Camera replacement support device

Abstract

The present invention reduces the number of workers or shortens the work time required to replace a camera installed for surveillance monitoring, for example.　A camera replacement support device 40 according to one embodiment of the present invention has: a function of comparing a reference output image captured in advance by a camera 10 before replacement with a confirmation output image captured by a replacement camera 15 to determine whether or not the confirmation output image includes an image part having the same angle of view as that of the reference output image; a function of notifying a worker of the completion of camera direction adjustment work upon determining that the confirmation output image includes an image part having the same angle of view as that of the reference output image; and a function, after completion of the camera direction adjustment work, of executing parameter adjustment processing for automatically adjusting imaging parameters including the angle of view, zoom, focus, etc., of the camera 15 so that an image similar to that of the camera 10 before replacement can be obtained by the replacement camera 15.

Description

Camera exchange support device

[0001] The present invention relates to a camera replacement support device that assists in the replacement of cameras installed for surveillance purposes.

[0002] Traditionally, surveillance systems have been developed to ensure safety in monitored areas, detect intruders and abandoned objects, and investigate incidents and accidents by capturing images of the monitored area with cameras and displaying them on a monitor. For example, station surveillance systems that capture images of the platforms at each station with cameras and display them on a monitor are in practical use. When operating such surveillance systems over the long term, camera deterioration or malfunctions can hinder camera operation, making it necessary to replace the cameras in a timely manner.

[0003] When replacing cameras, the process involved manually recording the image of the old camera displayed on the monitoring screen, either by memory or by taking a picture with a digital camera, and then adjusting the camera's orientation, zoom, and focus to ensure a similar image was captured with the replacement camera. Since this task is difficult for one person to perform alone, a pair of workers would typically be used: one would connect a monitor to the replacement camera, compare the image displayed on the monitor to the image of the old camera, and give work instructions; the other would adjust the camera's orientation and other settings according to those instructions. Furthermore, many monitoring systems operate 24 hours a day, meaning camera replacements are typically performed during times when stopping camera recording has minimal impact (for example, late at night when trains are not running in a station monitoring system), but the work must be completed quickly. Therefore, reducing the number of workers required for camera replacement and shortening the work time would significantly improve the operation of the monitoring system.

[0004] As prior arts related to the present invention, there are the following. For example, Patent Document 1 discloses an obstacle detection system that mounts a plurality of cameras for photographing a common area from different positions on a moving body, and determines the presence or absence of obstacles in the area based on the images photographed by these plurality of cameras. Patent Document 2 discloses an imaging device that eliminates the image mismatch between two cameras caused by the parallax between two cameras that capture electromagnetic waves in two different wavelength bands and convert them into video signals by imaging.

[0005] Japanese Patent Application Laid-Open No. 2019-046241, Patent No. 450151

[0006] As described above, when replacing a camera, it is necessary to pre-acquire the image photographed by the camera before replacement so that a similar image can be photographed (restored) by the camera after replacement. However, there are often restrictions on the working time. For example, in a place where camera replacement work is only allowed at night, only a limited number of hours can be secured for working time in a day. To give a specific example, for a camera installed on a station platform, there are passengers on the platform during daytime and train operation, so basically no work can be done. Therefore, only a few hours from the last train departure to the first train departure (roughly from after 1:00 am to after 4:30 am) can be secured for working time.

[0007] Although a worker with rich experience in camera replacement can shorten the working time somewhat, the working time depends on the degree of experience. That is, there is a difference in working time between a worker who is used to camera replacement and a worker who is not. Moreover, the feeling when comparing the images before and after camera replacement may be slightly different among workers. Also, when a situation occurs where fine adjustment of the shooting angle etc. is required after the worker who has completed the camera replacement work has withdrawn, it is necessary for the worker to go to the site again to readjust the camera. From such a situation, reducing the work burden and shortening the working time required for camera replacement are important elements in the operation of the monitoring system.

[0008] This invention has been made in view of the above-mentioned conventional circumstances, and aims to reduce the number of workers and shorten the working time required for replacing cameras installed for surveillance purposes.

[0009] A camera replacement support device according to one aspect of the present invention is a camera replacement support device that assists in the replacement of a camera installed for surveillance, and is characterized by having a function to determine whether or not the image of the replacement camera contains an image portion with the same field of view as the image of the camera before replacement by comparing an image previously captured by the camera before replacement with an image captured by the replacement camera, and a function to notify the worker that the work of adjusting the orientation of the replacement camera to match the orientation of the camera before replacement has been completed, in response to the determination that the image of the replacement camera contains an image portion with the same field of view as the image of the camera before replacement.

