Imaging support device, imaging support method, program and imaging system

Abstract

Provided are an imaging support device, an imaging support method, a program, and an imaging system, by which preferable imaging support in imaging using an imaging device mounted on a mobile body is realized. The imaging support device: acquires a two-dimensional shape of a feature obtained by projecting the feature onto a prescribed plane, the two-dimensional shape of the feature being represented using geographic coordinates or projected coordinates; sets an expansion starting point with respect to a first outer edge line of the two-dimensional shape of the feature; sets an expansion distance based on an observation angle and an imaging distance of an imaging device; and sets, as a movement route, a second outer edge line of an expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature on the basis of a plurality of expansion points set at positions having the expansion distance from the expansion starting point.

Description

Imaging Support Device, Imaging Support Method, Program, and Imaging System 【0001】 The present disclosure relates to an imaging support device, an imaging support method, a program, and an imaging system. 【0002】 Imaging images of ground features obtained by using a moving object such as a drone to image ground features such as buildings are used for external appearance inspections of buildings, such as inspecting the roofs and outer walls of buildings, and for surveys to determine the degree of damage to houses during disasters. 【0003】 For example, in imaging ground features, the ground imaging range, the degree of overlap between imaging ranges, the imaging resolution, etc. are set, a moving path of the moving object is determined based on the setting of the imaging resolution, etc., and the moving object is automatically driven based on the determined moving path. 【0004】 Non-Patent Document 1 describes a method for automatically calculating an optimal mission plan for simply imaging a building with a complex shape and scanning the building. Specifically, a rough model is generated using an orthophoto of an object captured during simple overhead flight, positions of cameras sufficient to cover the surface of the imaged object with sufficient overlap are set, and a path passing through all the generated viewpoints is calculated. 【0005】 Patent Document 1 describes an information processing device that generates imaging control information for imaging a subject by a moving object. The device described in the same document acquires the outer shape information of the subject, generates a moving path for imaging the side surface of the subject based on the imaging distance corresponding to the outer shape information, sets the imaging positions on the moving path, and sets the imaging method at the imaging positions based on the normal direction of the side surface of the subject. 【0006】Patent Document 2 describes a map data generation device that performs processing effective when generating small-scale map data by thinning out large-scale map data. The device described in the document applies processing to polygon data representing topography such as land, rivers, and lakes, moving the outer edges in the direction of increasing area and moving the outer edges in the direction of decreasing area. Furthermore, if the moved outer edges do not intersect, the device applies processing to connect the non-intersecting outer edges using an arc with a radius equal to the expansion distance r, centered at the point of refraction. 【0007】 Japanese Patent Publication No. 2020-36163 Japanese Patent Publication No. 2016-103180 【0008】 Kuu-satsu.com Co., Ltd., March 20, 2020, "Mission Plan Generation Function," Internet <URL: https: / / kuu-satsu.com / metashape-mission-plan / > 【0009】 However, the method described in Non-Patent Document 1 requires prior photography to generate a simple model. Furthermore, the flight paths generated by applying the method described in the same document are complex, making practical application difficult. 【0010】 The apparatus described in Patent Document 1 requires a balanced setting of shooting distance and shooting direction in order to capture the entire perimeter of a subject without omission. For example, when photographing a subject with the shape shown in Figure 7 of the same document, it is difficult to set the shooting direction and other parameters when photographing the corners of the subject and parts that extend into the outer shape of the subject. 【0011】 Patent Document 2 discloses the generation of map data based on polygon data representing terrain, but it does not describe or suggest matters concerning the generation of the movement path of a moving object when photographing geographical features using a moving object. 【0012】 The present invention has been made in view of these circumstances, and aims to provide a photography support device, a photography support method, a program, and a photography system that enable desirable photography support when photographing geographical features using a photography device mounted on a mobile body. 【0013】A first aspect of the present disclosure is a photographic support device that assists in photographing the area around a feature, which is mounted on a mobile body that moves around the feature and uses a photographic device whose photographic direction is fixed with respect to the movement path of the mobile body, and comprises a processor and a memory that stores instructions to be executed by the processor, wherein the processor executes instructions to obtain a two-dimensional shape of the feature, which is a two-dimensional shape of the feature enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined plane, and is represented using geographic coordinates or projected coordinates, sets an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature, sets an expansion distance based on the observation angle of the photographic device with respect to a photographic target point on the feature and the photographic distance between the photographic target point and the photographic device, expands the two-dimensional shape of the feature in a two-dimensional way based on a plurality of expansion points set at positions having an expansion distance from the expansion starting point, and sets a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as a movement path. 【0014】 According to the first embodiment of the photographic support device, an expanded two-dimensional shape is generated by expanding the two-dimensional shape of a feature, which is represented using geographic coordinates or projected coordinates, into a two-dimensional shape, and the second outer edge line of the expanded two-dimensional shape is set as the movement path of the mobile body. This enables desirable photographic support when photographing a feature using a photographic device mounted on a mobile body, where the movement path of the mobile body follows the outer edge of the feature. 【0015】 The plane on which the feature is projected may be a plane parallel to the horizontal plane. The two-dimensional shape of the feature may be a two-dimensional shape formed by combining multiple polygons. The two-dimensional shape of the feature may include at least one of a vertex angle, a line segment, and a circular arc. 【0016】 In the second embodiment of the imaging support device, the processor may apply alpha-shape processing to a plurality of expansion points to derive a second outer edge line, as is the case with the imaging support device of the first embodiment. 【0017】 In the third embodiment of the shooting support device, the processor may set the altitude of the movement path based on the observation angle and shooting distance, in the shooting support device of the first or second embodiment. 【0018】In the fourth embodiment of the shooting support device, the processor may derive the altitude using the observation angle and the shooting distance, as in the shooting support device of the third embodiment. 【0019】 In the fifth embodiment, the imaging support device, in the imaging support device of the third or fourth embodiment, may set a first altitude and a second altitude as altitudes such that the first imaging area in imaging to which the first altitude is applied and the second imaging area in imaging to which a second altitude different from the first altitude is applied overlap. 【0020】 In the sixth embodiment, the imaging support device is an imaging support device according to any one of the third to fifth embodiments, in which the processor may set movement paths to which different altitudes are applied based on different observation angles. 【0021】 In the seventh embodiment, the imaging support device is an imaging support device according to any one of the first to sixth embodiments, in which the processor may set a movement path corresponding to the entire circumference of a feature. 【0022】 In the eighth aspect of the imaging support device, in any one aspect of the first to seventh aspects, the processor may set the shooting distance based on the shooting resolution of the imaging device. 【0023】 The ninth aspect of the photographic support device is a photographic support device according to any one aspect of the first to eighth aspects, in which the processor may acquire the two-dimensional shape of the feature as the two-dimensional shape of the feature enclosed by contour lines defined on the feature, and set the second outer edge line of the expanded two-dimensional shape obtained by expanding the two-dimensional shape enclosed by contour lines as the movement path. 【0024】 In the photographic support device according to the tenth embodiment, the processor may acquire a two-dimensional shape of the feature, which is enclosed by a plurality of contour lines defined for each of a plurality of mutually different elevations, and set a plurality of second outer edges of each of the plurality of expanded two-dimensional shapes, which are obtained by expanding each of the two-dimensional shapes enclosed by the plurality of contour lines, as movement paths for each elevation. 【0025】A photographic support method according to an eleventh aspect of the present disclosure is a photographic support method that supports the photographing of the area around a feature, performed using a photographic device mounted on a mobile body that moves around the feature, the photographic direction being fixed with respect to the movement path of the mobile body, and comprising a processor and a memory that stores instructions to be executed by the processor, wherein the computer, which functions as a photographic support device in which the processor executes instructions, acquires the two-dimensional shape of the feature, which is enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined plane, and is represented using geographic coordinates or projected coordinates, sets an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature, sets an expansion distance based on the observation angle of the photographic device with respect to a target point on the feature and the photographic distance between the target point and the photographic device, expands the two-dimensional shape of the feature in a two-dimensional way based on a plurality of expansion points set at positions having an expansion distance from the expansion starting point, and sets a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as a movement path. 