Patent Application
20200293806
The present invention relates to a camera system and a facility.
An inspection technique using a terahertz wave is known. The terahertz wave can be defined as an electromagnetic wave having a frequency of 30 (inclusive) GHz to 30 THz (inclusive). Japanese Patent Laid-Open No. 2004-286716 discloses a method of inspecting a prohibited drug such as a narcotic drug enclosed in a sealed letter. In this method, a characteristic absorption spectrum that a prohibited drug such as a narcotic drug has in the terahertz band is used to identify a substance in a sealed letter without breaking the seal.
Recently, dangerous items such as knives being taken into a railroad coach through a railroad station is a serious problem from the viewpoint of crime prevention. There is strong demand for a technique of detecting such a dangerous item.
Some embodiments of the present invention provide a technique advantageous in improving crime prevention by a camera system installed in a facility.
According to some embodiments, a camera system arranged to form a part of a monitoring system arranged in a place of a facility, where an inspection object lines up, comprising an imaging system configured to acquire an image formed by a terahertz wave reflected by the inspection object, is provided.
According to some other embodiments, a facility including a camera system, wherein the camera system arranged to form a part of a monitoring system arranged in a place of a facility, where an inspection object lines up, comprises an imaging system configured to acquire an image formed by a terahertz wave reflected by the inspection object, is provided.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.
A camera system 200 according to some embodiments of the present invention will be described with reference to
The camera system 200 includes an imaging system 201 configured to acquire an image formed by a terahertz wave reflected by an inspection object 250. The imaging system 201 can include at least one illumination unit 202 configured to irradiate a terahertz wave, and at least one camera 203 configured to acquire an image formed by the terahertz wave. The illumination unit 202 is also referred to as the irradiation unit. To discriminate a plurality of illumination units 202 and a plurality of cameras 203 in the following explanation, a suffix is added to each reference numeral, like an illumination unit 202“a” and a camera 203“a”. If the illumination units and the cameras need not be discriminated, they are expressed simply as “illumination unit 202” and “camera 203”. This also applies to other constituent elements.
In this embodiment, the camera 203 that detects a terahertz wave is of a type called active camera, and can be used in combination with the illumination unit 202. However, the camera is not limited to this, and may be a camera of a passive type. In this case, without illuminating the inspection object 250 with a terahertz wave irradiated from the illumination unit 202, and an image can be acquired by a terahertz wave radiated from the inspection object 250.
The imaging system 201 can be arranged to capture the inspection object 250 that uses the station. The inspection object 250 is normally a person but may be an animal other than a person or a robot. A terahertz wave passes through a fabric, a leather, and the like. For this reason, a processor (for example, a control system 310 to be described later) (not shown) connected to the camera system 200 can detect a dangerous item such as a firearm, a cutting tool, or an explosive based on an image provided from the imaging system 201 of the camera system 200.
In the arrangement shown in
As shown in
The arrangement of the illumination unit 202 and the camera 203 is not limited to the above-described arrangement. For example, the illumination unit 202 and the camera 203 may be arranged on the ticket gate machine 211a. Alternatively, for example, the illumination unit 202 and the camera 203 may be arranged near the center of the ticket gate machine 211, or may be arranged near the end portion on the outer side of the ticket gate in
If the imaging system 201 of the camera system 200 is used as a surveillance camera, in some cases, post-processing such as image processing by a processor (not shown) at the subsequent stage of the imaging system 201 of the camera system 200 is facilitated by capturing the person who is the inspection object 250 one by one. The ticket gate machine 211 passes the person who is the inspection object 250 one by one at a high possibility. Hence, when the imaging system 201 is arranged in the ticket gate machine 211, the load of post-processing such as image processing can be suppressed. That is, the imaging system 201 can be arranged in a place where the inspection object 250 lines up. In addition, the time needed for the person that is the inspection object 250 to pass through the ticket gate machine 211 is about 1 sec. However, the imaging system 201 can acquire an image formed by a terahertz wave at a frame rate of 50 fps or more. For this reason, it is possible to perform capture one inspection object 250 at plurality of times. In the plurality of times of image capturing, the inspection object 250 may be captured wholly or may be captured only partially.
