlement start” is a state in which the customer finishing the registration of the purchased commodity declares a shift to settlement. A soft key of [checkout] is displayed on the touch panel  41  of the self-service POS terminal  11  in the state of “being registered.” The customer finishing the registration of the purchased commodity touches the soft key of [checkout]. This operation is declaration of the shift to the settlement. In response to the operation, the operation state of the self-service POS terminal  11  changes to the “settlement start.” 
     The “being settled” is a state in which settlement processing such as cash settlement, electronic money settlement, or credit card settlement is executed. For example, if bills or coins are deposited in the bill depositing port  47  or the coin depositing port  45 , the operation state of the self-service POS terminal  11  changes to the “being settled.” If the settlement processing is ended, the operation state of the self-service POS terminal  11  returns to the “standby.” 
     The error information field  73  is a field for displaying information concerning an error that occurs in the self-service POS terminal  11 . The error information is a communication error, a receipt run-out error, or the like. The declaration information field  74  is a field for displaying declaration operation content of the customer. For example, if the customer selects the “my bag,” the text string “bag is unnecessary” is displayed, indicating that the register bag is unnecessary. 
     The details field  75  is a field for displaying details information of a purchased commodity registered in the self-service POS terminal  11 . The details information is, for example, a commodity name, the number of articles, and an amount of the purchased commodity. The total field  76  is a field for displaying total information of the purchased commodity registered in the self-service POS terminal  11 . The total information is a total number of articles, a total amount, a deposited amount, change, and the like. 
     The configuration of the monitoring image SC is not limited to this. Fields in which other items are displayed may be arranged. Items of text data displayed in  FIG. 3  are not limited to this. Text data of other items may be displayed. 
       FIG. 4  is a block diagram illustrating a main part circuit configuration of the fraudulent act recognition device  22 . The fraudulent act recognition device  22  includes a processor  81 , a main memory  82 , an auxiliary storage device  83 , a clock  84 , a camera interface  85 , a communication interface  86 , and a system bus  87 . The system bus  87  includes an address bus and a data bus. In the fraudulent act recognition device  22 , a computer (e.g., a controller) is configured by connecting the processor  81 , the main memory  82 , the auxiliary storage device  83 , the clock  84 , the camera interface  85 , and the communication interface  86  with the system bus  87 . 
     The processor  81  is equivalent to a central part of the computer. The processor  81  controls the units according to an operating system or application programs in order to realize various functions of the fraudulent act recognition device  22 . The processor  81  is, for example, a central processing unit (CPU). 
     The main memory  82  is equivalent to a main storage part of the computer. The main memory  82  includes a nonvolatile memory region and a volatile memory region. The main memory  82  stores the operating system and the application programs in the nonvolatile memory region. The main memory  82  stores, in the volatile memory region, data necessary for the processor  81  to execute processing for controlling the units. The data of this type is sometimes stored in the nonvolatile memory region. The main memory  82  uses the volatile memory region as a work area in which data is rewritten as appropriate by the processor  81 . The nonvolatile memory region is, for example, a read-only memory (ROM). The volatile memory region is, for example, a random-access memory (RAM). 
     The auxiliary storage device  83  is equivalent to an auxiliary storage part of the computer. As the auxiliary storage device  83 , a well-known storage device such as a solid state drive (SSD), a hard disc drive (HDD), or an electric erasable programmable read-only memory (EEPROM) (registered trademark) is used alone or a plurality of the well-known devices are used in combination. The auxiliary storage device  83  stores data used by the processor  81  in performing various kinds of processing, data generated by the processing in the processor  81 , and the like. The auxiliary storage device  83  sometimes stores application programs. 
     The application programs stored in the main memory  82  or the auxiliary storage device  83  include a control program explained below. A method of installing the control program in the main memory  82  or the auxiliary storage device  83  is not particularly limited. The control program can be installed in the main memory  82  or the auxiliary storage device  83  by recording the control program in a removable recording medium or distributing the control program by communication via a network. A form of the recording medium may be any form if the recording medium can store programs and can be read by a device like a CD-ROM, a memory card, or the like. 
     The clock  84  functions as a time information source of the fraudulent act recognition device  22 . The processor  81  acquires present date and time based on time information tracked by the clock  84 . 
     The camera interface  85  is an interface for communicating with the cameras  21 . Imaging data output from the cameras  21  are captured into the fraudulent act recognition device  22  via the camera interface  85 . The imaging data are data obtained by photographing customers who operate the self-service POS terminals  11  corresponding to the cameras  21 . 
     The communication interface  86  is an interface for communicating with the display control device  13 . Image data output from the display control device  13  is captured into the fraudulent act recognition device  22  via the communication interface  86 . The image data is data of the monitoring image SC generated for each of the self-service POS terminals  11 . 
     The fraudulent act recognition device  22  having such a configuration uses a part of the volatile memory region in the main memory  82  as a region of a message table  821 . The fraudulent act recognition device  22  forms, in this region, the message table  821  having a data structure illustrated in  FIG. 5 . 
