JP2019219529A - Control device, imaging device, control method, program, and storage medium - Google Patents

Abstract

To provide a control device which can prevent a subject image from going out of a frame of a screen during execution of a subject tracking function and improve operability.SOLUTION: A control device (114) includes control means (120) for controlling a lens unit (101) so as to perform tracking control for a subject designated by subject designating means (118), and electronic vibration-proofing means (127) for electronically performing image blur correction on the basis of a shake detected by shake detection means (119). The control means performs the image blur correction by the electronic vibration-proofing means and zooms out the lens unit from a first position to a second position closer to a wide-angle side than the first position before the subject is designated.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an imaging device having a subject tracking function.

  2. Description of the Related Art Conventionally, there has been known an imaging apparatus having a function (subject tracking function) in which a user designates a main subject among subjects detected from an image and follows the exposure, focus, and angle of view of the designated main subject. In an imaging apparatus having a subject tracking function, a user designates a subject image displayed on a screen via an operation unit such as a touch panel or an operation switch, and displays a tracking frame in an area of the designated subject image. Then, a tracking function is realized by driving an aperture, a focus lens, a zoom lens, an anti-vibration lens, and the like according to a photometric value, a contrast evaluation value, and a size and a position of the tracking frame in the tracking frame. You.

  Patent Literature 1 discloses an imaging apparatus having an autofocus function of following a designated main subject with focus. Patent Literature 2 discloses an imaging apparatus having an auto-zoom function for preventing a subject image from going out of a frame and an auto-zoom function for maintaining a size of a subject image constant. Patent Literature 3 discloses an imaging apparatus having an image stabilizing function that maintains the position of a subject image at the center of the angle of view when the position of the detected subject image is shifted from the center of the angle of view.

JP-A-2017-112488 JP 2017-167438 A JP-A-2017-92592

  However, since the angle of view is narrow when the zoom is telephoto, when the user attempts to specify a subject via the operation unit during execution of the subject tracking function, the subject image is framed out of the screen by the user's operation. May be lost. Further, the image blur caused by the user's operation at this time is larger than the image blur caused by the camera shake at the time of normal framing, so that it is difficult to perform the image blur correction using the anti-vibration lens (optical anti-vibration means). As described above, it is difficult for the user to specify the subject while framing the subject during the execution of the subject tracking function.

  Therefore, the present invention provides a control device, an imaging device, a control method, a program, and a storage medium that can prevent a subject image from going out of a frame during execution of a subject tracking function and improve operability. The purpose is to provide.

  A control device according to an aspect of the present invention includes: a control unit that controls the lens unit so as to perform tracking control on a subject specified by a subject specifying unit; and a shake detected by a shake detection unit. An electronic image stabilizing unit that electronically performs image blur correction, wherein the control unit performs the image blur correction by the electronic image stabilizing unit before the subject is designated, and sets the lens unit to a first position. Is zoomed out from the position to a second position on the wide angle side of the first position.

  An imaging device according to another aspect of the present invention includes the control device and an imaging device that captures an image of the subject via the lens unit.

  In a control method according to another aspect of the present invention, before a subject is designated, image stabilization is performed by electronic image stabilization means, and a lens unit is moved from a first position to a second position on the wide angle side from the first position. Zooming out to the position 2; acquiring information indicating that the subject has been designated from the subject designating means; and performing the image blur correction by the electronic image stabilizing means after the subject has been designated. Stopping and zooming in on the lens unit from the second position to the first position.

  A program according to another aspect of the present invention causes a computer to execute the control method.

  A storage medium according to another aspect of the present invention stores the program.

  Other objects and features of the present invention will be described in the following embodiments.

  Advantageous Effects of Invention According to the present invention, a control device, an imaging device, a control method, a program, and a storage capable of preventing a subject image from going out of a frame during execution of a subject tracking function and improving operability. A medium can be provided.

It is a block diagram of an imaging device in this embodiment. FIG. 5 is a diagram illustrating a relationship between a focus position and a contrast evaluation value in the present embodiment. FIG. 3 is an explanatory diagram of an image stored in an image memory according to the embodiment. FIG. 4 is a diagram illustrating a relationship between a focal length and a focus lens position for each subject distance in the present embodiment. FIG. 4 is an explanatory diagram of control of an auto zoom function for keeping a size of a subject within a predetermined range in the embodiment. FIG. 4 is an explanatory diagram of control of a tracking vibration-proofing function for keeping the position of a subject near the center of the screen in the present embodiment. 5 is a flowchart of an entire process of a subject tracking function according to the embodiment. It is a flowchart of a subject designation process in the present embodiment. It is a flowchart of the optical zoom-in process in this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, an imaging device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram of a digital camera (imaging device) 100 having a subject tracking function. The lens barrel 101 has a lens unit (imaging optical system). The zoom lens 102 adjusts the focal length by moving in the direction (optical axis direction) along the optical axis OA of the lens barrel 101, and optically changes the angle of view (moves the zoom position). The focus lens 103 performs focus adjustment by moving in the optical axis direction of the lens barrel 101. The image stabilization lens (image blur correction lens) 104 moves in a direction perpendicular to the optical axis OA (a direction orthogonal to the optical axis) to correct image blur caused by camera shake or the like. An aperture / shutter 105 for adjusting the amount of light is used for exposure control. Note that, in the present embodiment, the digital camera 100 is an imaging device in which the lens barrel 101 and the camera main body are integrally formed, but is not limited to this. The present embodiment is also applicable to an imaging system including a camera body and an interchangeable lens (lens barrel) that is detachable from the camera body.