【0026】 According to the 11th aspect of this disclosure, the same effects and advantages as those of the photographic support device according to the first aspect can be obtained. The constituent elements of the photographic support device according to the second to tenth aspects can be applied as constituent elements of the photographic support method according to the other aspects. 【0027】A program according to a twelfth aspect of this disclosure is a program that supports the imaging of the area around a feature, which is carried out using an imaging device mounted on a mobile body that moves around the feature, and whose imaging direction is fixed with respect to the movement path of the mobile body, and the program enables a computer that functions as an imaging support device in which the processor executes instructions, to implement the following functions: a function to acquire the two-dimensional shape of a feature, which is enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined plane, and which is represented using geographic coordinates or projected coordinates; a function to set an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature; a function to set an expansion distance based on the observation angle of the imaging device with respect to the target point of imaging on the feature, and the imaging distance between the target point and the imaging device; a function to expand the two-dimensional shape of the feature in a two-dimensional manner based on a plurality of expansion points set at positions having an expansion distance from the expansion starting point; and a function to set a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as a movement path. 【0028】 According to the program of the twelfth aspect of this disclosure, it is possible to obtain the same effects and advantages as the imaging support device of the first aspect. The constituent elements of the imaging support device of the second to tenth aspects can be applied as constituent elements of the program of the other aspects. 【0029】A thirteenth aspect of the present disclosure is a photography system comprising: a mobile body that moves around a feature; a photography device mounted on the mobile body, the photography direction of which is fixed with respect to the movement path of the mobile body; and a photography support device that photographs the area around the feature using the photography device, wherein the photography support device comprises a processor and a memory that stores instructions to be executed by the processor, and the processor executes instructions to obtain a two-dimensional shape of the feature, which is a two-dimensional shape of the feature enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined plane, and is expressed using geographic coordinates or projected coordinates, sets an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature, sets an observation angle of the photography device with respect to a target point on the feature, and an expansion distance based on the photography distance between the target point and the photography device, expands the two-dimensional shape of the feature in a two-dimensional way based on a plurality of expansion points set at positions having an expansion distance from the expansion starting point, and sets a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as a movement path. 【0030】 According to the thirteenth aspect of this disclosure, the same effects and advantages as those of the imaging support device according to the first aspect can be obtained. The constituent elements of the imaging support device according to the second to tenth aspects can be applied as constituent elements of the imaging system according to the other aspects. 【0031】 According to this disclosure, an expanded two-dimensional shape is generated by expanding the two-dimensional shape of a feature, which is represented using geographic coordinates or projected coordinates, into a two-dimensional form, and the second outer edge line of the expanded two-dimensional shape is set as the movement path of the mobile body. This enables desirable photographic support when photographing a feature using a photographic device mounted on a mobile body, where the movement path of the mobile body follows the outer edge of the feature. 【0032】Figure 1 is a schematic diagram of building photography to which the photography system according to the first embodiment is applied. Figure 2 is a flowchart of the procedure of the photography method according to the first embodiment. Figure 3 is a functional block diagram showing the electrical configuration of a drone equipped with a camera. Figure 4 is a functional block diagram showing the electrical configuration of a photography support device according to the first embodiment. Figure 5 is a block diagram showing the hardware configuration of the electrical configuration of the photography support device according to the first embodiment. Figure 6 is a schematic diagram of acquiring building polygons. Figure 7 is a schematic diagram of the inflation process applied to building polygons. Figure 8 is a schematic diagram of the inflation process applied to building polygons. Figure 9 is a schematic diagram of the inflation process applied to building polygons. Figure 10 is a schematic diagram of flight path calculation. Figure 11 is a schematic diagram of flight path calculation with different alpha values. Figure 12 is a schematic diagram of flight path calculation according to another embodiment. Figure 13 is a schematic diagram of camera attitude setting. Figure 14 is a schematic diagram of flight altitude calculation. Figure 15 is a schematic diagram of flight altitude calculation according to another embodiment. Figure 16 is a schematic diagram of observation angle setting. Figure 17 is a schematic diagram showing the procedure for processing images of buildings. Figure 18 is a schematic diagram of mountain photography to which the photography system according to the second embodiment is applied. Figure 19 is a flowchart showing the procedure for calculating the flight path in mountain photography. Figure 20 is a functional block diagram showing the electrical configuration of the photography support device according to the second embodiment. Figure 21 is a schematic diagram of contour line expansion processing and flight path calculation. 【0033】 Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description and accompanying drawings, the same components are denoted by the same reference numerals, and redundant descriptions are omitted. Furthermore, when multiple components are listed illustratively in the following embodiments, it can be interpreted that at least one of the multiple components is included. 【0034】 [Example of shooting system configuration] Figure 1 is a schematic diagram of building photography to which the shooting system according to the first embodiment is applied. The figure schematically illustrates a state in which an operator OP operates a shooting support device 10 to which a tablet terminal device is applied, and a building BU is photographed using a camera 14 mounted on a drone 12. 【0035】The building BU has target shooting points SP set for each height. Figure 1 shows two target shooting points SP corresponding to two different heights, illustrating the target shooting points SP set around the entire perimeter of the building BU. The dashed line shown in Figure 1 schematically represents multiple target shooting points SP at the same height set around the entire perimeter of the building BU. Note that the entire perimeter of the building BU is an example of the perimeter of the feature in this disclosure. 【0036】 The two drones 12 shown in Figure 1 represent the same drone 12 moving between different flight altitudes. The same applies to the two drones 12 shown in Figures 14, 15, and 16. 【0037】 For photographing the upper target point SP1 in Figure 1, the flight altitude of the upper drone 12 in the same figure is applied, and for photographing the lower target point SP2 in the same figure, the position of the lower drone 12 in the same figure is applied. 【0038】 Here, the height applied to the building BU represents the distance from the reference plane defined for the building BU in the vertically upward direction. The vertically upward direction is the direction opposite to the vertically downward direction, which is the direction of gravity. The reference plane defined for the building BU may be a plane parallel to the horizontal plane of the elevation applied to the building BU. 【0039】 The term "parallel" as used herein is not limited to strictly parallel lines, but may include substantially parallel lines that are not strictly parallel but can be considered parallel. 【0040】 Figure 1 shows the expansion distance r, shooting distance D, and observation angle θ. Details of the expansion distance r, shooting distance D, and observation angle θ will be described later. The drone 12 is an example of a mobile body in this disclosure. The camera 14 is an example of a shooting device in this disclosure. 【0041】 [Procedure for the shooting method] Figure 2 is a flowchart showing the procedure for the shooting method according to the first embodiment. The shooting method illustrated in the figure is performed by one or more computers, which function as the shooting support device 10 etc. shown in Figure 1, executing a prescribed program. The shooting method includes an example of each step in the shooting support method of this disclosure. 【0042】 In step S10, the imaging support device 10 acquires a building polygon for each building BU, which represents a two-dimensional shape surrounded by the outer edge line of the building BU projected onto a specified plane. Examples of the specified plane include a horizontal plane or a plane parallel to the horizontal plane, such as the reference plane of the height of the building BU. For example, in step S10, a building polygon corresponding to the building BU of the imaging target selected in the base map information displayed on the display device of the imaging support device 10 is acquired. The building polygon may include vertices, line segments, and curves. For example, the building polygon may be a polygon composed of a plurality of vertices and two line segments sandwiching each of the plurality of vertices, and may be a shape including a curve such as an arc instead of the vertices and line segments. The building polygon may be a circle, an ellipse, or the like. 【0043】 In step S12, the imaging support device 10 acquires the observation angle θ of the camera 14 shown in FIG. 1. The observation angle θ of the camera 14 is grasped as the angle of the imaging optical axis of the camera 14 with respect to the vertical direction. As the observation angle θ of the camera 14, a set value of the tilt angle of the camera 14 may be acquired. Hereinafter, the term "acquisition" may include the concept of generating information by data processing such as calculation. 