       FIG. 5  is a schematic diagram illustrating an example of the message table  821 . As illustrated in  FIG. 5 , the message table  821  is a data table in which text data of a message is described in correlation with an error code EC. The error code EC and the text data of the message correlated with the error code EC are clarified in explanation below. 
     The fraudulent act recognition device  22  uses a part of the volatile memory region in the main memory  82  as a region of a time-series buffer  822 . In the fraudulent act recognition device  22 , time series buffers  822  having a data structure illustrated in  FIG. 6  are formed in this region as many as the number of the self-service POS terminals  11 . 
       FIG. 6  is a schematic diagram illustrating an example of the time-series buffer  822 . As illustrated in  FIG. 6 , the time-series buffer  822  includes a region for describing a status ST and the error code EC in ascending order of time TM for each of register numbers for identifying the self-service POS terminals  11 . The status ST is also clarified in the explanation below. 
     In order to suppress a fraudulent act of a customer to the self-service POS terminal  11 , the fraudulent act recognition device  22  realizes, with the processor  81  and a control program for controlling the processor  81 , functions of the action recognizing unit  221 , the operation recognizing unit  222 , the fraud detecting unit  223 , and the informing unit  224 . 
     The functions of the action recognizing unit  221 , the operation recognizing unit  222 , the fraud detecting unit  223 , and the informing unit  224  are functions included in each of the self-service POS terminals  11 . Therefore, in the following explanation, the functions of the action recognizing unit  221 , the operation recognizing unit  222 , the fraud detecting unit  223 , and the informing unit  224  corresponding to the one self-service POS terminal  11  are explained in detail. The functions of the action recognizing unit  221 , the operation recognizing unit  222 , the fraud detecting unit  223 , and the informing unit  224  corresponding to the other self-service POS terminals  11  are the same. Therefore, explanation of the functions is omitted. 
       FIG. 7  is a flowchart for explaining the function of the action recognizing unit  221 . In ACT  1 , the processor  81  waits for a customer to be recognized. The camera  21  is set in a position where the camera  21  is capable of photographing, from above, a customer standing in the front of the self-service POS terminal  11 . Therefore, if detecting from video data of the camera  21  that a person stands in the front of the self-service POS terminal  11 , the processor  81  determines that the processor  81  recognizes a customer. 
     If recognizing a customer, the processor  81  determines YES in ACT  1  and proceeds to ACT  2 . In ACT  2 , the processor  81  acquires a register number of the self-service POS terminal  11 . The cameras  21  correspond to the self-service POS terminals  11  in a one to one relation. Therefore, the processor  81  specifies the self-service POS terminal  11  from identification information of the camera  21  photographing the customer standing in the front of the self-service POS terminal  11  and acquires a register number of the self-service POS terminal  11 . 
     In ACT  3 , the processor  81  starts action recognition for the customer. Specifically, the processor  81  estimates a skeleton of the person, that is, the customer from an image photographed by the camera  21 . The skeleton estimation can be realized even by an inexpensive camera  21  by using an AI technology such as deep learning. The processor  81  recognizes a taking-out action, a registering action, a replacement action, a bagging action, or a store leaving action of the customer from a movement of a hand obtained by the skeleton estimation. 
     The taking-out action is an action of taking out a purchased commodity from a basket or other shopping container (e.g., a cart, a bag, etc.) placed on or nearby the basket table  60 . For example, if detecting a movement of a skeleton of one hand or both hands moving to the right side of the main body  40  (e.g., toward the basket) and lifting a purchased commodity, the processor  81  recognizes that the taking-out action is performed. 
     The registering action is an action of registering, in the self-service POS terminal  11 , data of the purchased commodity taken out from the basket. For example, if detecting a movement of the skeleton of the hand, which performs the taking-out action, holding the purchased commodity over the reading window  42  in the center of the main body  40 , the processor  81  recognizes that the registering action is performed. Alternatively, if detecting a movement of the skeleton of the one hand operating the touch panel  41  of the main body  40 , the processor  81  recognizes that the registering action is performed. 
     The replacing action is an action of moving the hand holding the purchased commodity, for which the registration is finished, in the floor direction or the back direction of the customer. By moving the hand holding the purchased commodity in the floor direction or the back direction of the customer, the customer can replace the registered commodity with another commodity having the same weight. For example, if detecting a movement of the skeleton of the hand, which performs the replacing action, taking out another commodity from a bag or the like placed at the customer&#39;s feet or behind the customer, replacing the purchased commodity, for which the registration is finished, with the other commodity, and directly putting the other commodity in a register bag or a “my bag,” the processor  81  recognizes that the replacing action is performed. 
     The bagging action is an action of putting the purchased commodity, for which the registration is finished, in the register bag, the “my bag,” or the like on the bagging table  50 . For example, if detecting a movement of the skeleton of the hand, which performs the registering action, moving to the left side of the main body and putting the purchased commodity in the register bag, the “my bag,” or the like, the processor  81  recognizes that the bagging action is performed. 
