Imaging device, imaging method, and program

Abstract

To properly adjust a focal position.SOLUTION: An imaging device 100 includes: an imaging element; an object information acquisition part which acquires the positional information on an object existing in an imaging region AR0 of an imaging element; an object region acquisition part for setting an object region AR based on the positional information on a reference object B acquired by the object information acquisition part; and a focus position control part for controlling the focal position of the imaging device 100 so as to align the focus position with an object when the object other than the reference object B is present in the object region AR.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] There are known autofocus imaging devices that automatically set a focal position. For example, Patent Document 1 describes that the focus is adjusted to a predetermined position designated by the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 141746 Summary of the Invention [Problem to be solved by the invention]

[0004] In an autofocus imaging device, it is required to properly adjust the focus.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide an imaging device, an imaging method, and a program that are capable of appropriately adjusting the focus. [Means for solving the problem]

[0006] An imaging device according to one aspect of the present invention is an imaging device capable of capturing an image of an object, and includes an imaging element, an object information acquisition unit that acquires positional information of an object present in an imaging area of ​​the imaging element, a target area acquisition unit that sets a target area based on positional information of a reference object acquired by the object information acquisition unit, and a focus position control unit that controls the focus position of the imaging device so as to focus on an object other than the reference object if the object is present in the target area.

[0007] An imaging method according to one aspect of the present invention is an imaging method for imaging an object, and includes the steps of acquiring position information of an object present in an imaging area, setting a target area based on the position information of a reference object acquired in the step of acquiring the position information of the object, and, if an object other than the reference object is present in the target area, controlling the focal position of an imaging device so as to focus on the object.

[0008] A program according to one aspect of the present invention is a program that causes a computer to execute an imaging method for imaging an object, and causes the computer to execute the following steps: acquiring positional information of an object present in an imaging area; setting a target area based on the positional information of a reference object acquired in the step of acquiring the positional information of the object; and, if an object other than the reference object is present in the target area, controlling the focal position of an imaging device so as to focus on the object. [Effects of the Invention]

[0009] According to the present invention, it is possible to appropriately adjust the focus. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic block diagram of an imaging device according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating an example of a target region. [Figure 3] FIG. 3 is a schematic diagram illustrating an example of a target region. [Figure 4] FIG. 4 is a schematic diagram showing an example in which a plurality of reference objects are set. [Figure 5] FIG. 5 is a flowchart illustrating the process flow for setting the focal position. [Figure 6] FIG. 6 is a schematic diagram illustrating an example of a target region according to the second embodiment. [Figure 7] FIG. 7 is a flowchart illustrating the process flow for setting the focal position. [Figure 8] FIG. 8 is a schematic diagram illustrating an example in which the motion of an object is set as a predetermined condition. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0012] (First embodiment) (Configuration of imaging device) FIG. 1 is a schematic block diagram of an imaging device according to a first embodiment. The imaging device 100 according to the first embodiment is an imaging device that captures an image of an object within an imaging range. The imaging device 100 is an autofocus camera that can automatically set the focal position. The imaging device 100 may be a video camera that captures moving images by capturing images every predetermined frame, or may be a camera that captures still images. The imaging device 100 may be used for any purpose, and may be used, for example, as a surveillance camera set at a predetermined position inside a facility or outdoors.

[0013] As shown in FIG. 1, the imaging device 100 includes an optical element 10, an imaging element 12, an image processing circuit 13, an object position measurement unit 14, an input unit 16, a display unit 18, a communication unit 20, a memory unit 22, and a control unit 24.

[0014] The optical element 10 is an element of an optical system such as a lens, etc. The optical element 10 may be one or more.

[0015] The imaging element 12 is an element that converts light incident through the optical element 10 into an image signal, which is an electrical signal. The imaging element 12 is, for example, a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor.

[0016] The image processing circuit 13 generates image data for each frame from the image signal generated by the imaging element 12. The image data is data including, for example, information on the luminance and color of each pixel in one frame, and may be data to which a gradation is assigned for each pixel.

[0017] The object position measuring unit 14 is a sensor that measures the position of the object to be measured with respect to the imaging device 100 (the relative position of the object). The object here may be any object, and may be a living or inanimate object, and the same applies hereinafter. Furthermore, the object here may refer to a movable object, but is not limited thereto and may also refer to an immobile object.