【0044】 In step S14, the imaging support device 10 acquires the imaging distance D, which is the distance between the building BU and the camera 14. The imaging distance D may be defined from the viewpoint of safety. For example, a separation distance, which is a certain distance to be placed between a plurality of imaging targets, may be applied. When imaging is performed at a plurality of heights, different imaging distances may be set for each height. 【0045】 In step S16, the imaging support device 10 calculates the flight path of the drone 12. The calculation of the flight path may include a dilation process for the building polygon acquired in step S10, a process of the alpha shape method for the dilated polygon obtained by dilating the building polygon, and the like. Note that the building polygon is an example of the two-dimensional shape of the ground object in the present disclosure, and the dilated polygon is an example of the dilated two-dimensional shape in the present disclosure. 【0046】The inflated polygon may be generated by two-dimensionally inflating the building polygon so as to increase the area of the building polygon. The process of two-dimensionally inflating the building polygon may be performed on a plane including the flight path of the drone 12 for each height of the building BU. The plane including the flight path may be parallel to the horizontal plane. 【0047】 In addition to the process performed numerically, as a process of inflating the building polygon, the building polygon is expressed as a binary image, a process of replacing the pixel value at the inflation distance r from the inflation starting pixel with the same value as the pixel value of the inflation starting pixel, and a process of filling all pixels within the range of the inflation distance r from the inflation starting pixel with the pixel value of the inflation starting pixel may be applied. Based on the inflated polygon in which the building polygon has been inflated two-dimensionally by performing the above process, the movement path of the drone 12 may be calculated. 【0048】 In calculating the flight path of the drone 12, a plurality of waypoints at which the drone 12 performs shooting of the building BU are defined. Adjacent waypoints are defined such that the shooting angles of the camera 14 at each have a specified overlap rate. Note that the waypoint is an example of the shooting position of the present disclosure. 【0049】 In step S18, the shooting support device 10 sets the shooting posture of the camera 14. In step S18, the observation angle θ acquired in step S12 is applied, and the shooting posture of the camera 14 is set. 【0050】 As the shooting posture of the camera 14, a posture in which the shooting optical axis of the camera 14 faces a direction orthogonal to the traveling direction of the drone 12 and the shooting optical axis of the camera 14 faces obliquely downward is applied. That is, the above posture is applied to the camera 14, and the shooting direction is fixed. Note that the camera 14 with the shooting posture set is an example of the shooting device in which the shooting direction of the present disclosure is fixed. 【0051】The term "orthogonal" as used herein is not limited to strictly orthogonal. For example, it may include non-orthogonal intersections that are strictly between 0 and 90 degrees but can be considered substantially orthogonal intersections that intersect at 90 degrees. Also, a diagonal downward direction is a direction that intersects the vertical downward direction at an angle greater than 0 degrees but less than 90 degrees. 【0052】 Methods for fixing the shooting direction of the camera 14 include physically fixing the gimbal head 13 in a direction perpendicular to the direction of travel of the drone 12, setting an azimuth angle as the shooting direction with respect to the gimbal head 13 mounted on the drone 12, and setting the shooting direction by applying POI. POI is an abbreviation for Point of Interest. 【0053】 In step S20, the shooting support device 10 calculates the flight altitude of the drone 12. The flight altitude of the drone 12 is calculated using the height of the building BU, the field of view of the camera 14, and the expansion distance r applied to the expansion process of the building polygon as parameters. If multiple different flight altitudes are used, multiple flight altitudes are calculated such that the field of view of the camera 14 at any given flight altitude overlaps with the field of view of the camera 14 at adjacent flight altitudes. 【0054】 In step S22, the drone 12 is performed to fly automatically around the entire perimeter of the building BU at one or more flight altitudes, and the camera 14 mounted on the drone 12 is used to photograph the entire perimeter of the building BU. That is, in step S22, at each of the multiple waypoints set along the flight path of the drone 12, photography is performed for each of the multiple target points SP defined for the building BU. 【0055】 In step S24, the building BU is photographed and the captured image of the building BU is saved. That is, in step S24, the captured image of the building BU is transmitted from the camera 14 to the storage device where the captured image is stored. The captured image of the building BU may have accompanying information saved, such as waypoint information, shooting target point SP information, shooting conditions such as shooting posture, and shooting date and time. 【0056】In this context, saving captured images is synonymous with storing them. Furthermore, the term "captured image" may also include the meaning of captured image data, which is the digital signal representing the captured image. 【0057】 The shooting support device 10 shown in Figure 1 may display the captured image of the building BU on a display device. The operator OP can visually confirm the captured image of the building BU displayed on the display device provided in the shooting support device 10. 【0058】 [Example of shooting system configuration] Figure 3 is a functional block diagram showing the electrical configuration of a drone equipped with a camera. The drone 12 includes a GNSS receiver 30, a barometric pressure sensor 32, a compass sensor 34, an inertial measurement unit 36, and a motor 38. 【0059】 Note that GNSS is an abbreviation for Global Navigation Satellite System, which represents a satellite positioning system. An inertial measurement unit may be referred to as IMU, which is an abbreviation for Inertial Measurement Unit. 【0060】 The inertial measurement unit 36 ​​includes a gyro sensor 362, an acceleration sensor 364, and a temperature sensor 366. The inertial measurement unit 36 ​​detects translational and rotational motion in the three orthogonal axis directions. 【0061】 Motor 38 is a power source that rotates a rotor, which may be called a rotor blade. The drone 12 is equipped with multiple motors 38 that drive multiple rotor blades. Note that the rotor blades are not shown in the diagram. 【0062】 The GNSS receiver 30 acquires positional information, including the latitude and longitude of the drone 12. The barometric pressure sensor 32 detects the atmospheric pressure at the drone 12. Based on the atmospheric pressure detected using the barometric pressure sensor 32, the drone 12 may acquire its flight altitude. The latitude, longitude, and flight altitude of the drone 12 constitute the positional information of the drone 12 and the camera 14. 【0063】The compass sensor 34 may be, for example, a geomagnetic sensor. The drone 12 can use the compass sensor 34 to detect the azimuth angle towards which the camera lens 14 is pointed. The azimuth angle towards which the camera lens 14 is pointed is determined as the shooting angle of the camera 14 as shown in Figure 1. 【0064】 The gyro sensor 362 detects the roll angle, which represents the rotation angle around the roll axis, the pitch angle, which represents the rotation angle around the pitch axis, and the yaw angle, which represents the rotation angle around the yaw axis. The drone 12 acquires attitude information based on the rotation angles acquired using the gyro sensor 362. Some or all of the sensors, such as the GNSS receiver 30, the barometric pressure sensor 32, the compass sensor 34, and the inertial measurement unit 36, may be located on the side of the camera 14. 【0065】 The camera 14 is mounted on the drone 12 via a gimbal head 13. The camera 14 comprises an optical system, an image sensor, and a signal processing circuit. The optical system includes one or more lenses, such as a focusing lens. The image sensor may be a CCD image sensor or a CMOS image sensor. 【0066】 Note that the optical system, image sensor, and signal processing circuit diagrams are omitted. CCD is an abbreviation for Charge Coupled Device. CMOS is an abbreviation for Complementary Metal-Oxide Semiconductor. 【0067】 Camera 14 processes the signal obtained from the image sensor using a signal processing circuit and generates digital image data of the captured object. The digital image data generated by camera 14 can become the captured image. The captured image taken using camera 14 is stored in a storage device. The storage device may be internal storage built into the drone 12, or it may be a memory card that is detachably attached to the drone 12. 【0068】Furthermore, the images captured using the camera 14 may be transferred to a remote controller that controls the operation of the drone 12 and the camera 14. Wireless communication may be used for transferring the captured images. Note that the remote controller is not shown in the illustration. The functions of the remote controller may be mounted on the shooting support device 10 shown in Figure 1. The remote controller may be a separate device from the shooting support device 10. 【0069】 The form of wireless communication applied to the remote controller may be a wireless LAN, for example, a communication format using radio waves in the 2.4 GHz band or the 5.7 GHz band, or a format utilizing a mobile communication network. 【0070】 The communication format for the control signals used to operate the drone 12 and the communication format for transferring images and other data captured by the camera 14 may be different, or they may be the same. LAN is an abbreviation for Local Area Network. 【0071】 The remote controller may include left and right sticks used to control the flight movements of the drone 12, a lever used to operate the gimbal head 13, a shooting button to instruct the camera 14 to take a picture, and a shooting mode button to switch between video and still image shooting. Furthermore, the display device on the remote controller may be a touch panel display, and the shooting button and other operation buttons may be implemented using the touch panel display. 