Camera interference detection device, camera interference detection system, and camera interference detection program

Abstract

To provide a technique for improving the precision of determination on whether photography by an imaging device is obstructed.SOLUTION: A photography obstruction detection device 100 comprises: an estimation information acquisition part 110 which acquires a plurality of pieces of obstruction information showing estimation results of whether a corresponding imaging device among a plurality of imaging devices 11-1, 11-2, ..., 11-N, classified into a plurality of sets according to illuminance environments where they are installed; and an obstruction specification part 160 which specifies whether a first imaging device is obstructed in photography, based upon obstruction estimation information corresponding to the first imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N among the plurality of pieces of obstruction estimation information that the estimation information acquisition part 110, and obstruction estimation information corresponding to a second imaging device belonging to the same set with the first imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a photographing obstruction detection device.

Background Art

[0002] For example, when the photographing lens is covered by an object, the imaging device cannot photograph the subject normally (hereinafter, the inability of the imaging device to photograph the subject normally is referred to as photographing obstruction). Therefore, the photographing obstruction detection device estimates whether the imaging device is being obstructed from photographing.

[0003] Patent Document 1 describes a photographing obstruction detection device that detects that a pedestal camera installed in a game hall is being obstructed from photographing based on the image information photographed by the pedestal camera. The photographing obstruction detection device includes a photographing obstruction determination unit that determines whether the photographing of the pedestal camera is being obstructed based on the image information indicating information obtained by quantifying the amount of light incident on the pedestal camera. The photographing obstruction determination unit determines a first state indicating that there is a possibility that the pedestal camera is being obstructed from photographing when the numerical information shown in the image information is within a specific threshold range, and determines a second state in which there is a higher possibility of being obstructed from photographing than the first state when the first state continues for a predetermined time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the conventional technology as described above, due to the environment in which the imaging device is placed, the amount of light incident on the photographing lens of the imaging device varies. Therefore, there is a problem that the imaging device may be erroneously determined to be obstructed from photographing even though it is not.

[0006] This disclosure is made to solve the problems described above and aims to provide a technology that improves the accuracy of determining whether or not an imaging device is being obstructed during imaging. [Means for solving the problem]

[0007] Each imaging interference detection device according to this disclosure includes: an estimation information acquisition unit that acquires a plurality of interference estimation information indicating whether or not a corresponding imaging device among a plurality of imaging devices classified into a plurality of sets according to the illumination environment in which it is installed is being interfered with; and an interference identification unit that identifies whether or not a first imaging device is being interfered with based on the plurality of interference estimation information acquired by the estimation information acquisition unit, specifically interference estimation information corresponding to a first imaging device among the plurality of imaging devices, and interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices. [Effects of the Invention]

[0008] According to this disclosure, it is possible to improve the accuracy of determining whether or not the imaging device is being obstructed during imaging. [Brief explanation of the drawing]

[0009] [Figure 1] This is a top-down view of the inside of a railway vehicle 10 in which multiple imaging devices of the imaging obstruction detection system according to Embodiment 1 are each installed. [Figure 2] This is a configuration diagram showing an example of the system configuration of the camera interference detection system according to Embodiment 1. [Figure 3] Figures 3A, 3B, 3C, and 3D are cross-sectional views showing examples of cross-sections along the dotted lines Ya1-Ya2, Yb1-Yb2, Yc1-Yc2, and Yd1-Yd2, respectively, when viewing the inside of the railway vehicle 10 from the direction of arrow X in Figure 1. [Figure 4] This figure shows an example of the range in which multiple imaging devices each photograph the interior of a railway vehicle. [Figure 5]Figures 5A, 5B, 5C, and 5D are diagrams showing examples of image information obtained by multiple imaging devices each capturing images. [Figure 6] This is a block diagram showing an example of the configuration of the main part of the camera interference detection device in the camera interference detection system according to Embodiment 1. [Figure 7] Figure 7A shows an example of when the interference detection unit identifies that a certain imaging device is not being interfered with. Figure 7B shows an example of when the interference detection unit identifies that a certain imaging device is being interfered with. [Figure 8] This figure shows an example of the presence or absence of imaging interference estimated for each of the four imaging devices shown in Figure 1, as well as an example of the presence or absence of imaging interference identified by the interference identification unit. [Figure 9] Figures 9A and 9B show an example of the hardware configuration of the camera interference detection device in the camera interference detection system according to Embodiment 1. [Figure 10] This is a flowchart illustrating an example of the processing of the camera interference detection device in the camera interference detection system according to Embodiment 1. [Figure 11] This is a block diagram showing an example of the configuration of the main part of the camera interference detection device in the camera interference detection system according to Embodiment 2. [Figure 12] This is a flowchart illustrating an example of the processing of the camera interference detection device in the camera interference detection system according to Embodiment 2. [Modes for carrying out the invention]

[0010] To provide a more detailed explanation of this disclosure, the forms for implementing this disclosure will be described below with reference to the attached drawings. Embodiment 1. Figure 1 is a top view of the interior of a railway vehicle 10 in which multiple imaging devices of the photography interference detection system 1 according to Embodiment 1 are each installed. In Embodiment 1, as shown in Figure 1, an example is described in which multiple imaging devices of the photography interference detection system 1 according to Embodiment 1 are each installed inside a railway vehicle 10. However, the multiple imaging devices of the photography interference detection system 1 may each be installed inside a vehicle other than a railway vehicle, or inside a building, etc., and are not limited to this example.

[0011] Figure 2 is a configuration diagram showing an example of the system configuration of the camera interference detection system 1 according to Embodiment 1. The camera interference detection system 1 comprises, as its main components, a railway vehicle 10, a plurality of imaging devices 11-1, 11-2, ..., 11-N (where N is a natural number), a communication network 12, an image recording device 13, a display device 14, and a camera interference detection device 100. Note that the camera interference detection system 1 does not necessarily have to include the image recording device 13.

[0012] Each of the imaging devices 11-1, 11-2, ..., 11-N is, for example, a digital still camera or a digital video camera, and is capable of outputting image information obtained through shooting to an external source. Each of the imaging devices 11-1, 11-2, ..., 11-N is installed inside the railway vehicle 10 and photographs the inside of the railway vehicle 10. Each of the imaging devices 11-1, 11-2, ..., 11-N outputs image information obtained through shooting to an external source via a communication network 12 such as a LAN (Local Area Network) or wireless LAN.

[0013] In the examples shown in Figures 1 and 2, only four of the multiple imaging devices 11-1, 11-2, ..., 11-N installed on the railway vehicle 10 are shown, and the configuration of the imaging devices of the imaging interference detection system 1 according to Embodiment 1 will be explained using these four imaging devices 11-1, 11-2, 11-3, 11-4. The number of imaging devices provided in the imaging interference detection system 1 may be multiple, and may be three or fewer, or five or more.

[0014] Figs. 3A, 3B, 3C, and 3D are cross-sectional views showing an example of the cross-section at dotted lines Ya1 - Ya2, Yb1 - Yb2, Yc1 - Yc2, and Yd1 - Yd2 when looking inside the railway vehicle 10 from the direction of arrow X in Fig. 1, respectively.

[0015] Fig. 4 is a diagram showing an example of the range in which a plurality of imaging devices 11-1, 11-2, 11-3, 11-4 photograph the interior of the railway vehicle 10, respectively. Figs. 5A, 5B, 5C, and 5D are diagrams showing an example of the image information obtained by photographing with a plurality of imaging devices 11-1, 11-2, 11-3, 11-4, respectively.

[0016] As can be seen from Figs. 3 to 5, the plurality of imaging devices 11-1, 11-2, 11-3, 11-4 are each installed above the door through which passengers enter and exit when boarding and alighting so that their arrangement is a staggered arrangement. Thereby, the plurality of imaging devices 11-1, 11-2, 11-3, 11-4 can photograph the entire interior of the railway vehicle 10. The plurality of imaging devices 11-1, 11-2, 11-3, 11-4 only need to be able to photograph the interior of the railway vehicle 10 respectively, and may be installed at positions different from above the door through which passengers enter and exit when boarding and alighting. The arrangement of the plurality of imaging devices 11-1, 11-2, 11-3, 11-4 may be an arrangement different from the staggered arrangement.

[0017] The image recording device 13 acquires each image information output by a plurality of imaging devices 11-1, 11-2, ···, 11-N, and associates the acquired each image information with identification information for identifying the imaging devices 11-1, 11-2, ···, and acquisition time information indicating the time when the image was acquired, and records it in a non-volatile storage medium or the like built in the image recording device 13. More specifically, for example, the image recording device 13 acquires each image information output by a plurality of imaging devices 11-1, 11-2, ···, 11-N via the communication network 12.

[0018] The image recording device 13 can acquire image information output by multiple imaging devices 11-1, 11-2, ..., 11-N via the communication network 12. As long as the image recording device 13 can acquire this image information, its installation location is not limited to inside the railway vehicle 10. For example, the image recording device 13 may be installed in a location separate from the railway vehicle 10. In Embodiment 1, the image recording device 13 will be described as being installed inside the railway vehicle 10.

[0019] As will be described later, the imaging interference detection device 100 identifies whether each of the multiple imaging devices 11-1, 11-2, ..., 11-N is being interfered with, based on multiple interference estimation information, each indicating whether the corresponding imaging device among the multiple imaging devices 11-1, 11-2, ..., 11-N is being interfered with, and outputs an identification display signal to identify the imaging device identified as being interfered with. Details will be described later.

[0020] The display device 14 displays the identification display signal output by the imaging interference detection device 100. The display device 14 is composed of multiple light-emitting elements, each corresponding to a plurality of imaging devices 11-1, 11-2, ..., 11-N. These light-emitting elements are, for example, light-emitting diodes or lamps. When the display device 14 is composed of multiple light-emitting elements, the imaging interference detection device 100 controls the light emission of each light-emitting element by outputting an identification display signal.

