JP6289207B2 - IMAGING DEVICE, IMAGING DEVICE CONTROL METHOD, IMAGING DEVICE CONTROL PROGRAM, AND STORAGE MEDIUM - Google Patents

Description

  The present invention relates to an imaging apparatus having a zoom function, a control method thereof, and the like.

  Conventionally, an imaging apparatus having a function of driving a zoom lens to perform optical zooming (optical zoom) and a function of enlarging a part of a captured image to perform electronic zooming (electronic zoom) It has been known. In particular, when taking a picture in a telephoto state, a function has been proposed that makes it possible to easily adjust the shooting angle of view, taking into consideration that the subject is likely to be out of frame.

  Patent Document 1 discloses an auto zoom function that zooms out a shooting range including a subject when it is determined that the detected subject does not fall within a predetermined region within the shooting range.

JP2013-9435A

  However, in Patent Document 1, if it is determined that the subject does not fall within a predetermined area, the photographer himself / herself moves the camera and zooms out even when the subject can be easily captured within the shooting range. For this reason, an unnecessary change in the angle of view may occur and the photographer may feel annoyed, or there is a possibility that a photo opportunity will be missed until the desired angle of view is restored.

  In view of the above-described problems, an object of the present invention is to suppress an unnecessary change in the angle of view and realize a more comfortable photographing operation in control for automatically zooming out according to a position where a subject is detected.

  In order to achieve the above object, the first aspect of the present invention is an imaging apparatus, and includes a subject detection unit that detects a subject from a captured image, and a calculation that calculates a motion amount of the subject detected by the subject detection unit. Means for detecting the amount of movement of the imaging device, and a first zoom for changing the zoom magnification to the wide-angle side when the subject is detected in the first predetermined area in the image by the subject detection means. And a control means for restricting execution of the first zoom operation according to the amount of movement of the subject and the amount of movement of the imaging device.

  According to the present invention, it is possible to suppress unnecessarily changing the zoom magnification according to the position where the subject is detected, and to realize a more comfortable photographing operation.

It is a block diagram which shows the structural example of the digital camera in this embodiment. It is the figure which illustrated the relationship between the focal distance in this embodiment, and the focus lens position for every object distance. It is the figure which illustrated the angle of view in the subject search state in the manual search mode of this embodiment, and the angle of view in the imaging preparation state. It is the figure which illustrated the zoom-out area | region and zoom-in area | region in the automatic tracking mode of this embodiment. It is a flowchart explaining FA zoom processing in this embodiment. It is a flowchart explaining the automatic FA zoom determination process in this embodiment. It is a figure explaining the automatic FA zoom determination in this embodiment. It is a flowchart explaining FA zoom-out operation | movement and FA zoom-in operation | movement in this embodiment. It is a figure explaining the calculation method of the zoom out position by the electronic zoom and optical zoom in this embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the function realized by the present embodiment is a framing support zoom function that supports framing by the user, and is referred to as a framing assist zoom function (hereinafter abbreviated as FA zoom function) for convenience.

  FIG. 1 is a block diagram illustrating a configuration example of a digital camera 100 as an example of an imaging apparatus according to the present embodiment. The digital camera 100 is configured to be able to execute the FA zoom function.

  The lens barrel 101 holds a lens group therein. The zoom lens 102 adjusts the focal length by moving in the optical axis direction, and optically changes the angle of view (moves the zoom position). The focus lens 103 adjusts the focus by moving in the optical axis direction. The anti-vibration lens 104 is a correction lens that corrects image blur caused by camera shake. The aperture and shutter 105 are configured to be able to adjust the amount of light, and are used for exposure control. In the present embodiment, the digital camera 100 is an imaging device in which the lens barrel 101 and the camera body are integrally configured, but is not limited to this. The present embodiment is also applicable to an imaging system that includes a camera body and an interchangeable lens that can be attached to and detached from the camera body.