  The imaging element 106 is an imaging sensor that captures an image of a subject via the lens barrel 101, receives light that has passed through the lens barrel 101, and generates an imaging signal by converting the subject image into an electric signal by photoelectric conversion. I do. The imaging element 106 is a CCD (charge coupled device) type or CMOS (complementary metal oxide semiconductor) type image sensor or the like. The image processing unit 107 performs various image processing such as pixel interpolation processing and color conversion processing on the imaging signal output from the imaging element 106. The image data after the image processing is stored in the image memory 108. The image memory 108 is a storage device such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory).

  The display unit 109 includes a TFT LCD (thin film transistor driven liquid crystal display) and the like, and displays a captured image (image data) and specific information (for example, imaging information). By displaying information such as a live view on a captured image, an electronic viewfinder (EVF) function for a user to adjust the angle of view can be provided.

  Image data generated by the photographing process is sent to the recording unit 116 via the I / F (interface unit 115) and recorded. The image data is stored in an external recording medium or the nonvolatile memory 117, or both. The external recording medium is a memory card or the like that is used by being attached to the digital camera 100. The nonvolatile memory 117 is a storage medium built in the digital camera 100. The memory 117 is Information such as settings of the digital camera 100 is stored in addition to the program data and the image data.

  The operation unit 118 includes a zoom operation member, a release switch for instructing start of photographing, a touch panel and operation switches for specifying a subject and setting the digital camera 100. The operation signal of the operation unit 118 is sent to the system control unit 114.

  The system control unit 114 is a control device such as a CPU (Central Processing Unit). The system control unit 114 controls the entire digital camera 100 by sending a control command to each unit according to a user operation. The system control unit 114 performs various control programs stored in the memory 117, such as control of the image sensor 106, AE / AF control, optical / electronic image stabilization control, zoom control (including automatic zoom processing), and the like. Run the program.

  The camera control unit 120 issues an instruction for controlling the overall functions of the digital camera 100. For example, when the release switch is half-pressed, the camera control unit 120 performs a shooting preparation operation such as AE / AF, and when fully pressed, instructs to perform a still image or moving image shooting operation. The camera control unit 120 instructs a zoom operation of an optical zoom and a start / stop of electronic image stabilization in a subject tracking function described later.

  The AE control unit (automatic exposure control unit) 121 calculates an exposure control value (aperture value (F value) and shutter speed) based on the photometric value obtained by the image processing of the image processing unit 107. The AE control unit 121 calculates a luminance value (photometric value) in an arbitrary area (photometric frame) on the screen according to the set photometric method. The light metering method can be spot metering that measures light at a specific position that has been set, evaluative metering that automatically determines the position of the light metering frame according to the scene, or averaged over the entire screen with emphasis on the center of the screen. There are photometric methods such as center-weighted average photometry for photometry. The AE control unit 121 controls the aperture shutter driving unit 110 based on the photometric result. The aperture shutter drive unit 110 drives the aperture / shutter 105 to realize automatic exposure adjustment. The aperture shutter drive unit 110 includes actuators such as a stepping motor and an electromagnetic plunger and a drive circuit for driving them, and drives the aperture / shutter 105.

  The optical image stabilization control unit 122 calculates a shake (shake amount) applied to the digital camera 100 based on shake detection information acquired from the shake detection unit (shake detection unit) 119. The shake detection unit 119 is an angular velocity sensor such as a gyro sensor, and the shake detection information is angular velocity information. The optical image stabilization control unit 122 drives the image stabilizing lens 104 based on the calculated shake (shake amount) so as to cancel (or reduce) the amount of shake applied to the digital camera 100, thereby performing optical image stabilization. Realize. The optical image stabilization control unit 122 calculates a target position for controlling the image stabilization lens 104 at a predetermined calculation cycle based on the shake amount, and outputs a driving instruction to the image stabilization lens driving unit 111. The image stabilizing lens driving unit 111 drives the image stabilizing lens 104 in a direction orthogonal to the optical axis based on the driving instruction received from the optical image stabilizing control unit 122.

  The anti-vibration lens driving unit 111 includes an actuator such as a voice coil motor (VCM), a driving circuit of the actuator, and a position detection sensor such as a Hall element. The optical image stabilization control unit 122 feeds back the position of the image stabilization lens 104 detected by the position detection sensor of the image stabilization lens driving unit 111, and performs feedback control so as to hold the image stabilization lens 104 at the target position.

  The electronic image stabilization control unit 127 calculates a shake (shake amount) applied to the digital camera 100 based on the shake detection information acquired from the shake detection unit 119, similarly to the optical image stabilization control unit 122. The electronic image stabilization control unit 127 implements electronic image stabilization so as to cancel (or reduce) the amount of shake applied to the digital camera 100 based on the calculated shake (shake amount). That is, the electronic image stabilization control unit 127 implements electronic image stabilization by changing the range of the image displayed on the display unit 109 or recorded in the recording unit 116 from the image stored in the image memory 108 for each frame image. I do.

  Here, the electronic image stabilization will be described with reference to FIG. FIG. 3 shows an image stored in the image memory 108. Reference numeral 300 denotes the entire image memory 108, and reference numeral 301 denotes a range of an image to be displayed and recorded as image data after electronic image stabilization control by the electronic image stabilization control unit 127. In the control of the electronic image stabilization, the range that can be controlled as the electronic image stabilization is increased by reducing the size of the output image to the display unit 109 and the recording unit 116, and the image stabilization effect can be enhanced. However, as the output image size decreases, the resolution of the image may decrease.

  The magnitude of the shake amount (shake amount) that can be stabilized by optical image stabilization is determined according to the movable range of the image stabilizing lens 104. That is, in order to stabilize a large camera shake caused by the subject designation operation, it is necessary to increase the movable range of the anti-shake lens 104. For this reason, it is necessary to increase the diameter of the lens barrel 101, and as a result, the digital camera 100 may be enlarged.