     The store leaving action is an action of the customer, who ends settlement, separating from (e.g., moving away from) the self-service POS terminal  11 . For example, after the skeleton of the hand of the customer, who ends the settlement, performs a movement of removing the register bag, the “my bag,” or the like from the holding arms  53 , if the customer cannot be detected from the video data of the camera  21 , the processor  81  recognizes that the store leaving action is performed. 
     In ACT  4  to ACT  8 , the processor  81  waits for the processor  81  to recognize the taking-out action, the registering action, the replacing action, the bagging action, or the store leaving action. 
     If recognizing the taking-out action in this waiting state, the processor  81  determines YES in ACT  4  and proceeds to ACT  9 . In ACT  9 , the processor  81  sets the status ST to “11.” If recognizing the registering action, the processor  81  determines YES in ACT  5  and proceeds to ACT  10 . In ACT  10 , the processor  81  sets the status ST to “12.” If recognizing the replacing action, the processor  81  determines YES in ACT  6  and proceeds to ACT  11 . In ACT  11 , the processor  81  sets the status ST to “13.” If recognizing the bagging action, the processor  81  determines YES in ACT  7  and proceeds to ACT  12 . In ACT  12 , the processor  81  sets the status ST to “14.” 
     If ending the processing in ACT  9 , ACT  10 , ACT  11 , or ACT  12 , the processor  81  proceeds to ACT  13 . In ACT  13 , the processor  81  acquires present time TM tracked by the clock  84 . In ACT  14 , the processor  81  describes the time TM and the status ST in correlation with each other in the time-series buffer  822  in which the register number acquired in the processing in ACT  2  is set. Thereafter, the processor  81  returns to the waiting state in ACT  4  to ACT  8 . 
     If the taking-out action for the self-service POS terminal  11  is recognized by the function of the action recognizing unit  221  in this way, “11” is described as the status ST together with the time TM in the time-series buffer  822  in which the register number of the self-service POS terminal  11  is set. Similarly, if the registering action is recognized, “12” is described as the status ST together with the time TM in the time-series buffer  822 . If the replacing action is recognized, “13” is described as the status ST together with the time TM in the time-series buffer  822 . If the bagging action is recognized, “14” is described as the status ST together with the time TM in the time-series buffer  822 . 
     Usually, the customer repeats, in order, the taking-out action, the registering action, and the bagging action for the self-service POS terminal  11  to register data of the purchased commodity in the self-service POS terminal  11 . Therefore, the status ST is stored in time series in the order of “11,” “12,” and “14” in the time-series buffer  822 . If the replacing action is performed, the taking-out action, the registering action, the replacing action, and the bagging action is performed on the self-service POS terminal  11  in this order. Therefore, the status ST is stored in time series in the order of “11,” “12,” “13,” and “14” in the time-series buffer  822 . 
     If recognizing the store leaving action in the waiting state in ACT  4  to ACT  8 , the processor  81  determines YES in ACT  8  and proceeds to ACT  15 . In ACT  15 , the processor  81  ends the action recognition for the customer. 
     In ACT  16 , the processor  81  ending the action recognition sets the status ST to “15.” In ACT  17 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  18 , the processor  81  describes the time TM and the status ST in correlation with each other in the time-series buffer  822  in which the register number acquired in the processing in ACT  2  is set. Therefore, “15” is stored as the status ST together with the time TM in the time-series buffer  822  corresponding to the self-service POS terminal  11  from which the customer separates. 
     Then, the processor  81  ends the function of the action recognizing unit  221 . Thereafter, if detecting again from the video data of the camera  21  that a person stands in the front of the self-service POS terminal  11 , the processor  81  executes the processing in ACT  2  to ACT  18  in the same manner as explained above. 
       FIG. 8  is a flowchart for explaining the function of the operation recognizing unit  222 . In ACT  21 , the processor  81  waits for a use start is declared for the self-service POS terminal  11 . If a use start is declared, the “use start” is displayed in the terminal state field  72  of the monitoring image SC corresponding to the self-service POS terminal  11 . The processor  81  confirms whether characters of “use start” can be recognized from the terminal state field  72  of the monitoring image SC acquired via the display control device  13 . If the characters of “use start” can be recognized, the processor  81  recognizes that the use start is declared. 
     If recognizing that the use start is declared, the processor  81  determines YES in ACT  21  and proceeds to ACT  22 . In ACT  22 , the processor  81  acquires a register number of the self-service POS terminal  11 . The register number is displayed in the register number field  71  of the monitoring image SC. The processor  81  recognizes characters of the register number from the register number field  71  of the monitoring image SC acquired via the display control device  13  and acquires the characters as the register number. 
     In ACT  23 , the processor  81  sets the status ST to “21.” In ACT  24 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  25 , the processor  81  describes the time TM and the status ST in correlation with each other in the time-series buffer  822  in which the register number acquired in the processing in ACT  22  is set. 
     Therefore, if the customer standing in the front of the self-service POS terminal  11  performs declaration operation for the use start, first, “21” is stored as the status ST together with the time TM in the time-series buffer  822  corresponding to the self-service POS terminal  11 . 
