Image playback device, image playback system, image playback method, and program

Abstract

To automatically extract an image to be displayed from recorded images.SOLUTION: An image playback device 100 includes an image acquisition unit 111 that acquires an image taken by one or more omnidirectional cameras to be displayed together with time information, a position information acquisition unit 112 that acquires position information for each identifier to be displayed together with the time information, an identifier acquisition unit 113 that acquires an identifier to be displayed, an image extraction unit 114 that extracts the image to be displayed from the image acquired by the image acquisition unit 111 on the basis of the time information and the position information acquired by the position information acquisition unit 112 and the identifier acquired by the identifier acquisition unit 113, and an image playback unit 115 that plays back the image extracted by the image extraction unit 114.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an image playback device, an image playback system, an image playback method, and a program. [Background technology]

[0002] Omnidirectional cameras that can capture 360-degree video around a shooting point using a video camera with a fisheye lens or multiple video cameras have been proposed. For example, Patent Document 1 discloses a video distribution system that can accurately compensate for packet loss when distributing omnidirectional video captured by an omnidirectional camera. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-217536 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional video distribution system such as that disclosed in Patent Document 1, when a video is played back, a portion desired by the user is extracted from the omnidirectional video and displayed on the display. This allows the image from the direction the user wants to view to be displayed from the omnidirectional image captured by the omnidirectional camera. However, conversely, the user has to specify each time which image from which direction in the omnidirectional image to display.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an image playback device, an image playback system, an image playback method, and a program that can automatically extract images to be displayed from recorded images. [Means for solving the problem]

[0006] In order to achieve the above object, an image reproducing apparatus according to a first aspect of the present invention comprises: an image acquisition means for acquiring images of a display object photographed by one or more omnidirectional cameras together with time information; a location information acquiring means for acquiring location information for each identifier of the display object together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with 、 In an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired by the image acquisition means, the image extraction means extracts images of all areas in which the display object is shown. .

[0010] In order to achieve the above object, an image reproducing apparatus according to a second aspect of the present invention comprises: an image acquisition means for acquiring images of a display object photographed by one or more omnidirectional cameras together with time information; a location information acquiring means for acquiring location information for each identifier of the display object together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with The image extraction means The position information of the display object is converted into polar coordinates (distance r, angle θ) with the installation position of the omnidirectional camera that captured the display object as the origin, and an image of the area centered in the direction of angle θ is extracted. before When the distance r is equal to or less than the threshold for a directly above image, an image in which the display object is photographed from directly above is extracted from the images acquired by the image acquisition means. 。

[0012] In order to achieve the above object, the present invention 3 The image reproduction system according to the aspect of The display system includes one or more omnidirectional cameras, a positioning device that measures the position of a display object, and an image playback device, The image reproduction device an image acquisition means for acquiring an image of the display object photographed by the omnidirectional camera together with time information; a position information acquisition means for acquiring position information for each identifier of the display object whose position has been measured by the positioning device together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with 、 In an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired by the image acquisition means, the image extraction means extracts images of all areas in which the display object is shown. .

[0013] In order to achieve the above object, the present invention 4 The image reproduction method according to the aspect of an image acquisition step of acquiring images of a display target photographed by one or more omnidirectional cameras together with time information; a location information acquisition step of acquiring location information for each identifier of the display object together with the time information; an identifier acquisition step of acquiring an identifier of the display object; an image extraction step of extracting an image of an area in which the display target exists from the image acquired in the image acquisition step, based on the location information and time information acquired in the location information acquisition step and the identifier acquired in the identifier acquisition step; an image reproduction step of reproducing the image extracted in the image extraction step; Equipped with 、 In the image extraction step, in an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired in the image acquisition step, images of all areas in which the display object is shown are extracted. .

[0014] In order to achieve the above object, the present invention 5 The program related to the above points is On the computer, an image acquisition step of acquiring images of the display object photographed by one or more omnidirectional cameras together with time information; a location information acquisition step of acquiring location information for each identifier of the display object together with the time information; an identifier acquisition step of acquiring an identifier of the display object; an image extraction step of extracting an image of an area in which the display target exists from the image acquired in the image acquisition step, based on the location information and time information acquired in the location information acquisition step and the identifier acquired in the identifier acquisition step; and an image reproduction step of reproducing the image extracted in the image extraction step; Run A program for: In the image extraction step, in an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired in the image acquisition step, images of all areas in which the display object is shown are extracted. . [Effects of the Invention]

[0015] According to the present invention, images to be displayed can be automatically extracted from recorded images. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of an image playback system according to a first embodiment. [Figure 2] 1 is a diagram showing an example of a situation in which an omnidirectional camera and a beacon receiver according to the first embodiment are installed indoors, viewed from the horizontal direction. [Figure 3] 1 is a diagram showing an example of a situation in which an omnidirectional camera and a beacon receiver according to the first embodiment are installed indoors, viewed from the vertical direction. [Figure 4] FIG. 4 is a diagram showing an example of received information according to the first embodiment. [Figure 5] 10A and 10B are diagrams illustrating a method for calculating the position of a beacon transmitter based on the angle of arrival of radio waves when viewed from the horizontal direction. [Figure 6] 10A and 10B are diagrams illustrating a method for calculating the position of a beacon transmitter based on the angle of arrival of radio waves when viewed from the vertical direction. [Figure 7] FIG. 2 is a block diagram showing an example of a hardware configuration of an image playback device. [Figure 8] FIG. 2 is a block diagram showing an example of a functional configuration of an image playback device. [Figure 9] FIG. 2 is a diagram illustrating an example of an image captured by an omnidirectional camera. [Figure 10] 10A and 10B are diagrams illustrating an example of an image extracted by an image extracting unit. [Figure 11] FIG. 10 is a diagram illustrating an example of an area photographed from directly above. [Figure 12] 10A and 10B are diagrams illustrating an example in which images of multiple regions are displayed on multiple sub-screens. [Figure 13] 10 is a flowchart showing the flow of an image reproduction process. [Figure 14] FIG. 10 is a schematic diagram of an image playback system according to a second embodiment. [Figure 15] 10 is a flowchart showing the flow of image extraction processing according to the second embodiment. [Figure 16] FIG. 10 is a diagram illustrating a range that is considered to be the front. [Figure 17] 11 is a first flowchart showing the flow of image extraction processing according to the third embodiment. [Figure 18] 11 is a second flowchart showing the flow of the image extraction process according to the third embodiment. [Figure 19] FIG. 10 is a diagram illustrating a method for calculating the priority of an omnidirectional camera. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0018] (Embodiment 1) The image playback system 1 according to the first embodiment of the present invention is a system that extracts and plays back images that show a specific person (such as a worker) from images captured and recorded by an omnidirectional camera. As shown in Fig. 1, the image playback system 1 includes an image playback device 100, an omnidirectional camera 200, a recording device 300, a beacon transmitter 400, a beacon receiver 500, and a positioning device 600.

