JP6413170B1 - Determination apparatus, imaging apparatus, imaging system, moving object, determination method, and program - Google Patents

Abstract

A driving amount of a focus lens in auto focus is further optimized.
A determination device is a determination device that determines a driving amount of a focus lens included in an imaging device. The determination apparatus may include an acquisition unit that acquires the contrast values of the plurality of images captured with the first F value by the imaging apparatus. The determination apparatus may include a selection unit that selects a second F value different from the first F value based on the contrast value. The determining device may include a determining unit that determines the driving amount of the focus lens based on the second F value and the contrast value.
[Selection] Figure 7

Description

  The present invention relates to a determination device, an imaging device, an imaging system, a moving object, a determination method, and a program.

Japanese Patent Application Laid-Open No. H10-228561 describes that in the autofocus process (AF process), the moving speed per unit time of the focus lens is determined according to the blurred state.
Patent Document 1 Patent No. 4323964

  As AF processing, AF processing using a plurality of images with different amounts of blur imaged with different shooting parameters is known. In such AF processing, the focus lens drive amount cannot be appropriately controlled only by controlling the drive amount of the focus lens in accordance with the blurred state.

  A determination device according to an aspect of the present invention is a determination device that determines a driving amount of a focus lens included in an imaging device. The determination apparatus may include an acquisition unit that acquires the contrast values of the plurality of images captured with the first F value by the imaging apparatus. The determination apparatus may include a selection unit that selects a second F value different from the first F value based on the contrast value. The determining device may include a determining unit that determines the driving amount of the focus lens based on the second F value and the contrast value.

  The selection unit may select a second F value smaller than the first F value when at least one of the plurality of contrast values is larger than the first threshold value.

  The selection unit may select a second F value larger than the first F value when at least one of the plurality of contrast values is smaller than the second threshold value.

  The selection unit selects a second F value smaller than the first F value when the plurality of contrast values are larger than the first threshold value, and selects the first F value when the plurality of contrast values are smaller than the first threshold value. A third F value greater than the value may be selected.

  The determination unit may determine the driving amount of the focus lens based on the second F value or the third F value and the contrast value.

  After the focus lens is driven with the drive amount of the focus lens determined by the determination unit, the acquisition unit may acquire each contrast value of a plurality of images captured with the first F value by the imaging device. The selection unit selects the second F value when the acquired plurality of contrast values is larger than the first threshold value, and selects the third F value when the acquired plurality of contrast values are smaller than the first threshold value. May be selected. The determination unit may determine the driving amount of the focus lens based on the second F value or the third F value and the contrast value.

  The determining unit may determine the speed of the focus lens as the driving amount of the focus lens. The focus lens may be driven at a speed determined by the determination unit for a predetermined time.

  An imaging device according to an aspect of the present invention may include the determination device. The imaging device may include an image sensor that captures a plurality of images. The imaging device may include a focus lens.

  The imaging system which concerns on 1 aspect of this invention may be provided with the said imaging device. The imaging system may include a support mechanism that supports the imaging device.

  A moving body according to one embodiment of the present invention may move with the imaging system.

  A moving object according to one embodiment of the present invention is a determination method for determining a driving amount of a focus lens included in an imaging device. The determination method may include obtaining a contrast value of each of a plurality of images captured with the first F value by the imaging device. The determination method may comprise selecting a second F value different from the first F value based on the contrast value. The determination method may include a step of determining a drive amount of the focus lens based on the second F value and the contrast value.

  A program according to one embodiment of the present invention is a program for causing a computer to determine a driving amount of a focus lens included in an imaging apparatus. The program may cause the computer to execute a step of acquiring each contrast value of a plurality of images captured with the first F value by the imaging device. The program may cause the computer to execute a step of selecting a second F value different from the first F value based on the contrast value. The program may cause the computer to execute a step of determining the driving amount of the focus lens based on the second F value and the contrast value.