【0072】 Live video footage of the subject captured by camera 14 can be displayed on the remote controller's display device. Furthermore, the remote controller can grasp the aircraft's status, such as flight position and flight speed, in real time based on data from various sensors equipped on the drone 12. The display device on the remote controller can display flight information indicating the aircraft's status. 【0073】The drone 12 includes a processor 40, a storage device 42, and a communication interface 44. The storage device 42 may be at least one of memory, internal storage, and external storage. The storage device 42 may be any combination of memory, internal storage, and external storage. 【0074】 The processor 40 acts as a flight controller and performs various calculations necessary for controlling the flight of the drone 12 based on sensor data obtained from various sensors. 【0075】 The communication interface 44 is a communication unit that performs wireless communication with a remote controller or the like. The communication interface 44 may also include a communication terminal that supports wired communication. Furthermore, the drone 12 is equipped with a battery and a battery charging terminal. The battery and battery charging terminal are not shown in the illustration. 【0076】 [Example of configuration of the shooting support device according to the first embodiment] Figure 4 is a functional block diagram showing the electrical configuration of the shooting support device according to the first embodiment. The shooting support device 10 assists the automatic flight of the drone 12 and assists in the shooting of the building BU performed using the camera 14 mounted on the drone 12. 【0077】 The shooting support device 10 includes a building polygon acquisition unit 50, an observation angle acquisition unit 52, a shooting distance acquisition unit 54, a shooting field of view acquisition unit 56, a building height acquisition unit 58, a flight path calculation unit 60, a camera attitude setting unit 62, and a flight altitude calculation unit 64. 【0078】 The building polygon acquisition unit 50 executes step S10 in Figure 2 to acquire the building polygons of each of the multiple building BUs in the area to be photographed. The building polygon acquisition unit 50 may convert the geographic coordinates applied to the building polygons into projected coordinates suitable for calculation processing. 【0079】 The observation angle acquisition unit 52 executes step S12 to acquire the observation angle θ of the camera 14 shown in Figure 1. For example, the observation angle acquisition unit 52 may acquire the tilt angle setting of the camera 14 as the observation angle θ, or it may acquire the observation angle θ input using a user interface. 【0080】 The shooting distance acquisition unit 54 executes step S14 and acquires the shooting distance D. The shooting distance acquisition unit 54 may acquire the shooting distance D input using the user interface. 【0081】 The shooting angle acquisition unit 56 acquires the shooting angle of the camera 14. The shooting angle acquisition unit 56 may acquire the shooting angle of the camera 14, which is calculated based on the specifications of the camera 14 such as the shooting resolution, the observation angle, and the shooting distance. 【0082】 The building height acquisition unit 58 acquires the height of each building BU that is being photographed. The height of each building BU may be calculated based on the map information of the building BU. The building height acquisition unit 58 may acquire the height of each building BU from a storage device that stores information on the height of the building BU, or it may acquire the measured value of the building BU height. 【0083】 The flight path calculation unit 60 executes step S16 and calculates the flight path for each building BU based on the building polygon for each building BU, by referring to the observation angle θ and the shooting distance D. 【0084】 The flight path calculation unit 60 may convert the coordinates applied to the calculated flight path into coordinates suitable for flight control of the drone 12. The flight path calculation unit 60 may set multiple waypoints for the calculated flight path. 【0085】 The camera attitude setting unit 62 executes step S18 and sets the attitude of the camera 14 using the observation angle θ and shooting distance D of the camera 14. The attitude of the camera 14 is used for flight control of the drone 12 and shooting control of the camera 14. 【0086】 The flight altitude calculation unit 64 performs step S20 and calculates the flight altitude of the drone 12 based on the shooting angle of view of the camera 14 and the height of the building BU. The flight altitude of the drone 12 is used for flight control of the drone 12. 【0087】[Hardware Configuration of the Imaging Support Device] Figure 5 is a block diagram showing the electrical hardware configuration of the imaging support device according to the first embodiment. The imaging support device 10 is comprised of one or more computers. The computers that function as the imaging support device 10 have a processor that executes programs to realize various functions of the imaging support device 10. 【0088】 A computer may be a general-purpose computer such as a personal computer, or a computer designed for a specific purpose such as a server computer. Any computer may be a system such as a workstation, or it may be other hardware elements capable of running programs, such as a virtual machine. 【0089】 The imaging support device 10 may have at least some of its functions implemented using cloud computing. At least some of the functions of the imaging support device 10 may be provided as SaaS. SaaS is an abbreviation for Software as a Service. 【0090】 The imaging support device 10 includes a processor 102, a computer-readable medium 104, a communication interface 106, an input / output interface 108, and a bus 110. 【0091】 The processor 102 is connected via the bus 110 to a computer-readable medium 104, a communication interface 106, an input / output interface 108, an input device 120, and a display device 122. 【0092】 The computer-readable medium 104 includes a main memory 112 and an auxiliary memory 114. The memory 112 includes RAM. The memory 112 may also include ROM. 【0093】 The storage 114 may be, for example, a hard disk drive, a solid-state drive, or a combination of these. The storage 114 may also include an external storage device such as removable media. 【0094】RAM is an abbreviation for Random Access Memory, and ROM is an abbreviation for Read Only Memory. Hard disk drives can be referred to as HDDs, using the abbreviation for Hard Disk Drive. Solid state drives can be referred to as SSDs, using the abbreviation for Solid State Drive. 【0095】 Memory 112 stores programs and data that enable various functions of the imaging support device 10. The processor 102 enables various functions by executing the programs stored in memory 112. The processor 102 comprehensively controls each part of the imaging support device 10 and performs various processes. 【0096】 The communication interface 106 includes a communication interface that can connect to a telecommunications line such as a local area network. The communication interface 106 may be wireless or wired. 【0097】 The input / output interface 108 includes connection interfaces that can connect to external devices. Examples of connection interfaces that can connect to external devices include the Universal Serial Bus and HDMI (HDMI is a registered trademark). HDMI is an abbreviation for High-Definition Multimedia Interface. 【0098】 Examples of input devices 120 include pointing devices such as keyboards and mice. Input devices 120 may include numeric keypads and various switch buttons. Input devices 120 may include voice input devices. Input devices 120 may be touch panel type input devices that are integrated with the display screen of the display device 122. 【0099】The display device 122 may be a liquid crystal display, an organic EL display, or a projector. The display device 122 may be an appropriate combination of liquid crystal displays, etc. The display device 122 displays various information in addition to the captured image acquired using the camera 14. The display device 122 is used as part of the user interface when receiving input from the input device 120. The display device 122 is not limited to one, and a multi-display configuration with multiple display devices 122 is also possible. Organic EL can be referred to as OEL, an abbreviation of organic electro-luminescence. 【0100】 [Specific Example of Building Polygon Acquisition] Figure 6 is a schematic diagram of building polygon acquisition. The figure schematically illustrates the acquisition of one building polygon 210 corresponding to one building 202A that is the subject of inspection based on captured images, from one or more buildings 202 included in the map information 200. 【0101】 The operator OP shown in Figure 1 is the operator OP, who selects one building 202A at a time from the map information 200 displayed on the display device 122 of the shooting support device 10, which includes one or more buildings 202. The selection of the building 202A to be photographed may be done by clicking on the building 202A to be photographed performed by the operator OP. Note that the building 202A to be inspected is synonymous with the building 202A to be photographed. 【0102】 The map information 200 shown in Figure 6 may be base map information downloaded from the Geospatial Information Authority of Japan's base map information site. A portion of the map information 200 may be enlarged and displayed on the display device 122 of the shooting support device 10. 【0103】The building polygon acquisition unit 50 shown in Figure 4 acquires a building polygon 210 corresponding to the selected building 202A to be photographed. The photography support device 10 may display the acquired building polygon 210 on the display device 122. For example, the photography support device 10 may display the building polygon 210 corresponding to the selected building 202A using a pop-up that is superimposed on the map information 200. The photography support device 10 may highlight the building 202A from which the building polygon 210 was acquired. 【0104】 [Specific Examples of Expansion Processing for Building Polygons] Figures 7, 8, and 9 are schematic diagrams of expansion processing for building polygons. Figures 7, 8, and 9 illustrate, in order, a stepwise expansion process in which the building polygon 210 is expanded and an expanded building polygon is generated, by marking a first expansion point 222, etc., at a position of expansion distance r from the building polygon 210. Marking the first expansion point 222, etc., here is synonymous with setting, defining, and determining the first expansion point 222. 【0105】 In the expansion process illustrated in Figure 7, a first expansion starting point 220 is defined with respect to the outer edge line 212 of the building polygon 210, and a plurality of first expansion points 222 having an expansion distance r from the first expansion starting point 220 are defined. 