[0019] The omnidirectional camera 200 and the recording device 300, the recording device 300 and the image playback device 100, the beacon receiver 500 and the positioning device 600, and the positioning device 600 and the image playback device 100 are communicably connected via a network NW. The network NW may be wired or wireless. The network NW may be any communication network, such as a wired local area network (LAN), a mobile phone communication network such as a 3G (3rd Generation) / LTE (Long Term Evolution) line, a short-range wireless network such as a wireless LAN (Wi-Fi) / IEEE802.15.4, a low-power wide area (LPWA) wireless network, a virtual private network (VPN), or the Internet.

[0020] The beacon receiver 500 is a device that receives a radio signal transmitted from the beacon transmitter 400. The number of each of the beacon transmitters 400 and beacon receivers 500 is arbitrary, and the image replay system 1 is configured to include a plurality of beacon transmitters 400 and a plurality of beacon receivers 500. Each device that configures the image replay system 1 will be described below.

[0021] Omnidirectional camera 200 is a fisheye camera using a fisheye lens that can capture images in all directions (360 degrees) centered on a capture point. Omnidirectional camera 200 is installed on a ceiling or the like indoors, as shown in FIGS. 2 and 3. Here, FIG. 2 is a view of the indoors as seen from the horizontal direction (side), and FIG. 3 is a view of the indoors as seen from the vertical direction (above). Omnidirectional camera 200 transmits captured image data (moving image data) to recording device 300 via network NW. Note that, although a fisheye camera is used as omnidirectional camera 200 in the first embodiment, omnidirectional camera 200 is not limited to a fisheye camera. For example, one omnidirectional camera 200 may be realized by arranging multiple normal cameras (e.g., eight cameras with a viewing angle of 45 degrees) in a circle to capture images in all directions.

[0022] Recording device 300 is a device that includes a storage unit such as an HDD (Hard Disk Drive) and stores omnidirectional image data captured by omnidirectional camera 200 as recorded data together with time information in the storage unit. Since the recorded data stored by recording device 300 includes time information, images can be played back from any time by specifying the time during playback.

[0023] The beacon transmitter 400 is a beacon tag device that periodically (for example, at one-second intervals) transmits a BLE (Bluetooth (registered trademark) Low Energy) wireless signal. This wireless signal includes a transmitter ID as information (identification information) of an identifier (ID) for uniquely identifying the beacon transmitter 400. The beacon transmitter 400 periodically transmits this wireless signal. Here, the time interval at which the beacon transmitter 400 transmits the wireless signal is referred to as a reference time unit (for example, one second).

[0024] In this embodiment, the display target in image playback by the image playback device 100 is a worker W, who is wearing a beacon transmitter 400 (for example, by wearing a helmet equipped with the beacon transmitter 400). In other words, the identifier (transmitter ID) included in the wireless signal transmitted by the beacon transmitter 400 is also used as the identifier (worker ID) of the worker W. Note that by using a correspondence table between the transmitter ID and the worker ID, the transmitter ID and the worker ID can be different IDs.

[0025] In addition, in this embodiment, the wireless signal periodically transmitted by the beacon transmitter 400 is a beacon signal conforming to the BLE standard (hereinafter also simply referred to as a "BLE beacon"). However, the wireless signal transmitted by the beacon transmitter 400 may be any signal transmitted to notify its own presence, and may be a signal other than a BLE beacon.

[0026] The beacon receiver 500 is a device that receives a BLE beacon transmitted by the beacon transmitter 400. The beacon receiver 500 can measure the angle of arrival (AOA (Angle Of Arrival)) of radio waves when receiving a BLE beacon transmitted from the beacon transmitter 400, by using an array antenna or the like. The beacon receiver 500 then transmits the measured angle of arrival, etc. to the positioning device 600 as reception information, which will be described later.

[0027] As shown in Fig. 2 and Fig. 3, a plurality of beacon receivers 500 are installed on ceilings, walls, etc. indoors. It is desirable to install the beacon receivers 500 in a location that is least affected by obstacles such as boards that block radio waves. The administrator of the image replay system 1 also makes it possible for the positioning device 600 to grasp information such as the installation position of each beacon receiver 500 in advance. In this embodiment, information on the installation position of each beacon receiver 500 (the installation height and position on a horizontal plane) is stored in a memory unit of the positioning device 600.

[0028] Every time the beacon receiver 500 receives a BLE beacon, it generates reception information indicating the arrival angle of the received BLE beacon and transmits the reception information to the positioning device 600 via the network NW. The reception information includes, for example, as shown in Fig. 4, identification information (receiver ID) of the beacon receiver 500, identification information (transmitter ID) of the beacon transmitter 400 that is the sender of the BLE beacon, the reception time of the BLE beacon (time information), and the angle at which the BLE beacon arrived (arrival angle).

[0029] Here, the arrival angle is, for example, as shown in FIG. 5, the angle θ with respect to a reference line (for example, a perpendicular line) when the arrival angle of the radio wave is viewed from the horizontal direction. A As shown in Figure 6, the angle φ of the radio wave arrival angle relative to the reference line (e.g., north direction) when viewed from the vertical direction is AThe positioning device 600 can calculate the position of the beacon transmitter 400 based on the information on the angle of arrival. Note that this calculation method is an example of a positioning method, and the positioning device 600 may use other methods to measure the position of the beacon transmitter 400. Furthermore, the positioning device 600 may measure the three-dimensional position of the beacon transmitter 400, or may measure the two-dimensional position ignoring the height direction (for example, at a constant height h (e.g., 1.5 m)).