  On the other hand, in the electronic image stabilization, the control range used for the electronic image stabilization control with respect to the image memory 108 can be increased to enhance the image stabilization effect. In recent years, the number of pixels of the image sensor 106 has been increased, and the number of pixels is sufficient for the resolution of the LCD. Therefore, even when the range of the image displayed on the display unit 109 is reduced and the range of the electronic image stabilization control is increased, a sufficient resolution can be obtained for the viewfinder function. However, since a recorded image may be displayed on a large-screen monitor or the like, a higher resolution is required. Therefore, in the present embodiment, the electronic image stabilization control is performed by the electronic image stabilization at the time of specifying the subject, and the image stabilization control is performed by the optical image stabilization at the time of image recording. Accordingly, the subject specifying operation can be effectively supported without increasing the size of the digital camera 100, and a high-resolution recorded image can be captured.

  An AF control unit (autofocus control unit) 123 performs automatic focus adjustment (AF) control using a contrast detection method. That is, the AF control unit 123 controls the focus lens driving unit 112 so that the subject is in focus, based on the focus adjustment information (contrast evaluation value) of the imaging optical system obtained by the image processing in the image processing unit 107. . The focus lens drive unit 112 includes an actuator such as a voice coil motor (VCM), a position detection sensor for feeding back the position of the actuator, and a drive circuit for driving them, and drives the focus lens 103. Note that the focus lens driving unit 112 is not limited to the above-described configuration, and may be a configuration that does not require a position detection sensor unlike a stepping motor.

  In the present embodiment, the AF control unit 123 may perform AF control other than the contrast detection method, such as the AF control using the phase difference detection method. Further, the AF control unit 123 may perform the AF control by a plurality of methods such as a combination of a contrast detection method and another method such as a phase difference detection method. The AF control unit 123 performs a scan operation by controlling the focus lens driving unit 112 when performing the AF control and moving the focus lens 103 within a predetermined range. The focus position, which is the focal point, is detected using a contrast evaluation value or the like obtained during the scanning operation.

  Here, the relationship between the focus position and the contrast evaluation value in AF control of the contrast detection method will be described with reference to FIG. FIG. 2 is a diagram illustrating a relationship between a focus position and a contrast evaluation value in AF control of a contrast detection method. In FIG. 2, the horizontal axis represents the focus position, and the vertical axis represents the contrast evaluation value.

  The contrast evaluation value is a value obtained by setting a region for calculating contrast called a distance measurement frame in an arbitrary region of the image, and digitizing high frequency components from image information in the region by a high-pass filter or the like. The higher the contrast evaluation value, the higher the degree of focusing. There are two types of AF control, a single AF mode that operates when the release switch is half-pressed in still image shooting, and a continuous AF mode that continuously focuses during EVF screen framing of a subject or moving image shooting. There is a control mode.

  The single AF mode is a mode in which the focus lens 103 is moved at a stretch until the subject distance is reduced from infinity to a close distance, thereby quickly detecting a focus position at which the peak of the contrast evaluation value reaches a peak. In the single AF mode, the focus position can be found at high speed, but the screen may be momentarily blurred during the scanning operation. Therefore, it is suitable for AF control at the time of shooting a still image in which the release time lag is to be reduced as much as possible.

  On the other hand, the continuous AF mode is a mode in which, when pursuing a moving subject or the like, focusing is continued by, for example, inverting the focus lens 103 within a range in which focus fluctuation is inconspicuous. In the continuous AF mode, it takes time to change from a large-blur state to an in-focus state, but once in the in-focus state, focus can be maintained even if the subject is moving. Therefore, it is suitable for an EVF screen for framing a subject or AF control at the time of moving image shooting in which a moving subject is always kept in focus.

  The zoom lens driving unit 113 drives the zoom lens 102 according to a zoom operation instruction. The zoom lens driving unit 113 includes an actuator such as a direct current (DC) motor that drives the zoom lens 102, a position detection sensor such as a rotary encoder that detects a motor position, and a drive circuit that drives them. Note that the zoom lens driving unit 113 is not limited to the above-described configuration, and may be a configuration that does not require a position detection sensor unlike a stepping motor. In the retractable lens barrel in which the lens barrel 101 extends from the camera body with the operation of turning on the power, it is necessary to detect an error when the lens barrel is pressed during the lens barrel extension operation. Is often adopted. In the case of an inner lens barrel in which the zoom lens 102 is driven inside the lens barrel 101, the latter, which is advantageous for noise reduction, is often employed. The zoom lens driving unit 113 of the present embodiment may have any configuration.

  The operation unit 118 includes a zoom lever or a zoom button as a zoom operation member for a user to instruct the digital camera 100 to perform zooming. The camera control unit 120 detects the operation amount and operation direction of the zoom operation member used for the zoom instruction operation, calculates the zoom drive speed and the zoom drive direction, and moves the zoom lens 102 along the optical axis OA according to the calculation results. Is controlled to move.

  In order to maintain a focused state when the angle of view is changed by optical zoom, when the lens barrel 101 is a rear focus type, it is necessary to move the focus lens 103 to an appropriate focus position according to the position of the zoom lens 102. . Such control is called computer zoom (CZ) control. The CZ control is performed by the CZ control unit 124 in the system control unit 114.

  Here, the relationship between the focal length of the zoom lens 102 and the focus position for each subject distance will be described with reference to FIG. FIG. 4 is a diagram illustrating the relationship between the focal length of the zoom lens 102 and the focus position for each subject distance. FIG. 4 is a graph showing the relationship between the focal length of the zoom lens 102 and the focus position where focus is achieved, as a data table indicating the distance to the subject. In this embodiment, this table is called a focus cam table.

