Patent Publication Number: US-2018033272-A1

Title: Monitoring system and monitoring method

Description:
TECHNICAL FIELD 
     The present invention relates to a monitoring system and a monitoring method. 
     BACKGROUND ART 
     Hitherto, monitoring service is run based on recorded data items of a monitoring target, which are acquired by a plurality of imaging apparatus. For example, Patent Literature 1 discloses a technology for facilitating detection of a moving body from the recorded data items acquired by the plurality of imaging apparatus. 
     Further, in recent years, data management such as software updates and file backup has not been carried out separately in information processing apparatus, and there has been utilized a technology of carrying out the data management in the information processing apparatus communicably with each other via a network. In the field of the monitoring service, data centers have started to utilize such a technology so as to carry out management of the image data items of the monitoring target. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Japanese Patent Application Laid-open No. 2006-067139 
     SUMMARY OF INVENTION 
     Technical Problem 
     The monitoring service involves continuous imaging of the monitoring site with the plurality of imaging apparatus. Thus, during the monitoring service, an enormous number of recorded data items are generated. Thus, when the data centers manage the recorded data items for the monitoring service, there is a problem in that a burden of running costs such as communication cost for transmitting the recorded data items of the monitoring target, and management cost for the management of the recorded data items is increased. 
     The present invention, which has been made in view of such circumstances, has an object of providing a monitoring system and a monitoring method that reduce a burden of running costs such as communication cost and management cost for recorded data items of a monitoring site as much as possible. 
     Solution to Problem 
     In order to solve the problems as described above and to achieve the above-mentioned object, according to an embodiment of the present application, there is provided a monitoring system including:
         an imaging apparatus configured to acquire a recorded data item of a monitoring site;   an information processing apparatus configured to control recording of the recorded data item; and   an external storage apparatus configured to store the recorded data item,   the imaging apparatus including:
           a first sensor and a second sensor each configured to detect a non-physical quantity in the monitoring site;   a calculation unit configured to calculate, through comparison between data sizes of frames of the recorded data item, an evaluation value corresponding to variation between the data sizes;   a data storing unit configured to correlate to each other
               the recorded data item,   a profile of the recorded data item,   the evaluation value corresponding to the recorded data item,   a value detected by the first sensor and corresponding to the recorded data item, and   a value detected by the second sensor and corresponding to the recorded data item,   
               the data storing unit being configured to cause the recorded data item, the profile, the evaluation value, the value detected by the first sensor, and the value detected by the second sensor to be stored into a storage unit;   a verification-data transmission unit configured to transmit a verification data item to the information processing apparatus, the verification data item being obtained by extracting, out of the recorded data item, the profile, the evaluation value, the value detected by the first sensor, and the value detected by the second sensor; and   a recorded-data transmission unit configured to acquire, when an instruction to transmit the recorded data item is received from the information processing apparatus, the recorded data item from the storage unit based on the profile contained in the instruction to transmit the recorded data item,   the recorded-data transmission unit being configured to transmit the acquired recorded data item to the information processing apparatus,   
           the information processing apparatus including:
           an event detection unit configured to execute detection of an abnormality in the monitoring site based on
               a result of comparison between the evaluation value contained in the verification data item received from the imaging apparatus and a threshold,   a result of comparison between the value detected by the first sensor and a threshold, the value detected by the first sensor being contained in the verification data item, and   a result of comparison between the value detected by the second sensor and a threshold, the value detected by the second sensor being contained in the verification data item; and   
               a recorded-data storing unit configured to cause the recorded data item received from the imaging apparatus to be stored into the external storage apparatus,   
           the event detection unit being configured to transmit, to the imaging apparatus, the instruction to transmit the recorded data item based on the profile when the abnormality in the monitoring site is detected.       

     In order to solve the problems as described above and to achieve the above-mentioned object, according to another embodiment of the present application, there is provided a monitoring method that is executed by a monitoring system including:
         an imaging apparatus configured to acquire a recorded data item of a monitoring site;   an information processing apparatus configured to control recording of the recorded data item; and   an external storage apparatus configured to store the recorded data item,   the monitoring method including causing the imaging apparatus to carry out:
           a step of detecting a non-physical quantity in the monitoring site;   a step of calculating, through comparison between data sizes of frames of the recorded data item, an evaluation value corresponding to variation between the data sizes;   a step of correlating to each other
               the recorded data item,   a profile of the recorded data item,   the evaluation value corresponding to the recorded data item,   a value detected by the first sensor and corresponding to the recorded data item, and   a value detected by the second sensor and corresponding to the recorded data item,   
               and of causing the recorded data item, the profile, the evaluation value, the value detected by the first sensor, and the value detected by the second sensor to be stored into a storage unit;   a step of transmitting a verification data item to the information processing apparatus, the verification data item being obtained by extracting, out of the recorded data item, the profile, the evaluation value, the value detected by the first sensor, and the value detected by the second sensor; and   a step of acquiring, when an instruction to transmit the recorded data item is received from the information processing apparatus, the recorded data item from the storage unit based on the profile contained in the instruction to transmit the recorded data item,   and of transmitting the acquired recorded data item to the information processing apparatus,   
           the monitoring method including causing the information processing apparatus to carry out:
           a step of executing detection of an abnormality in the monitoring site based on
               a result of comparison between the evaluation value contained in the verification data item received from the imaging apparatus and a threshold,   a result of comparison between the value detected by the first sensor and a threshold, the value detected by the first sensor being contained in the verification data item, and   a result of comparison between the value detected by the second sensor and a threshold, the value detected by the second sensor being contained in the verification data item;   
               a step of transmitting, to the imaging apparatus, the instruction to transmit the recorded data item based on the profile when the abnormality in the monitoring site is detected; and   a step of causing the recorded data item received from the imaging apparatus to be stored into the external storage apparatus.   