[0021] The display device 14 is not limited to a display device composed of multiple light-emitting elements. For example, the display device 14 may be a display such as a liquid crystal display. When the display device 14 is a display, the camera interference detection device 100 outputs an image to the display as an identification display signal to identify the imaging device that has been identified as being subjected to camera interference, and controls the display of the display.

[0022] Alternatively, for example, the display device 14 may be an audio output device such as a speaker or buzzer. If the display device 14 is an audio output device, the camera obstruction detection device 100 performs notification control to notify by voice by outputting an identification display signal to the audio output device.

[0023] Alternatively, for example, the display device 14 may display an image signal output by an external device such as a computer (not shown). If the display device 14 displays an image signal output by an external device, the camera interference detection device 100 outputs an identification signal to the external device via the communication network 12 to identify the imaging device that has been identified as being subjected to camera interference, and the external device generates an image signal based on the identification signal obtained from the camera interference detection device 100 and outputs it to the display device 14.

[0024] In Embodiment 1, as shown in Figure 2, the display device 14 is composed of multiple light-emitting elements 14-1, 14-2, 14-3, and 14-4, which correspond to multiple imaging devices 11-1, 11-2, 11-3, and 11-4, respectively, arranged in the housing of the imaging interference detection device 100. The display device 14 controls the emission of each of the multiple light-emitting elements 14-1, 14-2, 14-3, and 14-4 when the imaging interference detection device 100 outputs an identification display signal.

[0025] Figure 6 is a block diagram showing an example of the configuration of the main parts of the camera interference detection device 100 in the camera interference detection system 1 according to Embodiment 1. The camera interference detection device 100 includes an estimated information acquisition unit 110, an image acquisition unit 120, an image brightness acquisition unit 130, a reference brightness acquisition unit 140, an interference estimation unit 150, an interference identification unit 160, and an output control unit 170.

[0026] The image acquisition unit 120 acquires image information output by multiple imaging devices 11-1, 11-2, ..., 11-N via the communication network 12. The image acquisition unit 120 may also acquire image information output by multiple imaging devices 11-1, 11-2, ..., 11-N and recorded by the image recording device 13 via the communication network 12 from the image recording device 13.

[0027] The image brightness acquisition unit 130 divides each image captured by the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple partial images and acquires image brightness information indicating the brightness of each partial image in the image. More specifically, in Embodiment 1, the image brightness acquisition unit 130 divides the image indicated by each image information acquired by the image acquisition unit 120 into multiple partial images and acquires image brightness information indicating the brightness of each partial image in the image indicated by each image information.

[0028] More specifically, the image brightness acquisition unit 130 divides each image captured by the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple partial images, and calculates the average brightness value for each partial image, thereby acquiring image brightness information that shows the average brightness value for each partial image. Here, "average brightness value for each partial image" means the average brightness value obtained from each partial image.

[0029] For example, the image brightness acquisition unit 130 may acquire image brightness information indicating the brightness of each partial image in each image captured by the multiple imaging devices 11-1, 11-2, ..., 11-N, from the imaging devices 11-1, 11-2, ..., 11-N or the image recording device 13 via the communication network 12.

[0030] For example, the image brightness acquisition unit 130 divides each image captured by the multiple imaging devices 11-1, 11-2, ..., 11-N into an upper half and a lower half, and calculates the average brightness of the upper half of each image and the average brightness of the lower half of each image. In this case, the image brightness acquisition unit 130 may divide each image captured by the multiple imaging devices 11-1, 11-2, ..., 11-N into three or more parts, and may divide the images so that each part is of a different size.

[0031] The reason the image brightness acquisition unit 130 calculates brightness for each partial image is that, as will be described later, if multiple imaging devices 11-1, ..., 11-N are classified into multiple sets in advance, in sets with low brightness, even if an imaging device is tampered with, the change in brightness will be small, and therefore the tampering may not be detected.

[0032] As described above, by having the image brightness acquisition unit 130 calculate brightness for each partial image, it becomes possible to reduce the possibility that the detection of the shooting interference described later will not be possible in cases where strong light enters a part of the image, such as when an emergency light is turned on in front of the imaging device.

[0033] The reference brightness acquisition unit 140 acquires reference brightness information that indicates a predetermined reference brightness corresponding to each of the multiple imaging devices 11-1, 11-2, ..., 11-N. For example, the reference brightness acquisition unit 140 acquires reference brightness information from multiple imaging devices 11-1, 11-2, ..., 11-N or an image recording device 13 via a communication network 12. The reference brightness acquisition unit 140 may acquire reference brightness information by reading reference brightness information from a storage device (not shown) located inside or outside the housing of the shooting interference detection device 100.

[0034] The interference estimation unit 150 compares the brightness of each partial image indicated by the image brightness information acquired by the image brightness acquisition unit 130 and the reference brightness indicated by the reference brightness information acquired by the reference brightness acquisition unit 140 for each imaging device. Based on this comparison, the interference estimation unit 150 estimates for each imaging device whether or not it is being interfered with, and generates a plurality of interference estimation pieces of information indicating whether or not the corresponding imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N is being interfered with. More specifically, in Embodiment 1, the interference estimation unit 150 generates interference estimation period information indicating the interference estimation period for the imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N that is estimated to be being interfered with. The interference estimation unit 150 outputs the generated interference estimation information and interference estimation period information to the estimation information acquisition unit 110.

[0035] For example, when the interference estimation unit 150 estimates whether or not there is interference with the shooting, it may use the average value of the brightness in all images indicated by the image brightness information acquired by the image brightness acquisition unit 130 instead of the reference brightness indicated by the reference brightness information acquired by the reference brightness acquisition unit 140.

[0036] For example, if the lower half of the optical system, such as a lens, in any of the multiple imaging devices 11-1, 11-2, ..., 11-N is covered with a light-shielding cloth or the like, the brightness of each of the two partial images obtained by dividing the image captured by the imaging device into upper and lower halves will be higher for the upper half and lower for the lower half compared to the reference brightness of the imaging device. Therefore, the interference estimation unit 150 compares the brightness of each of the two partial images obtained by dividing an image into upper and lower halves with the reference brightness of the imaging device that captured the image. If it determines that the brightness of the upper half is higher than the reference brightness and the brightness of the lower half is lower than the reference brightness, it generates interference estimation information indicating that the imaging device is being interfered with, or interference estimation information indicating that the lower half of the optical system of the imaging device is being interfered with.

[0037] Alternatively, for example, the interference estimation unit 150 compares the brightness of each of the two partial images obtained by dividing an image into upper and lower halves with the reference brightness of the imaging device that captured the image. If it determines that the brightness of the upper half of the partial image is within a predetermined range centered on the reference brightness, and the brightness of the lower half of the partial image is outside a predetermined range centered on the reference brightness, it generates interference estimation information indicating that the imaging device is being interfered with, or interference estimation information indicating that the lower half of the optical system of the imaging device is being interfered with.

[0038] In other words, the interference estimation unit 150 may generate interference estimation information indicating whether or not the imaging device is partially being interfered with by comparing the brightness of each partial image with a reference brightness.

[0039] Alternatively, for example, if the optical system, such as the lens, of any of the multiple imaging devices 11-1, 11-2, ..., 11-N is covered entirely with a light-shielding cloth or the like, the brightness of each of the multiple partial images obtained by dividing the image captured by the imaging device will all be lower than the reference brightness of the imaging device. Therefore, for example, the interference estimation unit 150 compares the brightness of each of the multiple partial images obtained by dividing a certain image with the reference brightness of the imaging device that captured the image, and if it determines that all of the brightness values ​​are lower than the reference brightness, it generates interference estimation information indicating that the imaging device is being interfered with, or interference estimation information indicating that the entire optical system of the imaging device is being interfered with.

[0040] Alternatively, for example, if the optical system of any of the multiple imaging devices 11-1, 11-2, ..., 11-N is illuminated from the outside by strong white light or the like, the brightness of each of the multiple partial images obtained by dividing the image captured by the imaging device will all be higher than the reference brightness of the imaging device. In this case, for example, the interference estimation unit 150 compares the brightness of each of the multiple partial images obtained by dividing an image with the reference brightness of the imaging device that captured the image, and if it determines that all of the brightness values ​​are higher than the reference brightness, it generates interference estimation information indicating that the imaging device is being interfered with, or interference estimation information indicating that the entire optical system of the imaging device is being interfered with.

[0041] Alternatively, for example, the interference estimation unit 150 compares the brightness of each of the multiple partial images obtained by dividing an image with the reference brightness of the imaging device that captured the image. If it determines that all of the brightness values ​​are within a predetermined range centered on the reference brightness, it generates interference estimation information indicating that the imaging device is not being interfered with. On the other hand, if the interference estimation unit 150 determines that all of the brightness values ​​are outside a predetermined range centered on the reference brightness, it generates interference estimation information indicating that the imaging device is being interfered with, or interference estimation information indicating that the entire optical system of the imaging device is being interfered with.

[0042] In other words, the interference estimation unit 150 may generate interference estimation information indicating whether or not the imaging device as a whole is being interfered with by comparing the brightness of each partial image with a reference brightness.

[0043] In Embodiment 1, as an example, the interference estimation unit 150 compares the brightness of each of the two partial images obtained by dividing a certain image into upper and lower halves with the reference brightness of the imaging device that captured the image. If it determines that the brightness of the upper half of the partial image is higher than the reference brightness and the brightness of the lower half of the partial image is lower than the reference brightness, it generates interference estimation information indicating that the lower half of the optical system of the imaging device is being interfered with.