The imaging system 201 of the camera system 200 may include a sensor 260 configured to detect that the inspection object 250 approaches. For example, the ticket gate machine 211 may be provided with the sensor 260, as shown in
Additionally, in
An example in which the imaging system 201 is applied to a partition wall 213 on a platform 216 of a station will be described next with reference to
The imaging system 201 includes the illumination unit 202a and the camera 203a, which are arranged in the track-side area 217. The illumination unit 202a and the camera 203a perform illumination and image capturing of the passage 241 from the track-side area 217 when the door portion 214 opens. In addition, the imaging system 201 includes the illumination unit 202b and the camera 203b, which are arranged in the platform 216. The illumination unit 202b and the camera 203b perform illumination and image capturing of the passage 241 from the platform 216 when the door portion 214 opens. When the illumination unit 202a and the camera 203a, and the illumination unit 202b and the camera 203b are arranged, it is possible to acquire the front- and rear-side images of both the inspection object 250 that gets in a railroad coach 218 via a door 219 and the inspection object 250 that gets off the railroad coach 218 via the door 219. However, the present invention is not limited to this, and only the illumination unit 202a and the camera 203a or only the illumination unit 202b and the camera 203b may be arranged.
Each of the illumination units 202a and 202b may include a plurality of illumination devices, as shown in
In addition, as shown in
The arrangement of the illumination units 202a and 202b and the cameras 203a and 203b is not limited to the arrangement shown in
As described above, if the imaging system 201 is used as a surveillance camera, the load of post-processing such as image processing can be reduced by capturing the person who is the inspection object 250 one by one. Hence, the imaging system 201 included in the camera system 200 may be applied to the partition wall 213 installed in a station where a bullet train or a limited express for which persons line up and get in one by one stops. In this case, the width of the door 219 of the railroad coach 218 used for the bullet train or limited express is about 700 mm to 1,000 mm. Hence, in the arrangement shown in
For example, the imaging system 201 may be applied to, for example, the partition wall 213 in a railroad station of a commuter train or the like. In this case, it may be possible to acquire images of persons one by one except during rush hours. Even in a case in which a plurality of inspection objects 250 simultaneously get in or get off, the inspection objects 250 often line up in two or three lines and get in. Each inspection object 250 can be distinguished by image processing or the like using a processor included in the camera system 200. In a commuter train or the like, the width of a door is about 1,300 mm to 2,000 mm. For this reason, in the arrangement shown in
In some cases, the platform 216 is arranged outdoors. Hence, the imaging system 201 arranged on the platform 216 or the track-side area 217 is readily affected by the external environment. A terahertz wave is readily absorbed by water, and it may be impossible to obtain images with sufficient image quality in a highly humid environment such as a rainfall. Hence, the imaging system 201 may include a sensor 261 configured to detect the external environment, as shown in
In addition, for example, the illumination unit 202 or the camera 203 may be attached to the vehicle body of the railroad coach 218. That is, the camera system 200 may include an illumination unit or a camera mounted on the railroad coach 218. In this case, the camera system 200 can include a communication unit between the imaging system 201 arranged in a station and the imaging system including the illumination unit or the camera included in the railroad coach 218.
In addition, for example, the illumination unit 202 and the camera 203 may start operations when the door portion 214 of the partition wall 213 opens. For example, the imaging system 201 may synchronize with the operation of the door portion 214, or may include a sensor configured to detect that the door portion 214 has opened. This can suppress power consumption of the imaging system 201.