[0030] The positioning device 600 is a device that includes a storage unit such as a RAM (Random Access Memory), acquires the position of each beacon transmitter 400, and stores a history of position information (position information log) for each identifier of the beacon transmitter 400 in the storage unit. For example, the positioning device 600 receives reception information from each of a plurality of beacon receivers 500 installed indoors. The positioning device 600 then calculates the position of the beacon transmitter 400 from information about the position of the beacon receiver 500 that is known in advance and information about the angle of arrival included in the reception information. The positioning device 600 then stores the calculated position of the beacon transmitter 400 in the storage unit together with time information.

[0031] The beacon transmitter 400 transmits a BLE beacon every reference time unit (for example, one second) described above, and the beacon receiver 500 transmits reception information to the positioning device 600 every time it receives a BLE beacon, so the positioning device 600 can calculate the position of the beacon transmitter 400 every reference time unit. Therefore, the position of the beacon transmitter 400 is stored in the position information log at sampling times of the reference time unit.

[0032] Here, a specific method for calculating the three-dimensional position of the beacon transmitter 400 will be described. As shown in FIG. 5, the positioning device 600 calculates the arrival angle θ A and the arrival angle θ included in the received information from the beacon receiver 500B. BFrom this, the difference in altitude between the beacon receiver 500A and the beacon receiver 500B and the beacon transmitter 400 can be calculated, and by using information on the height of the beacon receiver 500A and the beacon receiver 500B that is known in advance, information on the height of the beacon transmitter 400 can be calculated.

[0033] 6, the positioning device 600 calculates the arrival angle φ included in the reception information from the beacon receiver 500A. A and the arrival angle φ included in the received information from the beacon receiver 500B. B From this, the positional relationship in the horizontal plane between the beacon receiver 500A, the beacon receiver 500B and the beacon transmitter 400 can be calculated, so the position of the beacon transmitter 400 can be calculated by using information on the positions of the beacon receiver 500A and the beacon receiver 500B that is known in advance.

[0034] As mentioned above, three-dimensional positioning using this positioning method requires two or more beacon receivers 500, but assuming that the beacon transmitter 400 moves at a certain height h above the floor, the position of the beacon transmitter 400 can be determined with just one beacon receiver 500. This can be done by calculating the position of the beacon transmitter 400 based on the intersection of a plane at height h and a straight line extended from the beacon receiver 500 in the direction of the angle of arrival, for example.

[0035] After calculating the position of the beacon transmitter 400 based on the reception information received from the beacon receiver 500, the positioning device 600 stores the position information together with the identification information (transmitter ID) of the beacon transmitter 400 and time information included in the reception information used for the calculation as a position information log in the storage unit. Then, when the positioning device 600 receives a transmission request for the position information log from the image reproducing device 100, it transmits the position information log to the image reproducing device 100. As described above, the identification information (transmitter ID) of the beacon transmitter 400 included in the position information log is also information on the identifier (worker ID) of the worker W to be displayed. Therefore, by referring to the position information log, the image reproducing device 100 can acquire the position information for each identifier to be displayed together with time information.

[0036] The image playback device 100 extracts and plays back images of the worker W (display target) that the user wants to display, using the recorded data stored in the recording device 300 and the location information log stored in the positioning device 600. This mechanism will be described in detail below.

[0037] First, the hardware configuration of the image playback device 100 will be described with reference to Fig. 7. As shown in Fig. 7, the image playback device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM 103, an HDD 104, a display 105, an input device 106, and a communication I / F 107. These components are electrically connected to each other via a bus line BL.

[0038] The CPU 101 is a computing device that implements the control and functions of the image playback device 100 by reading out programs and data from the ROM 102 and HDD 104 onto the RAM 103 and executing the processes.

[0039] The ROM 102 is a non-volatile memory that stores various programs executed by the CPU 101 and various data used when the programs are executed.

[0040] The RAM 103 is a volatile memory that temporarily stores programs and data read from the ROM 102 and the HDD 104 , and is used as a work area for the CPU 101 .

[0041] The HDD 104 is a large-capacity, non-volatile storage device whose contents are rewritable. The HDD 104 stores, for example, programs and data used in the image reproduction process described below. Note that instead of the HDD 104, or in addition to the HDD 104, a large-capacity, non-volatile storage device such as an SSD (Solid State Drive) may be provided.

[0042] The display 105 is a display device such as an LCD (Liquid Crystal Display), a PDP (Plasma Display Panel), or an organic EL (Electro-Luminescence) display, and displays various images under the control of the CPU 101.

[0043] The input device 106 is a keyboard, a mouse, operation buttons, etc., and accepts operations by a user such as an administrator of the image replay system 1, input of various data, etc. The input device 106 accepts input of instructions from the administrator to the image replay device 100, for example. The input device 106 may be configured as a touch panel consisting of the display screen of the display 105 and a touch sensor provided on top of the display screen.

[0044] The communication I / F 107 is an interface for communicating with each device constituting the image playback system 1. Under the control of the CPU 101, the communication I / F 107 causes the image playback device 100 to acquire recorded data from the omnidirectional camera 200 via the network NW, and acquire a position information log from the positioning device 600.

[0045] Next, the functional configuration of the image playback device 100 will be described with reference to Fig. 8. As shown in Fig. 8, the image playback device 100 includes a control unit 110, a storage unit 120, a display unit 131, an input unit 132, and a communication unit 133.

[0046] The control unit 110 is made up of a CPU 101, a ROM 102, a RAM 103, etc., and controls each of the components of the image playback device 100. By executing a control program stored in the storage unit 120, the control unit 110 functions as, for example, an image acquisition unit 111, a position information acquisition unit 112, an identifier acquisition unit 113, an image extraction unit 114, and an image playback unit 115. These will be described later.

[0047] The storage unit 120 is composed of a ROM 102, a RAM 103, an HDD 104, etc., and stores various programs executed by the control unit 110, various data used by the control unit 110 when executing the programs, various data generated by the control unit 110 through program execution, etc. The image playback device 100 can also have the functions of the recording device 300 and the positioning device 600. When the image playback device 100 also has the functions of the recording device 300, the storage unit 120 also stores recorded data. When the image playback device 100 also has the functions of the positioning device 600, the storage unit 120 also stores a location information log.

[0048] The display unit 131 is configured by the display 105 etc. For example, when the control unit 110 instructs the recording device 300 to play back recorded data, the display unit 131 displays (plays back) the recorded data.