[0010] Herein, the above-described camera exchange support device may further have a function to adjust the field of view, zoom, or focus of the replacement camera so that, after it is determined that the image of the replacement camera contains an image portion with the same field of view as the image of the camera before exchange, the replacement camera can obtain an image similar to that of the camera before exchange.

[0011] Furthermore, in the above-described camera replacement support device, the field of view of the replacement camera may be adjusted based on the position of objects present in the image captured by the camera before replacement.

[0012] Furthermore, in the above-described camera replacement support device, the zoom of the replacement camera may be adjusted based on the size of objects present in the image captured by the camera before replacement.

[0013] Furthermore, in the above-described camera exchange support device, the focus of the replacement camera may be adjusted based on the outline or brightness of an object present in the image captured by the camera before the exchange.

[0014] According to the present invention, it is possible to reduce the number of workers and shorten the working time required for replacing cameras installed for surveillance purposes.

[0015] This figure shows an overview of camera replacement work using a camera replacement support device according to one embodiment of the present invention. This figure shows an example of the configuration of the camera replacement support device. This figure shows an example of the processing flow related to camera replacement work using the camera replacement support device. This figure shows an example of a reference output image taken with the camera before replacement. This figure shows an example of a confirmation output image taken with the camera immediately after replacement. This figure shows an example of an original image actually taken with the camera immediately after replacement. This figure shows an example of a confirmation output image after adjustment of the cropped area. This figure shows an example of a confirmation output image when the camera orientation is inappropriate. This figure shows an example of a confirmation output image when the zoom is inappropriate. This figure shows an example of a confirmation output image when the focus is inappropriate.

[0016] One embodiment of the present invention will be described with reference to the drawings. Figure 1 shows an overview of camera replacement work using a camera replacement support device. The upper part of Figure 1 shows an example of the system configuration before camera replacement, the middle part shows an example of the system configuration during replacement work, and the lower part shows an example of the system configuration after camera replacement.

[0017] The surveillance system shown in Figure 1 includes a camera 10 positioned facing the surveillance area, a surveillance monitor 20 that displays images captured by the camera 10, and a recording device 30 that records images captured by the camera 10, all of which are connected to each other in a manner that allows for communication. Using such a surveillance system as an example, the process of replacing camera 10 with camera 15 will be explained.

[0018] Here, cameras 10 and 15 have a cropping function that cuts out a predetermined area from the original captured image and outputs it. In the following, the original captured image by camera 10 or camera 15 will be referred to as the "original image," and the image cropped from the original image for output will be referred to as the "output image." If the cropping function is turned off (or if no cropping area is set), the original image will be used as the output image. Furthermore, it is assumed that the replacement camera 15 is capable of capturing images over a wider area and at a higher resolution than the camera 10 before replacement.

[0019] The camera replacement work is carried out using a camera replacement support device 40, as shown in the middle section of Figure 1. The camera replacement support device 40 may be installed near the camera installation location or at a location away from the camera installation location (for example, in an equipment room). Installing the camera replacement support device 40 at a location away from the camera installation location has the advantage of not requiring installation work to be carried out during limited time periods such as at night, and it is possible to install it in advance of on-site camera replacement, thus reducing the constraints on working time.

[0020] The camera replacement support device 40 receives two inputs: an output image obtained when the monitoring area is photographed in advance with the camera 10 before replacement (hereinafter referred to as the "reference output image"), and an output image obtained when the monitoring area is photographed with the replacement camera 15 during the camera replacement operation (hereinafter referred to as the "confirmation output image"). In the illustrated example, the camera replacement support device 40 is connected to both the recording device 30 and the replacement camera 15, and the reference output image is obtained from the recording device 30 and the confirmation output image is obtained from the replacement camera 15, but this is just one example. For example, as a preliminary step, the camera replacement support device 40 may be connected to the recording device 30 to obtain the reference output image, and then the camera replacement support device 40 may be connected to the replacement camera 15 to obtain the confirmation output image. Alternatively, as a preliminary step, the reference output image may be obtained from the recording device 30 via a portable storage medium such as a USB memory stick and input to the camera replacement support device 40.