[0018] In this embodiment, the object position measuring unit 14 measures the distance from the image capturing device 100 to the object as the relative position of the object. The object position measuring unit 14 may be any sensor capable of measuring the relative position of the object, and may be, for example, a TOF (Time Of Flight) sensor. When the object position measuring unit 14 is a TOF sensor, for example, a light-emitting element (e.g., an LED (Light Emitting Diode)) that irradiates light and a light-receiving unit that receives the light are provided, and the distance to the object is measured based on the time of flight of light that is irradiated from the light-emitting element to the object and returned to the light-receiving unit. Note that the object position measuring unit 14 may measure, for example, the direction in which the object exists relative to the image capturing device 100 in addition to measuring the distance from the image capturing device 100 to the object as the relative position of the object. In other words, the object position measuring unit 14 may measure, as the relative position of the object, the position (coordinates) of the object in a coordinate system with the image capturing device 100 as the origin.

[0019] The input unit 16 is a mechanism for accepting input (operation) from the user, and may be, for example, a button, a keyboard, or a touch panel.

[0020] The display unit 18 is a display panel that displays an image. In addition to the image captured by the imaging device 100, the display unit 18 may also be capable of displaying an image for the user to set a target area AR (described later).

[0021] The communication unit 20 is a communication module that communicates with an external device, and may be, for example, an antenna, a Wi-Fi (registered trademark) module, etc. The imaging device 100 communicates with the external device via wireless communication, but wired communication may also be used, and any communication method may be used.

[0022] The storage unit 22 is a memory that stores various information such as captured image data, calculation contents and programs of the control unit 24, and includes at least one of a main storage device such as a RAM (Random Access Memory), a ROM (Read Only Memory), and an external storage device such as an HDD (Hard Disk Drive). The program for the control unit 24 stored in the storage unit 22 may be stored in a recording medium that can be read by the imaging device 100.

[0023] The control unit 24 is a computing device and includes an arithmetic circuit such as a CPU (Central Processing Unit). The control unit 24 includes a target area acquisition unit 30, an object information acquisition unit 32, a focus position control unit 34, an imaging control unit 36, and an image acquisition unit 38. The control unit 24 implements the target area acquisition unit 30, the object information acquisition unit 32, the focus position control unit 34, the imaging control unit 36, and the image acquisition unit 38 by reading and executing a program (software) from the storage unit 22. The control unit 24 may implement these processes using a single CPU, or may be provided with multiple CPUs and execute the processes using the multiple CPUs. At least a portion of the processes performed by the target area acquisition unit 30, the object information acquisition unit 32, the focus position control unit 34, the imaging control unit 36, and the image acquisition unit 38 may be implemented using hardware circuits.

[0024] (Object information acquisition unit) The object information acquisition unit 32 acquires position information of an object present within the imaging area AR0. The object information acquisition unit 32 controls the object position measurement unit 14 to cause the object position measurement unit 14 to measure the relative position of the object with respect to the imaging device 100. The object information acquisition unit 32 acquires the measurement result of the object's relative position with respect to the imaging device 100 by the object position measurement unit 14 as object position information. The object information acquisition unit 32 acquires object position information sequentially by acquiring object position information at predetermined time intervals. The object information acquisition unit 32 can also acquire information indicating the shape of the object (e.g., the 3D shape of the object) based on the object position information. For example, the object information acquisition unit 32 can acquire the 3D shape of the object by accumulating multiple pieces of position information, such as TOF image information.

[0025] (Target area acquisition section) The target area acquisition unit 30 acquires information about a target area AR set within the imaging area of ​​the imaging device 100. The target area AR is an area set to automatically adjust the focus position. The information about the target area AR is information indicating the position of the target area AR, i.e., position information about the target area AR. The target area AR will be described below.

[0026] 2 and 3 are schematic diagrams for explaining an example of a target area. FIG. 2 is a view of the imaging device 100 and the target area AR viewed from above in the vertical direction, and FIG. 3 is a view of the imaging device 100 and the target area AR viewed from the horizontal direction. Hereinafter, direction Z is defined as the vertical direction, direction X is defined as one horizontal direction perpendicular to direction Z, and direction Y is defined as a direction (horizontal direction) perpendicular to direction Z and direction X. As shown in FIGS. 2 and 3, the range in which an image can be captured by the imaging device 100 is defined as an imaging area AR0. The imaging area AR0 refers to the area (space) that falls within the angle of view of the imaging element 12, in other words, the range in real space that is captured as an image. The target area AR is an area (space) set within the range of the imaging area AR0.

[0027] More specifically, the target area acquisition unit 30 sets the target area AR based on position information of the reference object B. The reference object B is an object located within the imaging area AR0 that serves as a reference for setting the position of the target area AR. The target area acquisition unit 30 sets the target area AR based on the position information of the reference object B acquired by the object information acquisition unit 32.