               

     Advantageous Effects of Invention 
     The monitoring system and the monitoring method according to the present application provide an advantage of reducing a burden of running costs such as communication cost and management cost for recorded data items of a monitoring site as much as possible. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram showing a schematic configuration of a monitoring system. 
         FIG. 2  is a block diagram showing a functional configuration of an imaging apparatus. 
         FIG. 3  is a diagram showing an example of a file structure of a recorded data item. 
         FIG. 4  is a diagram showing an example of a file structure of a verification data item. 
         FIG. 5  is a diagram showing an example of a file structure of a recorded data item in case of an emergency. 
         FIG. 6  is a block diagram showing functional configurations of an information processing apparatus and an external storage apparatus. 
         FIG. 7  is a flowchart showing a flow of a scene-transition-amount calculation process according to a first embodiment. 
         FIG. 8  is a flowchart showing a flow of an event detection process according to the first embodiment. 
         FIG. 9  is another flowchart showing the flow of the event detection process according to the first embodiment. 
         FIG. 10  is a flowchart showing a flow of an offset-value update process according to the first embodiment. 
         FIG. 11  is a flowchart showing a flow of an event detection process according to a second embodiment. 
         FIG. 12  is a table showing an example of determination results of the event detection process according to the second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Below, monitoring systems and monitoring methods according to embodiments of the present application are described in detail with reference to the drawings. The monitoring systems and the monitoring methods according to the present application are not limited by the embodiments described below. Matters described in the following embodiments encompass what is called equivalents such as matters that can be easily conceived by those skilled in the art, and substantially the same matters. The matters described in the following embodiments are applied to processes regarding recorded data items of a monitoring target, which is acquired from imaging apparatus installed, for example, in office buildings, business parks, shopping malls, fashion malls, parks, amusement facilities, high-tech parks, and residential facilities. 
     First Embodiment 
     [Configuration of System] 
       FIG. 1  is a diagram showing a schematic configuration of a monitoring system. As shown in  FIG. 1 , the monitoring systems according to the following embodiments include an imaging apparatus  100 , an information processing apparatus  200 , an external storage apparatus  300 , and a user terminal  400 . The imaging apparatus  100 , the information processing apparatus  200 , and the user terminal  400  are communicably connected to each other via a network  1 . The imaging apparatus  100  is an apparatus that acquires recorded data items of a monitoring site, such as a digital camera that records the recorded data items as digital data items. The information processing apparatus  200  is an apparatus such as a server, which controls recording of the recorded data items acquired by the imaging apparatus  100 . The external storage apparatus  300  is an apparatus that stores the recorded data items acquired by the imaging apparatus  100 . The user terminal  400  is a terminal that is used by a user. Examples of the network  1  include a public telephone network, the Internet, and a carrier network. The network  1  is capable of transmitting and receiving data items by using a predetermined communication protocol via network communication devices such as a hub, a router, a bridge, and a proxy server. 
     [Configuration of Imaging Apparatus] 
       FIG. 2  is a block diagram showing a functional configuration of the imaging apparatus  100 . As shown in  FIG. 2 , the imaging apparatus  100  includes an image pickup element  106 , a capture unit  107 , encoding units  108   a  to  108   c,  a time measurement device  109 , an input processing unit  110 , a motion sensor  111 , a sound pressure sensor  112 , a thermal sensor  113 , a communication unit  114 , a recording memory  115 , and a control unit  120 . 
     The image pickup element  106  converts received light to electrical signals. Examples of the image pickup element  106  include image sensors using, for example, a complementary metal-oxide semiconductor (CMOS), a MOS, and a charge-coupled device (CCD). 
     The capture unit  107  processes the electrical signals generated by the image pickup element  106 . With this, the electrical signals are synthesized into digital images in frame units. 
     The encoding units  108   a  to  108   c  convert a format of the digital images synthesized by the capture unit  107  into respective formats. The encoding unit  108   a  converts the format of the digital images synthesized by the capture unit  107  to a national television standards committee (NTSC) format being a standard format of terrestrial analog television broadcast. The encoding unit  108   a  transmits data items after the format conversion to an analog television monitor. The encoding unit  108   b  converts the format of the digital images synthesized by the capture unit  107  to an H.264 format being a format of compression-coding of moving-image data items. The encoding unit  108   b  transmits data items after the format conversion to the control unit  120 . The encoding unit  108   c  converts the format of the digital images synthesized by the capture unit  107  to a joint photograph experts group (JPEG) format being a compression format of still-image data items. The encoding unit  108   c  transmits the data items after the format conversion to the control unit  120 . The above-mentioned formats used in the conversion by the encoding units  108   a  to  108   c  are merely examples, and formats other than the above-mentioned ones may be applied. 
     The time measurement device  109  measures time. The time measurement device  109  transmits data items of the measured time to the control unit  120 . 
     The input processing unit  110  transmits measurement values measured by the motion sensor  111 , the sound pressure sensor  112 , and the thermal sensor  113  to the control unit  120 . The motion sensor  111  detects presence of a person in the monitoring site based, for example, on infrared light, visible light, and ultrasonic waves. The motion sensor  111  transmits the number of detection times of the presence of the person (number of responses of the sensor) to the input processing unit  110 . The sound pressure sensor  112  detects sound pressure in the monitoring site. The sound pressure sensor  112  transmits the number of detection times of the sound pressure at a predetermined level or higher in the monitoring site (number of responses of the sensor) to the input processing unit  110 . The thermal sensor  113  detects abnormal high-temperature conditions in case, for example, of fire in the monitoring site. When a temperature at the monitoring site exceeds a certain temperature, the thermal sensor  113  transmits a corresponding signal to the input processing unit  110 . The motion sensor  111  and the sound pressure sensor  112  are examples of a first sensor and a second sensor. 