  According to one embodiment of the present invention, the driving amount of the focus lens in autofocus can be further optimized.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a figure which shows an example of the external appearance of an unmanned aircraft and a remote control device. It is a figure which shows an example of the functional block of an unmanned aerial vehicle. It is a figure for demonstrating the relationship between the position of an object, the position of a lens, and a focal distance. It is a graph which shows an example of the relationship between F value and contrast value in a BDAF system. It is a figure for demonstrating the curve referred when determining the drive amount of a focus lens. It is a figure for demonstrating the curve referred when determining the drive amount of a focus lens. It is a flowchart which shows an example of the procedure of AF process by an imaging control part. It is a figure which shows an example of a hardware constitutions.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Moreover, not all the combinations of features described in the embodiments are essential for the solution means of the invention. It will be apparent to those skilled in the art that various modifications or improvements can be made to the following embodiments. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The claims, the description, the drawings, and the abstract include matters subject to copyright protection. The copyright owner will not object to any number of copies of these documents as they appear in the JPO file or record. However, in other cases, all copyrights are reserved.

  Various embodiments of the present invention may be described with reference to flowcharts and block diagrams, where a block is either (1) a stage in a process in which an operation is performed or (2) an apparatus responsible for performing the operation. May represent a “part”. Certain stages and “units” may be implemented by programmable circuits and / or processors. Dedicated circuitry may include digital and / or analog hardware circuitry. Integrated circuits (ICs) and / or discrete circuits may be included. The programmable circuit may include a reconfigurable hardware circuit. Reconfigurable hardware circuits include logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logical operations, flip-flops, registers, field programmable gate arrays (FPGA), programmable logic arrays (PLA), etc. The memory element or the like may be included.

  Computer-readable media may include any tangible device that can store instructions executed by a suitable device. As a result, a computer readable medium having instructions stored thereon comprises a product that includes instructions that can be executed to create a means for performing the operations specified in the flowcharts or block diagrams. Examples of computer readable media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer readable media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory), Electrically erasable programmable read only memory (EEPROM), static random access memory (SRAM), compact disc read only memory (CD-ROM), digital versatile disc (DVD), Blu-ray (RTM) disc, memory stick, integrated A circuit card or the like may be included.

  The computer readable instructions may include either source code or object code written in any combination of one or more programming languages. The source code or object code includes a conventional procedural programming language. Conventional procedural programming languages include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or Smalltalk, JAVA, C ++, etc. It may be an object-oriented programming language and a “C” programming language or a similar programming language. Computer readable instructions may be directed to a general purpose computer, special purpose computer, or other programmable data processing device processor or programmable circuit locally or in a wide area network (WAN) such as a local area network (LAN), the Internet, etc. ). The processor or programmable circuit may execute computer readable instructions to create a means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

  FIG. 1 shows an example of the external appearance of an unmanned aerial vehicle (UAV) 10 and a remote control device 300. The UAV 10 includes a UAV main body 20, a gimbal 50, a plurality of imaging devices 60, and an imaging device 100. The gimbal 50 and the imaging device 100 are an example of an imaging system. The UAV 10 is an example of a moving body propelled by a propulsion unit. The moving body is a concept including a flying body such as another aircraft moving in the air, a vehicle moving on the ground, a ship moving on the water, etc. in addition to the UAV.

  The UAV main body 20 includes a plurality of rotor blades. The plurality of rotor blades is an example of a propulsion unit. The UAV main body 20 causes the UAV 10 to fly by controlling the rotation of a plurality of rotor blades. For example, the UAV main body 20 causes the UAV 10 to fly using four rotary wings. The number of rotor blades is not limited to four. The UAV 10 may be a fixed wing machine that does not have a rotating wing.

  The imaging device 100 is an imaging camera that images a subject included in a desired imaging range. The gimbal 50 supports the imaging device 100 in a rotatable manner. The gimbal 50 is an example of a support mechanism. For example, the gimbal 50 supports the imaging device 100 so as to be rotatable about the pitch axis using an actuator. The gimbal 50 further supports the imaging device 100 using an actuator so as to be rotatable about the roll axis and the yaw axis. The gimbal 50 may change the posture of the imaging device 100 by rotating the imaging device 100 about at least one of the yaw axis, the pitch axis, and the roll axis.

  The plurality of imaging devices 60 are sensing cameras that image the surroundings of the UAV 10 in order to control the flight of the UAV 10. Two imaging devices 60 may be provided in the front which is the nose of UAV10. Two other imaging devices 60 may be provided on the bottom surface of the UAV 10. The two imaging devices 60 on the front side may be paired and function as a so-called stereo camera. The two imaging devices 60 on the bottom side may also be paired and function as a stereo camera. Based on images picked up by a plurality of image pickup devices 60, three-dimensional spatial data around the UAV 10 may be generated. The number of imaging devices 60 included in the UAV 10 is not limited to four. The UAV 10 only needs to include at least one imaging device 60. The UAV 10 may include at least one imaging device 60 on each of the nose, the tail, the side surface, the bottom surface, and the ceiling surface of the UAV 10. The angle of view that can be set by the imaging device 60 may be wider than the angle of view that can be set by the imaging device 100. The imaging device 60 may have a single focus lens or a fisheye lens.