  In FIG. 4, the horizontal axis indicates the focal length corresponding to the zoom position, and the vertical axis indicates the focus position. A distance (subject distance) from the digital camera 100 to the subject is illustrated beside each graph line. The CZ control unit 124 detects a zoom position of the zoom lens 102 at a predetermined control cycle during a zoom operation. Then, the CZ control unit 124 controls the focus lens 103 to drive the detected zoom position so as to follow the focus cam table at the subject distance measured by the AF control unit 123. This makes it possible to perform the optical zoom operation while maintaining the in-focus state.

  The AZ control unit (auto-zoom control unit) 125 performs CZ control based on subject detection information acquired from a subject detection unit 126 described later so that the size of the subject in the screen (in the image) falls within a predetermined range. The unit 124 is controlled. Thereby, the AZ control unit 125 realizes automatic angle-of-view adjustment (auto-zoom).

  Next, the subject detection processing according to the present embodiment will be described. The subject detection unit (subject detection means) 126 detects a subject (subject area) from the image (image data) stored in the image memory 108. In the present embodiment, a subject detection method (face detection process, color detection process) for detecting a subject (a face such as a person or an object) based on face information or color information included in image data will be described.

  First, the face detection processing and the color detection processing in the subject detection unit 126 will be described. The face detection process is a process of detecting a face region existing in image data by a known algorithm. For example, the subject detection unit 126 extracts a feature amount from a square partial region on the image data, and compares the feature amount with a previously prepared face feature amount. When the correlation value between the two exceeds a predetermined threshold, the subject detection unit 126 determines that the partial area is a face area. This determination processing is repeated while changing the combination of the size, arrangement position, and arrangement angle of the partial area, so that various face areas existing in the image data can be detected. When the subject detection unit 126 has a face authentication function, the subject detection unit 126 performs pattern matching with a feature amount of a face image registered in advance and a feature amount of a detected face region using a known algorithm, and has the highest correlation value. The registered face image is authenticated as a detected face. When the correlation values for all the registered face images are smaller than the predetermined value, the subject detection unit 126 determines that the detected face area is a face that has not been registered.

  The color detection process is a process of detecting and storing, as a characteristic color, color information of a subject area designated according to a subject designation method described later. The color detection process is performed when the subject to be detected is an object. As the color information, an RGB signal, a luminance signal (Y signal), a color difference (RY, BY) signal, or the like, which is an output signal from the image processing unit 107, is used. When detecting a subject, the subject detection unit 126 divides the image data into a plurality of partial regions and calculates an average value of luminance and color difference for each partial region. Further, the subject detection unit 126 compares the previously stored characteristic color information with the color information of each region at the time of subject detection, and determines a partial region in which each difference in luminance and color difference is equal to or less than a predetermined amount as a candidate for a subject region. .

  Then, the subject detection unit 126 performs a process of setting a group of adjacent partial regions as candidates for the subject region as the same color region and a region where the same color region has a predetermined size range as a final subject region. When the subject is an object, the shape of the subject region may be different depending on the object. Therefore, the subject detection unit 126 sets the smallest rectangular area including all the same color areas as the object area. Therefore, the object area may be a rectangular area having different sizes in the horizontal and vertical directions. The position of the object region is the center position of the rectangular region. The frame display unit 128 displays the face area and the object area detected in the subject detection processing on the display unit 109 as a frame (subject detection frame).

  Next, tracking processing of the subject detection frame detected by the subject detection unit 126 will be described. The tracking process of the subject detection frame is a process of keeping track of a subject region that moves between successive frame images. When the camera control unit 120 starts the subject tracking function, an area of a person or an object as a main subject is designated according to a subject designation method described later. When the specified subject is a person, that is, a face, the subject detection unit 126 detects all faces in the frame image. When a plurality of faces are detected in the same image, the subject detection unit 126 determines that the person tracks the face closest to the position of the face in the immediately preceding frame image. When the detected face is a face registered by the face authentication function, the subject detection unit 126 determines that the authenticated face is a person who preferentially tracks the face regardless of the positional relationship between the frame images. .

  When the specified subject is an object, the subject detection unit 126 starts the starting position of the comparison process of the characteristic color information from the position of the object region of the immediately preceding frame image. If the frame rate is sufficiently higher than the speed of the moving object, there is a high possibility that the same object is detected in a nearby area between the previous and next frame images. Therefore, the subject detection unit 126 can track the moving object region by performing matching processing of the same color region while shifting the partial region to be compared left, right, up, and down with the position of the immediately preceding object region as a starting point. The frame display unit 128 displays, on the display unit 109, the face area and the object area tracked by the tracking processing of the subject detection frame as the subject tracking frame.

  Next, control related to the subject tracking function in the camera control unit 120 will be described. In the present embodiment, a function of performing photometry / distance measurement by interlocking the photometry frame and the distance measurement frame (focus detection frame) of the AE / AF control with the position of the subject tracking frame is referred to as a tracking AE function and a tracking AF function, respectively. Call. The functions of driving the zoom lens 102 and the image stabilizing lens 104 according to the size and position of the subject tracking frame are called a tracking AZ function and a tracking image stabilizing function, respectively. These functions are collectively referred to as a subject tracking function. The user specifies the main subject by operating the touch panel of the operation unit 118 or the operation switch for specifying the subject. The camera control unit 120 executes each tracking function for the main subject designated by the user such that the exposure, focus, and angle of view are appropriate. These multiple tracking functions may be performed simultaneously, or only at least one of the multiple tracking functions may be performed.