An example in which the imaging system 201 is applied to an escalator 221 will be described next with reference to
The imaging system 201 is arranged to be adjacent to the escalator 221 to acquire the image of the inspection object 250 that passes through the escalator 221. In the arrangement shown in
For example, as shown in
As described above, if the imaging system 201 is used as a surveillance camera, it may be advantageous that the person who is the inspection object 250 can be captured one by one. Since the escalator 221 operates at a predetermined speed, the possibility that the image of the inspection object 250 can be acquired one by one is high. Additionally, as shown in
In addition, as described above, a terahertz wave can pass through a resin or the like. For this reason, the illumination unit 202 or the camera 203 may be embedded in the floor, wall, or ceiling of the portion where the escalator 221 is arranged. For example, the illumination unit 202 may be installed on the deck board of the escalator 221 together with a normal illumination.
An example in which the imaging system 201 is applied to a staircase 222 will be described next with reference to
The imaging system 201 is arranged in the staircase 222 to acquire the image of the inspection object 250 that passes through the staircase 222. In the arrangement shown in
Since the person who is the inspection object 250 goes up or down the staircase 222 one by one (or by about two steps), the image of the inspection object 250 can sequentially be acquired from the head (or foot) of the inspection object 250 to the foot (or head).
For the window 224 provided in the riser portion 223 of the staircase 222, various kinds of resins that pass a terahertz wave can be used, as described above. When an appropriate resin material is selected in accordance with the material used for the riser portion 223 or a tread portion 225 of the staircase 222, where the imaging system 201 is not arranged, the imaging system 201 can be made unnoticeable (its existence can be hidden).
An example in which the imaging system 201 is applied to a passage 242 will be described next with reference to
The imaging system 201 is arranged in the passage 242 to acquire the image of the inspection object 250 that passes through the passage 242. The imaging system 201 includes the illumination unit 202 and the camera 203. At this time, one of the illumination unit 202 and the camera 203 is arranged on a ceiling 227 of the passage 242, and the other of the illumination unit 202 and the camera 203 is embedded in a floor 226 of the passage 242. In the arrangement shown in
In the arrangement shown in
Additionally, in the arrangement shown in
However, the arrangement of the illumination unit 202 and the camera 203 on the passage 242 is not limited to the arrangement shown in
As described above, when the imaging system 201 is arranged in the staircase 222 or the passage 242, a plurality of cameras 203 may be arranged in the widthwise direction of the staircase 222 or the passage 242. Accordingly, the possibility that the image of the inspection object 250 can be captured one by one becomes high. In addition, the imaging system 201 may be arranged in a portion of the staircase 222 or the passage 242, where the width decreases. In the portion of the staircase 222 or the passage 242, where the width decreases, the inspection object 250 can easily line up.
Additionally, the camera system 200 according to this embodiment can monitor the inspection object 250 shown in
The control system 310 can specify the inspection object 250 based on the feature information of the inspection object 250 and correspondence information that associates the feature information with seat information assigned to a passenger having a feature corresponding to the feature information. The feature information can be information extracted by the control system 310 from an image obtained by the imaging system 201. The feature information may be, for example, a feature amount specified based on the shape, the size, and the like of a partial image extracted from an image obtained by the imaging system 201, may be information that specifies the type of a dangerous item, or may be information representing another feature. Alternatively, the feature information may be information representing the above-described risk. Extraction of the partial image from the image acquired by the imaging system 201 can include, for example, extracting a portion having a brightness more than a predetermined brightness. AI (Artificial Intelligence) can be used to extract the feature information. More specifically, AI that has undergone deep learning is installed in the control system 310, and the feature information can be extracted by the AI. For example, information representing a risk in an image captured by the camera 203 appears in a different manner depending on the position and orientation of the camera 203. Hence, deep learning can be executed based on images captured by a plurality of cameras 203.
The control system 310 can transmit the result of the above-described processing to a terminal 320 set in advance via the communication unit 315. The terminal 320 can be carried by, for example, a conductor in the railroad coach 218. The terminal 320 may include a terminal carried by a person other than the conductor in the railroad coach 218, a terminal provided in a security office arranged in a station or the like, and a terminal provided in an administrative body such as a police station.