  The remote operation device 300 communicates with the UAV 10 to remotely operate the UAV 10. The remote operation device 300 may communicate with the UAV 10 wirelessly. The remote control device 300 transmits to the UAV 10 instruction information indicating various commands related to movement of the UAV 10 such as ascending, descending, accelerating, decelerating, moving forward, moving backward, and rotating. The instruction information includes, for example, instruction information for raising the altitude of the UAV 10. The instruction information may indicate the altitude at which the UAV 10 should be located. The UAV 10 moves so as to be located at an altitude indicated by the instruction information received from the remote operation device 300. The instruction information may include an ascending command that raises the UAV 10. The UAV 10 rises while accepting the ascent command. Even if the UAV 10 receives the ascending command, the UAV 10 may limit the ascent when the altitude of the UAV 10 has reached the upper limit altitude.

  FIG. 2 shows an example of functional blocks of the UAV 10. The UAV 10 includes a UAV control unit 30, a memory 32, a communication interface 34, a propulsion unit 40, a GPS receiver 41, an inertial measurement device 42, a magnetic compass 43, a barometric altimeter 44, a gimbal 50, an imaging device 60 and an imaging device 100.

  The communication interface 34 communicates with other devices such as the remote operation device 300. The communication interface 34 may receive instruction information including various commands for the UAV control unit 30 from the remote operation device 300. In the memory 32, the UAV control unit 30 controls the propulsion unit 40, the GPS receiver 41, the inertial measurement device (IMU) 42, the magnetic compass 43, the barometric altimeter 44, the gimbal 50, the imaging device 60, and the imaging device 100. Stores necessary programs etc. The memory 32 may be a computer-readable recording medium and may include at least one of flash memory such as SRAM, DRAM, EPROM, EEPROM, and USB memory. The memory 32 may be provided inside the UAV main body 20. It may be provided so as to be removable from the UAV main body 20.

  The UAV control unit 30 controls the flight and imaging of the UAV 10 according to a program stored in the memory 32. The UAV control unit 30 may be configured by a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The UAV control unit 30 controls the flight and imaging of the UAV 10 according to a command received from the remote control device 300 via the communication interface 34. The propulsion unit 40 propels the UAV 10. The propulsion unit 40 includes a plurality of rotating blades and a plurality of drive motors that rotate the plurality of rotating blades. The propulsion unit 40 causes the UAV 10 to fly by rotating a plurality of rotor blades via a plurality of drive motors in accordance with a command from the UAV control unit 30.

  The GPS receiver 41 receives a plurality of signals indicating times transmitted from a plurality of GPS satellites. The GPS receiver 41 calculates the position of the GPS receiver 41, that is, the position of the UAV 10 based on the received signals. The IMU 42 detects the posture of the UAV 10. The IMU 42 detects, as the posture of the UAV 10, acceleration in the three axial directions of the front, rear, left, and right of the UAV 10, and angular velocity in the three axial directions of pitch, roll, and yaw. The magnetic compass 43 detects the heading of the UAV 10. The barometric altimeter 44 detects the altitude at which the UAV 10 flies. The barometric altimeter 44 detects the atmospheric pressure around the UAV 10, converts the detected atmospheric pressure into an altitude, and detects the altitude.

  The imaging device 100 includes an imaging unit 102 and a lens unit 200. The lens unit 200 is an example of a lens device. The imaging unit 102 includes an image sensor 120, an imaging control unit 110, and a memory 130. The image sensor 120 may be configured by a CCD or a CMOS. The image sensor 120 outputs image data of an optical image formed through the plurality of lenses 210 to the imaging control unit 110. The imaging control unit 110 may be configured by a microprocessor such as a CPU or MPU, a microcontroller such as an MCU, or the like. The imaging control unit 110 may control the imaging device 100 in accordance with an operation command for the imaging device 100 from the UAV control unit 30. The memory 130 may be a computer-readable recording medium and may include at least one of flash memory such as SRAM, DRAM, EPROM, EEPROM, and USB memory. The memory 130 stores a program and the like necessary for the imaging control unit 110 to control the image sensor 120 and the like. The memory 130 may be provided inside the housing of the imaging device 100. The memory 130 may be provided so as to be removable from the housing of the imaging apparatus 100.