【0106】 The expansion distance r is expressed as r = D × cosθ, where D is the shooting distance and θ is the observation angle shown in Figure 1. Each of the multiple first expansion points 222 is understood as a group of points that constitute a circular arc with radius equal to the expansion distance r, centered on the first expansion starting point 220 defined by the outer edge line 212 of the building polygon 210. The multiple first expansion points 222 may be defined outside the building polygon 210. 【0107】 Figure 7 illustrates a first expansion starting point 220 defined for one arbitrary outer edge line 212 in a building polygon 210. However, a point cloud containing multiple first expansion starting points 220 may be defined for at least one of the multiple outer edge lines 212 of the building polygon 210. The outer edge line 212 is an example of a first outer edge line representing the outer edge of a feature when the feature of this disclosure is projected onto a defined plane. 【0108】In the expansion process illustrated in Figure 8, a second expansion starting point 230 is defined for one arbitrary vertex among the multiple vertices of the building polygon 210, and a plurality of second expansion points 232 having an expansion distance r from the second expansion starting point 230 are defined. 【0109】 In the expansion process illustrated in Figure 9, a second expansion starting point 230 is defined for all eight vertices included in the building polygon 210, and for each of the multiple second expansion starting points 230, multiple second expansion points 232 are defined having an expansion distance r from the second expansion starting point 230. 【0110】 Figure 9 illustrates an embodiment in which a second expansion starting point 230 is defined for all vertices of the building polygon 210, but a second expansion starting point 230 may be defined for at least one vertex of the building polygon 210. However, from the viewpoint of performing a uniform expansion process on the shape of the building polygon 210, the embodiment in which a second expansion starting point 230 is defined for all vertices of the building polygon 210 is preferred. 【0111】 The first expansion point 222 shown in Figure 7, the second expansion point 232 shown in Figure 8, and the point cloud of multiple expansion points including the second expansion point 232 shown in Figure 9 constitute an expanded polygon obtained by expanding the building polygon 210. 【0112】 [Specific Example of Flight Path Calculation] Figure 10 is a schematic diagram of flight path calculation. The figure schematically illustrates a curve 252 calculated as a result of alpha shape processing for a point cloud containing multiple expansion points 250 obtained as a result of expansion processing on a building polygon 210. 【0113】 The expansion point 250 shown in Figure 10 includes the first expansion point 222 shown in Figure 7, the second expansion point 232 shown in Figure 8, and the second expansion point 232 shown in Figure 9. In other words, the point group containing multiple expansion points 250 constitutes an expanded polygon obtained by expanding the building polygon 210. 【0114】The curve 252 shown in Figure 10 represents the outer edge of the expanded polygon, formed by connecting the multiple expanded points 250A that are located furthest out of the multiple expanded points 250 relative to the building polygon 210. The outer edge of the expanded polygon is applied to the flight path of the drone 12. That is, the curve 252 applied to the flight path of the drone 12 is a closed curve that encloses the multiple expanded points 250 and is understood as a closed curve passing through the multiple expanded points 250A. Note that the outer edge of the expanded polygon shown as curve 252 is an example of a second outer edge representing the outer edge of the expanded two-dimensional shape of this disclosure. 【0115】 Figure 11 is a schematic diagram of flight path calculation using different alpha values ​​applied to the alpha shape method. The curve 254 shown in Figure 11 is calculated using a larger alpha value compared to the alpha value used when calculating the curve 252 shown in Figure 10. For example, the alpha value applied to the calculation of curve 252 is 1, while the alpha value applied to the calculation of curve 254 is 8. Note that the calculation of curve 252 is an example of the derivation of the second outer edge line in this disclosure. 【0116】 As shown in Figure 11, a convex hull is formed when the alpha value is relatively large. As shown in Figure 10, a concave hull is formed when the alpha value is relatively small. The curves 252 and 254 calculated as the flight path of the drone 12 may be displayed on the display device 122 provided in the shooting support device 10. 【0117】 An operator OP who has visually observed the flight path of the drone 12 can optimize the flight path of the drone 12 by adjusting the alpha value in the alpha shape processing. The outer edge line of the inflated polygon shown as curve 254 is an example of a second outer edge line representing the outer edge of the inflated two-dimensional shape of this disclosure. 【0118】 Figure 12 is a schematic diagram of flight path calculation according to another embodiment. This figure schematically illustrates the calculation of the flight path of a drone 12, in which a first expansion starting point 220 interpolated for multiple outer edge lines 212 constituting a building polygon 210 is used. 【0119】Due to the interpolation of the first expansion starting point 220 with respect to the outer edge line 212 of the building polygon 210, the flight path of the drone 12 along the outer wall of the building BU can be calculated more precisely. In addition, the radius 1 / α when the alpha value is α is adjusted, and the switching between convex and concave hulls is controlled. 【0120】 For example, the two outer edge lines 212A shown in Figure 12 do not have an interpolated first expansion starting point 220. In this case, it is difficult to calculate the flight path represented as line segment 260. Also, at vertex 213 where the interior angle is obtuse, the flight path represented as line segment 262 is not calculated, resulting in a calculated flight path that does not follow the outer wall of building BU, raising concerns about obtaining images of building BU that do not include building BU. 【0121】 Therefore, the first expansion starting point 220 is interpolated to the outer edge line 212, which is not a vertex of the building polygon 210, so that the distribution of the first expansion point 222 and the second expansion point 232 becomes uniform, and the first expansion point 222 is defined based on the interpolated first expansion starting point 220. This enables the calculation of a flight path that follows the outer wall of the building BU. 【0122】 [Specific Example of Camera Attitude Setting] Figure 13 is a schematic diagram of camera attitude setting. The figure schematically shows the attitude of camera 14 when the building BU is viewed from above. In the figure, the building BU is shown as a building polygon 210. 【0123】 The camera attitude setting unit 62 shown in Figure 4 is positioned perpendicular to the direction of travel of the drone 12 along the flight path 270, and sets the attitude of the camera 14 so that its optical axis points towards the building BU. In Figure 13, the direction in which the optical axis of the camera 14 points on an arbitrary plane parallel to the horizontal plane is illustrated using arrow lines. Furthermore, as shown in Figure 1, the attitude of the camera 14 is such that the optical axis points diagonally downward, making an observation angle θ with respect to the vertical downward direction. 【0124】The flight path 270 is defined by multiple waypoints 272. At each waypoint 272, the drone 12 is temporarily stopped and photographs of the building BU are taken. The distance between adjacent waypoints 272 is defined such that the field of view of the cameras 14 for each adjacent waypoint 272 overlaps with a specified overlap rate. 【0125】 Here, the flight path 270 is straight with respect to the outer edge line 212 of the building polygon 210 that follows the outer wall of the building BU, and curved with respect to the vertices of the building polygon 210 that correspond to the corners of the building BU. When a flight path 270 similar in shape to the building polygon 210 is applied, even if photography is performed around the entire perimeter of the building BU, a portion of the building BU may be missing from the captured image of the building BU. 【0126】 If the two-dimensional shape of the flight path 270 has vertices, then when photographing the corners of the building BU corresponding to the vertices of the building polygon 210, there is a possibility that a portion of the building BU may be missing from the image of the building BU. On the other hand, by applying a curved shape to a portion of the flight path 270 corresponding to the vertices of the building polygon 210, the loss of a portion of the building BU from the image of the building BU is suppressed when photographing the corners of the building BU. 【0127】 [Specific Example of Flight Altitude Calculation] Figure 14 is a schematic diagram of flight altitude calculation. The figure schematically illustrates a state in which an arbitrary wall WA of building BU is photographed using a camera 14 mounted on drone 12. Note that the outer edge line of the arbitrary wall WA of building BU is shown for convenience only, and the wall WA shown in Figure 14 may differ from the actual shape of the wall WA. 【0128】 The flight path 270A shown in Figure 14 is applied to a horizontal movement method in which the drone 12 is flown along the horizontal direction, with a constant flight altitude hH applied. The flight path 270B corresponding to the flight altitude hL is the same as the flight path 270A. The flight altitudes hH and hL are determined by the distance in the vertical upward direction from the height reference plane of the building BU, and the relationship hH > hL exists. 【0129】The flight altitude hH is calculated based on the height of the building BU to be photographed, the field of view AV of the camera 14, and the expansion distance r shown in Figure 7, etc. The field of view AV may be centered on the target point SP. The height of the building BU to be photographed may be the number of floors of the building. For example, the flight altitude h may be calculated based on the number of floors of the building BU corresponding to the target point SP. 【0130】 Flight path 270A to which flight altitude hH applies may be defined around the entire perimeter of building BU, and flight path 270B to which flight altitude hL applies may also be defined around the entire perimeter of building BU. 【0131】 For example, the drone 12 may be automatically flown along the flight path 270A to take photographs of the entire perimeter of the building BU at a flight altitude hH. The drone 12 may then be descended from flight altitude hH to flight altitude hL, and the drone 12 may be automatically flown along the flight path 270B to take photographs of the entire perimeter of the building BU at flight altitude hL. 