The imaging system 201 can acquire the image of the inspection object 250 that passes through the ticket gate machine 211 and transmit the obtained image to the control system 310. The control system 310 can decide the risk of the inspection object based on the image received from the imaging system 201. In addition, the control system 310 can extract the feature information of the inspection object from the image received from the imaging system 201.
The control system 310 generates correspondence information that associates the feature information of the inspection object 250 extracted from the image received from the imaging system 201 with seat information read by the ticket gate machine 211. For example, the feature information can be information strongly suggesting holding of a gun, and the seat information can be seat information read by the ticket gate machine 211 from a ticket held by the inspection object 250 that holds the gun. The correspondence information can be transmitted from the control system 310 to the terminal 320 in the railroad coach 218. The feature information may include information that identifies the ID of the inspection object 250 (that is, information that specifies an individual). The imaging system 201 may include a visible light camera, and the ID of the inspection object 250 can be identified from the visible light image of the inspection object 250 or from the visible light image by AI or the like. The visible light image of the inspection object having a predetermined risk can be transmitted to the railroad coach 218 together with the above-described correspondence information and can further be transmitted to the terminal 320. A case in which the image of the inspection object 250 is acquired by the imaging system 201 arranged on the ticket gate machine 211 has been described here. However, tracking of the inspection object 250 may be started or continued based on an image obtained from the imaging system 201 arranged on the partition wall 213, the escalator 221, the staircase 222, or the passage 242. In addition, tracking of the inspection object 250 may be started based on an image obtained by the imaging system 201 arranged on the ticket gate machine 211, and after that, tracking of the inspection object 250 may be continued using a surveillance camera using visible light.
The operation of the camera system 200 will be described next with reference to
First, in step S1001, the illumination unit 202 irradiates the inspection object 250 with a terahertz wave under a desired condition. Next, in step S1002, the camera 203 detects the terahertz wave reflected by the inspection object 250 and acquires information based on the terahertz wave. In step S1003, a control unit performs processing of converting the information based on the terahertz wave into an image. Here, the control unit can be, for example, the control system 310 shown in
Next, the control unit evaluates the quality of the acquired terahertz image (step S1004). As the evaluation items, items representing whether an appropriate terahertz image according to the inspection object 250 can be acquired, whether an article can be detected from the terahertz image of the image quality, and the like can appropriately be set. In the image quality evaluation, if desired image quality is not satisfied, the camera system 200 performs the operation of step S1005. In step S1005, the control unit supplies, to the illumination unit 202, a control signal for changing the wavelength and increasing the power of the irradiated terahertz wave. The illumination unit 202 performs terahertz wave irradiation (step S1001) again. With the series of operations, a desired article can appropriately be detected.
Note that in the image evaluation, upon determining that the desired image quality can be obtained, the control unit judges the presence and absence of a detected article, and in some cases, the type of the article (step S1006). If an article is detected, the control unit causes a monitor system to display an alert. Alternatively, the control unit outputs an instruction to perform an operation of adding a flag to an article or person of high risk (step S1007). If no article is detected, the control unit may add a flag to the confirmed person of low risk (step S1008).
For the series of operations, the illumination unit 202 and the camera 203 can be used in the following combinations. If there are the illumination unit 202 and the camera 203 used in the first capturing, second and subsequent capturing may be executed using the same illumination unit 202 and the same camera 203. In addition, if there are the illumination unit 202 and the camera 203 used in the first capturing, second and subsequent capturing may be executed using the same illumination unit 202 as in the first capturing and the camera 203 different from that in the first capturing. Furthermore, if there are the illumination unit 202 and the camera 203 used in the first capturing, second and subsequent capturing may be executed using the illumination unit 202 different from that in the first capturing and the same camera as in the first capturing. Furthermore, if there are the illumination unit 202 and the camera 203 used in the first capturing, second and subsequent capturing may be executed using the illumination unit 202 and the camera 203 which are different from those in the first capturing.