[0049] The input unit 132 is configured with the input device 106 and the like, and receives input from a user such as the administrator of the image reproducing system 1.

[0050] The communication unit 133 is configured with the communication I / F 107 and the like, and performs data communication with other devices (such as the recording device 300 and the positioning device 600).

[0051] Next, we will explain the image acquisition unit 111, location information acquisition unit 112, identifier acquisition unit 113, image extraction unit 114, and image playback unit 115, which are realized by the control unit 110 executing the control program stored in the memory unit 120.

[0052] The image acquisition unit 111 acquires images (recorded data captured by the omnidirectional camera 200) transmitted by the recording device 300 via the communication unit 133. As described above, the recorded data contains information about the time at which the image was captured, so the image acquisition unit 111 can acquire an image at a specified time by specifying a time and requesting the image from the recording device 300. The image acquisition unit 111 functions as an image acquisition means.

[0053] The position information acquisition unit 112 acquires the position information log transmitted by the positioning device 600 via the communication unit 133. As described above, the position information log records the position information for each identifier (transmitter ID = worker ID) together with time information, so the position information acquisition unit 112 can acquire the position information for each identifier together with time information. The position information acquisition unit 112 functions as a position information acquisition means.

[0054] The identifier acquisition unit 113 acquires the identifier of the display target via the input unit 132. Specifically, the user inputs, via the input unit 132 (such as a keyboard), the identifier (worker ID) of the worker W that the user wants to display in order to check the status of work, and the like, and the identifier acquisition unit 113 acquires the identifier of the display target. Also, for example, a correspondence table between the name of the worker W and the identifier (worker ID) may be stored in the storage unit 120, and when the user inputs the name of the worker W, the identifier acquisition unit 113 may acquire the identifier of the worker W based on the correspondence table. The identifier acquisition unit 113 functions as an identifier acquisition means.

[0055] Image extraction unit 114 extracts an image of the display target from the images (recorded data) acquired by image acquisition unit 111, based on the location information and time information acquired by location information acquisition unit 112 and the identifier acquired by identifier acquisition unit 113. Details of this process will be described later. Image extraction unit 114 functions as an image extraction means.

[0056] The image playback unit 115 plays back the images extracted by the image extraction unit 114 by displaying them on the display unit 131. The image playback unit 115 functions as an image playback means.

[0057] Here, a supplementary explanation will be given of the images acquired by the image acquisition unit 111 and the images extracted by the image extraction unit 114. Because the omnidirectional camera 200 is a fisheye camera, the captured images are recorded as distorted images in which what are actually straight lines (in FIG. 9, the boundaries between the floor and the wall, and the boundaries between walls) appear elliptical, as shown in FIG. 9, for example. The image acquisition unit 111 then acquires such distorted images. Since it is desirable for the image playback device 100 to display undistorted images like those captured by a normal camera, the image extraction unit 114 divides the omnidirectional image into eight regions, from region R1 to region R8, at 45 degrees each, as shown in FIG. 10, for example, and extracts each divided region as a normal (undistorted) image.

[0058] Then, by acquiring the position information of the worker W, the image extracting unit 114 can extract the image of the part in which the worker W is captured (the image of area R3 in FIG. 10) as a normal (undistorted) image. Note that simply dividing the omnidirectional image as shown in FIG. 10 makes it difficult to see the image directly below the omnidirectional camera. Therefore, in cases such as when the worker W is directly below the omnidirectional camera, the image extracting unit 114 may extract the part directly below the omnidirectional camera (area R9) as a normal (undistorted) image as shown in FIG. 11.

[0059] Furthermore, if the area is fixed as shown in FIG. 10, a situation may occur in which worker W straddles multiple areas. Therefore, the angle θ of the direction of worker W as seen from omnidirectional camera 200 may be calculated based on information on the installation position of omnidirectional camera 200 and position information of worker W, and worker W may be tracked by extracting an image of the area centered on the direction of angle θ.

[0060] Fixing the area has the disadvantage that the display target (worker W) may span multiple areas. However, fixing the area has the advantage that it becomes easier to grasp where worker W is indoors by setting multiple sub-screens on the display unit 131 and displaying images of each area on each sub-screen, as shown in Fig. 12. Therefore, the image extraction unit 114 may be configured to have an "area fixed mode" in which an area is fixed and an image is extracted, as shown in Fig. 12, and a "tracking mode" in which an image is extracted by tracking the display target (worker W).

[0061] Next, the image playback process executed by the control unit 110 of the image playback device 100 will be described with reference to Fig. 13. The image playback process starts when an administrator of the image playback system 1 or the like issues an instruction to start the image playback process.

[0062] First, the control unit 110 performs an initialization process (step S101). In the initialization process, various variables are initialized. In addition to the usual initialization of variables, the initialization process may also set whether to use an image of the worker W taken from directly above, and if so, the conditions for using an image of the worker W taken from directly above (for example, to use the image when the distance on a plane (for example, a floor) between the installation position of the omnidirectional camera and the position of the worker W when projected onto the plane is equal to or less than a directly above image threshold value ri (for example, 1 m)).

[0063] Next, the identifier acquisition unit 113 acquires the identifier of the worker W via the input unit 132 (step S102). Step S102 is also referred to as an identifier acquisition step. The identifier acquisition unit 113 may acquire the identifier in any manner; for example, a correspondence table between the name of the worker W and the identifier may be stored in advance in the storage unit 120. In this way, when the name of the worker W is input via the input unit 132, the identifier acquisition unit 113 can acquire the identifier corresponding to the name of the worker W by referring to the correspondence table.

[0064] Next, control unit 110 acquires the playback start date and time and the playback end date and time via input unit 132 (step S103). For example, control unit 110 may acquire the playback start date and time and the playback end date and time by displaying a calendar on display unit 131 and having the user click on a date on the calendar (for example, by setting the playback start date and time to midnight on the clicked date and the playback end date and time to 12:00 PM on the clicked date). This step S103 may be skipped if images are to be played back for all time periods recorded by recording device 300. If this step is skipped, the playback start date and time will be the date and time when recording started on recording device 300, and the playback end date and time will be the date and time when recording ended on recording device 300.

[0065] Next, the position information acquisition unit 112 transmits a request to the positioning device 600 to transmit a position information log, and acquires the position information log from the positioning device 600 (step S104). Step S104 is also called a position information acquisition step.