【0132】 Figure 15 is a schematic diagram of flight altitude calculation according to another embodiment. The figure schematically illustrates the flight path 270C in the vertical movement method. The flight path 270C illustrated in Figure 15 moves the drone 12 in a zigzag pattern along an arbitrary wall WA of the building BU. 【0133】 In other words, flight path 270C includes an ascending flight path 270C1, a horizontal flight path 270C2, a descending flight path 270C3, a horizontal flight path 270C4, and an ascending flight path 270C5. 【0134】 Drone 12 traveling along the ascending flight path 270C1, the descending flight path 270C3, and the ascending flight path 270C5 will take photographs of the wall WA of building BU. Drone 12 traveling along the horizontal flight path 270C2 and the horizontal flight path 270C4 will not take photographs, but will change its horizontal shooting position. The horizontal flight path 270C2 may be higher than the highest flight altitude h at which photographs are taken. Below the horizontal flight path 270C4, drone 2 may be prohibited from flying. This can ensure the safety of the operator OP who is below the flight path of drone 12. 【0135】Figures 14 and 15 illustrate two ways in which flight altitude h is calculated, but there may be one or more types of flight altitude h. The flight altitude h may be the vertical distance from the reference plane in the height direction of the building BU, similar to the height of the building BU, or it may be the elevation. 【0136】 One of the flight altitudes hH and hL is an example of the first altitude in this disclosure, and the other is an example of the second altitude in this disclosure. One of the shooting angle AV to which flight altitude hH is applied and the shooting angle AV to which flight altitude hL is applied is an example of the first shooting area in this disclosure, and the other is an example of the second shooting area in this disclosure. 【0137】 [Specific Example of Observation Angle Setting] Figure 16 is a schematic diagram of observation angle setting. The figure illustrates how the observation angle is set for each flight altitude h. The shooting resolution of the camera 14 mounted on the drone 12 is ensured in a series of shots of the building BU by keeping the shooting distance D constant. That is, the shooting distance D is determined according to the shooting resolution in the shots of the building BU. 【0138】 For example, the shooting distance D1 of the camera 14 mounted on the drone 12 flying at altitude h1 is the same as the shooting distance D2 of the camera 14 mounted on the drone 12 flying at altitude h2. This ensures that the shooting resolution of the camera 14 mounted on the drone 12 flying at altitude h1 and the shooting resolution of the camera 14 mounted on the drone 12 flying at altitude h2 remain constant. 【0139】 When the uppermost part of a building BU, such as the roof, is photographed, the expansion distance r1 may be set smaller than the expansion distance r2 when the wall WA of the building BU is photographed. When different expansion distances r are set depending on the flight altitude h, the observation angle θ is adjusted to keep the shooting distance D constant. Specifically, the observation angle θ1 when the uppermost part of a building BU is photographed is set smaller than the observation angle θ2 when the wall WA of the building BU is photographed. 【0140】When different observation angles θ are set for each flight altitude h, the position, spacing, and number of waypoints are changed in accordance with the enlargement or reduction of the shooting field of view AV. In particular, when the shooting field of view is reduced, the position, spacing, and number of waypoints may be adjusted so that the overlap rate of the shooting field of view is maintained for adjacent waypoints. 【0141】 [Uses of building images] Figure 17 is a schematic diagram showing the procedure for processing building images. For example, building images (BU) are used to investigate the extent of damage in the event of a disaster such as an earthquake. 【0142】 In step S100, the shooting support device 10 shown in Figure 1 is used, and steps S10 to S20 shown in Figure 2 are executed to calculate the flight path of the drone 12. In step S102, the drone 12 is made to fly automatically, and at each of the multiple waypoints defined in the flight path, the building BU is photographed using the camera 14. 【0143】 In step S104, as a 360-degree view of the building BU, the drone 12 is automatically flown around the entire perimeter of the building BU, and the camera 14 is used to photograph the building BU. In step S104, a 360-degree view of the building BU may be generated. 【0144】 In step S106, an inspection is conducted around the entire perimeter of the building BU based on images taken of the entire perimeter of the building BU. This inspection may be an inspection of the damage to the building BU, or an investigation of changes in the building BU over time. This inspection may be an external inspection of a newly constructed or renovated building. 【0145】 In step S108, a 3D reconstruction process of the building BU is performed, and a 3D model of the building BU is generated. In step S110, an inspection of the building BU is performed based on the 3D model of the building BU. Similar to step S106, this inspection may be an inspection of the damage status of the building BU, an investigation of changes in the building BU over time, or an external inspection of a new or renovated building. 【0146】[Modification of building polygons] If there are no building polygons that represent the two-dimensional shape of buildings such as houses, a two-dimensional CAD drawing showing the exterior of the building, and a two-dimensional simplified drawing showing the exterior of the building may be generated as substitutes for building polygons, and the flight path of the drone 12 may be calculated based on these substitute building polygons. 【0147】 In other words, the two-dimensional shape of the feature in this disclosure includes a building polygon representing the two-dimensional shape enclosed by the building's outer boundary line obtained from map information such as base map information, and may also include alternative building polygons such as a two-dimensional CAD drawing showing the building's exterior and a two-dimensional simplified drawing showing the building's exterior. 【0148】 [Specific Examples of Objects to be Photographed] In this embodiment, a building BU is given as an example of an object to be photographed. Examples of buildings BU include houses, buildings, and towers. Objects to be photographed are not limited to buildings BU. For example, objects to be photographed may be bridges, roads, rivers, harbors, rocks, and trees. In other words, objects to be photographed may be man-made or natural objects, and their vertical length may be expressed using the height from a reference plane. 【0149】 [Modification] In this embodiment, an example is given in which one drone 12 is used for one building, but multiple drones 12 may be used to perform photography at different flight altitudes. 【0150】 In this embodiment, aerial photography of a building is exemplified using a drone 12, but ground photography of the building may be performed using a self-propelled robot or the like. In the case of ground photography, instead of setting the altitude of the drone 12, the shooting angle of the camera 14 in the vertical upward direction is set. 【0151】 Furthermore, photographs of the building from the sea or rivers may be taken using ship-based robots or the like that navigate the sea and rivers. In ground photography, multiple drones 12 with different shooting angles may be used at multiple different heights of the building BU. 【0152】[Effects of the First Embodiment] The shooting support device and shooting support method according to the first embodiment can obtain the following effects. 【0153】 [1] A building polygon 210 corresponding to the building BU, which is the object to be photographed, is acquired. The building polygon 210 is subjected to an expansion process, and an expanded polygon, which is a point cloud containing multiple expansion points 250, is generated. A curve 252, etc., representing the flight path of the drone 12 is calculated by connecting the multiple expansion points 250A that are located furthest out of the building polygon 210 among the multiple expansion points 250. This calculates a preferred flight path for the drone 12 when photographing the entire perimeter of the building BU. 【0154】 [2] The expansion distance r applied to the expansion process for the building polygon 210 is calculated based on the observation angle θ and the shooting distance D. This allows for the calculation of the flight path of the drone 12 when photographing the building BU to which the shooting angle based on the observation angle θ and the shooting resolution based on the shooting distance D are applied. 【0155】 [3] The alpha shape method is applied to the inflated polygon, and the flight path of the drone 12 based on the inflated polygon is calculated. This calculates the flight path of the drone 12 along the wall WA of the building BU. Furthermore, optimization of the flight path of the drone 12 based on adjustment of the alpha value can be achieved. 【0156】 [4] A second expansion starting point 230 is set for the vertices of the building polygon 210. This allows an arc-shaped flight path to be calculated for the corners of the building BU, suppressing the loss of part of the building BU in the captured image of the building BU. 【0157】 [5] A first expansion starting point 220 is set with respect to the outer edge line 212 of the building polygon 210. This allows the flight path of the drone 12 following the wall WA of the building BU to be calculated. 【0158】 [6] Multiple waypoints 272 are defined in the flight path 270. Multiple waypoints 272 are defined so that the shooting angle AV of each waypoint 272 overlap. This suppresses the loss of part of the building BU in the captured image of the building BU. 【0159】 [7] The camera 14 mounted on the drone 12 is positioned so that its optical axis is perpendicular to the drone's direction of travel and forms an observation angle θ with respect to the vertically downward direction. This allows for the calculation of a flight path for the drone 12 that enables the capture of images around the entire perimeter of the building BU using the camera 14 with a fixed orientation. 【0160】 [8] The flight altitude h of the drone 12 is calculated based on the height of the building BU, the shooting angle AV of the camera 14, and the expansion distance r. This allows for the application of a flight path corresponding to the height of the building BU, and enables the shooting of the building BU with the specified shooting resolution. 【0161】 [9] Multiple flight paths with different flight altitudes h are calculated. Multiple flight paths are calculated so that the shooting angles overlap for each flight path. This suppresses the loss of part of the building BU in the captured image of the building BU. 【0162】