[0044] For example, even if multiple already installed imaging devices 11-1, 11-2, ..., 11-N, and image recording device 13 are each unable to generate interference estimation information, as described above, the shooting interference detection device 100 can generate interference estimation information by comprising an image acquisition unit 120, an image brightness acquisition unit 130, a reference brightness acquisition unit 140, and an interference estimation unit 150. Therefore, a shooting interference detection system 1 using interference estimation information can be constructed.

[0045] The estimation information acquisition unit 110 acquires multiple pieces of interference estimation information, each indicating whether or not a corresponding imaging device among the multiple imaging devices 11-1, 11-2, ..., 11-N is being interfered with. More specifically, in Embodiment 1, the estimation information acquisition unit 110 acquires multiple pieces of interference estimation information generated by the interference estimation unit 150.

[0046] More specifically, in Embodiment 1, the estimation information acquisition unit 110 further acquires interference estimation period information indicating the interference estimation period during which the imaging device is continuously estimated to be experiencing interference, with respect to the imaging device that is estimated to be experiencing interference among the plurality of imaging devices 11-1, 11-2, ..., 11-N. More specifically, in Embodiment 1, the estimation information acquisition unit 110 further acquires interference estimation period information generated by the interference estimation unit 150. Alternatively, the estimation information acquisition unit 110 may acquire interference estimation period information by measuring the interference estimation period based on the plurality of acquired interference estimation information. The estimation information acquisition unit 110 outputs the acquired plurality of interference estimation information and interference estimation period information to the interference identification unit 160.

[0047] The estimated information acquisition unit 110 may acquire interference estimation information generated by the multiple imaging devices 11-1, 11-2, ..., 11-N from the multiple imaging devices 11-1, 11-2, ..., 11-N. In this case, each of the multiple imaging devices 11-1, 11-2, ..., 11-N estimates whether or not each imaging device 11-1, 11-2, ..., 11-N is experiencing interference by comparing the brightness of each of the multiple partial images obtained by dividing each captured image with a predetermined reference brightness corresponding to each imaging device 11-1, 11-2, ..., 11-N. Then, each of the multiple imaging devices 11-1, 11-2, ..., 11-N generates interference estimation information indicating whether or not the imaging device is experiencing interference based on the estimation result. Then, each of the imaging devices 11-1, 11-2, ..., 11-N outputs the generated interference estimation information to the imaging interference detection device 100 via the communication network 12. In this way, by having multiple imaging devices 11-1, 11-2, ..., 11-N each generate interference estimation information, the processing load of the imaging interference detection device 100 can be reduced.

[0048] Alternatively, the estimated information acquisition unit 110 may acquire interference estimation information generated by the image recording device 13 from the image recording device 13. In this case, the image recording device 13 divides the image represented by each image information acquired from the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple partial images and calculates the brightness of each partial image in the image represented by each image information. The image recording device 13 then generates interference estimation information by comparing the calculated brightness of each partial image with predetermined reference brightness corresponding to each of the multiple imaging devices 11-1, 11-2, ..., 11-N. The image recording device 13 then outputs the generated interference estimation information to the imaging interference detection device 100 via the communication network 12.

[0049] In this way, the image recording device 13 generates interference estimation information, thereby reducing the processing load on the imaging interference detection device 100. Furthermore, even if multiple imaging devices 11-1, 11-2, ..., 11-N that have already been installed are each unable to generate interference estimation information, the image recording device 13 generates interference estimation information, thereby enabling the construction of an imaging interference detection system 1 that utilizes interference estimation information.

[0050] Furthermore, when the estimated information acquisition unit 110 acquires interference estimation information generated by multiple imaging devices 11-1, 11-2, ..., 11-N, or the image recording device 13, the image acquisition unit 120, image brightness acquisition unit 130, reference brightness acquisition unit 140, and interference estimation unit 150 are not essential components of the imaging interference detection device 100.

[0051] The interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets, and determines whether the first imaging device is being interfered with based on the interference estimation information corresponding to the first imaging device and the interference estimation information corresponding to the second imaging device belonging to the same set as the first imaging device among the multiple imaging devices 11-1, 11-2, ..., 11-N, acquired by the estimation information acquisition unit 110.

[0052] More specifically, in Embodiment 1, the interference identification unit 160 identifies that none of the imaging devices are being interfered with when all of the interference estimation information corresponding to each imaging device in the set to which the first imaging device and the second imaging device belong, among the multiple interference estimation information acquired by the estimation information acquisition unit 110, indicate that the corresponding imaging device is being interfered with.

[0053] More specifically, for example, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a single set, and if it is estimated that imaging device 11-1 is being interfered with, and it is also estimated that all of the multiple imaging devices 11-2, ..., 11-N are being interfered with, then it identifies that imaging device 11-1 is not being interfered with.

[0054] This is because, for example, when a railway vehicle 10 equipped with multiple imaging devices 11-1, ..., 11-N is entered into a depot with all interior lights turned on, it is conceivable that the upper half of the image captured by each imaging device will be brightly lit by the interior lights, while the lower half of the image will appear dark.

[0055] Alternatively, for example, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set and a second set, and if it is estimated that all of the multiple imaging devices 11-1 to 11-M (1 ≤ M ≤ N-1) belonging to the first set are being interfered with, it identifies that imaging device 11-1 is not being interfered with.

[0056] This is because, for example, in a railway vehicle 10 equipped with multiple imaging devices 11-1, ..., 11-N, when the interior lighting on the front of multiple imaging devices 11-1 to 11-M (1 ≤ M ≤ N-1) is turned on and the interior lighting on the front of the other imaging devices is turned off, and the railway vehicle 10 is being stored in a depot, it is conceivable that the upper half of each image captured by the multiple imaging devices 11-1 to 11-M will appear bright due to the interior lighting, the lower half of the image will appear dark, and the image captured by the other imaging devices will appear dark. Alternatively, for example, when a railway vehicle 10 equipped with multiple imaging devices 11-1, ..., 11-N is being stored in a depot with all interior lighting turned off, it is conceivable that the overall illumination inside the railway vehicle will be insufficient.

[0057] Regarding classification, for example, in Embodiment 1, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set including multiple imaging devices 11-1, 11-2, ..., 11-M (1 ≤ M ≤ N-1) and a second set including multiple imaging devices 11-K, ..., 11-N (K = M + 1). In this case, the interference identification unit 160 identifies whether imaging device 11-1 is being interfered with based on the interference estimation information corresponding to the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, and identifies whether imaging device 11-K is being interfered with based on the interference estimation information corresponding to imaging devices 11-K, ..., 11-N belonging to the second set.

[0058] For example, the interference identification unit 160 may classify the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on the current time. In that case, for example, if the current time falls within the daytime, the interference identification unit 160 will classify the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets, and if the current time falls within the nighttime, it will either not classify the multiple imaging devices 11-1, 11-2, ..., 11-N, or classify them into a single set. Here, the daytime is, for example, the time from sunrise to sunset. Here, the nighttime is, for example, the time from sunset to sunrise.

[0059] Alternatively, for example, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on the vehicle's current position. In this case, for example, the interference identification unit 160 further classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on positional influence information, which associates the position on the vehicle's route with sunlight influence information indicating whether or not each of the multiple imaging devices 11-1, 11-2, ..., 11-N is affected by sunlight when taking images at that position.

[0060] Alternatively, for example, the interference identification unit 160 may classify the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on the multiple interference estimation information acquired by the estimation information acquisition unit 110. In that case, for example, the interference identification unit 160 classifies imaging devices corresponding to interference estimation information indicating that the imaging device is being interfered with overall, from among the multiple interference estimation information acquired by the estimation information acquisition unit 110, into a first set. Also, for example, the interference identification unit 160 classifies imaging devices corresponding to interference estimation information indicating that the imaging device is being interfered with partially, from among the multiple interference estimation information acquired by the estimation information acquisition unit 110, into a second set.

[0061] More specifically, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N as follows, based on any of the above information or predetermined classification criteria. For example, when some of the interior lighting is turned on, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set that includes imaging devices installed in front of the interior lighting that is turned on, and a second set that includes imaging devices that are not installed in front of the interior lighting that is turned on.

[0062] Alternatively, for example, when ambient light enters the vehicle, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first group that includes imaging devices that are susceptible to ambient light, and a second group that includes imaging devices that are less susceptible to ambient light.

[0063] Alternatively, for example, when imaging devices are installed in the passenger compartment and outside the passenger compartment (such as the deck or connecting section), the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set which includes imaging devices installed in the passenger compartment that photograph areas where the brightness of the interior lighting is relatively high, and a second set which includes imaging devices installed outside the passenger compartment that photograph areas where the brightness of the interior lighting is relatively low.

[0064] Alternatively, for example, when installing imaging devices to photograph both the inside and outside of a vehicle (such as a pantograph), the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set including imaging devices that photograph the inside of the vehicle and are less affected by ambient light, and a second set including imaging devices that photograph the outside of the vehicle and are more susceptible to ambient light.

[0065] Alternatively, for example, if the installation heights of the multiple imaging devices are different, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first group including imaging devices installed at a height that is prone to interference and a second group of imaging devices installed at a height that is less prone to interference.

[0066] More specifically, in Embodiment 1, the interference identification unit 160 further determines whether the first imaging device is being interfered with based on the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110.

[0067] For example, if the interference identification unit 160 estimates that the first imaging device among the multiple imaging devices 11-1, 11-2, ..., 11-M included in the first set is being interfered with, it determines whether the first imaging device is being interfered with based on interference estimation information indicating whether the second imaging device among the multiple imaging devices 11-1, 11-2, ..., 11-M included in the first set is being interfered with, and the length of the interference estimation period during which it was continuously estimated that the first imaging device was being interfered with.