     The communication unit  114  transmits and receives various data items to be exchanged between the communication unit  114  and the information processing apparatus  200 . The communication unit  114  communicates in a wired or wireless manner via the predetermined communication protocol. 
     The recording memory  115  stores a recorded data item  115   a  of the monitoring site, which is acquired by the imaging apparatus  100 . Examples of the recording memory  115  include nonvolatile memories such as a flash memory (storage medium capable of only readout, such as a CD-ROM), volatile memories such as a random access memory (RAM), or combinations thereof. The recorded data item  115   a  is stored under a state in which the recorded data item of the monitoring site, a profile of the recorded data item, and the values detected by the motion sensor  111  and the sound pressure sensor  112 , which correspond to the recorded data item, are integrated with each other on the basis of the time.  FIG. 3  is a diagram showing an example of a file structure of the recorded data item. As shown in  FIG. 3 , the recorded data item  115   a  is obtained in a form of a single file in which data items, that is, a profile (time and recording condition)  11 , a video KEY frame  12 , video difference frames  13 , a scene transition amount  14 , a motion-sensor data item  15 , a sound-pressure-sensor data item  16 , and a thermal-sensor data item  17  are synchronized with each other on the basis of the time measured by the time measurement device  109 . 
     The profile  11  contains data items of an installation site of the imaging apparatus  100 , and of the time measured by the time measurement device  109 , and a data item of the recording condition that is set by an administrator of the imaging apparatus  100 . The video KEY frame  12  is obtained from the data items after the format conversion by the encoding unit  108   c.  The video difference frames  13  are obtained from the data items after the format conversion by the encoding unit  108   b.  The scene transition amount  14  is obtained from data items based on results of processes by the control unit  120  described below. The motion-sensor data item  15  is obtained from the value detected by the motion sensor  111 . The sound-pressure-sensor data item  16  is obtained from the value detected by the sound pressure sensor  112 . The thermal-sensor data item  17  is obtained from a data item based on the detection result from the thermal sensor  113 . 
     The control unit  120  includes hardware resources such as a central processing unit (CPU)  121  being an arithmetic device, and a program memory  122  being a storage device. With use of those hardware resources, the control unit  120  executes programs stored in the program memory  122 . In this way, the various processes are executed. Examples of the arithmetic processing apparatus may include a system-on-a-chip (SoC), a micro control unit (MCU), a field-programmable gate array (FPGA), and a coprocessor, but are not limited thereto. 
     The program memory  122  stores data items and the programs that are necessary for the various processes to be executed by the control unit  120 . Examples of the program memory  122  include nonvolatile memories such as a flash memory, volatile memories such as a random access memory (RAM), or combinations thereof. The program memory  122  functions also as a working memory at the time when the control unit  120  executes the various programs. A working memory other than the program memory  122  may be installed. As one of the data items necessary for the various processes to be executed by the control unit  120 , the program memory  122  stores data sizes of the video difference frames  13 , specifically, a frame data size  122   d  being a latest data size. 
     As shown in  FIG. 2 , the program memory  122  stores a scene-transition-amount detection program  122   a,  a data storing program  122   b,  a data transmission program  122   c,  and the frame data size  122   d.  In accordance with the scene-transition-amount detection program  122   a,  processes regarding the digital images to be synthesized by the capture unit  107  are successively executed. In accordance with the data storing program  122   b  and the data transmission program  122   c,  in units of a predetermined time period (for example, every 1 minute), the data items regarding the digital images to be synthesized by the capture unit  107  are processed and integrated with each other into the single file having a predetermined file structure. The units of the time period for integrating the digital images may be arbitrarily changed. 
     The scene-transition-amount detection program  122   a  provides a function to calculate a value of the scene transition amount  14  corresponding to variation between the data sizes through comparison between the data sizes of the frames of the recorded data item. Specifically, by execution of the scene-transition-amount detection program  122   a,  the following processes are carried out. A latest video difference frame  13  is acquired, a data size of a previously-received video difference frame  13  is acquired from the program memory  122 , and a difference between data sizes of the current frame and the previous frame is calculated. When the calculated difference exceeds a threshold, the value of the scene transition amount is incremented (+1), and the data size of the previous frame is overwritten by the data size of the current frame. When the calculated difference does not exceed the threshold, the data size of the previous frame is overwritten by the data size of the current frame without incrementing the value of the scene transition amount. The scene-transition-amount detection program  122   a  is an example of a calculation unit. The value of the scene transition amount calculated by the scene-transition-amount detection program  122   a  is an example of an evaluation value. 
     The data storing program  122   b  provides a function to correlate and integrate the data items of the profile  11 , the video KEY frame  12 , the video difference frames  13 , the scene transition amount  14 , the motion-sensor data item  15 , the sound-pressure-sensor data item  16 , and the thermal-sensor data item  17  with each other into the recorded data item  115   a  being the single file, and to cause the recorded data item  115   a  to be stored into the recording memory  115 . Specifically, by execution of the data storing program  122   b,  the following processes are carried out. The video difference KEY frame  12  and the video difference frames  13  are acquired. The profile is generated based, for example, on the time measured by the time measurement device  109  and on the preset recording condition. Within the predetermined time period (for example, 1 minute) after acquisition of a first video difference frame  13 , the video KEY frame  12 , the video difference frames  13 , the motion-sensor data item  15 , the sound-pressure-sensor data item  16 , and the thermal-sensor data item  17  are gathered. Within the predetermined time period (for example, 1 minute) after the acquisition of the first video difference frame  13 , the data items of the scene transition amount  14  calculated by the scene-transition-amount detection program  122   a  are gathered. Within the predetermined time period (for example, 1 minute) after the acquisition of the first video difference frame  13 , the video KEY frame  12 , the video difference frames  13 , the scene transition amount  14 , the motion-sensor data item  15 , the sound-pressure-sensor data item  16 , and the thermal-sensor data item  17  are gathered as data items to be synchronized, and are integrated into the single file. The single file is stored into the recording memory  115 . After those data items are stored, whenever the video difference KEY frame  12  and the video difference frames  13  are acquired, the above-described processes are executed. In the case where the above-mentioned data items being the data items to be synchronized are integrated into the single file, marks such as sequence numbers or flags corresponding to the video difference frames  13  may be added to the data items such that the integration may be performed based on those marks. The data storing program  122   b  is an example of a data storing unit. 