[0021] Figure 2 shows an example of the configuration of the camera exchange support device 40. The camera exchange support device 40 is implemented, for example, by a computer equipped with hardware resources such as a processor and memory, and is configured to realize functions and processes related to the present invention by reading a predetermined program from memory and executing it with the processor. The camera exchange support device 40 shown in Figure 2 has a reference output image acquisition unit 41, a confirmation output image acquisition unit 42, a camera direction determination unit 43, a shooting parameter adjustment unit 44, and a notification unit 45.

[0022] The reference output image acquisition unit 41 performs the process of acquiring a reference output image from the recording device 30. The reference output image acquired by the reference output image acquisition unit 41 is stored in the memory of the camera exchange support device 40. The confirmation output image acquisition unit 42 performs the process of acquiring a confirmation output image from the replacement camera 15. The acquisition of the confirmation output image is repeated until the exchange work is completed.

[0023] The camera direction determination unit 43 performs a process to determine whether the orientation of the replacement camera 15 is appropriate (i.e., whether it is pointed in the same direction as the camera 10 before replacement) by comparing the reference output image and the confirmation output image. Specifically, if the confirmation output image contains an image portion with the same field of view as the reference output image, the orientation of the replacement camera 15 is determined to be appropriate. In this case, the camera direction adjustment work by the worker to match the orientation of the replacement camera 15 to that of the camera 10 before replacement is completed. On the other hand, if the confirmation output image does not contain an image portion with the same field of view as the reference output image, the orientation of the replacement camera 15 is determined to be inappropriate. In this case, the camera direction adjustment work continues. In other words, the worker needs to readjust the orientation of the replacement camera 15.

[0024] It is possible to determine whether the verification output image contains an image portion with the same field of view as the reference output image using various methods. For example, methods such as extracting and comparing edges from each output image, extracting and comparing vectors, or extracting and comparing features can be used. It is also possible to use publicly known artificial intelligence models. Furthermore, the appearance of objects (reference objects) within the monitoring area in each output image can also be used as a basis for determination.

[0025] After the camera direction adjustment is complete, the shooting parameter adjustment unit 44 performs a parameter adjustment process to automatically adjust the shooting parameters of the replacement camera 15 so that the replacement camera 15 can produce an image similar to that of the original camera 10. Examples of shooting parameters to be adjusted include the field of view, zoom, and focus of the camera 15. The shooting parameter adjustment unit 44 can control the shooting parameters of the camera 15 by transmitting a shooting parameter control signal to the camera 15 that includes the set values ​​of these shooting parameters.

[0026] The angle of view of camera 15 can be adjusted, for example, based on the position of an object present in the reference output image. That is, the cropping area of ​​the original image should be set so that the same object present in the reference output image is in a similar position in the confirmation output image. The zoom of camera 15 can be adjusted, for example, based on the size of an object present in the reference output image. That is, the zoom of the camera lens should be adjusted so that the same object present in the reference output image is of a similar size in the confirmation output image. The focus of camera 15 can be adjusted, for example, based on the outline or brightness of an object present in the reference output image. That is, the focus of the camera lens should be adjusted so that the same object present in the reference output image has a similar outline or brightness in the confirmation output image. Note that these are merely examples, and it is possible to adjust the shooting parameters in various other ways.

[0027] The notification unit 45 performs processing to notify the user when the camera direction adjustment work is completed or when the parameter adjustment process is completed. In the example in Figure 1, a notification device 50 is optionally attached to the replacement camera 15, and notifications are made using the notification device 50. For example, when the camera direction adjustment work is completed, the lamp on the notification device 50 lights up yellow, and when the parameter adjustment process is completed, the lamp on the notification device 50 lights up green. Notifications in other forms, such as voice messages or text displays, are also possible. In addition, instead of the camera-mounted notification device 50, a portable communication terminal such as a smartphone or tablet that can be carried by the worker can be used for notifications, and in this case, the portable communication terminal should be registered as a notification device in advance.

[0028] Figure 3 shows an example of a processing flow related to camera replacement work using the camera replacement support device 40. First, the worker installs the camera replacement support device 40 (step S11). Next, the camera replacement support device 40 acquires a reference output image from the recording device 30 (step S12). Then, the worker removes the camera 10 and installs the camera 15 in the same position (step S13). After that, the camera replacement support device 40 acquires a confirmation output image from the camera 15 and determines whether the confirmation output image contains an image portion with the same field of view as the reference output image (step S14).