[0028] The reference object B may be an object located between a first position AX1 and a second position AX2 within the imaging region AR0. The first position AX1 is a position at a first distance L1 from the image capture device 100, and the second position AX2 is a position at a second distance L2 that is shorter than the first distance L1. As shown in FIGS. 2 and 3 , in this embodiment, the first position AX1 can be considered to be a virtual plane that includes positions (coordinates) within the imaging region AR0 that are at the first distance L1 from the image capture device 100. Similarly, the second position AX2 can be considered to be a virtual plane that includes positions (coordinates) within the imaging region AR0 that are at the second distance L2 from the image capture device 100. That is, the reference object B can be considered to be located within a region (space) AR0a within the imaging region AR0 that is surrounded by a virtual plane at which the distance from the image capture device 100 is the second distance L2 and a virtual plane at which the distance from the image capture device 100 is the first distance L1. Note that the first position AX1 is not limited to being a virtual plane on which all positions (coordinates) included in the first position AX1 are the first distance L1 from the imaging device 100, but may be a virtual plane on which at least some positions (coordinates) included in the first position AX1 are the first distance L1 from the imaging device 100. Similarly, the second position AX2 may be a virtual plane on which at least some positions (coordinates) included in the second position AX2 are the second distance L2 from the imaging device 100.

[0029] However, the reference object B is not limited to being located between the first position AX1 and the second position AX2, and may be located at any position within the imaging area AR0. For example, if the range measurable by the object position measurement unit 14 is defined as the ranging area (ranging space), the reference object B may be an object located within the ranging area. In this case, the imaging area AR in FIGS. 2 to 4 may be treated as the ranging area.

[0030] In this embodiment, the reference object B may be an object that is stationary within the image capture area AR0, i.e., an object that does not move. For example, the reference object B may be an object such as a facility whose position is fixed within the image capture area AR0.

[0031] The reference object B may be set by any method. For example, the target area acquisition unit 30 may automatically set the reference object B. In this case, for example, the target area acquisition unit 30 may select the reference object B from among the objects located within the image capture area AR0 by any method. Alternatively, for example, the reference object B may be set by the user. In this case, for example, the user may input information for selecting the reference object B to the input unit 16, and the target area acquisition unit 30 may set the reference object B based on the information specifying the reference object B specified by the user. In this case, for example, an image within the image capture area AR may be displayed in real time on the display unit 18, and the user may input information for selecting the reference object B by selecting an image of the reference object B from among the objects captured in the image within the image capture area AR.

[0032] The target area acquisition unit 30 sets the target area AR based on the position information of the reference object B acquired by the object information acquisition unit 32. In this embodiment, the target area acquisition unit 30 sets a region (space) of a predetermined size around the reference object B, that is, a region of a predetermined size that includes the position of the reference object B, as the target area AR. In the example of FIGS. 2 and 3, the target area acquisition unit 30 sets a circle (here, a sphere) of a predetermined radius centered on the position of the reference object B as the target area AR. Furthermore, in this embodiment, since the reference object B is located within the area AR0a between the first position AX1 and the second position AX2 as described above, the target area AR is also located within the area AR0a between the first position AX1 and the second position AX2. However, the target area AR is not limited to being set as a sphere centered on the position of the reference object B, and may be a region arbitrarily set based on the position information of the reference object B, and may not be located within the area AR0a between the first position AX1 and the second position AX2.

[0033] 4 is a schematic diagram showing an example in which a plurality of reference objects are set. A plurality of reference objects B may be set. In this case, the target area acquisition unit 30 sets the target area AR based on the position information of the plurality of reference objects B. For example, as shown in FIG. 4, the target area acquisition unit 30 may set an area (space) surrounded by the plurality of reference objects B as the target area AR.

[0034] (Focus position control unit) The focus position control unit 34 sets the focus position of the imaging device 100. The focus position control unit 34 controls the focus position by controlling the position of the optical element 10, that is, by moving the position of the optical element 10.

[0035] The focus position control unit 34 adjusts the focus position to an object present within the target area AR. Here, the object refers to an object other than the reference object B, and in this embodiment, it preferably refers to a moving object. The focus position control unit 34 sets the focus position to the position of an object determined to be present within the target area AR. In this embodiment, the focus position control unit 34 determines whether an object is present within the target area AR based on position information of the object acquired by the object information acquisition unit 32. If the position of the object acquired by the object information acquisition unit 32 overlaps with the position of the target area AR, the focus position control unit 34 determines that the object is present within the target area AR and adjusts the focus position to the position of the object acquired by the object information acquisition unit 32. On the other hand, the focus position control unit 34 does not adjust the focus position to an object not present within the target area AR.