  The lens unit 200 includes a plurality of lenses 210, a lens moving mechanism 212, and a lens control unit 220. The plurality of lenses 210 may function as a zoom lens, a varifocal lens, and a focus lens. At least some or all of the plurality of lenses 210 are arranged to be movable along the optical axis. The lens unit 200 may be an interchangeable lens that is detachably attached to the imaging unit 102. The lens moving mechanism 212 moves at least some or all of the plurality of lenses 210 along the optical axis. The lens control unit 220 drives the lens moving mechanism 212 in accordance with a lens control command from the imaging unit 102 to move one or more lenses 210 along the optical axis direction. The lens control command is, for example, a zoom control command and a focus control command.

  The imaging apparatus 100 configured as described above performs autofocus processing (AF processing) and images a desired subject.

  The imaging apparatus 100 determines the distance from the lens to the subject (subject distance) in order to execute AF processing. As a method for determining the subject distance, there is a method of determining based on a parameter indicating the degree of blur of a plurality of images captured in a state where the positional relationship between the lens and the imaging surface is different. Here, this method is referred to as a blur detection auto focus (BDAF) method.

With reference to FIG. 3, the procedure for calculating the distance in the BDAF method will be described. The distance from the lens L (principal point) to the object 510 (object surface) is A, the distance from the lens L (principal point) to the position (image plane) where the object 510 forms an image on the imaging surface is B, and the focal length is F. And In this case, the relationship between the distance A, the separation B, and the focal length F can be expressed by the following formula (1) from the lens formula.

  The focal length F is specified by the lens position. Therefore, if the distance B at which the object 510 forms an image on the imaging surface can be specified, the distance A from the lens L to the object 510 can be specified using Expression (1).

  As shown in FIG. 3, the distance B is specified by calculating the position at which the object 510 is imaged from the blur size (the circles of confusion 512 and 514) of the object 510 projected on the imaging surface, and further the distance A can be specified. That is, the imaging position can be specified in consideration of the fact that the blur amount is proportional to the imaging surface and the imaging position, using the blur size (blur amount) as a parameter indicating the degree of blur.

Here, the distance from the image I ₁ close to the imaging surface to the lens L and D _1. The distance from the image I ₂ far from the image plane to the lens L is D ₂ . Each image is blurred. The point spread function at this time is PSF, and the images at D ₁ and D ₂ are I _d1 and I _d2 , respectively. In this case, for example, the image I ₁ can be expressed by the following equation (2) by a convolution operation.

Further, the Fourier transform function of the image data _{I d1} and _{I d2} as f, the point spread image _{I d1} and _{I d2} function PSF ₁ and the optical transfer function of the PSF ₂ Fourier transform (Optical Transfer Function) of the OTF ₁ and OTF ₂ , the ratio is as shown in the following equation (3).

The value C shown in Expression (3) corresponds to the amount of change in the blur amount of each of the images I _d1 and I _d2 , that is, the value C corresponds to the difference between the blur amount of the image I _{d1 and} the blur amount of the image I _d2n. .

  FIG. 4 is a graph showing an example of the relationship between the F value and the contrast value in the BDAF method. The smaller the contrast value, the larger the blur amount, and the larger the contrast value, the smaller the blur amount. That is, the contrast value and the blur amount are in an inversely proportional relationship. Therefore, in this embodiment, a contrast value is used as a parameter indicating the degree of blur.

  As shown in FIG. 4, the smaller the contrast value, the longer the moving distance of the focus lens required to reach the predicted in-focus position. Therefore, for example, in order to shorten the AF processing time, it is conceivable to increase the driving amount of the focus lens as the contrast value is smaller. However, even if the contrast value is the same, the required moving distance of the focus lens up to the predicted in-focus position varies depending on the F value. Therefore, it is not always possible to optimize the drive amount of the focus lens only by changing the drive amount of the focus lens according to the contrast value.

  Therefore, in the present embodiment, the driving amount of the focus lens is determined in consideration of the F value in addition to the contrast value.