     The data transmission program  122   c  provides a function to transmit, as a verification data item, the data items, that is, the profile  11 , the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  out of the recorded data item  115   a  to the information processing apparatus  200 . Specifically, by execution of the data transmission program  122   c,  the following processes are carried out. The data items, that is, the profile  11 , the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  are extracted out of the recorded data item  115   a.  Those extracted data items are transmitted as the verification data item to the information processing apparatus  200  via the communication unit  114 .  FIG. 4  is a diagram showing an example of a file structure of the verification data item. As shown in  FIG. 4 , the file structure of the verification data item is a single file containing the data items, that is, the profile (time and recording condition)  11 , the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  out of the recorded data item  115   a.  The data transmission program  122   c  is an example of a data transmission unit. 
     Further, the data transmission program  122   c  provides a function to acquire the recorded data item  115   a  from the recording memory  115  based on the profile  11  contained in an instruction to transmit the recorded data item  115   a  when the instruction is received from the information processing apparatus  200 , and to transmit the acquired recorded data item  115   a  to the information processing apparatus  200 . Specifically, by execution of the data transmission program  122   c,  the following processes are carried out. Based on the profile  11  (such as time and installation site) contained in the transmission instruction, an identical recorded data item having the same profile  11  containing the same data items is acquired from among the recorded data items stored in the recording memory  115 . The acquired recorded data item is transmitted to the information processing apparatus  200 . Note that, all the data items contained in the file of the recorded data item  115   a  are transmitted to the information processing apparatus  200 . The data transmission program  122   c  is an example of a recorded-data transmission unit. 
     Further, the data transmission program  122   c  provides a function to automatically transmit the recorded data item  115   a  to the information processing apparatus  200  even when the instruction to transmit the recorded data item  115   a  is not received from the information processing apparatus  200  in case where it is determined that the monitoring site has been in the abnormal high-temperature condition in response to the signal transmitted from the thermal sensor  113 .  FIG. 5  is a diagram showing an example of a file structure of a recorded data item in case of an emergency. As shown in  FIG. 5 , this file structure is basically the same as the file structure of the recorded data item shown in  FIG. 3  except that a data item indicating the emergency is inserted into the profile  11 . 
     As long as the file structure of the recorded data item to be transmitted to the information processing apparatus  200  can be processed in the information processing apparatus  200 , this file structure may be the same as the file structure of the recorded data item  115   a.  When the file structure of the recorded data item to be transmitted to the information processing apparatus  200  cannot be processed in the information processing apparatus  200 , this file structure may be changed in accordance with the data transmission program  122   c  to a structure that can be processed in the information processing apparatus  200 . 
     [Configuration of Information Processing Apparatus] 
       FIG. 6  is a block diagram showing functional configurations of the information processing apparatus  200  and the external storage apparatus  300 . 
     The external storage apparatus  300  shown in  FIG. 6  stores a scene-transition-amount offset value  300   a,  a motion-sensor offset value  300   b,  a sound-pressure-sensor offset value  300   c,  a video database  300   d,  and an operation history database  300   e.    
     The scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  are used in the processes in the information processing apparatus  200 . The scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  are updated by the information processing apparatus  200  in accordance with the installation site of the imaging apparatus  100  and a time zone. At a stage before start of the processes in the information processing apparatus  200 , the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  are each set to a predetermined default value. 
     The video database  300   d  is a database that records the recorded data item  115   a  of the monitoring site, which is received from the imaging apparatus  100 . The operation history database  300   e  stores histories (logs) of access to the external storage apparatus  300  by the administrator of the information processing apparatus  200  and the external storage apparatus  300 . The histories (logs) of the access are utilized at the time of, for example, detection of illegal access to the external storage apparatus  300 . 
     The information processing apparatus  200  shown in  FIG. 6  includes a communication unit  210  and a control unit  220 . 
     The communication unit  210  transmits and receives various data items to be exchanged between the communication unit  210  and the imaging apparatus  100 , the external storage apparatus  300 , and the user terminal  400 . The communication unit  210  communicates in a wired or wireless manner via the predetermined communication protocol. 
     The control unit  220  includes hardware resources such as a central processing unit (CPU)  221  being an arithmetic device, and a program memory  222  being a storage device. With use of those hardware resources, the control unit  220  executes programs stored in the program memory  222 . In this way, the various processes are executed. Examples of the arithmetic processing apparatus may include a system-on-a-chip (SoC), a micro control unit (MCU), a field-programmable gate array (FPGA), and a coprocessor, but are not limited thereto. 
     The program memory  222  stores the data items and the programs that are necessary for the various processes to be executed by the control unit  220 . Examples of the program memory  222  include nonvolatile memories such as a flash memory, volatile memories such as a random access memory (RAM), or combinations thereof. The program memory  222  functions also as a working memory at the time when the control unit  220  executes the various programs. As one of the data items necessary for the various processes to be executed by the control unit  220 , the program memory  222  stores, for example, verification data items  222   e  received from the imaging apparatus  100 . 