     In ACT  26 , the processor  81  starts operation recognition for the self-service POS terminal  11 . Specifically, the processor  81  recognizes commodity registration operation, settlement start operation, or settlement end operation from transition of information acquired by character recognition of the monitoring image SC acquired via the display control device  13 . 
     For example, if details (e.g., information) such as a commodity name, the number of articles, and an amount of a purchased commodity is added to the details field  75 , the processor  81  recognizes that commodity registration operation is performed. For example, if the display of the terminal state field  72  is switched to the “settlement start,” the processor  81  recognizes that settlement start operation is performed. For example, if the display of the terminal state field  72  is switched to the “standby,” the processor  81  recognizes that the settlement end operation is performed. 
     In ACT  27  to ACT  29 , the processor  81  waits for the processor  81  to recognize the commodity registration operation, the settlement start operation, or the settlement end operation. If recognizing the commodity registration operation, the processor  81  determines YES in ACT  27  and proceeds to ACT  30 . In ACT  30 , the processor  81  sets the status ST to “22.” If recognizing the settlement start operation, the processor  81  determines YES in ACT  28  and proceeds to ACT  31 . In ACT  31 , the processor  81  sets the status ST to “23.” 
     If ending the processing in ACT  30  or ACT  31 , the processor  81  proceeds to ACT  32 . In ACT  32 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  33 , the processor  81  describes the time TM and the status ST in correlation with each other in the time-series buffer  822  in which the register number acquired in the processing in ACT  22  is set. Thereafter, the processor  81  returns to the waiting state in ACT  27  to ACT  29 . 
     If the commodity registration operation for the self-service POS terminal  11  is recognized by the function of the operation recognizing unit  222  in this way, “22” is described as the status ST together with the time TM in the time-series buffer  822  in which a register number of the self-service POS terminal  11  is set. Similarly, if the settlement start operation is recognized, “23” is described as the status ST together with the time TM in the time-series buffer  822 . 
     Usually, the commodity registration operation is performed on the self-service POS terminal  11  by the registering action of the customer. Therefore, in the time-series buffer  822 , after the status ST indicating the registering action, that is, “12,” the status ST indicating the commodity registration operation, that is, “22” is stored. 
     The customer ending the bagging action of all purchased commodities declares a settlement start. Therefore, in the time-series buffer  822 , after the status ST indicating the bagging action, that is, “14,” the status ST indicating the settlement start operation, that is, “23” is stored. 
     If recognizing the settlement end operation in the waiting state in ACT  27  to ACT  29 , the processor  81  determines YES in ACT  29  and proceeds to ACT  34 . In ACT  34 , the processor  81  ends the operation recognition with respect to the self-service POS terminal  11 . 
     In ACT  35 , the processor  81  ending the operation recognition sets the status ST to “24.” In ACT  36 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  37 , the processor  81  describes the time TM and the “status ST=24” in correlation with each other in the time-series buffer  822  in which the register number acquired in the processing in ACT  22  is set. Therefore, “24” is stored as the status ST together with the time TM in the time-series buffer  822  corresponding to the self-service POS terminal  11  for which the settlement is ended. 
     Then, the processor  81  ends the function of the operation recognizing unit  222 . Thereafter, if detecting the use start operation for the self-service POS terminal  11  from the data of the monitoring image SC again, the processor  81  executes the processing in ACT  22  to ACT  37  in the same manner as explained above. 
       FIGS. 9 to 11  are flowcharts for explaining the function of the fraud detecting unit  223 . In ACT  41 , the processor  81  waits for the taking-out action to be recognized by the action recognizing unit  221 . As explained above, “11” is described as the status ST in the time-series buffer  822  in which a register number of the self-service POS terminal  11 , in which the taking-out action is recognized, is set. If detecting that “11” is described as the status ST in the time-series buffer  822 , the processor  81  determines YES in ACT  41  and proceeds to ACT  42 . 
     In ACT  42 , the processor  81  confirms whether the taking-out action is performed after the use start operation (e.g., while the self-service POS terminal  11  is in the standby state). If the use start operation is performed on the self-service POS terminal  11 , “21” is described as the status ST in the time-series buffer  822 . Therefore, the processor  81  searches through the time-series buffer  822  in a direction going back from the time TM when “11” is described as the status ST. If detecting that “21” is described as the status ST, the processor  81  determines that the taking-out action is performed after the use start operation. In contrast, if detecting “15” or “24” as the status ST or ending the search through the time-series buffer  822 , the processor  81  determines that the taking-out action is not performed after the use start operation. 
     If the taking-out action is not performed after the use start operation, the processor  81  determines NO in ACT  42  and proceeds to ACT  43 . In ACT  43 , the processor  81  sets the error code EC to “91.” In ACT  44 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  45 , the processor  81  describes the time TM and the error code EC in correlation with each other in the time-series buffer  822 . Thereafter, the processor  81  proceeds to ACT  46 . 
     On the other hand, if the taking-out action is performed after the use start operation, the processor  81  determines YES in ACT  42 . The processor  81  skips the processing in ACT  43  to ACT  45  and proceeds to ACT  46 . 