  The light that has passed through the lens barrel 101 is received by an imaging device 106 that includes a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor). The imaging element 106 generates an imaging signal by converting a subject image into an electrical signal by photoelectric conversion. The imaging signal is input to the image processing circuit 107. The image processing circuit 107 performs various processes such as a pixel interpolation process and a color conversion process on the input image pickup signal, and outputs image data to the image memory 108. The image memory 108 is a storage means that includes a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), and the like.

  The display unit 109 includes a TFT type LCD (Thin Film Transistor Driven Liquid Crystal Display) and the like, and displays a captured image (image data). The display unit 109 displays specific information (for example, shooting information and an FA zoom frame described later) along with the shot image. By displaying information such as live view, an electronic viewfinder (EVF) function for the photographer to adjust the angle of view is realized.

  The aperture shutter drive unit 110 calculates an exposure control value (aperture value and shutter speed) based on luminance information obtained by image processing in the image processing circuit 107, and drives the aperture and shutter 105 based on the calculation result. To do. Thereby, AE (automatic exposure) control is performed. The anti-vibration lens driving unit 111 calculates an amount of shake applied to the digital camera 100 based on information from an angular velocity sensor such as a gyro sensor, and drives the anti-vibration lens 104 so as to cancel (reduce) the shake.

  The focus lens driving unit 112 drives the focus lens 103. In the present embodiment, the digital camera 100 performs AF (autofocus) control using a contrast method. For this reason, the focus lens driving unit 112 drives the focus lens 103 so that the subject is in focus based on the focus adjustment information (contrast evaluation value) of the photographing optical system obtained by the image processing of the image processing circuit 107. However, the present embodiment is not limited to this, and AF control using a plurality of methods such as AF control other than the contrast method such as the phase difference AF method or a combination of the contrast method and another method is performed. You may comprise.

  The zoom lens driving unit 113 drives the zoom lens 102 in accordance with a zoom operation instruction. The operation unit 117 includes a zoom lever, a zoom button, or the like as a zoom operation member for the photographer to instruct the camera to perform zooming. Based on the operation amount and operation direction of the zoom operation member used for the zoom instruction operation, the system control unit 114 calculates the zoom drive speed and drive direction, and the zoom lens 102 is moved along the optical axis according to the calculation result.

  The image data generated by the shooting operation is sent to the recording unit 116 via the interface unit (hereinafter referred to as I / F unit) 115 and recorded. The image data is recorded on an external recording medium such as a memory card used by being attached to the digital camera 100, a nonvolatile memory 118 built in the digital camera 100, or both.

  In addition to the zoom operation member, the operation unit 117 includes a release switch for instructing start of photographing, an FA zoom operation switch for instructing start and end of an FA zoom function, and the like. A signal from the operation unit 117 is sent to the system control unit 114 described later. In addition to program data and image data, the memory 118 stores setting information of the digital camera 100 and information such as a zoom-in position in an FA zoom function described later. Here, the zoom-in position is a zoom return position which is a target when zooming in at the end of the FA zoom, and details thereof will be described later.

  The system control unit 114 is configured to include an arithmetic device such as a CPU (Central Processing Unit), and controls the entire digital camera 100 by sending a control command to each unit in accordance with a photographer's operation. The system control unit 114 executes various control programs stored in the memory 118, for example, programs for performing control of the image sensor 106, AE / AF control, zoom control (including FA zoom processing), and the like.

  Next, control related to the FA zoom function in the system control unit 114 will be described. As shown in FIG. 1, the system control unit 114 includes a CZ control unit 119, an electronic zoom control unit 120, an FA zoom frame control unit 121, an FA zoom control unit 122, and a subject detection unit 123. .

  In order to maintain the in-focus state when the angle of view is changed by the optical zoom, in the case of a rear focus type lens barrel such as the lens barrel 101, the focus lens 103 is moved to an appropriate focus position according to the position of the zoom lens 102. Must be moved. Such control is called computer zoom (CZ) control. FIG. 2 is a relationship diagram between the focal length of the zoom lens and the focus position for each subject distance. In FIG. 2, a data table showing the relationship between the focal length of the zoom lens and the focus position in focus for each distance to the subject is graphed. In the present embodiment, this table is referred to as a focus cam table. In FIG. 2, the horizontal axis indicates the focal length corresponding to the zoom position, and the vertical axis indicates the focus position. Next to each graph line, the distance from the digital camera 100 to the subject (subject distance) is shown.