     As shown in  FIG. 6 , the program memory  222  stores an event detection program  222   a,  a data storing program  222   b,  an offset-value update program  222   c,  an offset-value update-reference data item  222   d,  the verification data item  222   e,  and an administrator information item  222   f.    
     The event detection program  222   a  provides a function to execute a process of detecting an abnormality (event) in the monitoring site based on a result of comparison between the value of the scene transition amount  14  contained in the verification data item  222   e  received from the imaging apparatus  100  and a threshold, based on a result of comparison between the value of the motion-sensor data item  15  contained in the verification data item  222   e  and a threshold, and based on a result of comparison between the value of the sound-pressure-sensor data item  16  contained in the verification data item  222   e  and a threshold. The event detection program  222   a  is an example of an event detection unit. 
     Specifically, by execution of the event detection program  222   a,  the following processes are carried out. When the verification data item  222   e  is received, the scene-transition-amount off set value  300   a  is acquired from the external storage apparatus  300 , and the scene-transition-amount offset value  300   a  is subtracted from the value of the scene transition amount contained in the verification data item. A determination as to whether a value of the scene transition amount as a result of the subtraction of the scene-transition-amount offset value  300   a  is 1 or more is made. When a determination that this value is 1 or more is made, an email is sent to the registered administrator (user terminal  400 ). Subsequently, the instruction to transmit the recorded data item corresponding to the received verification data item  222   e  is transmitted to the imaging apparatus  100 . Meanwhile, when the value of the scene transition amount as a result of the subtraction of the scene-transition-amount offset value  300   a  is not 1 or more, the motion-sensor offset value  300   b  is acquired from the external storage apparatus  300 , and the motion-sensor offset value  300   b  is subtracted from the value of the motion-sensor data item  15  contained in the verification data item  222   e.  A determination as to whether a value of the motion-sensor data item  15  as a result of the subtraction of the motion-sensor offset value  300   b  is 1 or more is made. When a determination that this value is 1 or more is made, an email is sent to the registered administrator (user terminal  400 ). Subsequently, the instruction to transmit the recorded data item corresponding to the received verification data item  222   e  is transmitted to the imaging apparatus  100 . Meanwhile, when the value of the motion-sensor data item  15  as a result of the subtraction of the motion-sensor offset value  300   b  is not 1 or more, the sound-pressure-sensor offset value  300   c  is acquired from the external storage apparatus  300 , and the sound-pressure-sensor offset value  300   c  is subtracted from the value of the sound-pressure-sensor data item  16  contained in the verification data item  222   e.  A determination as to whether a value of the sound-pressure-sensor data item  16  as a result of the subtraction of the sound-pressure-sensor offset value  300   c  is 1 or more is made. When a determination that this value is 1 or more is made, an email is sent to the registered administrator (user terminal  400 ). Subsequently, the instruction to transmit the recorded data item corresponding to the received verification data item  222   e  is transmitted to the imaging apparatus  100 . Meanwhile, when the value of the sound-pressure-sensor data item  16  as a result of the subtraction of the sound-pressure-sensor offset value  300   c  is not 1 or more, the processes regarding the corresponding verification data item  222   e  is ended. The above-mentioned transmission instruction contains the profile  11  contained in the verification data item  222   e.  In the imaging apparatus  100 , based on the information items (such as time and installation site) of the profile  11  contained in the transmission instruction, the recorded data item  115   a  corresponding to the transmission instruction is searched for. 
     The data storing program  222   b  provides a function to execute a process of causing the recorded data item  115   a  received from the imaging apparatus  100  to be stored into the external storage apparatus  300 . Specifically, by execution of the data storing program  222   b,  the following processes are carried out. When the instruction to transmit the recorded data item  115   a  is transmitted to the imaging apparatus  100  in accordance with the event detection program  222   a,  and then the recorded data item  115   a  of a corresponding time (time contained in the profile  11  of the verification data item  222   e ) is received, this received recorded data item is stored into the external storage apparatus  300 . Further, when the recorded data item  115   a  in case of an emergency is received from the imaging apparatus  100 , this received recorded data item is stored into the external storage apparatus  300 . The data storing program  222   b  is an example of a recorded-data storing unit. 
     The offset-value update program  222   c  provides a function to execute a process of updating the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  based on the offset-value update-reference data item  222   d.  Specifically, by execution of the offset-value update program  222   c,  the following processes are carried out. When the updates of the offset values are determined, the default values of the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  are acquired from the external storage apparatus  300 . From the offset-value update-reference data item  222   d,  an adjustment value corresponding to the installation site and the time that are contained in the profile  11  of the verification data item  222   e  is acquired. Values obtained by multiplying respective default values of the scene transition amount, the motion sensor, and the sound pressure sensor by the corresponding adjustment value are set as offset values in the corresponding time zone. In this way, the offset values are updated. The default values of the offset values are each calculated in advance from a sum of average values of a non-physical quantity contained in the verification data item  222   e.  The value of the scene transition amount, the value detected by the motion sensor, and the value detected by the sound pressure sensor are examples of the non-physical quantity. For example, an offset value of a scene transition amount corresponding to 12 o&#39;clock is calculated by multiplying a sum of average values of scene transition amounts in 30 minutes around 12 o&#39;clock by the adjustment value corresponding to the installation site of the imaging apparatus  100  and the time zone. The offset value of the motion sensor and the offset value of the sound pressure sensor are calculated in the same way as that of updating the offset value of the scene transition amount as described above. 