     Therefore, if the taking-out action of a commodity is recognized in the self-service POS terminal  11  in which the declaration operation for the use start is not performed, “91” is stored as the error code EC in the time-series buffer  822  in which a register number of the self-service POS terminal  11  is set. 
     If the use start operation is not recognized but the taking-out action is recognized in this way, “91” is stored as the error code EC in the time-series buffer  822 . That is, “91” of the error code EC is a code for identifying, as a fraudulent act “fraudulent take-out,” an act of the customer who performs the taking-out action without performing the declaration operation for the use start. 
     In ACT  46 , the processor  81  confirms whether the bagging action is recognized by the action recognizing unit  221 . As explained above, if the bagging action is recognized, “14” is described as the status ST in the time-series buffer  822 . If “14” is not described as the status ST in the time-series buffer  822 , the processor  81  determines NO in ACT  46  and proceeds to ACT  47 . 
     In ACT  47 , the processor  81  confirms whether the taking-out action is recognized by the action recognizing unit  221 . As explained above, if the taking-out action is recognized, “11” is described as the status ST in the time-series buffer  822 . If “11” is not described as the status ST in the time-series buffer  822 , the processor  81  determines NO in ACT  47  and proceeds to ACT  48 . 
     In ACT  48 , the processor  81  confirms whether the store leaving action is recognized by the action recognizing unit  221 . As explained above, if the store leaving action is recognized, “15” is described as the status ST in the time-series buffer  822 . If “15” is not described as the status ST in the time-series buffer  822 , the processor  81  determines NO in ACT  48  and returns to ACT  46 . 
     In ACT  46  to ACT  48 , the processor  81  waits for the customer, who performs the taking-out action of a first commodity, to thereafter perform the bagging action, perform the taking-out action of another commodity, or perform the store leaving action. 
     If “14” is described as the status ST in the time-series buffer  822  in this waiting state, the processor  81  determines YES in ACT  46  and proceeds to ACT  61  in  FIG. 10 . 
     In ACT  61 , the processor  81  confirms whether the bagging action is performed after the commodity registration operation. As explained above, if the commodity registration operation is recognized in the operation recognizing unit  222 , “22” is described as the status ST in the time-series buffer  822 . Therefore, if “22” is described as the status ST in correlation with the time TM immediately preceding the time TM when “14” is described as the status ST, the processor  81  recognizes that the bagging action is performed after the commodity registration operation. The processor  81  determines YES in ACT  61  and proceeds to ACT  62 . 
     In ACT  62 , the processor  81  confirms whether the replacing action is recognized by the action recognizing unit  221 . As explained above, if the replacing action is recognized, “13” is described as the status ST in the time-series buffer  822 . If “13” is not described as the status ST in the time-series buffer  822 , the processor  81  determines NO in ACT  48  and returns to ACT  46  in  FIG. 9 . That is, the processor  81  returns to the waiting state in ACT  46  to ACT  48 . 
     If “13” is described as the status ST in the time-series buffer  822 , the processor  81  determines YES in ACT  62  and proceeds to ACT  63 . In ACT  63 , the processor  81  sets the error code EC to “93.” In ACT  64 , the processor  81  acquires the present time TM tracked by clock  84 . In ACT  65 , the processor  81  describes the time TM and the error code EC in correlation with each other in the time-series buffer  822  in which “13” is described as the status ST. Thereafter, the processor  81  returns to ACT  46  in  FIG. 9 . That is, the processor  81  returns to the waiting state in ACT  46  to ACT  48 . 
     In this way, if the replacing action is recognized after the commodity registration operation is recognized, “93” is stored as the error code EC in the time-series buffer  822 . That is, “93” of the error code EC is a code for identifying, as a fraudulent act “replacement,” an action of a customer who performs the replacing action of a commodity for which the commodity registration operation is performed. 
     In contrast, if “22” is not described as the status ST in correlation with the time TM immediately preceding the time TM when “15” is described as the status ST, the processor  81  recognizes that the bagging action is not performed after the commodity registration operation. The processor  81  determines NO in ACT  61  and proceeds to ACT  66 . 
     In ACT  66 , the processor  81  sets the error code EC to “92.” In ACT  67 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  68 , the processor  81  describes the time TM and the error code EC in correlation with each other in the time-series buffer  822  in which “14” is described as the status ST. Thereafter, the processor  81  returns to ACT  46  in  FIG. 9 . That is, the processor  81  returns to the waiting state in ACT  46  to ACT  48 . 
     In this way, if the commodity registration operation is not recognized but the bagging action is recognized, “92” is stored as the error code EC in the time-series buffer  822 . That is, “92” of the error code EC is a code for identifying, as a fraudulent act “false registration,” an act of a customer who performs the bagging action of a commodity for which the commodity registration operation is not performed. 