[10] The drone 12 is flown along a flight path 270 parallel to the horizontal direction to take photographs of the building BU. The drone 12 is moved vertically to change the flight altitude h. This operation is repeated to take photographs of the building BU. This ensures that the entire surface of any wall included in the building BU is photographed. 【0163】

[11] The drone 12 is flown along a flight path 270 parallel to the vertical direction to take photographs of the building BU. The drone 12 is moved horizontally to change the horizontal target point SP. This operation is repeated to take photographs of the building BU. This ensures that the entire surface of any wall included in the building BU is photographed. 【0164】

[12] When the expansion distance r is adjusted according to the flight altitude h, the observation angle θ is adjusted according to the expansion distance r. This maintains the specified shooting distance D and the specified shooting resolution. 【0165】

[13] When the expansion distance r is adjusted according to the flight altitude h, the position, number, and spacing of the waypoints are adjusted. This suppresses the loss of parts of the building BU in the captured images of the 360-degree view of the building BU. 【0166】 [Place photography to which the photography support device according to the second embodiment is applied] Figure 18 is a schematic diagram of mountain photography to which the photography system according to the second embodiment is applied. The figure schematically illustrates the photography of the entire surroundings of a mountain MO, in which a drone 12 is flown automatically and a camera 14 mounted on the drone 12 is used. 【0167】 Figure 18 illustrates the imaging of a target point SP corresponding to contour line 300 at an elevation, and a target point SP corresponding to contour line 302 at an elevation. In the second embodiment, the imaging support device sets an elevation at which imaging of the entire surrounding area is performed for a feature representing terrain such as a mountain, and acquires the two-dimensional shape of the feature as the two-dimensional shape enclosed by closed curves represented as contour lines at the set elevation. The elevation of the object to be photographed is determined according to the imaging resolution and the three-dimensional shape of the feature. That is, in the imaging system according to this embodiment, the two-dimensional shape enclosed by contour lines on a plane where contour lines are defined is treated as a two-dimensional shape for which the elevation value is a representative value. Contour lines for features representing terrain such as mountains can be obtained from map information such as base map information. 【0168】 The shooting support device according to the second embodiment expands the two-dimensional shape enclosed by contour lines, similar to the expansion of building polygons in the first embodiment, and calculates flight paths for each elevation. That is, the shooting support device according to the second embodiment calculates one or more flight paths corresponding to one or more elevations for a single feature. Note that the two drones 12 shown in Figure 18 represent the same drone 12 moving between different flight altitudes. 【0169】 Figure 18 illustrates a mountain MO as an example of a feature to be photographed. The vertical position of a feature to be photographed is expressed using elevation. A mountain MO may be a topographic feature having slopes within a specified gradient range relative to a flat area, such as peaks, mountains, hills, plateaus, and valleys, and may be a complex mountain range, mountain range, mountain massif, etc., having multiple peaks. 【0170】 The expansion distance r, observation angle θ, and shooting distance D shown in Figure 18 are defined for predetermined contour lines at each elevation in the same way as the calculation of the flight path based on building polygons in the first embodiment. 【0171】 [Procedure for Calculating Flight Paths] Figure 19 is a flowchart showing the procedure for calculating flight paths in mountain photography. Each step included in the flight path calculation method shown in the figure is implemented by a computer functioning as a photography support device according to the second embodiment, by executing a prescribed program. Note that the flight path calculation method is an example of the photography support method of this disclosure. 【0172】 In step S200, the shooting support device acquires vector-format contour lines of the mountain MO, which is the object to be photographed. In step S200, vector-format contour lines are acquired to which geographic coordinates expressed using latitude and longitude are applied. 【0173】 In step S202, the imaging support device converts the vector-format contour lines to projected coordinates. That is, in step S202, contour lines in geographic coordinates, which are unsuitable for calculations involving distance and angle, are converted to contour lines in projected coordinates. 【0174】 In step S204, the shooting support device extracts contour lines at the elevation where the target shooting point SP is defined. For example, in step S204, contour lines 300 and 302 shown in Figure 18 are extracted. 【0175】 In step S206, the imaging support device performs an expansion process on the two-dimensional shape enclosed by the contour lines 300 etc. extracted in step S204. In the expansion process on the two-dimensional shape enclosed by the contour lines 300 etc., for each of the multiple expansion origins, which are point clouds included in the contour vector, an expansion point is defined at an expansion distance r from the expansion origin, and an expansion polygon, which is a two-dimensional point cloud containing multiple expansion points, is generated. 【0176】 If multiple contour lines, such as contour line 300 and contour line 302, are extracted in step S204, then in step S206, multiple inflated polygons corresponding to each of the multiple contour lines are generated. 【0177】 In step S208, the shooting support device applies the alpha shape method to the inflated polygon generated in step S206 to calculate the outer edge of the inflated polygon as the flight path of the drone 12. If multiple inflated polygons are generated in step S206, the outer edge of each of the multiple inflated polygons is calculated in step S208. 【0178】 In step S210, the shooting support device converts the flight path of the drone 12 to which projected coordinates are applied into geographic coordinates. In step S212, the shooting support device sets multiple waypoints along the flight path of the drone 12. 【0179】 The shooting support device transmits flight paths for each contour line, which have multiple waypoints set, to the control unit that controls the flight of the drone 12. The control unit then controls the flight of the drone 12 based on the acquired flight paths. 【0180】 [Example of the configuration of the imaging support device according to the second embodiment] Figure 20 is a functional block diagram showing the electrical configuration of the imaging support device according to the second embodiment. The following explanation will mainly focus on the differences from the imaging support device 10 shown in Figure 4. 【0181】 The shooting support device 10A shown in Figure 20 replaces the building polygon acquisition unit 50 shown in Figure 4 with a contour line acquisition unit 50A. The contour line acquisition unit 50A performs step S200 shown in Figure 19 and acquires contour lines in vector format that correspond to the elevation of the shooting target point SP of the mountain MO, which is the object to be photographed. 【0182】 The contour line acquisition unit 50A performs step S202 to convert the vector-format contour lines into projected coordinates. The contour line acquisition unit 50A performs step S204 to extract contour lines at the elevation where the target shooting point SP is defined. 【0183】 The shooting support device 10A is equipped with an elevation acquisition unit 58A in place of the building height acquisition unit 58. The elevation acquisition unit 58A acquires the elevation of each shooting target point SP used to calculate the flight altitude of the drone 12. 【0184】 The flight path calculation unit 60 performs steps S206 and S208 to calculate the flight path of the drone 12. The flight path calculation unit 60 performs step S210 to convert the flight path of the drone 12 from projected coordinates to geographic coordinates. The flight path calculation unit 60 performs step S212 to set multiple waypoints for the flight path of the drone 12. 【0185】 The observation angle acquisition unit 52, shooting distance acquisition unit 54, shooting field of view acquisition unit 56, camera attitude setting unit 62, and flight altitude calculation unit 64 shown in Figure 20 are configured in the same way as the observation angle acquisition unit 52, shooting distance acquisition unit 54, shooting field of view acquisition unit 56, camera attitude setting unit 62, and flight altitude calculation unit 64 shown in Figure 4. 【0186】 [Specific Example of Contour Line Expansion Processing and Flight Path Calculation] Figure 21 is a schematic diagram of contour line expansion processing and flight path calculation. The map information 320 shown in the figure includes multiple contour lines corresponding to multiple elevations for the mountain MO, which is the object to be photographed. 【0187】 For example, contour lines 322 are extracted as the target for flight path calculation applied to the automatic flight of the drone 12, and contour polygons 330 having the same two-dimensional shape as the two-dimensional shape enclosed by the contour lines 322 are generated. The contour polygons 330 may be polygons composed of multiple vertices and two line segments enclosing each of the multiple vertices, and the shapes may include curves such as circular arcs instead of vertices and line segments. The contour polygons 330 may be circles, ellipses, etc. 【0188】 Herein, the term "identical" as used herein is not limited to strict identicalness, but may refer to substantial identicalness, differing to the extent that the required precision is maintained in the inflation process and the calculation of the flight path. 【0189】 Multiple expansion points are defined for the contour polygon 330, and these expansion points are defined around the entire circumference of the contour polygon 330. Figure 21 shows expansion points 340 and 342 as examples of multiple expansion points. 【0190】Multiple expansion points 350 are defined at an expansion distance r from the expansion starting point 340. Similarly, multiple expansion points 352 are defined at an expansion distance r from the expansion starting point 342. In this way, for each of the expansion starting points, multiple expansion points are defined at an expansion distance r. The two-dimensional point group containing multiple expansion points constitutes an expanded polygon 354. 【0191】 An appropriate alpha value is specified for the inflated polygon 354, and the alpha shape method is applied to calculate the curve 356, which is the outer edge of the inflated polygon 354. The curve 356 is the flight path of the drone 12, which corresponds to the contour lines 322. 【0192】 Setting the shooting orientation of the camera 14 and calculating the flight altitude of the drone 12 may be performed using the same configuration and procedure as in the first embodiment. 【0193】 The contour polygon 330 is an example of the two-dimensional shape of a feature in this disclosure. The contour line 322 is an example of the first outer boundary line in this disclosure. The inflated polygon 354 is an example of the inflated two-dimensional shape in this disclosure, and the curve 356, which is the outer boundary line of the inflated polygon 354, is an example of the second outer boundary line in this disclosure. 【0194】 [Effects and Effects of the Shooting Support Device and Shooting Support Method According to the Second Embodiment] The shooting support device and shooting support method according to the second embodiment can obtain the same effects and effects as the shooting support device and shooting support method according to the first embodiment when taking 360-degree photographs of geographical features such as mountain MOs. 【0195】 [Hardware configuration for executing each process] In this embodiment, each process is executed on any computer. Furthermore, any computer may execute these processes using a processor, a program, or a combination thereof. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other hardware element capable of executing a program. 【0196】A processor may be composed of one or more hardware components, and the type of hardware is not limited. For example, a processor may be composed of hardware such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), FPGA (Field Programmable Gate Array) or other programmable logic devices, ASIC (Application Specific Integrated Circuit) or other dedicated circuits for executing specific processes, GPU (Graphic Processing Unit), or NPU (Neural Processing Unit). Furthermore, the processor has various parts (Units) or means (Means) that execute the various processes in this embodiment. The type of hardware may also be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a processor, these multiple hardware components may be located in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. Hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements. 【0197】Furthermore, this embodiment may be implemented by hardware, software, firmware, microcode, or a combination thereof. The software, firmware, and microcode are composed of a program. The program may also be, for example, a group of program modules, each of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located on devices that are physically separated from each other. The program code or code segment may represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. The program code or code segment may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents. 【0198】 [Examples of application to programs and program products] The imaging support method according to the embodiment may be configured such that a processor or a computer equipped with a processor is configured as a program or program product that realizes the functions of each step. 【0199】 For example, the program or program product may implement on a computer the following functions: acquiring the two-dimensional shape of a feature, setting an expansion starting point relative to a first outer edge, setting an expansion distance, setting expansion points, expanding the two-dimensional shape of a feature, and setting a second outer edge of the expanded two-dimensional shape as a movement path. 【0200】A program or program product may be stored in a computer-readable medium, which is a tangible, non-temporary information storage medium, and may be provided through such an information storage medium. Alternatively, instead of storing and providing the program in a tangible, non-temporary computer-readable medium, it is also possible to provide the program signal as a download service using a telecommunications line. 【0201】 This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the technical idea of ​​this disclosure. Furthermore, the first embodiment, the second embodiment, and the modifications can be combined as appropriate. 【0202】10 Shooting support device 10A Shooting support device 12 Drone 13 Gimbal head 14 Camera 30 GNSS receiver 32 Barometric pressure sensor 34 Direction sensor 36 Inertial measurement unit 38 Motor 40 Processor 42 Storage device 44 Communication interface 50 Building polygon acquisition unit 50A Contour line acquisition unit 52 Observation angle acquisition unit 54 Shooting distance acquisition unit 56 Shooting field of view acquisition unit 58 Building height acquisition unit 58A Elevation acquisition unit 60 Flight path calculation unit 62 Camera attitude setting unit 64 Flight altitude calculation unit 102 Processor 104 Computer-readable medium 106 Communication interface 108 Input / output interface 110 Bus 112 Memory 114 Storage 120 Input device 122 Display device 200 Map information 202 Building 202A Building 210 Building Polygon 212 Outer Edge 212A Outer Edge 213 Vertex 220 First Expansion Starting Point 222 First Expansion Point 230 Second Expansion Starting Point 232 Second Expansion Point 250 Expansion Point 250A Expansion Point 252 Curve 254 Curve 260 Line Segment 262 Line Segment 270 Flight Path 270A Flight Path 270B Flight Path 270C Flight Path 270C1 Ascending Flight Path 270C2 Horizontal Flight Path 270C3 Descending Flight Path 270C4 Horizontal Flight Path 270C5 Ascending Flight Path 272 Waypoint 300 Contour 302 Contour 320 Map Information 322 Contour 330 Contour Polygon 340 Expansion Starting Point 342 Expansion starting point 350 Expansion point 352 Expansion point 354 Expansion polygon 356 Curve 362 Gyro sensor 364 Accelerometer 366 Temperature sensor AV Shooting angle BU Building D Shooting distance D1 Shooting distance D2 Shooting distance h Flight altitude h1 Flight altitude h2 Flight altitude hH Flight altitude hL Flight altitude MO Mountain OP Operator r Expansion distance r1 Expansion distance r2 Expansion distance SP Target shooting point SP1 Target shooting point SP2 Target shooting point WA Wall θ Observation angle θ1 Observation angle θ2 Observation angle S10 to S24 Each step of the shooting method S100 to S110 Each step of processing the captured image S200 to S212 Each step of the flight path calculation method