[0036] The focus position control unit 34 continues to focus on the object for a period during which the object for which the focus position is set is present within the target area AR. That is, the focus position control unit 34 determines whether the object continues to exist within the target area AR based on the object's position information acquired at predetermined time intervals by the object information acquisition unit 32, and continues to focus on the object for a period during which the object continues to exist within the target area AR. On the other hand, if the object for which the focus position is set moves outside the target area AR, i.e., if it is no longer present within the target area AR, the focus position control unit 34 moves the focus position away from the object and focuses on a position other than the object.

[0037] Note that the focus position control unit 34 does not need to adjust the focus position for an object that has been present in the target area AR since the imaging device 100 started operating (the timing when imaging is possible). That is, the focus position control unit 34 may adjust the focus position for an object that enters the target area AR after operation has started. In other words, the focus position control unit 34 may adjust the focus position for an object that exists in the target area AR at a certain timing but did not exist in the target area AR at a timing prior to that timing, from the timing when the object begins to exist in the target area AR. In other words, when an object moves from outside the target area AR into the target area AR, the focus position control unit 34 may recognize the object as a target to be focused on. That is, the focus position control unit 34 may adjust the focus position for an object that moves from outside the target area AR into the target area AR.

[0038] Furthermore, when no object is present within the target area AR, the focus position control unit 34 may adjust the focus position to a preset position. The position may be set arbitrarily, but is preferably set within the target area AR, such as the center position of the target area AR.

[0039] An example of the above-described process for adjusting the focal position will be described with reference to FIG. 2. FIG. 2 illustrates an example in which object A moves from position A0 outside the target area AR to position A1 within the target area AR to position A2 outside the target area AR in this order. In this case, the focal position control unit 34 does not adjust the focal position on object A when object A is at position A0, but instead adjusts the focal position to, for example, a set position. Then, when object A is at position A1, i.e., when object A enters the target area AR, the focal position control unit 34 adjusts the focal position on object A. While object A is located within the target area AR, the focal position control unit 34 continues to adjust the focal position on object A. Thereafter, when object A moves to position A2, i.e., when object A leaves the target area AR, the focal position control unit 34 removes the focal position from object A and returns the focal position to the set position. That is, the focus position control unit 34 adjusts the focus position to object A from the moment object A enters the target area AR, moves the focus position to match the moving object A while object A is moving within the target area AR, and removes the focus position from object A when object A moves out of the target area AR.

[0040] The focal position may be set by the user. In this case, for example, the camera may be able to switch between an auto mode in which the focal position is automatically set and a manual mode in which the user sets the focal position. In the auto mode, the focal position is set by the focal position control unit 34 as described above. On the other hand, in the manual mode, the user inputs an operation to set the focal position into the input unit 16, and the focal position control unit 34 sets the focal position in accordance with the user's operation.

[0041] (imaging control unit) The imaging control unit 36 ​​controls imaging by the imaging device 100 to capture an image. The imaging control unit 36 ​​controls, for example, the imaging element 12 to cause the imaging element 12 to acquire an image signal. For example, the imaging control unit 36 ​​may cause the imaging element 12 to acquire an image signal automatically, or may cause the imaging element 12 to acquire an image signal in response to a user operation.

[0042] (Image acquisition section) The image acquisition unit 38 acquires image data acquired by the imaging element 12. The image acquisition unit 38, for example, controls the image processing circuit 13 to cause the image processing circuit 13 to generate image data from the image signal generated by the imaging element 12, and acquires the image data. The image acquisition unit 38 stores the image data in the storage unit 22.

[0043] (Focus position setting flow) Next, the process flow for setting the focal position described above will be described. FIG. 5 is a flowchart illustrating the process flow for setting the focal position. As shown in FIG. 5, the control unit 24 acquires position information of the reference object B using the object information acquisition unit 32 (step S10), and sets a target area AR based on the position information of the reference object B using the target area acquisition unit 30 (step S12). Then, the control unit 24 acquires position information of the object using the object information acquisition unit 32 (step S14). The order of steps S10, S12, and S14 may be arbitrary. The control unit 24 determines, using the focus position control unit 34, whether the object is located within the target area AR based on the position information of the object (step S16). If the object is not located within the target area AR (step S16; No), the process returns to step S14 and continues to acquire position information of the object. On the other hand, if the object is located within the target area AR (step S16; Yes), the focus position control unit 34 adjusts the focal position to the object (step S18). Thereafter, the acquisition of object position information is continued, and it is determined whether the object has moved outside the target area AR (step S20). If the object has not moved outside the target area AR (step S20; No), that is, if the object continues to exist within the target area AR, the process returns to step S18, and the focus position continues to be adjusted to the object. If the object has moved outside the target area AR (step S20; Yes), the focus position control unit 34 removes the focus position from the object (step S22). Thereafter, if the process is not to be ended (step S24; No), the process returns to step S14, and if the process is to be ended (step S24; Yes), the process ends.