[0066] Then, the control unit 110 determines whether or not the location information log acquired in step S104 contains the location information of the identifier acquired in step S102 (step S105). If the location information log does not contain the location information of the identifier (step S105; No), it means that the image of the worker W with that identifier cannot be played back, so the control unit 110 displays a message such as "Playback not possible" on the display unit 131 (step S106) and ends the image playback process.

[0067] If the location information log contains the location information of the identifier (step S105; Yes), the control unit 110 sets the playback start date and time to time t (step S107). Time t is a variable for indicating the playback point of the recorded data stored in the recording device 300.

[0068] Next, the image acquisition unit 111 acquires an image at time t from the recording device 300 (step S108). Step S108 is also called an image acquisition step.

[0069] Then, the image extraction unit 114 acquires the location information of the identifier (worker W) acquired in step S102 at time t from the location information log acquired in step S104, and extracts an image of the area where worker W is present from the image acquired in step S108 (step S109). Step S109 is also called an image extraction step.

[0070] For example, if at time t, worker W is located in a position as shown in FIG. 10, in step S109, the image extraction unit 114 extracts an image of area R3. Note that worker W does not necessarily appear in only one area (e.g., area R3) shown in FIG. 10. Therefore, in the above-mentioned "fixed area mode," the image extraction unit 114 may, for example, select one of the multiple areas in which worker W appears and extract an image of the selected area, or may extract images of two or more (e.g., all) of the multiple areas in which worker W appears.

[0071] Furthermore, in the above-mentioned "following mode," the image extraction unit 114 may convert the position information of the worker W at time t into polar coordinates (distance r from the origin, angle θ centered on the origin) with the installation position of the omnidirectional camera 200 as the origin, and extract an image of an area centered on θ. In this case, the image extraction unit 114 may enlarge the extracted image based on r (the larger r is), thereby enabling the image extraction unit 114 to always extract an image of an area where the worker W is located near the center.

[0072] Furthermore, in step S101, if a condition is set such that an image of worker W taken from directly above is used when the distance between the omnidirectional camera and worker W is equal to or less than the directly above image threshold value ri, the image extraction unit 114 may extract an image of area R9 shown in FIG. 11 if the distance between the omnidirectional camera 200 and worker W is equal to or less than the directly above image threshold value ri.

[0073] Then, the image playback unit 115 plays back the images extracted by the image extraction unit 114 in step S109 (step S110). Step S110 is also called an image playback step.

[0074] Then, the image playback unit 115 updates the time t indicating the playback point to t+1 (step S111). Note that the extent to which the actual time is advanced by updating the time t to t+1 is arbitrary, but here, by updating the time t to t+1, the time is advanced by the above-mentioned reference time unit (the sampling time of the position information). Then, the processes from step S108 to step S110 are performed collectively in this reference time unit.

[0075] Next, the control unit 110 determines whether the time t is before the playback end date and time (step S112). If the time t is before the playback end date and time (step S112; Yes), the control unit 110 returns to step S108. If the time t is after the playback end date and time (step S112; No), the control unit 110 ends the image playback process.

[0076] Through the above image playback process, the image playback device 100 can automatically extract the image to be displayed (the image showing worker W) from the recorded images, and the user can easily check the image showing worker W specified in step S102.

[0077] In the image playback process (FIG. 13), the order of image acquisition (step S108) and image extraction (step S109) can be reversed (image acquisition can be performed after determining the image extraction method). When reversing the order of the processes, the image extraction unit 114 first determines the extraction method for the omnidirectional image (which portion to extract) by acquiring the location information of the identifier (worker W) acquired in step S102 at time t from the location information log acquired in step S104. Next, the image acquisition unit 111 acquires from the recording device 300 an image extracted (extracted) using the extraction method determined by the image extraction unit 114 for the image at time t. This also makes it possible to extract and acquire an image of the area where worker W is present.

[0078] (Embodiment 2) In the first embodiment, one omnidirectional camera 200 is provided, but in order to record a wider range, a plurality of omnidirectional cameras 200 may be provided. An image playback system 2 according to the second embodiment, which is provided with a plurality of omnidirectional cameras 200, will be described.

[0079] The configuration of the image playback system 2 according to the second embodiment is the same as that of the image playback system 1 according to the first embodiment, except that it has multiple omnidirectional cameras 200, as shown in FIG. 14, and therefore a description of each component will be omitted.

[0080] Since the image playback system 2 includes a plurality of omnidirectional cameras 200, the problem in the image playback process is which of the plurality of omnidirectional cameras 200 has captured an image to display. In the second embodiment, the image extraction unit 114 selects, from the plurality of omnidirectional cameras 200, the omnidirectional camera 200 that is located closest to the worker W that the user wants to display as the omnidirectional camera 200 suitable for capturing images of the worker W, and extracts the image of the worker W captured by the selected omnidirectional camera.

[0081] However, if the worker W is photographed from the omnidirectional camera 200 that is closest to the worker W, the worker W will be photographed from above, which may make it difficult to confirm the work content of the worker W. Therefore, the image replay system 2 according to the second embodiment has two modes: a mode that uses the omnidirectional camera 200 that photographs the worker W from above (directly above camera enabled), and a mode that uses the omnidirectional camera 200 that is closest to the worker W among the omnidirectional cameras 200 other than the omnidirectional camera 200 that would photograph the worker W from above (directly above camera disabled).

[0082] The image reproduction process executed by the control unit 110 of the image reproduction device 100 according to the second embodiment is the same as the image reproduction process according to the first embodiment described with reference to Fig. 13, except for the process of step S109. Here, the detailed process of step S109 of the image reproduction process according to the second embodiment will be referred to as image extraction process, and this image extraction process will be described with reference to Fig. 15. However, in step S108, it is assumed that the image acquisition unit 111 has acquired all of the images captured by all of the omnidirectional cameras 200 at time t.

[0083] It is assumed that the image playback device 100 according to the second embodiment has information on the installation position of each omnidirectional camera 200 stored in advance in the storage unit 120. It is also assumed that in the image playback process according to the second embodiment, the distance at which the omnidirectional camera 200 is deemed to be directly above the worker W (directly above camera threshold ra (e.g., 1 m)) and whether or not to use the omnidirectional camera 200 directly above the worker W (enabled / disabled directly above camera) are set in step S101. The directly above camera threshold ra and enabled / disabled directly above camera may be set by having the user input them through the input unit 132, similar to the acquisition of the identifier in step S102.