[0068] At the same time, for example, if it is estimated that the third imaging device among the multiple imaging devices 11-K,...,11-N included in the second set is being interfered with, the interference identification unit 160 determines whether the third imaging device is being interfered with based on interference estimation information indicating whether the fourth imaging device among the multiple imaging devices 11-K,...,11-N included in the second set is being interfered with, and the length of the interference estimation period during which it was continuously estimated that the third imaging device was being interfered with.

[0069] More specifically, for example, if there are four imaging devices 11-1, ..., 11-4, and the interference identification unit 160 defines the multiple imaging devices 11-1, 11-2 as a first group and the multiple imaging devices 11-3, 11-4 as a second group, the interference identification unit 160 will determine that imaging device 11-1 is not being interfered with if it is estimated that only the lower half of the image of imaging device 11-1 is being interfered with, and also estimated that only the lower half of the image of imaging device 11-2 is being interfered with.

[0070] At the same time, for example, if the interference identification unit 160 estimates that the entire image of the imaging device 11-3 is being interfered with, and also estimates that the entire image of the imaging device 11-4 is being interfered with, then it identifies that the imaging device 11-3 is not being interfered with.

[0071] This is because, for example, in a railway vehicle 10 equipped with multiple imaging devices 11-1, ..., 11-4, if the interior lighting on the front of imaging devices 11-1 and 11-2 is turned on, and the interior lighting on the front of the other imaging devices is turned off when the vehicle is entered into the depot, it is conceivable that the upper half of the images captured by imaging devices 11-1 and 11-2 will appear bright due to the interior lighting, the lower half of the images will appear dark, and the images captured by the other imaging devices will appear dark.

[0072] Alternatively, for example, if the estimation information acquisition unit 110 does not acquire further interference estimation period information, the following configuration may be adopted. That is, if the interference identification unit 160 estimates that imaging device 11-1 is being interfered with, and estimates that none of imaging devices 11-2, ..., 11-N are being interfered with, it may measure the length of the interference estimation period during which imaging device 11-1 is continuously estimated to be being interfered with. In that case, based on the interference estimation information corresponding to imaging device 11-1, the interference identification unit 160 measures, for example, the interference estimation period from the time it was first determined that imaging device 11-1 was being interfered with to the time it was continuously determined that imaging device 11-1 was being interfered with, as the length of the interference estimation period during which imaging device 11-1 is continuously estimated to be being interfered with, using a timer (not shown).

[0073] For example, the interference identification unit 160 determines that the imaging device 11-1 is not being interfered with if the length of the interference estimation period, during which the imaging device 11-1 is continuously estimated to be being interfered with, is shorter than a predetermined period.

[0074] This is because it is assumed that the optical system of the imaging device 11-1 may be temporarily covered, for example, if it is inadvertently covered by luggage of passengers or others riding in the railway vehicle 10.

[0075] The interference identification unit 160 identifies that the imaging device 11-1 is being interfered with if the length of the interference estimation period, during which it is continuously estimated that the imaging device 11-1 is being interfered with, is equal to or greater than a predetermined period. This is because it is assumed that the optical system of the imaging device 11-1 is continuously covered.

[0076] For example, the interference identification unit 160 may classify the multiple imaging devices 11-1, ..., 11-N into multiple sets in advance, and measure the length of the interference estimation period during which it is continuously estimated that the imaging device is being interfered with in each set.

[0077] More specifically, if the interference identification unit 160 estimates that imaging device 11-1, one of the multiple imaging devices 11-1, 11-2, ..., 11-M (1 ≤ M ≤ N-1), is being interfered with, it measures the length of the interference estimation period during which imaging device 11-1 is continuously estimated to be being interfered with, for example, using a timer (not shown), from the time it is first determined that imaging device 11-1 is being interfered with until it is determined that imaging device 11-1 is being continuously interfered with. Furthermore, if the interference identification unit 160 estimates that imaging device 11-K, among the multiple imaging devices 11-K, ..., 11-N (K=M+1), is being interfered with, it measures the length of the interference estimation period during which imaging device 11-K is continuously estimated to be being interfered with, for example, using a timer (not shown), from the time it is first determined that imaging device 11-K is being interfered with to the time it is determined that imaging device 11-K is continuously being interfered with.

[0078] The interference identification unit 160 identifies that the imaging device 11-1 is not being interfered with if the length of the interference estimation period during which the imaging device 11-1 is continuously estimated to be being interfered with is shorter than a predetermined period. Furthermore, the interference identification unit 160 identifies that the imaging device 11-K is not being interfered with if the length of the interference estimation period during which the imaging device 11-K is continuously estimated to be being interfered with is shorter than a predetermined period.

[0079] This is because it is anticipated that the optical system of imaging device 11-1 may be temporarily covered, for example, when the optical systems of imaging devices 11-1 and 11-K are covered by workers or other personnel performing inspections of the railway vehicle 10.

[0080] The interference identification unit 160 identifies that the imaging device 11-1 is being interfered with if the length of the interference estimation period during which it is continuously estimated that the imaging device 11-1 is being interfered with is longer than a predetermined period. Furthermore, the interference identification unit 160 identifies that the imaging device 11-K is being interfered with if the length of the interference estimation period during which it is continuously estimated that the imaging device 11-K is being interfered with is longer than a predetermined period. This is because it is assumed that the optical systems of imaging devices 11-1 and 11-K are continuously covered.

[0081] The following explanation, with reference to Figure 7, describes the length of the interference estimation period that the interference identification unit 160 determines when determining whether or not the imaging device 11-1 is being interfered with. Figure 7A shows an example of a case in which the interference identification unit 160 identifies that a certain imaging device is not being interfered with. Figure 7B shows an example of when the interference identification unit 160 identifies that a certain imaging device is being interfered with. In Figures 7A and 7B, the horizontal axis represents time, and the vertical axis represents brightness. The solid line represents the brightness in an image captured by a certain imaging device. The dashed line represents the reference brightness of the imaging device.

[0082] As shown in Figure 7A, if the brightness of an image captured by a certain imaging device is lower than the standard brightness of that imaging device, but this lower brightness is not continuously observed over a predetermined period of time, the interference identification unit 160 identifies that the imaging device is not being interfered with.

[0083] Furthermore, as shown in Figure 7B, if the brightness of an image captured by a certain imaging device is continuously lower than the standard brightness of the imaging device for a predetermined period of time, the interference identification unit 160 identifies that the imaging device is being interfered with.

[0084] The following describes how the interference identification unit 160 identifies whether or not there is interference with filming, based on the interference estimation information acquired by the estimation information acquisition unit 110, with reference to Figure 8. Figure 8 shows an example of the presence or absence of imaging interference estimated for each of the four imaging devices 11-1, 11-2, 11-3, and 11-4 shown in Figure 1, and the presence or absence of imaging interference identified by the interference identification unit 160.

[0085] At the time point shown in Figure 8(1), it is estimated that none of the four imaging devices 11-1, 11-2, 11-3, and 11-4 were being interfered with. Figure 8 shows an example in which, starting from the point indicated in (1), the estimated information acquisition unit 110 acquires interference estimation information corresponding to the four imaging devices 11-1, 11-2, 11-3, and 11-4 every 15 minutes, and the interference identification unit 160 identifies whether or not there is interference with imaging based on the interference estimation information acquired by the estimated information acquisition unit 110.

[0086] At the time points shown in Figure 8 (2) to (8), it is estimated that among the four imaging devices 11-1, 11-2, 11-3, and 11-4, imaging device 11-1 is being interfered with, while it is estimated that the other imaging devices are not being interfered with.

[0087] Figure 8 shows an example in which the interference identification unit 160 identifies the imaging device 11-1 as being interfered with when it is estimated that the imaging device 11-1 has been continuously interfered with for more than a predetermined period of one hour.

[0088] When the interference identification unit 160 identifies that the first imaging device is being interfered with, the output control unit 170 outputs an identification display signal to identify the first imaging device that has been identified as being interfered with.

[0089] More specifically, the output control unit 170 outputs an identification indicator signal to identify the imaging device that the interference identification unit 160 has identified as being interfered with among the imaging devices 11-1, 11-2, ..., 11-N. More specifically, for example, the output control unit 170 outputs the identification indicator signal to the display device 14.

[0090] For example, the output control unit 170 may output an identification indicator signal to identify the imaging device that the interference identification unit 160 has identified as not being interfered with among the imaging devices 11-1, 11-2, ..., 11-N.

[0091] For example, as shown in Figure 2, if the display device 14 is composed of multiple light-emitting elements 14-1, 14-2, 14-3, and 14-4 corresponding to multiple imaging devices 11-1, 11-2, 11-3, and 11-4, the output control unit 170 controls the output to turn off the light-emitting elements corresponding to imaging devices that have been identified as not being interfered with and to turn on the light-emitting elements corresponding to imaging devices that have been identified as being interfered with. The display device 14 displays the identification display signal output by the output control unit 170. Details of the identification display signals were explained in the display device 14 above, so they will not be explained here.

[0092] Figures 9A and 9B show an example of the hardware configuration of the camera interference detection device 100 in the camera interference detection system 1 according to Embodiment 1. Referring to the figure, the hardware configuration of the main parts of the shooting interference detection device 100 in the shooting interference detection system 1 according to Embodiment 1 will be described.

[0093] As shown in Figure 9A, the camera interference detection device 100 is composed of a computer, which has a processor 901 and a memory 902. The memory 902 stores a program that causes the computer to function as an estimated information acquisition unit 110, an image acquisition unit 120, an image brightness acquisition unit 130, a reference brightness acquisition unit 140, an interference estimation unit 150, an interference identification unit 160, and an output control unit 170. The processor 901 reads and executes the program stored in the memory 902, thereby realizing the functions of the estimated information acquisition unit 110, the image acquisition unit 120, the image brightness acquisition unit 130, the reference brightness acquisition unit 140, the interference estimation unit 150, the interference identification unit 160, and the output control unit 170.