[0044] (effect) As described above, the imaging device 100 according to this embodiment includes the image sensor 12, the object information acquisition unit 32, the target area acquisition unit 30, and the focus position control unit 34. The object information acquisition unit 32 acquires position information of an object present in the imaging area AR0 of the image sensor 12. The target area acquisition unit 30 sets the target area AR based on the position information of the reference object B acquired by the object information acquisition unit 32. If an object other than the reference object B is present in the target area AR, the focus position control unit 34 controls the focus position of the imaging device 100 so as to focus on that object.

[0045] Here, autofocus imaging devices are required to appropriately adjust the focal position. In contrast, the imaging device 100 according to this embodiment sets a target area AR based on the position of a reference object B, and if an object exists within the target area AR, controls the focal position of the imaging device 100 so as to adjust the focal position to the object. Therefore, for example, when there is an object that requires attention in surveillance, the object can be used as the reference object B, and the focus can be appropriately adjusted to an object nearby.

[0046] The target area acquisition section 30 may set the area around the reference object B as the target area AR. This makes it possible to appropriately focus on an object near the reference object B that is of interest.

[0047] The target area acquisition unit 30 may set, as the target area AR, an area surrounded by a plurality of reference objects B. This makes it possible to appropriately focus on an object near the plurality of reference objects B that should be noted.

[0048] The target area acquisition unit 30 may set the target area AR based on the position information of the reference object B that is stationary within the imaging area AR0. This makes it possible to appropriately focus on an object near the stationary reference object B.

[0049] The target area acquisition unit 30 may set the target area AR based on position information of a reference object B located between a first position AX1, which is a first distance L1 from the image capture device 100, and a second position AX2, which is a second distance L2 from the image capture device 100 that is shorter than the first distance L1. By setting the object located between the first position AX1 and the second position AX2 as the reference object B, it becomes possible to appropriately focus on an object near the reference object B located at such a position.

[0050] Next, a second embodiment will be described. The second embodiment differs from the first embodiment in that the target area AR is set based on position information of a moving reference object B. Descriptions of parts of the second embodiment that are common to the first embodiment will be omitted.

[0051] In the second embodiment, the target area acquisition unit 30 sets the target area AR based on position information of a moving reference object B. The object information acquisition unit 32 sequentially acquires position information of the reference object B. The target area acquisition unit 30 sets the target area AR so that the target area AR also moves as the reference object B moves, i.e., as the position information of the reference object B changes. It is preferable that the target area acquisition unit 30 sets the target area AR so that the target area AR also moves while maintaining the same position (relative position) of the target area AR with respect to the reference object B. In other words, it can be said that the target area acquisition unit 30 sequentially updates the position of the target area AR while maintaining the same position of the target area AR with respect to the reference object B as the reference object B moves.

[0052] The focus position control unit 34 adjusts the focus position on an object present within the target area AR. In the second embodiment, when a stationary (non-moving) object is positioned within the target area AR due to movement of the target area AR, the focus position control unit 34 does not adjust the focus position on the object. In other words, even if the stationary object is positioned within the target area AR, the focus position control unit 34 does not treat the object as an object to be adjusted in focus, and does not adjust the focus position on the object. On the other hand, when a moving object is positioned within the target area AR, that is, when the moving object reaches the target area AR, the focus position control unit 34 adjusts the focus position on the object. Whether an object is moving can be determined based on the object's position information obtained by the object information acquisition unit 32. In other words, when the position information of consecutive objects changes in time series, it can be determined that the object is moving.

[0053] An example of the above-described process for adjusting the focal position will be described with reference to FIG. 6. FIG. 6 is a schematic diagram illustrating an example of a target area according to the second embodiment. FIG. 6 illustrates an example in which a reference object B moves from position B1 to position B2, then to position B3, and then to position B4, and the target area AR is set as an area centered around the reference object B. In this case, the target area AR also moves along with the movement of the reference object B. In the following, the position of the target area AR when the reference object B is at position B1 is referred to as position AR1, the position of the target area AR when the reference object B is at position B2 is referred to as position AR2, the position of the target area AR when the reference object B is at position B3 is referred to as position AR3, and the position of the target area AR when the reference object B is at position B4 is referred to as position AR4. In the example of FIG. 6, since no object exists within the target area AR at position AR1, when the reference object B is at position B1 (the target area AR is at position AR1), the focus position control unit 34 does not adjust the focal position to the object but adjusts the focal position to the set position. Furthermore, at the time when the target area AR moves from position AR1 to position AR2, a stationary object Aa is located within the target area AR. In this case, the object Aa is stationary, and as the target area AR moves, the stationary object Aa is located within the target area AR. Therefore, the focus position control unit 34 does not focus on the object Aa, but instead focuses on the set position. Note that since the set position here is set based on the target area AR, the set position also moves as the target area AR moves. It is preferable that the set position moves while maintaining the same position (relative position) with respect to the target area AR.