     The offset-value update-reference data item  222   d  is used in the processes for updating the offset values in accordance with the offset-value update program  222   c.  For example, the adjustment value (magnification) corresponding to the installation site of the imaging apparatus  100  and the time zone is set as the offset-value update-reference data item  222   d.  Specifically, the adjustment value is set to from 3 to 5 for a time zone of from 11 o&#39;clock to 16 o&#39;clock in a commercial building, and set to 2 for a time zone of from 18 o&#39;clock to 24 o&#39;clock in the commercial building. The adjustment value that is used at the time of calculating the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  need not necessarily be changed in accordance with the types of the data items, or may be changed in accordance with the types of the data items. 
     The verification data items  222   e  are data items that are transmitted at predetermined time intervals from the imaging apparatus  100 . The verification data items  222   e  may be deleted one by one from the program memory  222  whenever the processes in accordance with the event detection program  222   a  are completed, or may collectively be deleted at once. 
     The administrator information item  222   f  contains an information item of an email address of the user terminal  400  that is notified of occurrence of the abnormality (event) in the monitoring site. 
     Processes According to First Embodiment 
     With reference to  FIG. 7  to  FIG. 10 , flows of the processes according to the first embodiment are described.  FIG. 7  is a flowchart showing a flow of the scene-transition-amount calculation process according to the first embodiment.  FIG. 8  and  FIG. 9  are flowcharts showing a flow of the event detection process according to the first embodiment.  FIG. 10  is a flowchart showing a flow of the offset-value update process according to the first embodiment. 
     [Scene-Transition-Amount Calculation Process] 
     First, with reference to  FIG. 7 , the flow of the scene-transition-amount calculation process that is executed in the imaging apparatus  100  is described. The scene-transition-amount calculation process shown in  FIG. 7  is carried out when the CPU  121  executes the scene-transition-amount detection program  122   a.    
     As shown in  FIG. 7 , the imaging apparatus  100  determines whether a latest video difference frame  13  has been acquired (Step S 101 ). When a determined result that the latest video difference frame  13  has been acquired is obtained (Yes in Step S 101 ), the imaging apparatus  100  acquires a data size of a previously-received video difference frame  13  from the working memory  122  (Step S 102 ). 
     Then, the imaging apparatus  100  calculates a difference between the data size of the latest video difference frame  13  (current frame) acquired in Step S 101 , and the data size of the previous frame acquired in Step S 102  (Step S 103 ). 
     Next, the imaging apparatus  100  determines whether the difference calculated in Step S 103  has exceeded a threshold (Step S 104 ). 
     When a determination result that the difference calculated in Step S 103  has exceeded the threshold is obtained (Yes in Step S 104 ), the imaging apparatus  100  increments (+1) a value of the scene transition amount  14  (Step S 105 ). Then, the imaging apparatus  100  updates the data size of the previous frame with the data size of the current frame (Step S 106 ). 
     In Step S 104 , when a determination result that the difference calculated in Step S 103  has not exceeded the threshold is obtained (No in Step S 104 ), the imaging apparatus  100  does not increment the value of the scene transition amount  14 , and advances the procedure to the process of Step S 106  described above. 
     After that, the imaging apparatus  100  determines whether processes on all the video difference frames  13  to be processed have been completed (Step S 107 ). For example, when digital images are acquired at 30 fps from the encoding unit  108   b,  the imaging apparatus  100  determines whether processes on the digital images corresponding to the thirty frames have been completed. 
     When a determination result that the processes on all the video difference frames  13  to be processed have been completed is obtained (Yes in Step S 107 ), the imaging apparatus  100  ends the flow shown in  FIG. 7 . In contrast, when a determination result that the processes on all the video difference frames  13  to be processed have not been completed is obtained (No in Step S 107 ), the imaging apparatus  100  returns the procedure to the process of Step S 101  described above. 
     In the process of Step S 101  described above, when a determination result that the latest video difference frame  13  has not been acquired is obtained (No in Step S 101 ), the imaging apparatus  100  advances the procedure to the process of Step S 107  described above. 
     Event Detection Process (First Embodiment) 
     Next, with reference to  FIG. 8  and  FIG. 9 , the flow of the event detection process that is executed in the information processing apparatus  200  is described. The event detection process shown in  FIG. 8  and  FIG. 9  is carried out when the CPU  221  executes the event detection program  222   a.    
     As shown in  FIG. 8 , the information processing apparatus  200  determines whether the verification data item  222   e  has been received (Step S 201 ). 
     When a determination result that the verification data item  222   e  has been received is obtained (Yes in Step S 201 ), the information processing apparatus  200  acquires the scene-transition-amount offset value  300   a  (Step S 202 ). 
     Then, the information processing apparatus  200  subtracts the scene-transition-amount offset value  300   a  from the value of the scene transition amount  14  contained in the verification data item  222   e  (Step S 203 ). Next, the information processing apparatus  200  determines whether a result of the subtraction in Step S 203  is 1 or more (Step S 204 ). 
     When a determination result that the result of the subtraction is 1 or more is obtained (Yes in Step S 204 ), the information processing apparatus  200  determines that an abnormality has been detected in a monitoring site, and sends an email (Step S 205 ) to the registered administrator (user terminal  400 ). Subsequently, the information processing apparatus  200  transmits an instruction to the imaging apparatus  100  (Step S 206 ) such that the recorded data item of a corresponding time (time contained in the profile  11  of the verification data item  222   e ) is transmitted. The information processing apparatus  100  determines whether the recorded data item has been received (Step S 207 ). 
     When a determination result that the recorded data item has not been received is obtained (No in Step S 207 ), the information processing apparatus  200  waits until the recorded data item is received, and repeats the determination in Step S 207 . 
     Meanwhile, when a determination result that the recorded data item has been received is obtained (Yes in Step S 207 ), the information processing apparatus  200  causes the received recorded data item to be stored into the external storage apparatus  300  (Step S 208 ), and ends the event detection process. 