[0094] Furthermore, as shown in Figure 9B, the camera interference detection device 100 may be composed of a processing circuit 903. In this case, the functions of the estimated information acquisition unit 110, image acquisition unit 120, image brightness acquisition unit 130, reference brightness acquisition unit 140, interference estimation unit 150, interference identification unit 160, and output control unit 170 may be realized by the processing circuit 903.

[0095] Furthermore, the camera interference detection device 100 may be composed of a processor 901, a memory 902, and a processing circuit 903 (not shown). In this case, some of the functions of the estimated information acquisition unit 110, image acquisition unit 120, image brightness acquisition unit 130, reference brightness acquisition unit 140, interference estimation unit 150, interference identification unit 160, and output control unit 170 may be implemented by the processor 901 and memory 902, and the remaining functions may be implemented by the processing circuit 903.

[0096] The processor 901 uses, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a microprocessor, a microcontroller, or a DSP (Digital Signal Processor).

[0097] Memory 902 uses, for example, semiconductor memory or magnetic disks. More specifically, memory 902 uses RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), SSD (Solid State Drive), or HDD (Hard Disk Drive).

[0098] The processing circuit 903 may utilize, for example, an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field-Programmable Gate Array), a SoC (System-on-a-Chip), or a system LSI (Large-Scale Integration).

[0099] Referring to Figure 10, the operation of the camera obstruction detection device 100 in the camera obstruction detection system 1 according to Embodiment 1 will be explained. Figure 10 is a flowchart illustrating an example of the processing of the camera obstruction detection device 100 in the camera obstruction detection system 1 according to Embodiment 1. The camera obstruction detection device 100 repeatedly executes the processing in the flowchart at predetermined time intervals, such as every 15 minutes, as shown in the example in Figure 8.

[0100] As shown in Figure 10, in step ST101, the reference brightness acquisition unit 140 acquires reference brightness information that indicates a predetermined reference brightness corresponding to each of the multiple imaging devices 11-1, 11-2, ..., 11-N. Next, in step ST102, the image acquisition unit 120 acquires image information output by multiple imaging devices 11-1, 11-2, ..., 11-N via the communication network 12.

[0101] Next, in step ST103, the image brightness acquisition unit 130 divides the image indicated by each image information acquired by the image acquisition unit 120 into multiple partial images and acquires image brightness information indicating the brightness of each partial image in the image indicated by each image information. Also in step ST103, the reference brightness acquisition unit 140 acquires reference brightness information indicating a predetermined reference brightness corresponding to each of the multiple imaging devices.

[0102] Next, in step ST104, the interference estimation unit 150 generates multiple interference estimation information by comparing the brightness of each partial image indicated by the image brightness information acquired by the image brightness acquisition unit 130 and the reference brightness indicated by the reference brightness information acquired by the reference brightness acquisition unit 140 for each imaging device, thereby estimating whether or not each of the multiple imaging devices 11-1, 11-2, ..., 11-N is experiencing interference during imaging. Furthermore, for the imaging devices among the multiple imaging devices 11-1, 11-2, ..., 11-N that are estimated to be experiencing interference during imaging, the interference estimation unit 150 generates interference estimation period information indicating the interference estimation period by measuring the interference estimation period during which the imaging device is continuously estimated to be experiencing interference. The interference estimation unit 150 outputs the generated interference estimation information and interference estimation period information to the estimation information acquisition unit 110.

[0103] Next, in step ST105, the estimated information acquisition unit 110 acquires multiple pieces of interference estimation information generated by the interference estimation unit 150. Also in step ST105, the estimated information acquisition unit 110 acquires further interference estimation period information generated by the interference estimation unit 150.

[0104] Next, in step ST110, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into a first set and a second set. The first set consists of multiple imaging devices 11-1, 11-2, ..., 11-M (1 ≤ M ≤ N-1). The second set consists of multiple imaging devices 11-K, ..., 11-N (K = M + 1).

[0105] Next, in step ST111, the interference identification unit 160 determines whether at least one of the multiple imaging devices 11-1, 11-2, ..., 11-M is estimated to be experiencing interference, based on the interference estimation information corresponding to the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, from among the multiple interference estimation information acquired by the estimation information acquisition unit 110. Also in step ST111, the interference identification unit 160 determines whether at least one of the multiple imaging devices 11-K, ..., 11-N is estimated to be experiencing interference, based on the interference estimation information corresponding to the multiple imaging devices 11-K, ..., 11-N belonging to the second set, from among the multiple interference estimation information acquired by the estimation information acquisition unit 110.

[0106] If the interference identification unit 160 determines in step ST111 that all of the imaging devices 11-1, 11-2, ..., 11-M belonging to the first set are not being interfered with, then in step ST112, it identifies all of the imaging devices 11-1, 11-2, ..., 11-M as not being interfered with. After step ST112, in step ST113, the output control unit 170 outputs identification indicator signals to identify each of the imaging devices 11-1, 11-2, ..., 11-M belonging to the first set that the interference identification unit 160 has identified as not being interfered with.

[0107] Furthermore, if the interference identification unit 160 determines in step ST111 that all of the imaging devices 11-K,...,11-N belonging to the second set are not being interfered with, then in step ST112, it identifies that all of the imaging devices 11-K,...,11-N are not being interfered with. After step ST112, in step ST113, the output control unit 170 outputs identification indicator signals to identify each of the imaging devices 11-K, 11-2,...,11-N belonging to the second set that the interference identification unit 160 has identified as not being interfered with.

[0108] After step ST113, the camera interference detection device 100 terminates the processing of the flowchart, and the camera interference detection device 100 repeatedly executes the processing of the flowchart at predetermined time intervals.

[0109] In step ST111, if the interference identification unit 160 determines that at least one of the multiple imaging devices 11-1, 11-2, ..., 11-M (1 ≤ M ≤ N-1) belonging to the first set is estimated to be experiencing interference, then in step ST121, the interference identification unit 160 determines, based on the multiple interference estimation information acquired by the estimation information acquisition unit 110, which corresponds to the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, whether or not all of the multiple imaging devices 11-1, 11-2, ..., 11-M are estimated to be experiencing interference. Furthermore, in step ST111, if the interference identification unit 160 determines that at least one of the multiple imaging devices 11-K,...,11-N (K=M+1) belonging to the second set is estimated to be experiencing interference, then in step ST121, the interference identification unit 160 determines, based on the interference estimation information corresponding to the multiple imaging devices 11-K,...,11-N belonging to the second set, from among the multiple interference estimation information acquired by the estimation information acquisition unit 110, whether or not all of the multiple imaging devices 11-K,...,11-N are estimated to be experiencing interference.

[0110] If, in step ST121, the interference identification unit 160 determines that all of the imaging devices 11-1, 11-2, ..., 11-M belonging to the first set are estimated to be experiencing interference, the imaging interference detection device 100 executes the process in step ST112. If, in step ST121, the interference identification unit 160 determines that all of the imaging devices 11-K, ..., 11-N belonging to the second set are estimated to be experiencing interference, the imaging interference detection device 100 executes the process in step ST112.

[0111] In step ST121, if the interference identification unit 160 determines that at least one of the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set is estimated not to be experiencing interference, then in step ST131, the interference identification unit 160 determines whether the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 exceeds a predetermined period with respect to the imaging device (the imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) that is estimated to be experiencing interference among the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set.

[0112] Furthermore, in step ST121, if the interference identification unit 160 determines that at least one of the multiple imaging devices 11-K,...,11-N belonging to the second set is estimated not to be experiencing interference, then in step ST131, the interference identification unit 160 determines whether the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 exceeds a predetermined period with respect to the imaging device (the imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) that is estimated to be experiencing interference among the multiple imaging devices 11-K,...,11-N belonging to the second set.

[0113] With respect to an imaging device (an imaging device that the interference identification unit 160 determined to be presumed to be interfering with imaging) among the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, if the interference identification unit 160 determines in step ST131 that the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 does not exceed a predetermined period, then in step ST132 the interference identification unit 160 determines that the said imaging device (the imaging device that the interference identification unit 160 determined to be presumed to be interfering with imaging) is not being interfered with.

[0114] With respect to an imaging device (an imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) among the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, if the interference identification unit 160 determines in step ST131 that the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 exceeds a predetermined period, the interference identification unit 160 determines in step ST133 that the said imaging device (the imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) is experiencing interference.

[0115] Furthermore, with respect to an imaging device (an imaging device that the interference identification unit 160 determined to be presumed to be interfering with imaging) among the multiple imaging devices 11-K,...,11-N belonging to the second set, if the interference identification unit 160 determines in step ST131 that the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 does not exceed a predetermined period, then in step ST132, the interference identification unit 160 determines that the said imaging device (the imaging device that the interference identification unit 160 determined to be presumed to be interfering with imaging in step ST111) is not being interfered with imaging.

[0116] With respect to an imaging device (an imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) among the multiple imaging devices 11-K, ..., 11-N belonging to the second set, if the interference identification unit 160 determines in step ST131 that the interference estimation period indicated by the interference estimation period information further acquired by the estimation information acquisition unit 110 exceeds a predetermined period, the interference identification unit 160 determines in step ST133 that the said imaging device (the imaging device that the interference identification unit 160 determined to be experiencing interference in step ST111) is experiencing interference.

[0117] After step ST132 or step ST133, in step ST134, with respect to an imaging device (an imaging device that the interference identification unit 160 determined to be not interfering with imaging) among the multiple imaging devices 11-1, 11-2, ..., 11-M belonging to the first set, the interference identification unit 160 identifies that the said imaging device is not interfering with imaging.

[0118] After step ST132 or step ST133, in step ST134, with respect to an imaging device (an imaging device that the interference identification unit 160 determined to be not interfering with imaging) among the multiple imaging devices 11-K,...,11-N belonging to the second set, the interference identification unit 160 identifies that the said imaging device is not interfering with imaging.