  Next, a tracking auto-zoom function according to the present embodiment will be described with reference to FIG. FIG. 5 is an explanatory diagram of the control of the auto zoom function for keeping the size of the subject within a predetermined range. FIGS. 5A to 5C illustrate a zoom operation automatically performed by the digital camera 100 when the subject 501 approaches the digital camera 100, and the ratio of the subject image to the screen is determined by a predetermined value. The zoom-out operation for keeping the ratio within the range is shown.

  FIG. 5A shows the angle of view when the subject 501 is designated according to the subject designation method described later. The size of the subject tracking frame 500a when the subject is designated is stored in the memory 117 as a reference subject size (reference size). FIG. 5B shows an angle of view when the subject 501 approaches the digital camera 100 in a state where the zoom magnification is not changed from the state of FIG. 5A. For example, a size that is 150% of the size of the subject tracking frame 500a, which is the reference subject size, is set as the start size of the zoom-out operation. If the relationship between the subject tracking frames is “subject tracking frame 500b> subject tracking frame 500a × 150%”, that is, if the tracking frame changes by more than a predetermined change amount with respect to the reference size, the AZ control unit 125 Determines the start of the zoom-out operation.

  FIG. 5C illustrates an angle of view obtained by zooming out from the angle of view of FIG. 5B by a predetermined zoom magnification, and a subject tracking frame 500c. Here, the predetermined zoom magnification is set to 1 / 1.5 in consideration of the change rate (150%) of the subject tracking frame size to the reference subject size when starting the zoom-out operation. Thereafter, when the subject 501 comes closer to the digital camera 100, the subject image can be kept within a predetermined ratio by further zooming out to the wide angle side. Therefore, the user can concentrate on operating the release switch.

  On the other hand, FIGS. 5D to 5F illustrate a zoom operation automatically performed by the digital camera 100 when the subject 501 moves away from the digital camera 100, and the ratio of the subject image to the screen is determined by a predetermined value. The zoom-in operation for keeping the area within the range is shown. FIG. 5D shows the angle of view when the subject 501 is designated according to the subject designation method described later. The size of the subject tracking frame 500d when the subject is specified is stored in the memory 117 as a reference subject size.

  FIG. 5E shows an angle of view when the subject 501 moves away from the digital camera 100 in a state where the zoom magnification is not changed from the state of FIG. 5D. For example, a size that is 50% of the size of the subject tracking frame 500d, which is the reference subject size, is set as the start size of the zoom-in operation. When the relationship between the subject tracking frames is “subject tracking frame 500e <subject tracking frame 500d × 50%”, it is determined that the tracking frame has changed by more than a predetermined change amount with respect to the reference size.

  FIG. 5F shows an angle of view obtained by zooming in from the angle of view of FIG. 5E by a predetermined zoom magnification, and a subject tracking frame 500f. Here, the predetermined zoom magnification is set to 1 / 0.5 times in consideration of the change rate (50%) of the subject tracking frame size to the reference subject size when starting the zoom-in operation.

  Next, a tracking stabilization function according to the present embodiment will be described with reference to FIG. FIG. 6 is an explanatory diagram of the control of the tracking stabilization function for keeping the position of the subject 601 near the center of the screen. FIG. 6A shows the angle of view when the subject 601 is designated according to the subject designation method described later. FIG. 6B illustrates an angle of view when the subject 601 moves away from the vicinity of the center of the screen due to movement or camera shake from the state of FIG. 6A. For example, assuming that the coordinates of the center of the screen are O and the coordinates of the center position of the subject tracking frame 600b are T, the camera control unit 120 calculates the distance OT from the center of the screen to the subject tracking frame 600a (600b). Then, when the distance OT is equal to or more than the predetermined amount, the camera control unit 120 starts the tracking vibration-proofing operation.

  FIG. 6C shows the angle of view obtained by correcting the subject 601 (subject tracking frame 600c) to the vicinity of the center of the screen by the tracking stabilization operation of the image stabilizing lens 104 from the angle of view in FIG. In the tracking image stabilization operation, the optical image stabilization control unit 122 calculates the amount of camera shake calculated based on the shake detection information from the shake detection unit 119 such as a gyro sensor, and the amount of movement of the center position of the subject tracking frame 600b with respect to the center of the screen. The control output of the value obtained by adding is performed to control the image stabilizing lens 104. This makes it possible to effectively prevent the subject image from going out of frame while preventing image blur due to camera shake or the like.

  Next, the processing of the subject tracking function will be described with reference to FIGS. FIG. 7 is a flowchart showing the entire processing of the subject tracking function. The following subject tracking function is performed based on a command from the camera control unit 120 unless otherwise specified.

  First, in step S700, the camera control unit 120 determines whether or not a subject has already been designated by the user. If the subject has been specified, the process proceeds to step S708, and the camera control unit 120 performs control of subject tracking. On the other hand, if the subject has not been specified, the process proceeds to step S701.

  In step S701, the camera control unit 120 calculates a zoom magnification based on the position of the zoom lens 102, and determines whether the zoom magnification is equal to or greater than a predetermined magnification. If the zoom magnification is smaller than the predetermined magnification, that is, the zoom angle is wide, the process proceeds to step S702, and the camera control unit 120 executes a subject specifying process described later. On the other hand, if the zoom magnification is larger than the predetermined magnification, that is, if it is telephoto, the process proceeds to step S703. In step S703, the camera control unit 120 zooms out the zoom lens 102 from the current position (first position) to a position on the wide angle side (second position).