     In Step S 204 , when a determination result that the result of the subtraction is not 1 or more is obtained (No in Step S 204 ), the information processing apparatus  200  acquires the motion-sensor offset value  300   b  (Step S 209 ). 
     Then, the information processing apparatus  200  subtracts the motion-sensor offset value  300   b  from a value of the motion-sensor data item  15  contained in the verification data item  222   e  (Step S 210 ). Next, the information processing apparatus  200  determines whether a result of the subtraction in Step S 210  is 1 or more (Step S 211 ). 
     When a determination result that the result of the subtraction is 1 or more is obtained (Yes in Step S 211 ), the information processing apparatus  200  advances the procedure to the process of Step S 205  described above. In contrast, when a determination result that the result of the subtraction is not 1 or more is obtained (No in Step S 211 ), the information processing apparatus  200  acquires the sound-pressure-sensor offset value  300   c  (Step S 212 ). 
     Then, the information processing apparatus  200  subtracts the sound-pressure-sensor offset value  300   c  from a value of the sound-pressure-sensor data item  16  contained in the verification data item  222   e  (Step S 213 ). Next, the information processing apparatus  200  determines whether a result of the subtraction in Step S 213  is 1 or more (Step S 214 ). 
     When a determination result that the result of the subtraction is 1 or more is obtained (Yes in Step S 214 ), the information processing apparatus  200  advances the procedure to the process of Step S 205  described above. In contrast, when a determination result that the result of the subtraction is not 1 or more is obtained (No in Step S 214 ), the information processing apparatus  200  ends the event detection process. 
     In Step S 201 , when a determination result that the verification data item  222   e  has not been received is obtained (No in Step S 201 ), the information processing apparatus  200  ends the event detection process. 
     In the case described with reference to the example shown in  FIG. 8 , an email is sent to the registered administrator (Step S 205 ). However, the process of sending the email need not necessarily be contained in the procedure. In the case described with reference to the example shown in  FIG. 8  and  FIG. 9 , the processes are executed sequentially on the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16 . However, the order of the processes on the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  is not limited thereto, and may be changed. 
     [Offset-Value Update Process] 
     Next, with reference to  FIG. 10 , the flow of the offset-value update process that is executed in the information processing apparatus  200  is described. The offset-value update process shown in  FIG. 10  is carried out when the CPU  221  executes the offset-value update program  222   c.    
     As shown in  FIG. 10 , the information processing apparatus  200  determines whether to execute the updates of the offset values (Step S 301 ). For example, the information processing apparatus  200  determines, based on the time recorded in the profile  11  of the verification data item  222   e,  whether to update currently-set offset values in accordance with a current time zone. 
     When the updates of the offset values are executed as a result of the determination (Yes in Step S 301 ), the information processing apparatus  200  acquires the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  (Step S 302 ). Then, the information processing apparatus  200  acquires the offset-value update-reference data item  222   d  (Step S 303 ). 
     Based on the offset-value update-reference data item  222   d,  the information processing apparatus  200  updates the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  (Step S 304 ). 
     Next, the information processing apparatus  200  determines whether to end the offset-value update process (Step S 305 ). 
     When the offset-value update process is ended as a result of the determination (Yes in Step S 305 ), the information processing apparatus  200  initializes the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  (Step S 306 ), and ends the offset-value update process. In contrast, when the offset-value update process is not ended as a result of the determination (No in Step S 305 ), the information processing apparatus  200  returns the procedure to the process of Step S 301  described above. 
     Advantages of First Embodiment 
     As described hereinabove, in the first embodiment, when the abnormality in the monitoring site is detected, the information processing apparatus  200  transmits the instruction to the imaging apparatus  100  such that the recorded data item of the monitoring site is transmitted, and causes the recorded data item received from the imaging apparatus  100  to be stored into the external storage apparatus  300 . In this way, according to the first embodiment, only the recorded data item in the case of the abnormality in the monitoring site can be recorded. As a result, a burden of running costs such as communication cost and management cost for the recorded data item of the monitoring site can be reduced as reliably as possible. 
     Further, in the first embodiment, when the abnormality in the monitoring site is detected based on at least one of the data items of the scene transition amount, the motion sensor, and the sound pressure sensor, the information processing apparatus  200  transmits the instruction to the imaging apparatus  100  such that the recorded data item of the monitoring site is transmitted. Thus, according to the first embodiment, in the case where a transition of a state occurs in the monitoring site, recorded data items can be stored as reliably as possible. 
     Further, in the first embodiment, the information processing apparatus  200  executes the process of detecting the abnormality in the monitoring site based on the values obtained by the subtractions of the corresponding offset values from the scene transition amount, the motion sensor, and the sound pressure sensor. Thus, according to the first embodiment, the transition of the state in the monitoring site can be detected with as high accuracy as possible. 
     Second Embodiment 
     In the example described above in the first embodiment, when the abnormality in the monitoring site is detected based on the at least one of the data items of the scene transition amount, the motion sensor, and the sound pressure sensor, the instruction to transmit the recorded data item of the monitoring site is transmitted to the imaging apparatus  100 . However, the present invention is not limited to this example. When the abnormality in the monitoring site is detected based on all the data items of the scene transition amount, the motion sensor, and the sound pressure sensor, the instruction to transmit the recorded data item of the monitoring site may be transmitted to the imaging apparatus  100 . In a second embodiment described below, with reference to  FIG. 11  and  FIG. 12 , processes according to the second embodiment are described.  FIG. 11  is a flowchart showing a flow of an event detection process according to the second embodiment.  FIG. 12  is a table showing an example of determination results of the event detection process according to the second embodiment. 