Claims

1. A photographic support device that assists in photographing the area around a feature, which is mounted on a mobile body that moves around the feature and has a fixed shooting direction relative to the movement path of the mobile body, comprising: a processor; a memory that stores instructions to be executed by the processor, wherein the processor executes the instructions to obtain the two-dimensional shape of the feature, which is enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined plane, and is represented using geographic coordinates or projected coordinates; sets an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature; sets the observation angle of the shooting device with respect to a shooting target point on the feature, and the expansion distance based on the shooting distance between the shooting target point and the shooting device; expands the two-dimensional shape of the feature in a two-dimensional manner based on a plurality of expansion points set at a position having the expansion distance from the expansion starting point; and sets a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as the movement path.

2. The imaging support apparatus according to claim 1, wherein the processor applies alpha-shape processing to a plurality of the expansion points to derive the second outer edge line.

3. The imaging support device according to claim 1, wherein the processor sets the altitude of the movement path based on the observation angle and the shooting distance.

4. The imaging support device according to claim 3, wherein the processor derives the altitude using the observation angle and the shooting distance.

5. The imaging support device according to claim 3, wherein the processor sets the first imaging area in imaging to which the first imaging area to which the first imaging area to which the first imaging area to which the second imaging area to which a second imaging area different from the first imaging area to which the first imaging area to which the second imaging area to which the first imaging area to which the second imaging area to which the first imaging area to which the first imaging area to which the first imaging area to be applied overlaps.

6. The imaging support device according to claim 3, wherein the processor sets the movement paths to which different altitudes are applied based on different observation angles.

7. The imaging support device according to claim 1, wherein the processor sets the movement path corresponding to the entire circumference of the feature.

8. The imaging support device according to claim 1, wherein the processor sets the imaging distance based on the imaging resolution of the imaging device.

9. The imaging support device according to claim 1, wherein the processor acquires a two-dimensional shape of the feature as the two-dimensional shape of the feature enclosed by contour lines defined on the feature, and sets the second outer edge line of the expanded two-dimensional shape obtained by expanding the two-dimensional shape enclosed by the contour lines as the movement path.

10. The imaging support device according to claim 9, wherein the processor obtains a two-dimensional shape of the feature, which is enclosed by a plurality of contour lines defined for the feature for each of a plurality of mutually different elevations, and sets a plurality of second outer edge lines of each of the plurality of expanded two-dimensional shapes obtained by expanding each of the plurality of contour lines as the movement path for each elevation.

11. A photographic support method for assisting in the photography of the area around a feature, which is carried out using a photographic device mounted on a mobile body that moves around the feature, and whose photographic direction is fixed with respect to the movement path of the mobile body, comprising: a processor; a memory storing instructions to be executed by the processor; a computer that functions as a photographic support device in which the processor executes the instructions; acquires the two-dimensional shape of the feature, which is enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined surface, and is represented using geographic coordinates or projected coordinates; sets an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature; sets the observation angle of the photographic device with respect to a target point on the feature, and an expansion distance based on the photographic distance between the target point and the photographic device; expands the two-dimensional shape of the feature in a two-dimensional manner based on a plurality of expansion points set at a position having the expansion distance from the expansion starting point; and sets a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as the movement path.

12. A program that supports the imaging of the area around a feature, performed using an imaging device mounted on a mobile body that moves around the feature, the imaging direction of which is fixed relative to the movement path of the mobile body, the program comprising: a processor; a memory storing instructions to be executed by the processor, wherein the processor functions as an imaging support device to execute the instructions, the program enables the following functions: acquiring the two-dimensional shape of the feature, which is enclosed by a first outer edge line representing the outer edge of the feature when the feature is projected onto a predetermined surface, and which is represented using geographic coordinates or projected coordinates; setting an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the feature; setting an expansion distance based on the observation angle of the imaging device with respect to a target point on the feature, and the imaging distance between the target point and the imaging device; expanding the two-dimensional shape of the feature in a two-dimensional manner based on a plurality of expansion points set at positions having the expansion distance from the expansion starting point; and setting a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the feature as the movement path.

13. A non-temporary and computer-readable recording medium on which the program described in claim 12 is recorded.

14. A photography system comprising: a mobile body that moves around a geographic feature; a photography device mounted on the mobile body, the photography direction of which is fixed with respect to the movement path of the mobile body; and a photography support device that photographs the area around the geographic feature using the photography device, wherein the photography support device comprises: a processor; a memory that stores instructions to be executed by the processor, wherein the processor executes the instructions to obtain the two-dimensional shape of the geographic feature, which is the two-dimensional shape of the geographic feature enclosed by a first outer edge line representing the outer edge of the geographic feature projected onto a predetermined plane, and is represented using geographic coordinates or projected coordinates; setting an expansion starting point with respect to the first outer edge line of the two-dimensional shape of the geographic feature; setting the observation angle of the photography device with respect to a target photography point on the geographic feature, and an expansion distance based on the photography distance between the target photography point and the photography device; expanding the two-dimensional shape of the geographic feature in a two-dimensional manner based on a plurality of expansion points set at a position having the expansion distance from the expansion starting point; and setting a second outer edge line representing the outer edge of the expanded two-dimensional shape obtained by expanding the two-dimensional shape of the geographic feature as the movement path.

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