[0054] When the target area AR moves from position AR2 to position AR3, the moving object Ab is located within the target area AR. In this case, since the moving object Ab is located within the target area AR, the focus position control unit 34 adjusts the focus position to the object Ab and continues to adjust the focus position to the object Ab while the object Ab is located within the target area AR. Thereafter, when the target area AR moves from position AR3 to position AR4, the object Ab is located outside the target area AR. When the object Ab is located outside the target area AR, the focus position control unit 34 removes the focus position from the object Ab and adjusts the focus position to the set position.

[0055] Next, a process flow for setting the focal position in the second embodiment will be described. FIG. 7 is a flowchart illustrating the process flow for setting the focal position. As shown in FIG. 7, the control unit 24 acquires position information of the reference object B using the object information acquisition unit 32 (step S30), and sets a target area AR based on the position information of the reference object B using the target area acquisition unit 30 (step S32). Then, the control unit 24 acquires position information of the object using the object information acquisition unit 32 (step S34). Steps S30, S32, and S34 may be performed in any order. The control unit 24 determines, using the focus position control unit 34, whether the object is located within the target area AR based on the position information of the object (step S36). If the object is not located within the target area AR (step S36; No), the process returns to step S30, and the control unit 24 continues to acquire position information of the object while acquiring position information of the reference object and updating the target area AR. On the other hand, if the object is located within the target area AR (step S36; Yes), the focus position control unit 34 determines whether the object is moving (step S38). If the object in the target area AR has not moved (step S38; No), the focus position control unit 34 returns to step S30, acquires position information of the reference object, updates the target area AR, and continues acquiring position information of the object. If the object in the target area AR has moved (step S38; Yes), the focus position control unit 34 adjusts the focus position on the object (step S40). Thereafter, the focus position control unit 34 acquires position information of the reference object, updates the target area AR, and continues acquiring position information of the object to determine whether the object has moved outside the target area AR (step S42). If the object has not moved outside the target area AR (step S42; No), that is, if the object remains within the target area AR, the process returns to step S40, and the focus position continues to be adjusted on the object. If the object has moved outside the target area AR (step S42; Yes), the focus position control unit 34 removes the focus position from the object (step S44). Thereafter, if the process is not to be ended (step S46; No), the process returns to step S30, and if the process is to be ended (step S46; Yes), the process is ended.

[0056] As described above, in the second embodiment, the target area acquisition unit 30 sets the target area AR based on position information of the moving reference object B. The target area acquisition unit 30 sets the target area AR so that the target area AR also moves in accordance with the movement of the reference object B. Therefore, for example, when an object that requires attention moves in surveillance, the target area AR can be moved to match the object, thereby making it possible to appropriately focus on the vicinity of the moving object.

[0057] (Third embodiment) Next, a third embodiment will be described. The third embodiment differs from the first embodiment in that the focal position is adjusted to an object that exists within the target area AR and satisfies a predetermined condition. Explanations of parts of the third embodiment that are common to the first embodiment will be omitted. The third embodiment can also be applied to the first embodiment.

[0058] In the third embodiment, the focus position control unit 34 adjusts the focus position on an object that exists within the target area AR and satisfies a predetermined condition. The focus position control unit 34 does not adjust the focus position on an object that does not satisfy at least one of the following conditions: existence within the target area AR; and the predetermined condition. The focus position control unit 34 continues to adjust the focus position on the object for a period during which the object satisfies the predetermined condition and remains within the target area AR. On the other hand, the focus position control unit 34 shifts the focus position from the object when the object no longer satisfies at least one of existence within the target area AR and the predetermined condition. That is, for example, the focus position control unit 34 shifts the focus position from the object when the object satisfies the predetermined condition but moves outside the target area AR, or when the object exists within the target area AR but no longer satisfies the predetermined condition.

[0059] The focus position control unit 34 may determine whether the predetermined conditions are met using any method, but may determine whether the predetermined conditions are met based on at least one of object position information and an image of the object. The object position information here may refer to the measurement results of the object position measurement unit 14, and the image of the object may refer to image data of the object acquired by the image sensor 12.