[0084] First, the image extraction unit 114 determines whether or not the directly above camera is valid (the directly above omnidirectional camera 200 is used) (step S201). This is set in step S101 as described above.

[0085] If the directly above camera is not valid (the directly above omnidirectional camera 200 is not used) (step S201; No), the image extraction unit 114 determines the omnidirectional camera 200 closest to the worker W among the omnidirectional cameras 200 whose distance from the worker W is greater than the directly above camera threshold ra as the omnidirectional camera 200t at time t, based on the position information of the worker W at time t obtained from the position information log and the information on the installation position of each omnidirectional camera 200 (step S202).

[0086] On the other hand, if the overhead camera is valid (step S201; Yes), the image extraction unit 114 determines the omnidirectional camera 200 that is closest to the worker W among the omnidirectional cameras 200 as the omnidirectional camera 200t at time t, based on the position information of the worker W at time t obtained from the position information log and the information on the installation position of each omnidirectional camera 200 (step S203).

[0087] Next, the image extraction unit 114 converts the position information of the worker W at time t into polar coordinates (distance r from the origin, angle θ centered on the origin) with the installation position of the omnidirectional camera 200t at time t as the origin (step S204).

[0088] Then, the image extracting unit 114 extracts an image of the area showing the worker W from the image taken by the omnidirectional camera 200t at time t based on the polar coordinates acquired in step S204 (step S205). For example, the image extracting unit 114 uses the value of the angle θ of the polar coordinates acquired in step S204 to extract an image of the area centered at θ from the image taken by the omnidirectional camera 200t at time t. The image extracting unit 114 may also use the value of the distance r of the polar coordinates acquired in step S204 to extract an image by changing the magnification rate according to the value of r.

[0089] After extracting the image of the area showing worker W in step S205, the image extraction unit 114 ends the image extraction process and continues the image playback process (FIG. 13) from step S110.

[0090] Through the above image extraction process, the image playback device 100 according to the second embodiment can select, from among the multiple installed omnidirectional cameras 200, the omnidirectional camera 200 that is considered to be at the most appropriate distance from the worker W as the omnidirectional camera 200 suitable for photographing the worker W, and can automatically extract the image to be displayed (the image showing the worker W) from the images photographed by the selected omnidirectional camera 200.

[0091] (Embodiment 3) In the second embodiment, the omnidirectional camera 200 is selected based on the distance between the worker W and the omnidirectional camera 200 without considering which direction the worker W is facing, but it is conceivable that the user may want to check an image captured from the front of the worker W. Therefore, an image playback system 3 according to a third embodiment will be described, in which an omnidirectional camera 200 that captures the worker W from the front as much as possible is selected as the omnidirectional camera 200 suitable for capturing an image of the worker W, and the image captured by the selected omnidirectional camera 200 is used.

[0092] As shown in FIG. 14, the configuration of the image reproducing system 3 according to the third embodiment is the same as the configuration of the image reproducing system 2 according to the second embodiment, and therefore a description of each component will be omitted.

[0093] In the third embodiment, the image extraction unit 114 selects, from among the multiple omnidirectional cameras 200, the omnidirectional camera 200 located in front of the worker W that the user desires to display, and extracts an image of the worker W captured by the selected omnidirectional camera. If there are multiple omnidirectional cameras 200 located in front of the worker W, the image extraction unit 114 calculates a priority, which will be described later, for each omnidirectional camera 200, and selects the omnidirectional camera 200 with the highest priority.

[0094] Here, a method for determining the front of worker W at time t will be described with reference to FIG. 16. Here, it is assumed that worker W is walking or moving forward. As shown in FIG. 16, worker W is at position P1 at time t-1 and has moved to P2 at time t. Here, each position is a position on a plane viewed from directly above worker W. The actual time difference between time t-1 and time t is in the above-mentioned reference time unit (e.g., 1 second). The position P2 of worker W at time t is set as the origin, and the angle θ when position P1 of worker W at time t-1 is expressed in polar coordinates is set as θ1. In this case, the range FR that is considered to be the front of worker W is defined as a range that is angle α (e.g., 30 degrees) on both the left and right in the opposite direction of θ1 (i.e., the direction of θ1 + π) from the origin.

[0095] The image playback process executed by the control unit 110 of the image playback device 100 according to the third embodiment is the same as the image playback process according to the second embodiment, except for the process of step S109 (image extraction process). Therefore, the detailed process (image extraction process) of step S109 of the image playback process according to the third embodiment will be described with reference to Fig. 17 and Fig. 18. However, in step S108, it is assumed that the image acquisition unit 111 has acquired all of the images captured by all of the omnidirectional cameras 200 at time t.

[0096] It is assumed that the image playback device 100 according to the third embodiment has information on the installation positions of the omnidirectional cameras 200 stored in advance in the storage unit 120, similar to the image playback device 100 according to the second embodiment. Also, in the image playback process according to the third embodiment, similar to the image playback process according to the second embodiment, it is assumed that the distance at which the omnidirectional camera 200 is deemed to be directly above the worker W (directly above camera threshold ra) is set and whether or not to use the omnidirectional camera 200 directly above the worker W (directly above camera enable / disable) is set in step S101. Also, in step S101, a threshold (movement threshold rv) for determining whether or not the worker W is moving is set.

[0097] First, the image extraction unit 114 determines whether or not position information at time t-1 exists in the position information log (step S301). If position information at time t-1 does not exist (step S301; No), the process proceeds to step S201. If position information at time t-1 does not exist, the range regarded as the front cannot be calculated, and therefore, the omnidirectional camera 200 is selected based on the distance to the worker W, as in the second embodiment. The processing from step S201 onwards is the same as the image extraction processing in the second embodiment, and therefore a description thereof will be omitted.

[0098] If position information for time t-1 exists (step S301; Yes), the image extraction unit 114 determines whether the distance between the position of worker W at time t-1 and the position at time t is equal to or greater than the movement threshold rv (e.g., 1 m) (step S302). If the distance between the position of worker W at time t-1 and the position at time t is less than the movement threshold rv (step S302; No), the image extraction unit 114 determines whether the omnidirectional camera 200 at time t-1 exists (step S303). The omnidirectional camera 200 at time t-1 is the omnidirectional camera 200 that was previously used as the omnidirectional camera 200t at time t.