     Referring back to  FIG. 9 , if “11” is described as the status ST in the time-series buffer  822  and the taking-out action is recognized in the waiting state in ACT  46  to ACT  48 , the processor  81  proceeds to ACT  71  in  FIG. 11 . In ACT  71 , the processor  81  confirms whether the taking-out action is performed after the settlement start operation. As explained above, if the settlement start operation is recognized in the operation recognizing unit  222 , “23” is described as the status ST in the time-series buffer  822 . Therefore, if “23” is described as the status ST in correlation with the time TM immediately preceding the time TM when “11” is described as the status ST, the processor  81  recognizes that the taking-out action is performed after the settlement start operation. In other words, if “23” is not described as the status ST in correlation with the time TM immediately preceding the time TM when “11” is described as the status ST, the processor  81  recognizes that the taking-out action is not performed after the settlement start operation. 
     If the taking-out action is not performed after the settlement start operation, the processor  81  determines NO in ACT  71  and proceeds to ACT  72 . In ACT  72 , the processor  81  confirms whether the taking-out action is performed after the settlement end operation. As explained above, if the settlement end operation is recognized in the operation recognizing unit  222 , “24” is described as the status ST in the time-series buffer  822 . Therefore, if “24” is described as the status ST in correlation with the time TM immediately preceding the time TM when “11” is described as the status ST, the processor  81  recognizes that the taking-out action is performed after the settlement end operation. In other words, if “24” is not described as the status ST in correlation with the time TM immediately preceding the time TM when “11” is described as the status ST, the processor  81  recognizes that the taking-out action is not performed after the settlement end operation. 
     If the taking-out action is not performed after the settlement end operation, the processor  81  determines NO in ACT  72  and returns to ACT  46  in  FIG. 9 . That is, the processor  81  returns to the waiting state in ACT  46  to ACT  48 . 
     On the other hand, if the taking-out action is performed after the settlement start operation or after the settlement end operation, the processor  81  determines YES in ACT  71  or ACT  72  and proceeds to ACT  73 . In ACT  73 , the processor  81  sets the error code EC to “94.” In ACT  74 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  75 , the processor  81  describes the time TM and the error code EC in correlation with each other in the time-series buffer  822  in which “11” is described as the status ST. Thereafter, the processor  81  returns to ACT  46  in  FIG. 9 . That is, the processor  81  returns to the waiting state in ACT  46  to ACT  48 . 
     In this way, if the commodity taking-out action is recognized after the settlement start operation or the settlement end operation is recognized (e.g., after the customer has caused the self-service POS terminal  11  to initiate a settlement operation), “94” is stored as the error code EC in the time-series buffer  822 . That is, “94” of the error code EC is a code for identifying, as a fraudulent act “registration omission,” an act of a customer taking out an unregistered commodity from a basket after the settlement start operation or the settlement end operation. 
     Referring back to  FIG. 9 , if “15” is described as the status ST in the time-series buffer  822  and the store leaving action is recognized in the waiting state in ACT  46  to ACT  48 , the processor  81  determines YES in ACT  48  and proceeds to ACT  49 . In ACT  49 , the processor  81  confirms whether the store leaving action is performed after the settlement end operation. As explained above, if the settlement end operation is recognized in the operation recognizing unit  222  (e.g., the self-service POS terminal  11  has completed the settlement operation), “25” is described as the status ST in the time series buffer  822 . Therefore, if “24” is described as the status ST in correlation with the time TM immediately preceding the time TM when “15” is described as the status ST, the processor  81  recognizes that the store leaving action is performed after the settlement end operation. In other words, if “24” is not described as the status ST in correlation with the time TM immediately preceding the time TM when “15” is described as the status ST, the processor  81  recognizes that the store leaving action is not performed after the settlement end operation. 
     If the store leaving action is performed after the settlement end operation, the processor  81  determines YES in ACT  49 . The processor  81  ends the function of the fraud detecting unit  223 . 
     In contrast, if the store leaving action is not performed after the settlement end operation, the processor  81  determines NO in ACT  49  and proceeds to ACT  50 . In ACT  50 , the processor  81  sets the error code EC to “95.” In ACT  51 , the processor  81  acquires the present time TM tracked by the clock  84 . In ACT  52 , the processor  81  describes the time TM and the error code EC in correlation with each other in the time-series buffer  822  in which “15” is described as the status ST. 
     If the settlement end operation is not recognized but the store leaving action is recognized, “95” is stored as the error code EC in the time-series buffer  822 . That is, “95” of the error code EC is a code for identifying, as a fraudulent act “unsettled,” an act of a customer who performs the store leaving action before the settlement end operation. 
     Then, the processor  81  ends the function of the fraud detecting unit  223 . Thereafter, if the taking-out action is recognized again, the processor  81  executes the processing in ACT  42  to ACT  52 , ACT  61  to ACT  68 , and ACT  71  to ACT  75  in the same manner as explained above. 
       FIG. 12  is a flowchart for explaining the function of the informing unit  224 . In ACT  81 , the processor  81  waits for the error code EC to be described in the time-series buffer  822 . If the error code EC is described in the time-series buffer  822 , the processor  81  determines NO in ACT  81  and proceeds to ACT  82 . In ACT  82 , the processor  81  confirms whether the error code EC is “91.” 