  The determination process of step S701 is a process of determining whether or not to start the support mode for the subject specification operation, and whether to perform optical zoom-out or electronic image stabilization for supporting the subject specification operation according to the zoom magnification. It is for determining whether or not. When the zoom magnification is small (when the angle of view is wide), the user can relatively easily specify the subject even with the angle of view, so that the camera control unit 120 performs zoom-out for supporting the subject specifying operation. Or electronic vibration control is not performed. On the other hand, when the zoom magnification is large (when the angle of view is narrow), there is a possibility that the subject may go out of frame from the angle of view by slightly moving the digital camera 100 by the operation of designating the subject. Therefore, the camera control unit 120 zooms out the zoom lens 102 to the wide-angle side and executes a process of supporting a subject specifying operation for performing electronic image stabilization.

  In step S703, the camera control unit 120 causes the zoom lens 102 to zoom out to the wide-angle side by a predetermined magnification (optical zoom-out operation). When the zoom-out operation is completed in step S703, the process proceeds to step S704. In step S704, the camera control unit 120 instructs the electronic image stabilization control unit 127 to start electronic image stabilization.

  Here, the effects of the optical zoom-out and the electronic image stabilization in the support mode of the subject specification operation will be described. As described above, in the case of telephoto and a narrow angle of view (when the zoom magnification is large), the digital camera 100 may move due to the operation of designating the subject, and the subject may go out of frame from the angle of view. Therefore, the camera control unit 120 performs the zoom-out operation by the optical zoom to prevent the subject from going out of the frame.

  On the other hand, in this state, the subject image becomes small, and it becomes difficult to specify the subject on the screen. Therefore, the camera control unit 120 electronically enlarges the display range of the screen as a control range of the electronic image stabilization (range 301 in FIG. 3), and displays the subject in a size that can be easily specified. Further, by enabling the electronic image stabilization in this range, it is possible to correct the camera shake caused by the subject designating operation and prevent the subject from going out of the frame.

  At this time, by adjusting the magnification for zooming out by the optical zoom and the enlargement range of the image by the electronic image stabilization, the angle of view finally photographed and the angle of view when the subject is designated can be matched. For example, when the optical zoom is zoomed out by a factor of 1/2, the control range of electronic image stabilization is set to 50% of the entire image memory 108 (corresponding to the display being enlarged twice). Further, the zoom-out magnification of the optical zoom and the control range of the electronic image stabilization may be dynamically changed according to the zoom magnification or the like for photographing as well as the unique magnification. For example, an example will be described in which a lens barrel having an optical zoom magnification of 20 times and the optical zoom is zoomed out to an angle of view of 5 times when the telephoto is larger than 5 times (corresponding to the predetermined zoom magnification in step S701). When the support mode for designating a subject is started when the optical zoom is to be photographed at 20 times the tele end, the camera control unit 120 zooms out the optical zoom from the zoom position at the tele end by 5/20 = 1/4 times. As a control range of the electronic image stabilization, the display is enlarged with a range of 25% of the entire image memory 108 as a control range, and the electronic image stabilization is executed. Further, when it is desired to take an optical zoom with a zoom magnification of 10 times, the zoom-out magnification of the optical zoom is 5/10 = 1/2 times, and the control range of the electronic image stabilization is 50% of the entire image memory 108. In this way, by changing the zoom-out magnification and the control range of the electronic image stabilization so that the optical zoom becomes the zoom magnification of 5 times in accordance with the zoom magnification to be photographed, the operability for designating the subject can be unified. it can. That is, the camera control unit 120 can set the changeable area of the display range by the electronic image stabilization control unit 127 based on the zoom-out magnification of the lens unit.

  Subsequently, in step S704, the camera control unit 120 starts electronic image stabilization. Subsequently, in step S705, the camera control unit 120 performs a process of specifying a subject. Here, the subject designation processing in steps S702 and S705 will be described with reference to FIG. FIG. 8 is a flowchart of the subject specifying process. FIG. 8A illustrates an example of a process in which a user specifies a desired subject using a touch panel included in the operation unit 118. In this example, it is assumed that the user performs an operation of touching and specifying the subject image displayed on the display unit 109.

  First, in step S800, the camera control unit 120 determines whether the touch panel has been pressed. If the touch panel has been pressed, the process proceeds to step S801. On the other hand, when the touch panel is not pressed, the determination processing of step S800 is repeated.

  In step S801, the camera control unit 120 acquires information on a position (touch position) touched by the user. Subsequently, in step S802, the camera control unit 120 notifies the subject detection unit 126 of the touch position. Then, the subject detection unit 126 performs face detection near the touch position. If a face is detected near the touch position in step S802, the camera control unit 120 determines that the main subject is a person, and proceeds to step S803. On the other hand, if no face is detected near the touch position in step S802, the camera control unit 120 determines that the main subject is an object other than a person, and proceeds to step S804.

  In step S803, the camera control unit 120 performs control to store the face information of the person to be automatically tracked in the memory 117. Specific face information includes information such as a face size when a subject is specified, a face detection position, and a face direction. When the digital camera 100 has a face authentication function, identification information such as an authentication ID is also stored in the memory 117.

  In step S804, the camera control unit 120 performs control to store the characteristic color near the touch position in the memory 117 as color information of an automatic tracking target. As specific color information, there are information such as the characteristic color at the time of subject designation, its luminance, the value of color difference, the size of the same color area, the position of the center of gravity of the same color area, and the like. When the digital camera 100 has a mono-authentication function, identification information such as an authentication ID is also stored in the memory 117. In the following description, face information and color information are collectively referred to as subject information (including subject size, subject detection position, and the like).

  After the subject information is stored in the memory 117 in step S803 or S804, the process proceeds to step S805. In step S805, the camera control unit 120 displays the subject tracking frame. That is, the camera control unit 120 controls the frame display unit 128 so that the display unit 109 displays a subject tracking frame having a size corresponding to the subject size at the center of the subject detection position. Thereafter, the subject designation processing ends.