  The imaging control unit 110 includes a focus control unit 140. The focus control unit 140 performs AF processing by the BDAF method. The focus control unit 140 includes an acquisition unit 142, a selection unit 144, and a determination unit 146. The focus control unit 140 is an example of a determination device.

  The acquisition unit 142 acquires the contrast value of each of a plurality of images captured with a predetermined F value as a parameter indicating the degree of blur in a state where the positional relationship between the focus lens and the imaging surface is different. The selection unit 144 selects an F value that is used to determine the driving amount of the focus lens. The determination unit 146 determines the driving amount of the focus lens based on the F value selected by the selection unit 144 and the respective contrast values acquired by the acquisition unit 142. The determination unit 146 may determine the speed of the focus lens as the drive amount of the focus lens. The determination unit 146 may determine the speed per unit time of the focus lens as the drive amount of the focus lens. The focus lens is driven at a speed determined by the determination unit 146 for a predetermined time via the lens control unit 220 and the lens moving mechanism 212.

  In the present embodiment, the selection unit 144 selects an F value different from the F value set at the time of imaging. The determination unit 146 determines the driving amount of the focus lens based on the different F values selected by the selection unit 144 and the respective contrast values acquired by the acquisition unit 142. As a result, when the moving distance of the focus lens is large, the driving amount of the focus lens is increased to shorten the AF processing time. Further, when the moving distance of the focus lens is small, the driving amount of the focus lens is further reduced to improve the AF processing accuracy.

  More specifically, the selection unit 144 selects an F value smaller than the F value set at the time of imaging when at least one of the plurality of contrast values is larger than the first threshold value. When at least one of the plurality of contrast values is larger than the first threshold value, the selection unit 144 may select an F value that is one step smaller than the F value set at the time of imaging. The selection unit 144 may select an F value that is two or more steps smaller than the F value set at the time of imaging from a plurality of F values. For example, when the contrast values P1 and P2 of the two images are larger than the threshold value t1 and the F value set at the time of imaging is “F5.6”, the selection unit 144 is “one step smaller than“ F5.6 ””. Select “F4”. Then, as illustrated in FIG. 5, the determination unit 146 determines the curve 603 based on the contrast values P1 and P2 of the two images and the characteristics of the curve 602 of F4, not the characteristics of the curve 601 of F5.6. To derive. The determination unit 146 determines the driving amount of the focus lens as an apparent predicted focus position 604 predicted from the curve 603 as an apparent predicted focus position. In this case, the determination unit 146 determines that the predicted focus position is closer to the actual predicted focus position, and determines the driving amount of the focus lens. Thereby, when at least one of the plurality of contrast values is larger than the first threshold, the driving amount of the focus lens determined by the determination unit 146 is determined based on the F value set at the time of imaging. It is smaller than the driving amount. Therefore, when the position of the focus lens is close to the predicted focus position, the drive amount of the focus lens can be further reduced, and the accuracy of AF processing can be improved.

  When at least one of the plurality of contrast values is smaller than the second threshold value, the selection unit 144 may select an F value that is larger than the F value set at the time of shooting. When at least one of the plurality of contrast values is smaller than the second threshold value, the selection unit 144 may select an F value that is one step higher than the F value set at the time of imaging. The selection unit 144 may select an F value that is two or more steps higher than the F value set at the time of imaging from a plurality of F values. For example, when the contrast values P1 and P2 of the two images are larger than the threshold value t2 and the F value set at the time of imaging is “F5.6”, the selection unit 144 is one step larger than “F5.6”. Select “F8”. Then, as shown in FIG. 6, the determination unit 146 determines the curve 606 based on the contrast values P1 and P2 of the two images and the characteristic of the curve 605 of F8, not the characteristic of the curve 601 of F5.6. To derive. The determination unit 146 determines the driving amount of the focus lens as an apparent predicted focus position 608 predicted from the curve 606 as an apparent predicted focus position. In this case, the determination unit 146 determines that the predicted focus position is far from the actual predicted focus position, and determines the driving amount of the focus lens. Thereby, when at least one of the plurality of contrast values is smaller than the second threshold value, the driving amount of the focus lens determined by the determination unit 146 is determined based on the F value set at the time of imaging. It is larger than the driving amount. Therefore, when the position of the focus lens is far from the predicted focus position, the drive amount of the focus lens can be increased, and the AF processing time can be shortened.