[0060] The predetermined condition here may be any condition other than the presence of an object within the target area AR. For example, the predetermined condition may be at least one of the following: the object is performing a predetermined motion, the object has a predetermined shape, and the object is facing a predetermined direction. Alternatively, any two of these may be the predetermined conditions, or all of these may be the predetermined conditions. When multiple predetermined conditions are set, the focus position control unit 34 determines that the predetermined conditions are met when all of the conditions are met.

[0061] A case where object movement is the predetermined condition will be described. In this case, the focus position control unit 34 determines whether the object is performing a predetermined movement based on the object's position information continuously acquired in time series. The focus position control unit 34 adjusts the focus position to an object that exists within the target area AR and is performing a predetermined movement. The focus position control unit 34 does not adjust the focus position to an object that does not satisfy at least one of the conditions of being present within the target area AR and performing a predetermined movement. The focus position control unit 34 continues to adjust the focus position to the object for a period during which the object is present within the target area AR and continues performing a predetermined movement. On the other hand, if the object no longer satisfies at least one of the conditions of being present within the target area AR and performing a predetermined movement, the focus position control unit 34 removes the focus position from the object. Note that the movement of the object here refers to the object's movement mode, and may refer to, for example, the object's movement direction and movement speed. For example, if the predetermined movement refers to vertically downward movement at a speed of 10 m / h or more, the focus position control unit 34 adjusts the focus position on an object moving vertically downward within the target area AR at a speed of 10 m / h or more. Note that the movement of an object is not limited to the direction and speed of the object's movement, but may refer to any movement pattern. For example, the movement of an object may refer to at least one of the direction and speed of the object's movement.

[0062] FIG. 8 is a schematic diagram illustrating an example in which the predetermined condition is the movement of an object. In the example of FIG. 8, the predetermined condition is the vertical downward movement of the object (opposite to the Z direction), i.e., the movement direction of the object. The example of FIG. 8 illustrates a case in which object A moves vertically downward from position A0a, passing through positions A1a and A2a, to position A3a, and stops at position A3a. Position A0a is outside the target area AR, while positions A1a, A2a, and A3a are within the target area AR. In this case, when object A is located at position A0a, object A is outside the target area AR, so the focus position control unit 34 does not focus on object A, but instead focuses on a set position, for example. Then, when object A is located at position A1a, i.e., when object A enters the target area AR while moving vertically downward, the focus position control unit 34 focuses on object A. The focal position control unit 34 continues to adjust the focal position to the object A even when the object A is at the position A2a, and when the object A moves to the position A3a and stops, it removes the focal position from the object A and returns the focal position to the set position.

[0063] Next, a case where the shape of an object is set as a predetermined condition will be described. In this case, the focus position control unit 34 determines whether the object has a predetermined shape based on image data containing the object. The focus position control unit 34 adjusts the focus position to an object that exists within the target area AR and has a predetermined shape. The focus position control unit 34 does not adjust the focus position to an object that does not satisfy at least one of the conditions of being present within the target area AR and having a predetermined shape. The focus position control unit 34 continues to adjust the focus position to the object for a period during which the object has the predetermined shape and continues to exist within the target area AR. On the other hand, if the object no longer satisfies at least one of the conditions of being present within the target area AR and having a predetermined shape, the focus position control unit 34 removes the focus position from the object. The shape of the object here may be, for example, at least one of the size and the outer shape of the object. For example, if the predetermined shape refers to an object that is equal to or larger than a predetermined size, the focus position control unit 34 adjusts the focus position to an object that exists within the target area AR and has the predetermined size or larger. Note that 3D shape information acquired by the object information acquisition unit 32 may be used to acquire the shape information of the object.

[0064] A case where the orientation of an object is set as a predetermined condition will be described. In this case, the focus position control unit 34 determines whether the object is facing a predetermined direction based on image data containing the object. The focus position control unit 34 adjusts the focus position to an object that exists within the target area AR and faces the predetermined direction. The focus position control unit 34 does not adjust the focus position to an object that does not satisfy at least one of the conditions of being present within the target area AR and facing the predetermined direction. The focus position control unit 34 continues to adjust the focus position to the object for a period during which the object continues to exist within the target area AR while facing the predetermined direction. On the other hand, if the object no longer satisfies at least one of the conditions of being present within the target area AR and facing the predetermined direction, the focus position control unit 34 removes the focus position from the object. Note that 3D shape information acquired by the object information acquisition unit 32 may be used to acquire information about the object's orientation.