Another operation of the camera system 200 will be described next with reference to
First, in the camera system 200, the illumination unit 202 is in a standby state (step S1101). At this time, the camera 203 may also be in the standby state. The control unit detects a door opening signal (step S1102). Upon detecting the door opening signal, the control unit supplies a control signal for irradiating the inspection object 250 to the illumination unit 202, and supplies a control signal for capturing the inspection object 250 to the camera 203. The illumination unit 202 starts terahertz wave irradiation in accordance with the control signal from the control unit (step S1103). The camera 203 starts detecting the terahertz wave in accordance with the start of illumination by the illumination unit 202 (step S1104). If the control unit does not detect the door opening signal, the standby state is maintained (step S1101). Upon detecting the door opening signal in step S1102, the control unit is set in a state in which it can always detect the door closing signal (step S1106). Upon detecting a door closing signal in step S1106, the control unit supplies a control signal for stopping terahertz wave irradiation to the illumination unit 202, and supplies a control signal for stopping terahertz wave detection to the camera 203 (steps S1107 and S1108). Here, if the control unit detects the door closing signal, at least one of steps S1107 and S1108 is performed. If the door closing signal is not detected, irradiation and detection of the terahertz wave are continued, and the camera system 200 continues capturing. By the series of operations of monitoring the open and close state of the door, power of the camera system 200 can be saved. In addition, by the series of operations, reliable capturing can be performed at a necessary timing.
Still another operation of the camera system 200 will be described next with reference to
First, in the camera system 200, the illumination unit 202 is in a standby state (step S1201). At this time, the camera may also be in the standby state. The control unit is in a state in which it can detect a door opening signal that notifies that the door provided in the ticket gate machine 211 opens (step S1202). If the control unit detects the door opening signal, the illumination unit 202 starts terahertz wave irradiation (step S1203). In addition, the camera 203 starts detecting the terahertz wave in accordance with the start of illumination by the illumination unit 202 (step S1204). If the control unit does not detect the door opening signal, the standby state is maintained (step S1201). To detect the door opening signal in step S1202, a signal generated by a ticket put into the ticket gate machine 211, a signal generated by bringing a ticket such as an IC card into contact with the ticket gate machine 211, or a signal for detecting the presence and absence of a ticket such as an IC card using a millimeter wave in the ticket gate machine 211 can be used. When the open and close state of the door of the ticket gate machine 211 is monitored in this way, power can be saved. In addition, by the operation, reliable capturing can be performed.
Still another operation of the camera system 200 will be described next with reference to
As described above, the sensor 260 detects the inspection object 250. Here, the sensor 260 may be, for example, a motion sensor using infrared rays or a camera using visible light. First, in the camera system 200, the illumination unit 202 is in a standby state (step S1301). At this time, the camera may also be in the standby state. Next, the inspection object 250 is detected using the sensor 260 (step S1302). The signal from the sensor 260 is sent to the control unit. Upon determining that the inspection object 250 is detected, the control unit supplies a control signal for irradiating the inspection object 250 to the illumination unit 202. The illumination unit 202 starts terahertz wave irradiation in accordance with the control signal from the control unit (step S1303). In addition, the control unit supplies a control signal for capturing the inspection object 250 to the camera 203. The camera 203 starts detecting the terahertz wave in accordance with the control signal from the control unit (step S1304). If the control unit does not determine that the inspection object 250 is detected, the standby state is maintained (step S1301).
By this operation, power can be saved. Additionally, with this operation, reliably capturing can be performed. In this embodiment, a case in which the inspection object 250 is a person has been described. However, the inspection object 250 may be an object. This arrangement can also be applied to the escalator 221 shown in
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application Nos. 2019-047788, filed on Mar. 14, 2019, and 2020-032193, filed on Feb. 27, 2020, which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-047788 | Mar 2019 | JP | national |
| 2020-032193 | Feb 2020 | JP | national |