  When the plurality of contrast values are larger than the first threshold, the selection unit 144 selects an F value (second F value) smaller than the F value (first F value) set at the time of shooting, When the contrast value is smaller than the first threshold value, an F value (third F value) larger than the F value (first F value) set at the time of shooting may be selected. The determination unit may determine the driving amount of the focus lens based on the F value (second F value or third F value) selected by the selection unit 144 and a plurality of contrast values. After the focus lens is driven with the drive amount of the focus lens determined by the determination unit 146, the acquisition unit 142 includes a plurality of images newly captured with the previous F value (first F value) by the imaging device 100. Each contrast value may be newly acquired. The selection unit 144 may select the second F value when the plurality of newly acquired contrast values are larger than the first threshold value. The selection unit 144 may select the third F value when the plurality of newly acquired contrast values are smaller than the first threshold value. The determination unit 146 may determine the driving amount of the focus lens based on the second F value or the third F value and the plurality of contrast values.

  When the plurality of contrast values are smaller than the first threshold and larger than the second threshold, the selection unit 144 may select the F value set at the time of shooting. When the plurality of contrast values are larger than the third threshold value larger than the first threshold value, the selection unit 144 may select an F value that is two steps smaller than the F value set at the time of imaging. In addition, when the plurality of contrast values are smaller than the fourth threshold value smaller than the second threshold value, the selection unit 144 may select an F value that is two steps larger than the F value set at the time of imaging.

  The memory 130 may store a function necessary for the determination unit 146 to derive a curve as illustrated in FIG. 4 for each F value. Then, the determination unit 146 may read a function corresponding to the F value selected by the selection unit 144 from the memory 130 and derive a curve corresponding to the F value. Further, the memory 130 may store data relating to a curve as shown in FIG. 4 for each F value. Then, the determination unit 146 may read data related to the curve corresponding to the F value selected by the selection unit 144 from the memory 130 and derive a curve corresponding to the F value.

FIG. 7 is a flowchart illustrating an example of an AF process procedure performed by the imaging control unit 110. The imaging control unit 110 sets the F value of the imaging apparatus 100 to F ₁ in order to execute AF processing by the BDAF method (S100). The F value may be set by the user. The F value may be set according to the shooting mode of the imaging apparatus 100. Imaging device 100 in a state the positional relationship between the focus lens and the imaging surface are different, and the F value in the state of F _1, captures a plurality of images (S102). For example, the imaging apparatus 100 is in a positional relationship between the focus lens and the imaging surface a first positional relationship, F value is in the state of F _1, to capture the first image. Further, the imaging apparatus 100, the positional relationship between the focus lens and the imaging surface is at a second positional relationship, F value for imaging a second image in a state of F _1.

The acquisition unit 142 acquires the contrast values of a plurality of images captured by the imaging device 100 (S104). The selection unit 144 determines whether or not each contrast value is equal to or greater than a predetermined threshold (S106). The selection unit 144 may determine that the contrast value is equal to or greater than the threshold if at least one of the plurality of contrast values is equal to or greater than the threshold. The selection unit 144 may determine that the contrast value is smaller than the threshold if all of the plurality of contrast values are smaller than the threshold. The selection unit 144 may determine that the contrast value is equal to or greater than the threshold if all of the plurality of contrast values are equal to or greater than the threshold. The selection unit 144 may determine that the contrast value is smaller than the threshold if at least one of the plurality of contrast values is smaller than the threshold. As a result of the determination, if the contrast value is smaller than the threshold value, the selection unit 144 selects F ₂ that is one step larger than F ₁ as the F value (S108). Determination unit 146, and each of the contrast value, based on the F _2, to derive the curve shown in FIG. Furthermore, the determination unit 146 determines an apparent predicted focus position from the derived curve. Determination unit 146, the determined predicted focus position, based on the current position of the fur Kas lens, as the drive amount of the focusing lens, determine the moving speed V ₂ of the focus lens (S110). Each contrast value, when the moving speed determined by the determination unit 146 on the basis of the F ₁ is the moving speed V _1, the moving speed V ₂ is faster than the moving speed V _1.

After the lens control unit 220 moves the focus lens at a moving speed V ₂ through a lens moving mechanism 212, the imaging apparatus 100 is in a state where the positional relationship between the focus lens and the imaging surface are different, F value is F ₁ A plurality of images are newly taken in the state (S102).