[0065] The predetermined conditions may be set in any manner, for example, they may be set in advance. In this case, the focus position control unit 34 may read information indicating the predetermined conditions (e.g., movement direction and movement speed) from the storage unit 22, or may acquire the predetermined conditions from another device via the communication unit 20. Furthermore, for example, if the predetermined conditions are not set in advance, the focus position control unit 34 may automatically set the predetermined conditions. Furthermore, for example, the user may set the predetermined conditions. In this case, for example, the user may input information specifying the predetermined conditions (e.g., movement direction and movement speed) to the input unit 16, and the focus position control unit 34 may set the predetermined conditions based on the information specified by the user.

[0066] As described above, in the third embodiment, the focus position control unit 34 may adjust the focus position on an object that is present in the target area AR and is performing a predetermined motion. The focus position control unit 34 continues to adjust the focus position on the object while the object is performing the predetermined motion, and removes the focus position from the object when the object stops performing the predetermined motion. In this way, by setting the condition for adjusting the focus position as being within the target area AR and also satisfying the predetermined motion, it becomes possible to track an object performing a specific motion and adjust the focus position appropriately.

[0067] In the third embodiment, the focus position control unit 34 may adjust the focus position to an object that exists in the target area AR and has a predetermined shape. In this way, by setting the condition for adjusting the focus position that the object has a predetermined shape in addition to being within the target area AR, it becomes possible to track an object of a specific shape and adjust the focus position appropriately.

[0068] In the third embodiment, the focus position control unit 34 may adjust the focus position to an object that exists in the target area AR and faces a predetermined direction. In this way, by setting the condition for adjusting the focus position as facing a predetermined direction in addition to being within the target area AR, it becomes possible to track an object facing a specific direction and adjust the focus position appropriately.

[0069] Although the embodiments of the present invention have been described above, the embodiments are not limited by the content of these embodiments. Furthermore, the above-described components include those easily conceivable to those skilled in the art, those that are substantially identical, and those within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate, and the configurations of each embodiment can be combined. Furthermore, various omissions, substitutions, or modifications of components can be made without departing from the spirit of the above-described embodiments. Furthermore, while each embodiment has been described with the focus position adjustment operation as a characteristic feature, the focus position adjustment operation may be combined with other operations. For example, the focus position adjustment operation may be combined with a zooming operation. Furthermore, in the description of each embodiment, the focus position adjustment operation may be replaced with other operations. For example, the focus position adjustment operation may be replaced with a zooming operation. Furthermore, in each embodiment, the control unit 24 of the imaging device may send a notification to a predetermined destination via the communication unit 20 when a set condition is met, such as an object entering or leaving a predetermined target area AR or moving in a predetermined direction. The set condition here may refer to, for example, adjusting the focus position to an object when the object moves into the target area AR. [Explanation of symbols]

[0070] 10 Optical Elements 12 Image sensor 14 Object position measurement section 30 Target area acquisition unit 32 Object information acquisition unit 34 Focus position control unit AR target area AR0 imaging area B Reference object

Claims

1. An imaging device capable of imaging an object, An imaging element; an object information acquisition unit that acquires three-dimensional position information of an object present in an imaging area of ​​the imaging element; a target area acquisition unit that sets a three-dimensional target area based on the position information of the reference object acquired by the object information acquisition unit; a focus position control unit that controls a focus position of the imaging device so as to focus on an object other than the reference object when the object is present in the target area; having Imaging device.

2. The imaging device according to claim 1 , wherein the target area acquisition unit sets an area around the reference object as the target area.

3. The imaging device according to claim 1 , wherein the target area acquisition unit sets an area surrounded by a plurality of the reference objects as the target area.

4. The imaging device according to claim 1 , wherein the target area acquisition unit sets the target area based on position information of the reference object that is stationary within the imaging area.

5. 5. The imaging device according to claim 1, wherein the target area acquisition unit sets the target area based on position information of the reference object located between a first position at a first distance from the imaging device and a second position at a second distance from the imaging device that is shorter than the first distance.

6. An imaging method for imaging an object, comprising: acquiring three-dimensional position information of an object present in an imaging area; setting a three-dimensional target region based on the position information of the reference object acquired in the step of acquiring the position information of the object; If an object other than the reference object is present within the target area, controlling the focal position of the imaging device so as to focus on the object; Including, Imaging method.

7. A program for causing a computer to execute an imaging method for imaging an object, acquiring three-dimensional position information of an object present in an imaging area; setting a three-dimensional target region based on the position information of the reference object acquired in the step of acquiring the position information of the object; If an object other than the reference object is present within the target area, controlling the focal position of the imaging device so as to focus on the object; causing the computer to execute program.

Images