[0029] In step 14, if it is determined that the confirmation output image contains an image portion with the same field of view as the reference output image, the completion of the camera direction adjustment work is notified via the notification device 50 (step S16), allowing the worker to move on to another task (for example, preparation work for the next camera replacement). On the other hand, if it is determined that the confirmation output image does not contain an image portion with the same field of view as the reference output image, the worker readjusts the direction of the camera 15 (step S15).

[0030] After the camera direction adjustment work is completed, the camera exchange support device 40 moves on to parameter adjustment processing. In the parameter adjustment processing, the camera exchange support device 40 performs processes such as automatically correcting the zoom amount of the camera 15 until the confirmation output image is the same size as the reference output image (steps S17, S18), and automatically correcting the cropping area of ​​the camera 15 relative to the original image until the confirmation output image has the same field of view as the reference output image (steps S19, S20). Once these processes are completed, the completion of the parameter adjustment processing is notified via the notification device 50 (step S21), so the worker removes the camera exchange support device 40 and moves to the next camera exchange site.

[0031] Referring to Figures 4 to 10, the camera direction adjustment and parameter adjustment processes will be explained in detail. Here, it is assumed that the initial setting of the replacement camera 15 is that a predetermined-sized area in the center of the original image is set as the cropping area.

[0032] Figure 4 shows an example of a reference output image 60 taken with camera 10 before replacement. Figure 5 shows an example of a verification output image 70 taken with camera 15 immediately after replacement. In the reference output image 60 shown in Figure 4, the reference object is located near the center of the image, whereas in the verification output image 70 shown in Figure 5, the object is located near the lower left of the image. In the examples in Figures 4 and 5, it can be seen that camera 15 immediately after replacement is installed in a slightly different orientation from camera 10 before replacement.

[0033] As mentioned above, since camera 15 has a cropping function, as shown in Figure 6, the original image 75 actually captured by camera 15 will be an image that encompasses the confirmation output image 70 output from camera 15. In other words, the original image 75 contains a wider range of captured images than the confirmation output image 70. Therefore, if the orientation of camera 15 is determined to be appropriate using the image obtained with the cropping function of camera 15 turned off (i.e., the original image 75), and the cropping area is adjusted based on the reference output image 60 after it is determined that the orientation of camera 15 is appropriate, it can be seen that an image similar to the reference output image 60 will be obtained as the confirmation output image 70 when the cropping function is turned on.

[0034] Therefore, it is desirable that the camera exchange support device 40 controls the camera 15 to turn off its cropping function at the time of camera direction adjustment work, acquires the original image 75 as a confirmation output image from the camera 15, and determines whether the orientation of the camera 15 is appropriate by comparing the original image 75 with the reference output image 60. As a result, as shown in Figure 8, if the original image 75 does not contain an image portion with the same field of view as the reference output image 60, it is determined that the orientation of the camera 15 is inappropriate. In this case, since there is no notification from the notification device 50 that the camera direction adjustment work is complete, the worker will continue to perform the camera direction adjustment work. On the other hand, as shown in Figure 6, if the original image 75 contains an image portion with the same field of view as the reference output image 60, it is determined that the orientation of the camera 15 is appropriate. In this case, the notification device 50 notifies the worker that the camera direction adjustment work is complete, so the worker finishes the camera direction adjustment work.

[0035] Subsequently, the camera exchange support device 40 adjusts the cropping area (i.e., adjusts the field of view) based on the reference output image 60 so that an image similar to the reference output image 60 is cropped from the original image 75, and then controls the camera 15 to turn on its cropping function. As a result, as shown in Figure 7, the camera 15 after the exchange outputs a confirmation output image 71 with a field of view similar to the reference output image 60. At this time, by setting the cropping area based on the position of an object present in the reference output image 60 so that the object appears in the same position as in the reference output image 60, it is possible to efficiently adjust the field of view. If fine adjustment of the field of view is required after the work is completed, it is also possible to perform fine adjustment of the field of view remotely using the camera exchange support device 40 or a camera operation terminal (not shown).

[0036] Figure 9 shows an example of a confirmation output image 72 when the zoom of camera 15 is inappropriate. The confirmation output image 72 shows that the zoom of camera 15 is different from that of camera 10. In this case, the camera exchange support device 40 can efficiently adjust the zoom by setting the zoom so that the object is photographed at a similar size to that of the reference output image 60, based on the size of the object present in the reference output image 60.