  As described above, in the system control unit 114, the subject detection unit 126 detects a subject at a position designated by the user via the display unit 109 or in the vicinity of the designated position. Then, the frame display unit 128 causes the display unit 109 to display the subject tracking frame. According to the processing example of FIG. 8A, the subject that the user wants to track can be easily specified in an intuitive manner. However, the method of designating the subject is not limited to this method. Another method will be described with reference to FIG.

  FIG. 8B is a flowchart illustrating a processing example when the user specifies a subject by using a subject specifying switch as an operation member configuring the operation unit 118. First, in step S806, the frame display unit 128 displays a frame serving as an indication of subject specification near the center of the screen of the display unit 109. The user adjusts the direction of the digital camera 100 so that the image of the subject to be tracked is placed near the center of the screen using the frame as a guide.

  Subsequently, in step S807, the camera control unit 120 determines whether the subject designation switch has been pressed. If the subject designation switch has been pressed, the process advances to step S808. On the other hand, when the subject specifying switch is not pressed, the determination process of step S807 is repeated in a waiting state.

  In step S808, the camera control unit 120 controls the subject detection unit 126 to perform face detection near the center of the screen. If a face is detected near the center of the screen, the camera control unit 120 determines that the main subject is a person, and proceeds to step S809. On the other hand, if no face is detected near the center of the screen, the camera control unit 120 determines that the main subject is an object other than a person, and proceeds to step S810.

  In step S809, the same processing as in step S803 of FIG. 8A is performed, and in step S810, the same processing as in step S804 of FIG. 8A is performed, and thus description thereof will be omitted. After the subject information is stored in the memory 117 in step S809 or S810, the process proceeds to step S811. In step S811, the camera control unit 120 displays the subject tracking frame. Thereafter, the subject designation processing ends.

  As described above, in the processing example of FIG. 8B, the subject detection unit 126 detects the subject at or near the screen center position of the display unit 109. Then, the frame display unit 128 causes the display unit 109 to display a subject tracking frame indicating the position of the subject. Even when the digital camera 100 does not have an operation member such as a touch panel, the user can easily specify a subject.

  When the digital camera 100 has both a touch panel and a switch for designating a subject that constitutes the operation unit 118 with respect to the subject designation process, both the method of FIG. 8A and the method of FIG. You may. Further, the subject specifying process to be applied may be changed according to the flow of the process.

  When the subject specifying process in step S705 in FIG. 7 ends, the process advances to step S706 to start a process of stopping the support mode for the subject specifying operation. In step S706, the camera control unit 120 ends the electronic image stabilization control for the subject specification support. When the electronic image stabilization is completed in step S706, the process proceeds to step S707. In step S707, the camera control unit 120 zooms in the optical zoom zoomed out in step S703 to the original zoom magnification.

  Here, the optical zoom-in process of step S707 will be described with reference to FIG. FIG. 9 is a flowchart of the optical zoom-in process after the subject is specified. First, in step S900, the camera control unit 120 acquires shake detection information from the shake detection unit 119 such as a gyro sensor, and the shake amount (shake amount) of the digital camera 100 is less than a predetermined value (from the predetermined shake amount). Is also smaller). Immediately after the subject is specified, the angle of view may not be stable due to the operation of the touch panel or the operation switch for specifying the subject. For this reason, the camera control unit 120 determines whether the operation of designating the subject has been completed and the digital camera 100 has returned to a firmly held state by detecting the shaking of the digital camera 100. If the swing amount is smaller than the predetermined value in step S900, the process proceeds to step S901.

  In step S901, the camera control unit 120 acquires the position of the subject specified in step S705 of FIG. 7 (the position of the specified subject) from the subject detection unit 126, and the position of the subject is zoomed in near the center of the angle of view. It is determined whether it is within the corner (within a predetermined range). This determination is for preventing the frame from being out of the angle of view due to the zoom-in operation when the subject is specified around the screen. If the subject is within the zoomed-in angle of view, the process advances to step S902.

  In step S902, the camera control unit 120 determines whether or not the amount of shaking is less than the predetermined value and the position of the designated subject is within the zoom-in angle of view, that is, whether the framing is stable for a predetermined time. judge. If the predetermined time has elapsed in step S902, the process proceeds to step S903. In step S903, the camera control unit 120 starts an optical zoom-in operation (optical zoom-in operation). On the other hand, if any of the conditions in steps S900 to S902 is not satisfied, the process returns to step S900, and the camera control unit 120 repeats the determination until all the conditions are satisfied.

  In the present embodiment, after ending the electronic image stabilization control in step S706, the camera control unit 120 executes the framing stabilization wait processing after the subject designation in steps S900 to S902. After that, the control of the electronic image stabilization may be ended. Further, control may be performed such that either the swing of the digital camera 100 or the position of the subject falls within a predetermined range.

  In step S903, the camera control unit 120 zooms in the zoom lens 102 to the zoom magnification before zooming out in step S703 in FIG. 7, and ends the optical zoom-in process. When the optical zoom-in process ends in step S707 of FIG. 7, the process proceeds to step S708.

  In step S708, the camera control unit 120 controls the subject tracking function. That is, the camera control unit 120 executes the control of each tracking function described above for the subject specified in step S705. As a result, the exposure, focus, and angle of view can be continuously adjusted even for a moving subject, so that the release time lag of still image shooting can be reduced and the performance of following a moving image can be improved.

  Subsequently, in step S709, the camera control unit 120 determines whether the release switch has been operated. If the release switch has been operated, the process proceeds to step S710. On the other hand, if the release switch has not been operated, the process proceeds to step S711.