[0099] If the omnidirectional camera 200 at time t-1 exists (step S303; Yes), the image extraction unit 114 sets the omnidirectional camera 200 at time t-1 as the omnidirectional camera 200t at time t (step S304), and proceeds to step S204. On the other hand, if the omnidirectional camera 200 at time t-1 does not exist (step S303; No), proceeds to step S201.

[0100] If the worker W is working without moving much, the determination in step S302 will be No. In such a case, the processing of steps S303 and S304 is performed to use the omnidirectional camera 200t at a past point in time that was set based on the direction in which the worker W most recently moved.

[0101] On the other hand, in step S302, if the distance between the position of worker W at time t-1 and the position at time t is equal to or greater than the movement threshold rv (step S302; Yes), the image extraction unit 114 calculates the range FR regarded as the front from the position P1 of worker W at time t-1 and the position P2 at time t, as described with reference to Figure 16 (step S305).

[0102] The image extraction unit 114 then creates a list (candidate camera list) of all omnidirectional cameras 200 included in the range FR considered to be the front (step S306). Next, the image extraction unit 114 determines whether or not the directly above camera is valid (the directly above omnidirectional camera 200 is used) (step S307). If the directly above camera is not valid (step S307; No), the image extraction unit 114 deletes from the candidate camera list created in step S306 the omnidirectional cameras 200 whose distance to the worker W is less than or equal to ra (step S308). On the other hand, if the directly above camera is valid (step S307; Yes), the process proceeds to step S309.

[0103] The image extraction unit 114 then determines whether the candidate camera list is empty (no omnidirectional cameras 200 are included in the candidate camera list) (step S309). If the candidate camera list is empty (step S309; ​​Yes), the process proceeds to step S201. If the candidate camera list is not empty (step S309; ​​No), the image extraction unit 114 selects the omnidirectional camera 200 with the highest priority, which will be described later, among the omnidirectional cameras 200 included in the candidate camera list as the omnidirectional camera 200t at time t (step S310), and the process proceeds to step S204.

[0104] Here, the priority of the omnidirectional cameras 200 included in the candidate camera list will be described with reference to Fig. 19. The basic idea is to set the priority so that the omnidirectional camera 200 that is located as directly in front of the worker W as possible and as close to the worker W as possible has a higher priority.

[0105] As shown in FIG. 19, the position of the omnidirectional camera 200 is expressed in polar coordinates with the position of the worker W as the origin, and the distance r c , angle θ c In this case, the priority PR of this omnidirectional camera 200 is expressed by the following equation (1): Note that a larger value of this PR indicates that the priority of the omnidirectional camera 200 is higher. PR=cos(θ c -(θ1+π)) / r c …(1)

[0106] Note that formula (1) is merely one example of a formula for calculating the priority, and any formula may be used as long as the priority is calculated based on the basic concept described above.

[0107] Through the image extraction process described above, the image playback device 100 according to embodiment 3 can select, from among the multiple installed omnidirectional cameras 200, an omnidirectional camera 200 that can capture images of the worker W from the front as much as possible as the omnidirectional camera 200 that is most suitable for capturing images of the worker W, and can automatically extract images to be displayed (images showing the worker W) from among the images captured by the selected omnidirectional camera 200.

[0108] (Fourth embodiment) In the above-described embodiment, the positioning device 600 always records the position of each worker W in a position information log. However, there may be cases where it is desired to focus on checking the status of a worker W who is in a position different from the usual work area. Therefore, an image replay system 4 according to a fourth embodiment will be described, in which a position information log is recorded only when a worker W is in a position different from the usual location (e.g., in an area other than work).

[0109] The configuration of the image playback system 4 according to the fourth embodiment is basically the same as that of the above-described embodiments (the first embodiment shown in FIG. 1 and the second and third embodiments shown in FIG. 14), but the processing content of the positioning device 600 is slightly different, so this point will be explained.

[0110] The positioning device 600 according to the fourth embodiment stores information on the usual work area of ​​each worker W as usual position information in advance in a storage unit. This usual position information is the usual location of each worker W for each predetermined time period. Here, the usual location of each worker W may be defined in detail in one-hour increments as the predetermined time period, or the usual location of each worker W may be defined for each relatively long time period, such as one day or one week.

[0111] The positioning device 600 can determine whether or not each worker W is in a normal work area by referring to this normal position information. After calculating the position of the beacon transmitter 400 carried by the worker W, the positioning device 600 determines whether or not the worker W is in a normal work area by referring to the normal position information, and only if the worker W is not in the normal work area, the position information is stored in the storage unit as a position information log together with the identification information (transmitter ID) of the beacon transmitter 400 and time information.

[0112] Except for the above points, the image replay system 4 according to the fourth embodiment is the same as the above-mentioned embodiments, and therefore a description thereof will be omitted. Note that, without changing the operation of the positioning device 600, the image replay device 100 may store normal position information in the storage unit 120, and the position information acquisition unit 112 may acquire only the position information log where the position of the worker W is not the normal location (the position information log of the normal location is read and discarded). In this case, the storage unit 120 also functions as normal location storage means for storing the normal location of the worker W.

[0113] The image replay system 4 according to the fourth embodiment can replay an image showing the worker W when the worker W has left the normal work area. When the worker W has left the normal work area, it is highly likely that some kind of problem has occurred. Therefore, the image replay system 4 according to the fourth embodiment allows the user to more efficiently check the work status when a problem has occurred.

[0114] (Variation) In the above-described embodiment, in step S102 of the image reproduction processing, the user can input any identifier of the worker W, but the identifiers of the worker W that can be input here may be limited. For example, similar to the fourth embodiment, the image reproduction device 100 stores the normal work area of ​​each worker W in advance in the storage unit 120 as normal position information. Then, in step S102, a list of workers W who deviate from the normal work area may be displayed on the display unit 131 based on the position information log and the normal position information, and the identifier acquisition unit 113 may acquire the identifier of the worker W when the user selects one from the list.