[0037] Figure 10 shows an example of a confirmation output image 73 when the focus of camera 15 is incorrect. The confirmation output image 73 shows that the focus of camera 15 is different from that of camera 10. In this case, the camera exchange support device 40 can efficiently adjust the focus by setting the focus so that the object is captured with the same clarity as the reference output image 60, based on the contours and brightness of the object present in the reference output image 60.

[0038] As described above, the camera replacement support device 40 in this example has the following functions: a function to determine whether the confirmation output image contains an image portion with the same field of view as the reference output image by comparing a reference output image previously captured by the camera 10 before replacement with a confirmation output image captured by the replacement camera 15; a function to notify the worker that the camera direction adjustment work is complete when it is determined that the confirmation output image contains an image portion with the same field of view as the reference output image; a function to perform a parameter adjustment process that automatically adjusts the shooting parameters of the camera 15, including the field of view, zoom, and focus, so that the replacement camera 15 can obtain an image similar to that of the camera 10 before replacement; and a function to notify the worker that the parameter adjustment process is complete when it is completed.

[0039] By using such a camera replacement support device 40, a single worker can perform the camera replacement work independently. Furthermore, even inexperienced workers can complete the camera replacement work in a short amount of time. The influence of differences in perception between workers when comparing images before and after camera replacement can be eliminated. Therefore, it is possible to reduce the number of workers required for camera replacement work and shorten the work time.

[0040] In the above explanation, the camera direction adjustment process is terminated when it is determined that the confirmation output image contains an image portion with the same field of view as the reference output image. In this case, the camera orientation may differ slightly before and after the replacement. This can be addressed by adjusting the cropping area as described above, but the orientation of the replacement camera 15 may also be guided to be closer to the orientation of the original camera 10. Specifically, for example, the position of the image portion in the confirmation output image with the same field of view as the reference output image may be identified, and instructions may be sent to the worker via the notification device 50 to orient the camera 15 in the direction that this position moves toward the center of the confirmation output image. This makes it possible to bring the orientation of the replacement camera 15 closer to the orientation of the original camera 10. Furthermore, if the camera orientations before and after the replacement are precisely matched, it is possible to omit the adjustment of the cropping area (adjustment of the field of view).

[0041] Although embodiments of the present invention have been described above, these embodiments are merely illustrative and do not limit the technical scope of the present invention. The present invention can take many other embodiments, and various modifications such as omissions and substitutions can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention as described herein, and are included in the scope of the invention and its equivalents as described in the claims.

[0042] Furthermore, the present invention can be provided not only as the devices described above or as systems composed of such devices, but also as methods executed by these devices, programs for a processor to realize the functions of these devices, and storage media for storing such programs in a computer-readable manner.

[0043] This invention can be used when replacing cameras installed for surveillance purposes.

[0044] 10, 15: Camera, 20: Surveillance monitor, 30: Recording device, 40: Camera exchange support device, 41: Reference output image acquisition unit, 42: Confirmation output image acquisition unit, 43: Camera direction determination unit, 44: Shooting parameter adjustment unit, 45: Notification unit, 50: Notification device,

Claims

1. A camera replacement support device for assisting in the replacement of cameras installed for surveillance, comprising: a function to determine whether the image of the replacement camera contains an image portion with the same field of view as the image of the camera before replacement by comparing an image previously captured by the camera before replacement with an image captured by the replacement camera; and a function to notify the worker that the work of adjusting the orientation of the replacement camera to match the orientation of the camera before replacement has been completed, in response to the determination that the image of the replacement camera contains an image portion with the same field of view as the image of the camera before replacement.

2. A camera exchange support device according to claim 1, further comprising a function to adjust the field of view, zoom, or focus of the replacement camera so that an image similar to that of the original camera can be obtained with the replacement camera after it has been determined that the image of the replacement camera contains an image portion with the same field of view as that of the original camera.

3. A camera replacement support device according to claim 2, characterized in that the angle of view of the replacement camera is adjusted based on the position of an object present in the image captured by the camera before replacement.

4. A camera replacement support device according to claim 2, characterized in that the zoom of the replacement camera is adjusted based on the size of an object present in the image captured by the camera before replacement.

5. A camera replacement support device according to claim 2, characterized in that the focus of the replacement camera is adjusted based on the contour or brightness of an object present in the image captured by the camera before replacement.

Images