A result of the determination in step S106, the selection unit 144, if the contrast value is greater than or equal to the threshold, as the F value, selects the _{F 3} stage smaller than _{F 1} (S112). Determination unit 146, and each of the contrast values, on the basis of the F _3, to derive the curve shown in FIG. Furthermore, the determination unit 146 determines an apparent predicted focus position from the derived curve. Determination unit 146, the determined predicted focus position, based on the current position of the fur Kas lens, as the drive amount of the focusing lens, determine the moving speed V ₃ of the focus lens (S114). Movement speed _{V 3} is slower than the moving speed _{V 1.} The focus control unit 140 determines whether or not the contrast value of the image satisfies a predetermined condition (S116). The focus control unit 140 may determine that the contrast value of the image satisfies a predetermined condition when the contrast value of the image indicates a contrast value corresponding to the maximum point.

If the contrast value of the image does not satisfy the predetermined condition, after the lens control unit 220 moves the focus lens at a moving speed V ₃ through the lens moving mechanism 212, the imaging apparatus 100, the focus lens and the imaging surface positional relationship between the in different states, F value is in the state of F _1, newly captured multiple images (S102). The focus control unit 140 repeats the processing from step S102 onward until the contrast value of the image indicates the contrast value corresponding to the maximum point.

  As described above, according to this embodiment, when the position of the focus lens is far from the predicted focus position, the drive amount of the focus lens can be increased, and the AF processing time can be shortened. Further, when the position of the focus lens is close to the predicted focus position, the drive amount of the focus lens can be further reduced, and the accuracy of AF processing can be improved. Therefore, according to the present embodiment, the BDAF AF process can be further optimized.

  FIG. 8 illustrates an example of a computer 1200 in which aspects of the present invention may be embodied in whole or in part. A program installed in the computer 1200 can cause the computer 1200 to function as an operation associated with the apparatus according to the embodiment of the present invention or as one or more “units” of the apparatus. Alternatively, the program can cause the computer 1200 to execute the operation or the one or more “units”. The program can cause the computer 1200 to execute a process according to an embodiment of the present invention or a stage of the process. Such a program may be executed by CPU 1212 to cause computer 1200 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

  A computer 1200 according to this embodiment includes a CPU 1212 and a RAM 1214, which are connected to each other by a host controller 1210. The computer 1200 also includes a communication interface 1222 and an input / output unit, which are connected to the host controller 1210 via the input / output controller 1220. Computer 1200 also includes ROM 1230. The CPU 1212 operates according to programs stored in the ROM 1230 and the RAM 1214, thereby controlling each unit.

  The communication interface 1222 communicates with other electronic devices via a network. A hard disk drive may store programs and data used by the CPU 1212 in the computer 1200. The ROM 1230 stores therein a boot program executed by the computer 1200 at the time of activation and / or a program depending on the hardware of the computer 1200. The program is provided via a computer-readable recording medium such as a CR-ROM, a USB memory, or an IC card or a network. The program is installed in the RAM 1214 or the ROM 1230 that is also an example of a computer-readable recording medium, and is executed by the CPU 1212. Information processing described in these programs is read by the computer 1200 to bring about cooperation between the programs and the various types of hardware resources. An apparatus or method may be configured by implementing information operations or processing in accordance with the use of computer 1200.

  For example, when communication is performed between the computer 1200 and an external device, the CPU 1212 executes a communication program loaded in the RAM 1214 and performs communication processing on the communication interface 1222 based on the processing described in the communication program. You may order. The communication interface 1222 reads transmission data stored in a RAM 1214 or a transmission buffer area provided in a recording medium such as a USB memory under the control of the CPU 1212 and transmits the read transmission data to a network, or The reception data received from the network is written into a reception buffer area provided on the recording medium.

  In addition, the CPU 1212 allows the RAM 1214 to read all or necessary portions of a file or database stored in an external recording medium such as a USB memory, and executes various types of processing on the data on the RAM 1214. Good. The CPU 1212 may then write back the processed data to an external recording medium.