     If the error code EC is “91,” the processor  81  determines YES in ACT  82  and proceeds to ACT  83 . In ACT  83 , the processor  81  informs a fraudulent act “fraudulent take-out.” That is, the processor  81  searches through the message table  821  and acquires message data in which the error code EC is “91.” The processor  81  acquires a register number of the time-series buffer  822  in which “91” is described as the error code EC. The processor  81  outputs an informing command added with the message data and the register number from the communication interface  86  to the display control device  13 . 
     The display control device  13  displays a text of the message data on the monitoring image SC of the attendant terminal  14  identified by the register number included in the informing command. As a result, a text for informing the fraudulent act such as “fraudulent take-out was performed in a register with a register No. X” is displayed on the monitoring image SC. Therefore, the attendant can direct, to the fraudulent act “fraudulent take-out,” attention of a customer using the self-service POS terminal  11  in which the register No. X is set. 
     If the error code EC is not “91,” the processor  81  determines NO in ACT  82  and proceeds to ACT  84 . In ACT  84 , the processor  81  confirms whether the error code EC is “92.” 
     If the error code EC is “92,” the processor  81  determines YES in ACT  84  and proceeds to ACT  85 . In ACT  85 , the processor  81  informs a fraudulent act “false registration.” That is, the processor  81  searches through the message table  821  and acquires message data in which the error code EC is “92.” The processor  81  acquires a registration number of the time-series buffer  822  in which “92” is described as the error code EC. The processor  81  outputs an informing command added with the message data and the register number from the communication interface  86  to the display control device  13 . 
     The display control device  13  displays a text of the message data on the monitoring image SC of the attendant terminal  14  identified by the registration number included in the informing command. As a result, a text for informing the fraudulent act such as “false registration was performed in the register with the register No. X” is displayed on the monitoring image SC. Therefore, the attendant can direct, to the fraudulent act “false registration,” attention of the customer using the self-service POS terminal  11  in which the register No. X is set. 
     If the error code EC is not “92,” the processor  81  determines NO in ACT  84  and proceeds to ACT  86 . In ACT  86 , the processor  81  confirms whether the error code EC is “93.” 
     If the error code EC is “93,” the processor  81  determines YES in ACT  86  and proceeds to ACT  87 . In ACT  87 , the processor  81  informs a fraudulent act “replacement.” That is, the processor  81  searches through the message table  821  and acquires message data in which the error code EC is “93.” The processor  81  acquires a register number of the time-series buffer  822  in which “93” is described as the error code EC. The processor  81  outputs an informing command added with the message data and the register number from the communication interface  86  to the display control device  13 . 
     The display control device  13  displays a text of the message data on the monitoring image SC of the attendant terminal  14  identified by the register number included in the informing command. As a result, a text for informing the fraudulent act such as “a commodity was replaced in the register with the register No. X” is displayed on the monitoring image SC. Therefore, the attendant can direct, to the fraudulent act “replacement,” attention of the customer using the self-service POS terminal  11  in which the register No. X is set. 
     If the error code EC is not “93,” the processor  81  determines NO in ACT  86  and proceeds to ACT  88 . In ACT  88 , the processor  81  confirms whether the error code EC is “94.” 
     If the error code EC is “94,” the processor  81  determines YES in ACT  88  and proceeds to ACT  89 . In ACT  89 , the processor  81  informs the fraudulent act “registration omission.” That is, the processor  81  searches through the message table  821  and acquires message data in which the error code EC is “94.” The processor  81  acquires a register number of the time-series buffer  822  in which “94” is described as the error code EC. The processor  81  outputs an informing command added with the message data and the register number from the communication interface  86  to the display control device  13 . 
     The display control device  13  displays a text of the message data on the monitoring image SC of the attendant terminal  14  identified by the register number included in the informing command. As a result, a text for informing the fraudulent act such as “registration omission occurred in the register with the register No. X” is displayed on the monitoring image SC. Therefore, the attendant can direct, to the fraudulent act “registration omission,” attention of the customer using the self-service POS terminal  11  in which the register No. X is set. 
     If the error code EC is not “94,” the processor  81  determines NO in ACT  88  and proceeds to ACT  90 . In ACT  90 , the processor  81  confirms whether the error code EC is “95.” 
     If the error code EC is “95,” the processor  81  determines YES in ACT  90  and proceeds to ACT  91 . In ACT  91 , the processor  81  informs a fraudulent act “unsettled.” That is, the processor  81  searches through the message table  821  and acquires message data in which the error code EC is “95.” The processor  81  acquires a register number of the time-series buffer  822  in which “95” is described as the error code EC. The processor  81  outputs an informing command added with the message data and the register number from the communication interface  86  to the display control device  13 . 
     The display control device  13  displays a text of the message data on the monitoring image SC of the attendant terminal  14  identified by the register number included in the informing command. As a result, a text for informing the fraudulent act such as “the register with the register No. X did not perform settlement yet” is displayed on the monitoring image SC. Therefore, the attendant can direct, to the fraudulent act “unsettled,” attention of the customer using the self-service POS terminal  11  in which the register No. X is set. 