[0119] After step ST134, in step ST135, the output control unit 170 outputs an identification display signal to identify an imaging device that the interference identification unit 160 has identified as being interfered with, or an imaging device that the interference identification unit 160 has identified as not being interfered with.

[0120] After step ST135, the camera interference detection device 100 terminates the processing of the flowchart, and the camera interference detection device 100 repeatedly executes the processing of the flowchart at predetermined time intervals.

[0121] Furthermore, the process in step ST101 may be configured to be executed only once when the camera interference detection device 100 repeatedly executes the process in the flowchart at predetermined intervals.

[0122] Furthermore, if, in step ST105, the estimated information acquisition unit 110 can acquire interference estimation information from each of the multiple imaging devices 11-1, 11-2, ..., 11-N, or from an external device such as the image recording device 13, then the processing from steps ST101 to ST104 is not mandatory.

[0123] In this embodiment, the interference identification unit 160 was described as classifying the multiple imaging devices into two types of sets, namely a first set and a second set. However, the interference identification unit 160 may classify the multiple imaging devices into three or more types of sets.

[0124] Furthermore, the number of sets of imaging devices defined in the interference identification unit 160, or the combination of imaging devices belonging to each set among multiple sets, may be dynamically changed according to the current time or the current location of the vehicle. More specifically, for example, if the vehicle is parked in a garage at night and there is little change in brightness in the images captured by the imaging devices, the interference identification unit 160 will set the set of imaging devices to one type based on the current time. On the other hand, for example, if the vehicle is operating in commercial service during the day and there is a large change in brightness in the images captured by the imaging devices, the interference identification unit 160 will set the set of imaging devices to two or more types based on the current time.

[0125] Alternatively, for example, if the vehicle is parked in the garage with some of its emergency lights on, the interference identification unit 160 may set up two or more sets of imaging devices based on the vehicle's current position. On the other hand, if the vehicle is parked in the garage with all its lights on or all its lights off, the interference identification unit 160 may set up one set of imaging devices based on the vehicle's current position.

[0126] Alternatively, for example, the interference identification unit 160 may, when the vehicle is parked in the garage in conditions where direct sunlight enters the vehicle, such as early morning or evening, set up two or more sets of imaging devices based on the current time and the vehicle's current position, and when the vehicle is parked in the garage in any other environment, set up one set of imaging devices based on the current time and the vehicle's current position.

[0127] In Embodiment 1, the image brightness acquisition unit 130 divides each image captured by multiple imaging devices into two partial images, acquires image brightness information indicating the brightness of each partial image, and the interference estimation unit 150 generates interference estimation information based on the image brightness information. However, the interference estimation information of the present application is not limited to this interference estimation information.

[0128] For example, the image brightness acquisition unit 130 may divide the image into two halves horizontally, or it may divide the image into two halves vertically and horizontally, thereby dividing it into a partial image where the shooting range of the imaging device 11-1 and the shooting range of the imaging device 11-2 overlap, and a partial image where the shooting range of the imaging device 11-2 does not overlap. In this case, the image brightness acquisition unit 130 may acquire image brightness information indicating the brightness of the left half and the brightness of the right half of the image, or image brightness information indicating the brightness of the upper left, upper right, lower left, and lower right of the image, and the interference estimation unit 150 may generate interference estimation information based on this image brightness information.

[0129] By configuring the device as described above, the camera interference detection device 100 can reduce the possibility of misjudging a camera to be in an abnormal state even when the imaging device is in a normal state, when there is a bias in the brightness of each image captured by multiple imaging devices. This allows for accurate determination of whether or not an imaging device installed in a railway vehicle is in an abnormal state. Furthermore, this configuration allows the camera interference detection device 100 to process at high speed because it places less load on the CPU and other hardware compared to image judgment techniques such as pattern matching, which compares image features to determine the presence or absence of camera interference based on the brightness of the image.

[0130] Furthermore, since the system is configured to calculate brightness for multiple partial images, it is possible to reduce the possibility of failing to detect abnormal shooting conditions in cases where strong light enters a part of the image, such as when an emergency light is on in front of the camera.

[0131] As described above, each imaging interference detection device 100 according to Embodiment 1 includes: an estimation information acquisition unit 110 that acquires a plurality of interference estimation information indicating whether or not a corresponding imaging device among a plurality of imaging devices 11-1, 11-2, ..., 11-N is being interfered with; and an interference identification unit 160 that classifies the plurality of imaging devices 11-1, 11-2, ..., 11-N into a plurality of sets, and identifies whether or not the first imaging device is being interfered with based on the interference estimation information corresponding to the first imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N, and the interference estimation information corresponding to the second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N, acquired by the estimation information acquisition unit 110.

[0132] According to the above configuration, whether or not the first imaging device is being interfered with is determined not only based on interference estimation information corresponding to the first imaging device, but also based on interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device. This improves the accuracy of determining whether or not the imaging device is being interfered with.

[0133] For example, when a vehicle is parked and external light enters the vehicle, or when a vehicle is parked with some of its interior lighting turned on as emergency lights, the illumination environment differs for each imaging device, resulting in a bias in brightness in each image captured by multiple imaging devices. Even in such situations, according to the above configuration of the imaging interference detection device 100 of Embodiment 1, By appropriately classifying multiple imaging devices into multiple groups according to the illumination environment in which they are placed, it is possible to determine whether or not an imaging device is being obstructed.

[0134] In the imaging interference detection device 100 according to Embodiment 1, the interference identification unit 160 classifies a plurality of imaging devices 11-1, 11-2, ..., 11-N into a plurality of sets based on the current time. According to the above configuration, the first imaging device and the second imaging device can be classified into the same set based on the current time. Therefore, based on the interference estimation information corresponding to the first imaging device and the interference estimation information corresponding to the second imaging device, it is possible to suitably determine whether or not the first imaging device is being interfered with. Accordingly, the accuracy of determining whether or not an imaging device is being interfered with can be improved.

[0135] In the imaging interference detection device 100 according to Embodiment 1, the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple groups if the current time is during the daytime, and does not classify the multiple imaging devices 11-1, 11-2, ..., 11-N if the current time is during the nighttime.

[0136] According to the above configuration, multiple imaging devices 11-1, 11-2, ..., 11-N are classified into multiple groups during daytime hours when the changes in the illuminance environment for the imaging devices are greater than at night. This allows for the classification of imaging devices and the determination of whether or not imaging interference is present based on the classification, even during daytime hours when there is a higher possibility than at night of misjudging that an imaging device is being interfered with when it is not.

[0137] In the first embodiment of the imaging interference detection device 100, the multiple imaging devices 11-1, 11-2, ..., 11-N are installed inside a vehicle, and the interference identification unit 160 classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on the current position of the vehicle.

[0138] According to the above configuration, the first imaging device and the second imaging device can be classified into the same set based on the vehicle's current position. Therefore, based on the interference estimation information corresponding to the first imaging device and the interference estimation information corresponding to the second imaging device, it is possible to suitably determine whether or not the first imaging device is being obstructed during imaging. Consequently, the accuracy of determining whether or not an imaging device is being obstructed during imaging can be improved.

[0139] In the first embodiment of the imaging interference detection device 100, the interference identification unit 160 further classifies the multiple imaging devices 11-1, 11-2, ..., 11-N into multiple sets based on positional influence information, which associates the position on the path the vehicle travels with sunlight influence information indicating whether or not each of the multiple imaging devices 11-1, 11-2, ..., 11-N is affected by sunlight when taking images at that position.

[0140] According to the above configuration, for example, imaging devices that are affected by sunlight when taking images can be classified into the same group. Therefore, for example, based on the interference estimation information corresponding to the first imaging device and the second imaging device that are affected by sunlight when taking images, it is possible to suitably determine whether or not the first imaging device is being interfered with. Therefore, the accuracy of determining whether or not an imaging device is being interfered with can be improved.

[0141] In the first embodiment of the imaging interference detection device 100, the interference identification unit 160 identifies that none of the imaging devices are being interfered with when, among the plurality of interference estimation information acquired by the estimation information acquisition unit 110, all of the interference estimation information corresponding to each imaging device in the set to which the first imaging device and the second imaging device belong all indicate an estimation result that the corresponding imaging device is being interfered with.

[0142] With the above configuration, in an unnatural situation where it is presumed that all imaging devices classified into the same group are being obstructed, it is possible to appropriately identify that none of the imaging devices are being obstructed. Therefore, the accuracy of determining whether or not an imaging device is being obstructed can be improved.

[0143] In the imaging interference detection device 100 according to Embodiment 1, the estimated information acquisition unit 110 further acquires interference estimation period information indicating the period during which it is continuously estimated that an imaging device among the plurality of imaging devices 11-1, 11-2, ..., 11-N is being interfered with. The interference identification unit 160 then determines whether or not the first imaging device is being interfered with based on the interference estimation period indicated by the interference estimation period information further acquired by the estimated information acquisition unit 110.

[0144] According to the above configuration, for example, it is possible to appropriately identify that the imaging device is being interfered with, in situations where there is a high probability that the imaging device is being interfered with, such as when the imaging device is being continuously interfered with, rather than when the imaging device is being temporarily interfered with. Therefore, the accuracy of determining whether or not the imaging device is being interfered with can be improved.