  When the release switch is fully pressed in the still image mode, in step S710, the camera control unit 120 executes shooting of a still image. In step S711, the camera control unit 120 determines whether the subject tracking function has ended. If the subject tracking function has not ended, the process returns to step S700, and the camera control unit 120 continues to control the subject tracking function. For example, when a mode that does not track the subject is selected in a menu or the like, or when an operation to end the function is performed by an operation button or the like that changes the mode, the subject tracking function ends.

  As described above, in the present embodiment, the control device (the system control unit 114) includes the control unit (the camera control unit 120) and the electronic image stabilization unit (the electronic image stabilization control unit 127). The control unit controls the lens unit (the lens barrel 101) so as to perform tracking control on the subject specified by the subject specifying unit (the operation unit 118) (via the subject specifying unit by the user). The electronic image stabilization unit electronically performs image blur correction based on the shake detected by the shake detection unit (shake detection unit 119). The control unit performs image blur correction by the electronic image stabilizing unit before the subject is specified, and zooms out the lens unit from the first position to the second position on the wider angle side than the first position (S703). , S704).

  Preferably, after the subject is specified, the control unit stops image blur correction by the electronic image stabilizing unit and zooms in the lens unit from the second position to the first position (S706, S707). More preferably, the control means, after the subject is designated, when the shake amount (shake amount) detected by the shake detection means is smaller than a predetermined shake amount (predetermined value), the image blur correction by the electronic image stabilization means. Is stopped, and the lens unit is zoomed in from the second position to the first position. Also preferably, when the position of the subject detected by the subject detection unit is within a predetermined range in the image after the designation of the subject, the control unit stops the image stabilization by the electronic image stabilization unit, The unit zooms in from the second position to the first position.

  Preferably, the electronic image stabilization unit performs image blur correction by changing a display range of an image formed via the lens unit based on the shake. More preferably, the control means sets a changeable area of the display range by the electronic image stabilizing means based on the zoom-out magnification of the lens unit. Also preferably, the first position is a zoom position set by a user. More preferably, the control means controls at least one of the zoom lens 102, the focus lens 103, the anti-vibration lens 104, the aperture, or the shutter (aperture / shutter 105) constituting the lens unit to perform tracking control. .

  As described above, in the present embodiment, when performing an operation of designating a subject, the camera control unit 120 performs zoom-out of the optical zoom and control of electronic image stabilization. The camera control unit 120 changes the control range of electronic image stabilization according to the zoom-out magnification of the optical zoom. This makes it possible to prevent the subject from going out of frame from the angle of view due to camera shake caused by an operation of designating the subject in the subject tracking function of tracking the exposure, focus, and angle of view of a moving subject.

(Other embodiments)
The present invention supplies a program for realizing one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus read and execute the program. It can also be realized by the following processing. Further, it can be realized by a circuit (for example, an ASIC) that realizes one or more functions.

  According to the present embodiment, a control device, an imaging device, a control method, a program, and the like that can prevent a subject image from going out of a frame during execution of a subject tracking function and improve operability are provided. A storage medium can be provided.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

114 System control unit (control device)
118 Operation unit (subject specifying means)
119 Shake detection unit (shake detection means)
120 Camera control unit (control means)
127 Electronic anti-vibration control unit (electronic anti-vibration means)

Claims (12)

Control means for controlling the lens unit so as to perform tracking control on the subject designated by the subject designating means;
An electronic image stabilization unit that electronically performs image blur correction based on the shake detected by the shake detection unit,
The control unit performs the image blur correction by the electronic image stabilizing unit before the subject is specified, and moves the lens unit from a first position to a second position on a wider angle side than the first position. A control device characterized by zooming out.   The control means stops the image blur correction by the electronic image stabilization means after the subject is specified, and zooms in the lens unit from the second position to the first position. The control device according to claim 1.   When the shake amount detected by the shake detection unit is smaller than a predetermined shake amount after the subject is specified, the control unit stops the image blur correction by the electronic image stabilization unit, and sets the lens 3. The control device according to claim 2, wherein the unit zooms in from the second position to the first position.   The control unit, after the subject is specified, when the position of the subject detected by the subject detection unit is within a predetermined range in the image, while stopping the image blur correction by the electronic image stabilization unit, The control device according to claim 2, wherein the lens unit zooms in from the second position to the first position.   5. The electronic image stabilization unit according to claim 1, wherein the electronic image stabilization unit performs the image blur correction by changing a display range of an image formed through the lens unit based on the shake. The control device according to claim 1.   The control device according to claim 5, wherein the control unit sets a changeable area of the display range by the electronic image stabilizing unit based on a zoom-out magnification of the lens unit.   The control device according to any one of claims 1 to 6, wherein the first position is a zoom position set by a user.   8. The control device according to claim 1, wherein the control unit controls the following by controlling at least one of a zoom lens, a focus lens, an anti-vibration lens, a diaphragm, and a shutter included in the lens unit. 9. The control device according to any one of claims 1 to 4. A control device according to any one of claims 1 to 8,
An image pickup device for picking up an image of the subject via the lens unit. Before the subject is designated, performing image blur correction by the electronic image stabilizing unit, and zooming out the lens unit from the first position to a second position wider than the first position,
Obtaining information indicating that the subject has been designated from the subject designating means;
Stopping the image blur correction by the electronic image stabilization unit after the subject is specified, and zooming in the lens unit from the second position to the first position. How to control. Before the subject is designated, performing image blur correction by the electronic image stabilizing unit, and zooming out the lens unit from the first position to a second position wider than the first position,
Obtaining information indicating that the subject has been designated from the subject designating means;
Stopping the image blur correction by the electronic image stabilizing unit after the subject is specified, and zooming in the lens unit from the second position to the first position. Program characterized by the following. A storage medium storing the program according to claim 11.