  Various types of information, such as various types of programs, data, tables, and databases, may be stored on a recording medium and subjected to information processing. The CPU 1212 describes various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, and information retrieval that are described throughout the present disclosure for data read from the RAM 1214 and specified by the instruction sequence of the program. Various types of processing may be performed, including / replacement, etc., and the result is written back to RAM 1214. In addition, the CPU 1212 may search for information in files, databases, etc. in the recording medium. For example, when a plurality of entries each having an attribute value of the first attribute associated with the attribute value of the second attribute are stored in the recording medium, the CPU 1212 specifies the attribute value of the first attribute. The entry that matches the condition is searched from the plurality of entries, the attribute value of the second attribute stored in the entry is read, and thereby the first attribute that satisfies the predetermined condition is associated. The attribute value of the obtained second attribute may be acquired.

  The programs or software modules described above may be stored on a computer-readable storage medium on or near the computer 1200. In addition, a recording medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, whereby the program is transferred to the computer 1200 via the network. provide.

  The execution order of each process such as operation, procedure, step, and stage in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. It is not a thing.

10 UAV
20 UAV body 30 UAV control unit 32 Memory 34 Communication interface 40 Propulsion unit 41 GPS receiver 42 Inertial measurement device 43 Magnetic compass 44 Barometric altimeter 50 Gimbal 60 Imaging device 100 Imaging device 102 Imaging unit 110 Imaging control unit 140 Focus control unit 142 Acquisition unit 144 Selection unit 146 Determination unit 120 Image sensor 130 Memory 200 Lens unit 210 Lens 212 Lens movement mechanism 220 Lens control unit 300 Remote operation device 1200 Computer 1210 Host controller 1212 CPU
1214 RAM
1220 Input / output controller 1222 Communication interface 1230 ROM

Claims (11)

A determination device that determines a moving speed of a focus lens included in an imaging device,
An acquisition unit that acquires a contrast value of each of a plurality of images captured with the first F value by the imaging device in a state where the positional relationship between the focus lens and the imaging surface is different ;
A selection unit that selects a second F value different from the first F value based on the contrast value;
Based on the first curve indicating the relationship between the lens position of the focus lens and the contrast value corresponding to the second F value , and a plurality of the contrast values, the relationship between the lens position of the focus lens and the contrast value is obtained. And a determining unit that derives a second curve to be shown and determines a moving speed of the focus lens based on the second curve .   The determination device according to claim 1, wherein the selection unit selects the second F value smaller than the first F value when at least one of the plurality of contrast values is larger than a first threshold value.   The determination device according to claim 1, wherein the selection unit selects the second F value larger than the first F value when at least one of the plurality of contrast values is smaller than a second threshold value. The selection unit selects the second F value smaller than the first F value when the plurality of contrast values are larger than a first threshold, and the plurality of contrast values are smaller than the first threshold. A third F value greater than the first F value is selected,
When the selection unit selects the third F value, the determination unit includes a third curve indicating a relationship between a lens position of the focus lens corresponding to the third F value and a contrast value , and a plurality of curves The fourth curve representing a relationship between a lens position of the focus lens and a contrast value is derived based on the contrast value, and a moving speed of the focus lens is determined based on the fourth curve. Decision device. After the focus lens is driven at the moving speed of the focus lens determined by the determination unit,
The acquisition unit acquires a contrast value of each of a plurality of images captured with the first F value by the imaging device,
The selection unit selects the second F value when the acquired plurality of contrast values are larger than the first threshold value, and the acquired plurality of contrast values are smaller than the first threshold value. , Select the third F value,
The determination apparatus according to claim 4, wherein the determination unit determines a moving speed of the focus lens based on the second F value or the third F value and the contrast value. The determination apparatus according to claim 1, wherein the focus lens is driven at a moving speed determined by the determination unit for a predetermined time. A determination device according to any one of claims 1 to 6;
An image sensor that captures the plurality of images;
An imaging apparatus comprising the focus lens. An imaging device according to claim 7;
An imaging system comprising: a support mechanism that supports the imaging device.   A moving body that moves with the imaging system according to claim 8. A determination method for determining a moving speed of a focus lens included in an imaging device,
Obtaining a contrast value of each of a plurality of images captured by the imaging device at a first F value in a state where the positional relationship between the focus lens and the imaging surface is different ;
Selecting a second F value different from the first F value based on the contrast value;
Based on the first curve indicating the relationship between the lens position of the focus lens and the contrast value corresponding to the second F value , and a plurality of the contrast values, the relationship between the lens position of the focus lens and the contrast value is obtained. Deriving a second curve to be shown, and determining a moving speed of the focus lens based on the second curve . The program for functioning a computer as a determination apparatus as described in any one of Claim 1 to 6 .

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