     Event Detection Process (Second Embodiment) 
     As shown in  FIG. 11 , the information processing apparatus  200  determines whether the verification data item  222   e  has been received (Step S 401 ). 
     When a determination result that the verification data item  222   e  has been received is obtained (Yes in Step S 401 ), the information processing apparatus  200  acquires the scene-transition-amount offset value  300   a  (Step S 402 ). 
     Then, the information processing apparatus  200  subtracts the scene-transition-amount offset value  300   a  from a value of the scene transition amount  14  contained in the verification data item  222   e  (Step S 403 ). Next, the information processing apparatus  200  acquires the motion-sensor offset value  300   b  (Step S 404 ), and subtracts the motion-sensor offset value  300   b  from a value of the motion-sensor data item  15  contained in the verification data item  222   e  (Step S 405 ). After that, the information processing apparatus  200  acquires the sound-pressure-sensor offset value  300   c  (Step S 406 ), and subtracts the sound-pressure-sensor offset value  300   c  from a value of the sound-pressure-sensor data item  16  contained in the verification data item  222   e  (Step S 407 ). 
     Then, the information processing apparatus  200  sums up the values calculated in Step S 403 , Step S 405 , and Step S 407  (Step S 408 ). 
     Next, the information processing apparatus  200  determines whether a sum in Step S 408  is 1 or more (Step S 409 ). 
     When a determination result that the sum in Step S 408  is 1 or more is obtained (Yes in Step S 409 ), the information processing apparatus  200  advances the procedure to the process of Step S 205  shown in  FIG. 8 . When the sum of the value obtained by the subtraction of the scene-transition-amount offset value  300   a  from the value of the scene transition amount  14 , the value obtained by the subtraction of the motion-sensor offset value  300   b  from the value of the motion-sensor data item  15 , and the value obtained by the subtraction of the sound-pressure-sensor offset value  300   c  from the value of the sound-pressure-sensor data item  16  exceeds 1, the information processing apparatus  200  generates a determination result that there is an abnormality in the monitoring site.  FIG. 12  shows an example of correspondences between the values of the scene transition amounts  14 , the motion-sensor data items  15 , and the sound-pressure-sensor data items  16  corresponding to hours of from 1 o&#39;clock to 24 o&#39;clock, the scene-transition-amount offset values  300   a,  the motion-sensor offset values  300   b,  and the sound-pressure-sensor offset values  300   c  corresponding to those hours, and determination results corresponding to those hours. Specifically, the value “−2” is obtained by a subtraction of the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  corresponding to 1 o&#39;clock from the sum of the values of the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  corresponding to 1 o&#39;clock. This value “−2” is normalized to “0,” and hence does not exceed “1.” Thus, a determination result that there is no abnormality in the monitoring site is generated. Meanwhile, the value “2” is obtained by a subtraction of the scene-transition-amount offset value  300   a,  the motion-sensor offset value  300   b,  and the sound-pressure-sensor offset value  300   c  corresponding to 23 o&#39;clock from the sum of the values of the scene transition amount  14 , the motion-sensor data item  15 , and the sound-pressure-sensor data item  16  corresponding to 23 o&#39;clock. This value “2” exceeds “1.” Thus, the determination result that there is an abnormality in the monitoring site is generated. In the example shown in  FIG. 12 , as a result of the determinations, for example, the determination results that there are abnormalities in the monitoring site at “23 o&#39;clock” and “24 o&#39;clock” are generated. 
     When a determination result that the sum in Step S 408  is not 1 or more is obtained (No in Step S 409 ), the information processing apparatus  200  ends the event detection process. 
     In Step S 401 , when a determination result that the verification data item  222   e  has not been received is obtained (No in Step S 401 ), the information processing apparatus  200  ends the event detection process. 
     Advantages of Second Embodiment 
     As described hereinabove, in the second embodiment, when the abnormality in the monitoring site is detected based on all the data items of the scene transition amount, the motion sensor, and the sound pressure sensor, the information processing apparatus  200  transmits the instruction to the imaging apparatus  100  such that the recorded data item of the monitoring site is transmitted. With this, according to the second embodiment, the abnormality in the monitoring site can be detected more reliably than in the event detection process described in the first embodiment. As a result, the burden of the running costs such as the communication cost and the management cost for the recorded data item of the monitoring site can be further reduced. 
     In the embodiments described hereinabove, the information processing apparatus  200  may instruct the imaging apparatus  100  to transmit the recorded data item in response to a request received from the user terminal  400 . Specifically, when the request for transmitting the recorded data item is received from the user terminal  400 , the information processing apparatus  200  transmits the instruction to the imaging apparatus  100  such that the recorded data item corresponding to the transmission request is transmitted. When receiving the recorded data item from the user terminal  400 , the information processing apparatus  200  causes the received recorded data item to be stored into the external storage apparatus  300 , and sends a message to the user terminal  400  so as to notify that the recorded data item can be viewed. 
     Note that, the configurations of the above-described embodiments of the present invention can be arbitrarily changed without departing from the gist of the present invention. For example, the programs of the above-described embodiments may be separately executed by a plurality of modules, or maybe integrated with other programs. Further, the functions of the information processing apparatus  200  may be separately exerted by a plurality of apparatus as appropriate. 
     REFERENCE SIGNS LIST 
       1  network 
       100  imaging apparatus 
       106  image pickup element 
       107  capture unit 
       108   a  to  108   c  encoding unit 
       109  time measurement device 
       110  input processing unit 
       111  motion sensor 
       112  sound pressure sensor 
       113  thermal sensor 
       114  communication unit 
       115  recording memory 
       120  control unit 
       121  CPU 
       122  program memory 
       200  information processing apparatus 
       210  communication unit 
       220  control unit 
       221  CPU 
       222  program memory 
       300  external storage apparatus 
       400  user terminal