[0145] The imaging interference detection device 100 according to Embodiment 1 further comprises: an image brightness acquisition unit 130 that divides each image captured by a plurality of imaging devices 11-1, 11-2, ..., 11-N into a plurality of partial images and acquires image brightness information indicating the brightness of each partial image; a reference brightness acquisition unit 140 that acquires reference brightness information indicating a predetermined reference brightness corresponding to each of the plurality of imaging devices 11-1, 11-2, ..., 11-N; and an interference estimation unit 150 that generates a plurality of interference estimation information by estimating for each imaging device whether or not the imaging device is being interfered with by comparing the brightness of each partial image indicated by the image brightness acquisition unit 130 and the reference brightness indicated by the reference brightness information acquired by the reference brightness acquisition unit 140 for each imaging device, and the estimation information acquisition unit 110 acquires the plurality of interference estimation information generated by the interference estimation unit 150.

[0146] With the above configuration, even in situations where the imaging device is partially obstructed, it is possible to appropriately estimate whether or not the imaging device is being obstructed for each imaging device by comparing the brightness of each partial image with the reference brightness. Then, based on the multiple obstruction estimation information generated in this way, it is possible to appropriately identify whether or not the imaging device is being obstructed. Therefore, the accuracy of determining whether or not the imaging device is being obstructed can be improved.

[0147] Although not explained with diagrams, the shooting interference detection device 100 may further include a shooting parameter acquisition unit and a reference shooting parameter acquisition unit. In that case, the shooting parameter acquisition unit acquires shooting parameter information indicating the shooting parameters used when each of the multiple imaging devices 11-1, 11-2, ..., 11-N took an image. Examples of shooting parameters here include ISO (International Organization for Standardization) sensitivity, shutter speed value, AE (Automatic Exposure) detection value, or AF (Autofocus) detection value. The reference shooting parameter acquisition unit acquires reference shooting parameter information indicating predetermined reference shooting parameters corresponding to each of the multiple imaging devices 11-1, 11-2, ..., 11-N. Examples of predetermined reference shooting parameters here include values ​​indicating the applicable range of shooting parameters such as ISO sensitivity value, shutter speed value, aperture value, or autofocus detection value, which serve as a reference when each of the multiple imaging devices 11-1, 11-2, ..., 11-N takes an image. Furthermore, the interference estimation unit 150 may generate multiple interference estimation pieces of information by comparing the shooting parameters indicated by the shooting parameter information acquired by the shooting parameter acquisition unit and the reference shooting parameters indicated by the reference shooting parameter information acquired by the reference shooting parameter acquisition unit for each imaging device, thereby estimating whether or not the imaging device is being interfered with. The estimation information acquisition unit 110 may also acquire the multiple interference estimation pieces of information thus generated by the interference estimation unit 150. With the above configuration, it is possible to appropriately estimate whether or not the imaging device is being interfered with.

[0148] Alternatively, although not explained with diagrams, the imaging interference detection system 1 may further include multiple other imaging devices having similar functions to the multiple imaging devices 11-1, 11-2, ..., 11-N, and another imaging interference detection device having similar functions to the imaging interference detection device 100. In that case, the above-described estimation information acquisition unit 110 may further acquire multiple other interference estimation information from the other imaging interference detection devices, each indicating the estimation result of whether or not a corresponding imaging device among the other multiple imaging devices is being interfered with. Then, if the multiple interference estimation information (information concerning imaging devices 11-1, 11-2, ..., 11-N) acquired by the estimation information acquisition unit 110 all indicate the estimation result that the corresponding imaging device is being interfered with, the above-described interference identification unit 160 may identify whether or not each of the multiple imaging devices 11-1, 11-2, ..., 11-N is being interfered with based on the other multiple interference estimation information acquired by the estimation information acquisition unit 110. For example, in such a configuration, multiple imaging devices 11-1, 11-2, ..., 11-N are installed in a first vehicle connected to a train set, and another set of imaging devices are installed in a second vehicle connected to the train set. With this configuration, the accuracy of determining whether or not the imaging device is being obstructed can be further improved.

[0149] Embodiment 2. Embodiment 2 will be described below with reference to the drawings. Components having the same function as those described in Embodiment 1 will be denoted by the same reference numerals, and their descriptions will be omitted. Figure 11 is a block diagram showing an example of the configuration of the main parts of the camera interference detection device 100a in the camera interference detection system 1a according to Embodiment 2. Note that the camera interference detection device 100a according to Embodiment 2 differs from the camera interference detection device 100 according to Embodiment 1 in that it includes a time mode switching unit 180 and a position mode switching unit 181, which are not included in the camera interference detection device 100 according to Embodiment 1. The camera interference detection device 100a in the camera interference detection system 1a according to Embodiment 2 comprises an estimated information acquisition unit 110, an image acquisition unit 120, an image brightness acquisition unit 130, a reference brightness acquisition unit 140, an interference estimation unit 150, an interference identification unit 160, an output control unit 170, a time mode switching unit 180, and a position mode switching unit 181.

[0150] The time mode switching unit 180 switches the operating mode of the imaging interference detection device 100a to either an interference detection mode, which detects whether each of the multiple imaging devices is being interfered with, or an interference detection pause mode, which pauses the interference detection that detects whether each of the multiple imaging devices is being interfered with, based on the current time.

[0151] For example, when the time mode switching unit 180 switches the operating mode of the shooting interference detection device 100a to interference detection mode, the above-described estimated information acquisition unit 110 acquires multiple pieces of interference estimation information, and the above-described interference identification unit 160 determines whether or not the first imaging device is being interfered with by the method described above.

[0152] More specifically, in Embodiment 1, the time mode switching unit 180 switches the operating mode of the camera interference detection device 100a to interference detection pause mode when the current time falls within the daytime, and switches the operating mode of the camera interference detection device 100a to interference detection mode when the current time falls within the nighttime.

[0153] More specifically, the time mode switching unit 180 switches between two operating modes based on time information indicating the current time: an interference detection mode that detects the presence or absence of interference for each of the multiple imaging devices 11-1, 11-2, ..., 11-N, and a detection pause mode that does not detect the presence or absence of interference for each of the multiple imaging devices 11-1, 11-2, ..., 11-N.

[0154] More specifically, for example, the time mode switching unit 180 switches the operating mode so that each of the multiple imaging devices 11-1, 11-2, ..., 11-N operates in detection-pause mode during the time periods when each of the multiple imaging devices 11-1, 11-2, ..., 11-N is affected by sunlight when taking pictures, based on predetermined time period information and time information indicating the current time, and switches the operating mode so that each of the multiple imaging devices 11-1, 11-2, ..., 11-N operates in interference detection mode during the time periods when each of the multiple imaging devices 11-1, 11-2, ..., 11-N is not affected by sunlight when taking pictures.

[0155] More specifically, for example, the time mode switching unit 180 switches the operating mode so that each of the multiple imaging devices 11-1, 11-2, ..., 11-N operates in detection-pause mode during daytime hours when they are affected by sunlight while taking pictures, and switches the operating mode so that each of the multiple imaging devices 11-1, 11-2, ..., 11-N operates in interference detection mode during nighttime hours when they are not affected by sunlight while taking pictures.

[0156] Time information is acquired, for example, using a clock function (not shown) provided in the camera interference detection device 100a. The clock function is similar to the clock function provided in electronic devices such as well-known general-purpose computers, and since it is a known technology, a detailed explanation is omitted.

[0157] Time zone information is, for example, stored in advance in the time mode switching unit 180. Alternatively, for example, time zone information may be acquired by the time mode switching unit 180 from a storage device (not shown) located inside or outside the housing of the camera interference detection device 100a, or from an external device such as an image recording device 13 via the communication network 12.

[0158] Thus, by including a time mode switching unit 180, the imaging interference detection device 100a can detect the presence or absence of imaging interference for each of the multiple imaging devices 11-1, 11-2, ..., 11-N during time periods when each of the multiple imaging devices 11-1, 11-2, ..., 11-N is not affected by sunlight when taking images, thereby suppressing false detections.

[0159] The position mode switching unit 181 switches the operating mode of the camera obstruction detection device to either an obstruction detection mode, which detects whether each of the multiple imaging devices is being obstructed, or an obstruction detection pause mode, which pauses the obstruction detection that detects whether each of the multiple imaging devices is being obstructed, based on the vehicle's current position.

[0160] Furthermore, when the position mode switching unit 181 switches the operating mode of the shooting interference detection device 100a to interference detection mode, the estimated information acquisition unit 110 acquires multiple pieces of interference estimation information, and the interference identification unit 160 determines whether or not the first imaging device is being interfered with by the method described above.

[0161] More specifically, the position mode switching unit 181 determines whether the current position is a position where multiple imaging devices are affected by sunlight when each imaging device takes an image, based on position influence information that associates the position on the vehicle's route with sunlight influence information indicating whether or not multiple imaging devices are affected by sunlight when each imaging device takes an image at that position. If the interference identification unit 160 determines that the current position is a position where multiple imaging devices are affected by sunlight when each imaging device takes an image, it switches the operating mode of the imaging interference detection device 100a to interference detection pause mode. If the interference identification unit 160 determines that the current position is not a position where multiple imaging devices are affected by sunlight when each imaging device takes an image, it switches the operating mode of the imaging interference detection device 100a to interference detection mode.

[0162] More specifically, the position mode switching unit 181 switches between two operating modes based on position information indicating the position where the railway vehicle 10 is traveling: an interference detection mode that detects whether or not there is interference with each of the multiple imaging devices 11-1, 11-2, ..., 11-N, and a detection pause mode that does not detect whether or not there is interference with each of the multiple imaging devices 11-1, 11-2, ..., 11-N.

[0163] More specifically, for example, the position mode switching unit 181, based on position influence information which is pre-associated with information indicating each of multiple locations on the route the railway vehicle 10 travels, and sunlight influence information which indicates whether or not sunlight has an effect when each of the multiple imaging devices 11-1, 11-2, ..., 11-N takes a picture at each location, and information regarding the current location, switches the operating mode to operate in detection-pause mode when the railway vehicle 10 travels through a location where sunlight has an effect when each of the multiple imaging devices 11-1, 11-2, ..., 11-N takes a picture, and switches the operating mode to operate in interference detection mode when the railway vehicle 10 travels through a location where sunlight has an effect when each of the multiple imaging devices 11-1, 11-2, ..., 11-N takes a picture.