     As explained above in detail, the fraudulent act recognition device  22  functions as the action recognizing unit  221  and recognizes, based on imaging data of the camera  21 , an action of a customer performing commodity registration operation in the self-service POS terminal  11 . The recognition of the action of the customer is based on the positions of the components of the self-service POS terminal  11  and the position of the hand of the customer facing the self-service POS terminal  11 . The fraudulent act recognition device  22  functions as the operation recognizing unit  222  and recognizes, based on data of the monitoring image SC output from the display control device  13  to the attendant terminal  14 , the commodity registration operation in the self-service POS terminal  11  by the customer. The fraudulent act recognition device  22  functions as the fraud detecting unit  223  and detects, based on a recognition result by the action recognizing unit  221  and a recognition result by the operation recognizing unit  222 , a fraudulent act of the customer from an action of the customer to a commodity for which the commodity registration operation is recognized. That is, the fraudulent act recognition device  22  detects the fraudulent act of the customer from a movement of the hand of the customer holding the commodity recognized by the action recognizing unit  221 . 
     For example, if the taking-out action is recognized without the declaration operation of the use start, the fraudulent act recognition device  22  detects the fraudulent act “fraudulent take-out.” If the bagging action of the commodity is recognized without the commodity registration operation, the fraudulent act recognition device  22  detects the fraudulent act “false registration.” If the replacing action is recognized after the commodity registration operation, the fraudulent act recognition device  22  detects the fraudulent act “replacement.” If the taking-out action is recognized after the settlement start operation or the settlement end operation, the fraudulent act recognition device  22  detects the fraudulent act “registration omission.” If the store leaving action is recognized without the settlement end operation, the fraudulent act recognition device  22  detects the fraudulent act “unsettled.” 
     The fraudulent act recognition device  22  functions as the informing unit  224  and includes the function of informing a fraudulent act of a customer to an attendant using the attendant terminal  14 . Therefore, the attendant confirming the fraudulent act of the customer can quickly call attention of the corresponding customer. As a result, the fraudulent act of the customer to the self-service POS terminal  11  is suppressed. 
     In this way, according to this embodiment, an effect of suppressing a fraudulent act of replacing a registered commodity with another commodity is achieved. Therefore, irrespective of presence or absence of a weight meter, it is possible to suppress a fraudulent act of replacing a registered commodity with another commodity having the same weight. 
     The embodiment of the technique for suppressing a fraudulent act of a customer to the self-service POS terminal  11  is explained above. However, such an embodiment is not limited to this. 
     In the embodiment, as an example, one camera  21  is disposed for one self-service POS terminal  11 . The camera  21  may not always be disposed for each of the self-service POS terminals  11 . For example, the number of the cameras  21  may be reduced if customers operating adjacent two self-service POS terminals  11  can be photographed by one camera  21 . However, in that case, in ACT  2  in  FIG. 7 , a register number of the self-service POS terminal  11  closest to the position of a person projected in a video is acquired. For example, a plurality of cameras  21  may be disposed for one self-service POS terminal  11 . Consequently, it is possible to reduce a dead angle of the self-service POS terminal  11  and accurately detect a fraudulent act of a customer. 
     In the embodiment, as an example, the processor  81  recognizes the replacing action of the customer from the movement of the hand obtained by the skeleton estimation. For example, the processor  81  may recognize the replacing action from the posture of the customer. In this case, the replacing action is, for example, an action of lowering the posture of the customer holding a purchased commodity for which registration is finished. 
     In the embodiment, as an example, the informing unit  224  informs the attendant via the attendant terminal  14 . An informing destination is not limited to the attendant terminal  14 . For example, the self-service POS terminal  11  in which a fraudulent act is performed may be set as the informing destination. In that case, for example, the light emitting unit  65  emits light in a predetermined color to let a store clerk know that the fraudulent act is performed. Alternatively, a warning message may be displayed on the touch panel  41  to let a customer know that the fraudulent act is detected. A warning of the fraudulent act may be emitted by display or sound through wireless communication with a communication terminal carried by the store clerk. 
     In the embodiment, the attendant terminal  14  may include the function of the display control device  13 . In this case, the operation recognizing unit  222  acquires data of the monitoring image SC from the attendant terminal  14  and recognizes operation of a customer on the self-service POS terminal  11 . Alternatively, the operation recognizing unit  222  may capture data signals output from the self-service POS terminals  11 , for example, from the communication network  15  via a router and recognize the operation of the customer on the self-service POS terminal  11  based on the data signals. 
     In the embodiment, the fraudulent act recognition device  22  may include a recording unit that records imaging data captured from the cameras  21 . Consequently, if a fraudulent act of a customer is detected, it is possible to reproduce the imaging data captured in the recording unit and verify the fraudulent act. 
     Besides, several embodiments are explained above. However, the embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms. Various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications of the embodiments are included in the scope and the gist of the invention and included in the inventions described in claims and the scope of equivalents of the inventions.