[0115] Similarly, a restriction may be placed on the playback date and time that can be entered in step S103 of the image playback processing. For example, the image playback device 100 stores the normal work area of ​​each worker W as normal position information in advance in the storage unit 120, as in the fourth embodiment. Then, in steps S102 and S103, a list of workers W who have deviated from the normal work area and the dates and times of the deviation (the date and time the deviation started and the date and time the worker returned to the normal work area) may be displayed on the display unit 131 based on the position information log and the normal position information. When the user selects one of the workers W from the list, the identifier acquisition unit 113 acquires the identifier of the worker W, and the control unit 110 acquires the date and time the deviation started as the playback start date and time and the date and time the worker returned to the normal work area as the playback end date and time.

[0116] (Other variations) The present invention is not limited to the above-described embodiment and modifications, and various other modifications are possible. For example, the omnidirectional camera 200 and the image playback device 100 may be connected via a network NW, and the image playback device 100 may incorporate the functions of the recording device 300. Furthermore, the beacon receiver 500 and the image playback device 100 may be connected via a network NW, and the image playback device 100 may incorporate the functions of the beacon receiver 500.

[0117] Furthermore, in the above-described embodiment, the image extraction unit 114 automatically extracts the image to be displayed (the image showing the worker W), but there may be cases where the user wants to check other images. Therefore, for example, as shown in Fig. 12, the image extracted by the image extraction unit 114 as the image to be displayed may be displayed large in the center of the display unit 131, and images in other directions may also be displayed as sub-screens, so that the image displayed large in the center can be switched in response to an instruction from the user (for example, the user touching or clicking on the sub-screen portion showing the image they want to select).

[0118] In the above-described embodiment and modifications, the display object (worker W) carries a beacon transmitter 400, and the beacon receiver 500 receives information from the beacon transmitter 400 and transmits the received information to the positioning device 600, thereby allowing the positioning device 600 to locate the position of each worker W. However, the method for locating the position of the worker W is not limited to this method. For example, the position of each display object may be located using a GPS (Global Positioning System).

[0119] In the above embodiment, the control programs for executing the various processes (image playback process, image extraction process, etc.) that define the operation of image playback device 100 have been described as being stored in storage unit 120. However, the present invention is not limited to this, and the control programs for executing the various processes described above may be implemented in a computer such as an ordinary PC (Personal Computer), causing the ordinary PC to function as a device equivalent to image playback device 100 according to the above embodiment.

[0120] Such programs may be provided in any manner, and may be distributed by storing them on a computer-readable recording medium (such as a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a DVD (Digital Versatile Disc), an MO (Magneto-Optical Disc), a memory card, or a USB (Universal Serial Bus) memory), or may be stored in storage on a network such as the Internet and provided by downloading it.

[0121] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and the present invention includes the inventions described in the claims and their equivalents. [Explanation of symbols]

[0122] 100...image playback device, 101...CPU, 102...ROM, 103...RAM, 104...HDD, 105...display, 106...input device, 107...communication I / F, 110...control unit, 111...image acquisition unit, 112...location information acquisition unit, 113...identifier acquisition unit, 114...image extraction unit, 115...image playback unit, 120...storage unit, 131...display unit, 132...input unit, 133...communication unit, 200, 200t...omnidirectional camera, 300...recording device, 400...beacon transmitter, 500, 500A, 500B...beacon receiver, 600...positioning device, BL...bus line, FR...range considered to be front, NW...network, P1, P2...position, R1, R2, R3, R4, R5, R6, R7, R8, R9...area, W...worker

Claims

1. an image acquisition means for acquiring images of a display object photographed by one or more omnidirectional cameras together with time information; a location information acquiring means for acquiring location information for each identifier of the display object together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with In an area fixing mode in which the area to be extracted is fixed, when the display object is shown in a plurality of areas in the image acquired by the image acquisition means, the image extraction means extracts images of all areas in which the display object is shown. Image reproduction device.

2. An image playback system including one or more omnidirectional cameras, a positioning device that measures the position of a display object, and an image playback device, The image reproduction device an image acquisition means for acquiring an image of the display object photographed by the omnidirectional camera together with time information; a position information acquisition means for acquiring position information for each identifier of the display object whose position has been measured by the positioning device together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with In an area fixing mode in which the area to be extracted is fixed, when the display object is shown in a plurality of areas in the image acquired by the image acquisition means, the image extraction means extracts images of all areas in which the display object is shown. Image playback system.

3. an image acquisition step of acquiring images of a display target photographed by one or more omnidirectional cameras together with time information; a location information acquisition step of acquiring location information for each identifier of the display object together with the time information; an identifier acquisition step of acquiring an identifier of the display object; an image extraction step of extracting an image of an area in which the display target exists from the image acquired in the image acquisition step, based on the location information and time information acquired in the location information acquisition step and the identifier acquired in the identifier acquisition step; an image reproduction step of reproducing the image extracted in the image extraction step; Equipped with In the image extraction step, in an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired in the image acquisition step, images of all areas in which the display object is shown are extracted. Image playback method.

4. On the computer, an image acquisition step of acquiring images of the display object photographed by one or more omnidirectional cameras together with time information; a location information acquisition step of acquiring location information for each identifier of the display object together with the time information; an identifier acquisition step of acquiring an identifier of the display object; an image extraction step of extracting an image of an area in which the display target exists from the image acquired in the image acquisition step, based on the location information and time information acquired in the location information acquisition step and the identifier acquired in the identifier acquisition step; and an image reproduction step of reproducing the image extracted in the image extraction step; A program for executing In the image extraction step, in an area fixing mode in which the area to be extracted is fixed, if the display object is shown in a plurality of areas in the image acquired in the image acquisition step, images of all areas in which the display object is shown are extracted. program.

5. An image acquisition means for acquiring images of a display object taken by one or more omnidirectional cameras together with time information; a location information acquiring means for acquiring location information for each identifier of the display object together with the time information; an identifier acquisition means for acquiring an identifier of the display object; an image extraction means for extracting an image of an area in which the display object exists from the image acquired by the image acquisition means, based on the location information and time information acquired by the location information acquisition means and the identifier acquired by the identifier acquisition means; an image reproducing means for reproducing the image extracted by the image extracting means; Equipped with The image extraction means The position information of the display object is converted into polar coordinates (distance r, angle θ) with the installation position of the omnidirectional camera that captured the display object as the origin, and an image of the area centered in the direction of the angle θ is extracted. When the distance r is equal to or smaller than a threshold for a directly above image, an image in which the display object is photographed from directly above is extracted from the images acquired by the image acquisition means. Image reproduction device.

Images