[0164] More specifically, for example, the position mode switching unit 181 switches the operating mode so that it operates in detection-pause mode when the railway vehicle 10 is traveling on the ground where sunlight is affecting the image capture of each of the multiple imaging devices 11-1, 11-2, ..., 11-N, and so that it operates in interference detection mode when the railway vehicle 10 is traveling underground where sunlight is not affecting the image capture of each of the multiple imaging devices 11-1, 11-2, ..., 11-N.

[0165] Location information is acquired, for example, using a running position detection function (not shown) installed in the railway vehicle 10 or a train to which the railway vehicle 10 is coupled. The running position detection function detects the position of the railway vehicle 10 by using, for example, a GNSS (Global Navigation Satellite System) such as GPS (Global Positioning System). Since the method of position detection using GNSS is publicly known, a detailed explanation is omitted.

[0166] For example, location influence information is pre-stored in the location mode switching unit 181. Alternatively, for example, location influence information may be acquired by the location mode switching unit 181 from a storage device (not shown) located inside or outside the housing of the imaging interference detection device 100a, or from an external device such as an image recording device 13 via the communication network 12.

[0167] Thus, by including a position mode switching unit 181, the imaging interference detection device 100a can detect the presence or absence of imaging interference for each of the multiple imaging devices 11-1, 11-2, ..., 11-N at a position where each of the multiple imaging devices 11-1, 11-2, ..., 11-N is not affected by sunlight when taking images, thereby suppressing false detections.

[0168] Furthermore, the camera interference detection device 100a may include either a time mode switching unit 180 or a position mode switching unit 181, or it may include both a time mode switching unit 180 and a position mode switching unit 181.

[0169] For example, if the camera interference detection device 100a includes both a time mode switching unit 180 and a position mode switching unit 181, the camera interference detection device 100a may operate in interference detection mode during the time period when the operating mode is set to interference detection mode by the time mode switching unit 180, and operate in interference detection mode only at positions where the operating mode is set to interference detection mode by the position mode switching unit 181 during the time period when the operating mode is set to detection pause mode by the time mode switching unit 180.

[0170] The hardware configuration of the main parts of the imaging interference detection device 100a is the same as that described in Embodiment 1 with reference to Figures 9A and 9B, so its illustration and description are omitted. That is, the functions of the estimation information acquisition unit 110, image acquisition unit 120, image brightness acquisition unit 130, reference brightness acquisition unit 140, interference estimation unit 150, interference identification unit 160, output control unit 170, time mode switching unit 180, and position mode switching unit 181 may be realized by the processor 901 and memory 902, or by the processing circuit 903.

[0171] Figure 12 is a flowchart illustrating an example of the processing of the camera interference detection device 100a in the camera interference detection system 1a according to Embodiment 2. The processing of the camera interference detection device 100a in the camera interference detection system 1a according to Embodiment 2 will be explained with reference to this figure.

[0172] The camera interference detection device 100a repeatedly executes the process shown in the flowchart in Figure 12 as a preliminary step to the process shown in the flowchart in Figure 10, and the camera interference detection system 1a executes the process shown in the flowchart in Figure 10 only when the operating mode is interference detection mode.

[0173] First, in step ST1201, the time mode switching unit 180 determines whether the current time is within the period affected by sunlight. If, in step ST1201, the time mode switching unit 180 determines that the current time is not within the period affected by sunlight, then in step ST1202, the time mode switching unit 180 switches the operating mode to interference detection mode.

[0174] After step ST1202, the camera interference detection device 100a terminates the processing of the flowchart, and the camera interference detection device 100a repeatedly executes the processing of the flowchart. If, in step ST1201, the time mode switching unit 180 determines that the current time is within the period affected by sunlight, then in step ST1203, the time mode switching unit 180 switches the operation mode to detection pause mode.

[0175] After step ST1203, in step ST1204, the position mode switching unit 181 determines whether the position in which the railway vehicle 10 is traveling is a position affected by sunlight. In step ST1204, if the position mode switching unit 181 determines that the position where the railway vehicle 10 is traveling is affected by sunlight, the photography interference detection device 100a terminates the processing of the flowchart and repeatedly executes the processing of the flowchart.

[0176] In step ST1204, if the position mode switching unit 181 determines that the position where the railway vehicle 10 is traveling is not affected by sunlight, in step ST1205, the position mode switching unit 181 switches the operation mode to interference detection mode. After step ST1205, the camera interference detection device 100a terminates the processing of the flowchart, and the camera interference detection device 100a repeatedly executes the processing of the flowchart.

[0177] With the above configuration, the camera interference detection device 100a can accurately determine whether or not an imaging device installed inside a railway vehicle is in an abnormal state during imaging. Furthermore, with this configuration, the camera interference detection device 100a can detect the presence or absence of camera interference for each of the multiple imaging devices 11-1, 11-2, ..., 11-N during periods when each of the multiple imaging devices 11-1, 11-2, ..., 11-N is not affected by sunlight when it is taking pictures, thereby suppressing false detections.

[0178] Furthermore, the camera interference detection device 100 or camera interference detection device 100a may detect the presence or absence of camera interference using camera parameters such as the color tone and focus of the image, instead of the brightness of the image. In addition, the camera interference detection device 100 or camera interference detection device 100a is not limited to application to railway vehicles 10, but can also be applied to vehicles such as large buses or buildings such as houses. Furthermore, it is possible to freely combine the embodiments, modify any component of each embodiment, or omit any component in each embodiment. [Industrial applicability]

[0179] The camera obstruction detection device described herein can be applied to a camera obstruction detection system. Furthermore, the camera obstruction detection device described herein is not limited to railway vehicles, but can also be applied to vehicles such as large buses, or buildings such as houses. [Explanation of symbols]

[0180] 1,1a,1b,1c Camera interference detection system, 10,10-1,···,10-m,···,10-M Railway vehicle, 11-1,11-2,···,11-N,11-1-1,11-2-1,···,11-N-1,11-1-m,11-2-m,···,11-Nm,11-1-M,11-2-M,···,11-NM Imaging device, 12 Communication network, 13 Image recording device, 14 Display device, 14-1,14-2,14-3,14-4 Light-emitting device, 100,100a,100b,100b-1,100b-2,···,100b-M,100c Camera interference detection device, 110 Estimated information acquisition unit, 111 120 Image acquisition unit for estimating shooting parameters, 130 Image acquisition unit for estimating image brightness, 131 Shooting parameter acquisition unit, 140 Reference brightness acquisition unit, 141 Reference shooting parameter acquisition unit, 150 Interference estimation unit, 151 Shooting parameter interference estimation unit, 160, 160b, 160c Interference identification unit, 170 Output control unit, 180 Time mode switching unit, 181 Position mode switching unit, 901 Processor, 902 Memory, 903 Processing circuit.

Claims

1. Each unit acquires multiple pieces of interference estimation information, each indicating whether the corresponding imaging device among multiple imaging devices classified into multiple sets according to the installed illumination environment is being interfered with. An interference detection device comprising: interference identification unit, which identifies whether or not the first imaging device is being interfered with based on interference estimation information corresponding to a first imaging device among the plurality of imaging devices, and interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices, from among the plurality of interference estimation information acquired by the estimation information acquisition unit.

2. A camera interference detection device that determines whether or not multiple imaging devices installed on a vehicle are being interfered with, An estimation information acquisition unit acquires multiple pieces of interference estimation information indicating whether or not a corresponding imaging device among the multiple imaging devices, which are classified into multiple sets according to whether or not they are installed in the passenger compartment of the vehicle or outside the passenger compartment, is being interfered with; An interference detection device comprising: interference identification unit, which identifies whether or not the first imaging device is being interfered with based on interference estimation information corresponding to a first imaging device among the plurality of imaging devices, and interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices, from among the plurality of interference estimation information acquired by the estimation information acquisition unit.

3. The camera interference detection device according to claim 1 or claim 2, further comprising an output control unit that outputs an identification display signal for identifying the first imaging device that has been identified as being subjected to camera interference when the interference identification unit identifies that the first imaging device is being subjected to camera interference.

4. The camera interference detection device according to Claim 3, The plurality of imaging devices, A camera interference detection system characterized by comprising a display device that displays an identification display signal output by the output control unit.

5. An estimation information acquisition process that acquires a plurality of interference estimation pieces of information, each indicating whether or not a corresponding imaging device among a plurality of imaging devices classified into a plurality of sets according to the installed illumination environment is being interfered with, A shooting interference detection program that causes a computer to function as a shooting interference detection device, which performs interference identification processing to determine whether or not the first imaging device is being interfered with, based on interference estimation information corresponding to a first imaging device among the plurality of imaging devices, and interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices, from among the plurality of interference estimation information acquired by the estimation information acquisition process.

6. A camera interference detection program that causes a computer to function as a camera interference detection device for determining whether or not multiple imaging devices installed in a vehicle are being interfered with, An estimation information acquisition process that acquires multiple pieces of interference estimation information indicating whether or not a corresponding imaging device among the multiple imaging devices, which are classified into multiple sets according to whether or not they are installed in the passenger compartment of the vehicle or outside the passenger compartment, is being interfered with; A shooting interference detection program that causes the computer to function as a shooting interference detection device, which performs interference identification processing to determine whether or not the first imaging device is being interfered with, based on interference estimation information corresponding to a first imaging device among the plurality of imaging devices, and interference estimation information corresponding to a second imaging device belonging to the same set as the first imaging device among the plurality of imaging devices, from among the plurality of interference estimation information acquired by the estimation information acquisition process.

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