  The system control unit 114 controls the focus lens driving unit 112 when performing AF control, and performs a scanning operation by moving the focus lens 103 within a predetermined range. A focus position which is a focal point is detected by a known method using a contrast evaluation value or the like obtained during this operation. The subject distance can be measured by referring to the focus cam table using the zoom position and the focus position at that time.

  The digital camera 100 has an optical zoom function and an electronic zoom function. The CZ control unit 119 and the zoom lens driving unit 113 perform optical zoom driving. The CZ control unit 119 detects the zoom position of the zoom lens 102 at every predetermined control period during the zoom operation. Then, the CZ control unit 119 drives the focus lens 103 so as to follow the focus cam table at the subject distance measured by the AF control according to the zoom position. This makes it possible to perform an optical zoom operation while maintaining the in-focus state.

  On the other hand, the electronic zoom control unit 120 and the image memory 108 perform electronic zoom. The electronic zoom control unit 120 implements an electronic zoom function by cutting out a target area from the image data transferred to the image memory 108. In addition, the electronic zoom control unit 120 realizes a smooth electronic zoom display by displaying the display unit 109 while gradually increasing the range to be extracted at the frame rate period of the image to be captured by the image sensor 106.

  The subject detection unit 123 detects a desired subject region from the image data stored in the image memory 108. In the present embodiment, a subject detection method (face detection processing, color detection processing) for detecting a subject (face or object) based on face information or color information included in image data will be described.

  The face detection process is a process for detecting a face area existing in image data by a known algorithm. For example, the subject detection unit 123 extracts a feature amount from a square partial region on the image data, and compares the feature amount with a facial feature amount prepared in advance. If the correlation between the two exceeds a predetermined threshold, the subject detection unit 123 determines that the partial area is a face area. By repeating this determination while changing the combination of the size, the arrangement position, and the arrangement angle of the partial areas, various face areas existing in the image data can be detected.

  In the color detection process, the color information of the subject area designated according to the subject designation method described later is stored as a characteristic color. The color detection process is executed when the subject to be detected is an object (a “thing” other than a person). As the color information, RGB, luminance Y, color differences RY, BY, and the like, which are output signals from the image processing circuit 107, are used. At the time of subject detection, the subject detection unit 123 divides the image data into a plurality of partial areas, and calculates an average value of luminance and color difference for each partial area. In addition, the subject detection unit 123 compares the characteristic color information stored in advance with the color information of each region at the time of subject detection, and sets a partial region in which the difference in luminance and color difference is equal to or less than a predetermined amount as a subject region candidate. A group of partial areas adjacent to each other in this area candidate is defined as the same color area, and an area where the same color area falls within a predetermined size range is defined as a final subject area.

  The subject detection unit 123 estimates the size of the subject region on the image data by using the subject distance information measured by the CZ control unit 119 and the focal length information of the zoom lens 102 together with the face information and the color information. be able to.

  The shake detection unit 124 detects the shake state of the digital camera 100 based on information such as a gyro sensor (angular velocity detection means). The shake detection unit 124 detects the shake amount of the camera according to the shake amount applied to the gyro sensor or the like. The gyro sensor used for shake detection may be configured to be used also as a sensor used as control information for the anti-vibration lens driving unit 111. Further, the camera shake amount may be detected using an acceleration sensor.

  Next, an overview of the FA zoom function and the FA zoom frame control unit 121 and the FA zoom control unit 122 will be described. The digital camera 100 of the present embodiment has two modes, a manual search mode and an automatic tracking mode, as modes for executing FA zoom. These two modes are modes in which the photographer operates the FA zoom operation switch when the subject is out of the frame to recapture the subject, or the camera automatically detects the subject and supports angle adjustment. It is different in whether it is. Hereinafter, an overview of the functions of each mode will be described.

  In a camera not equipped with the FA zoom function, the photographer needs to perform the following operation when the photographer is framing in the telephoto state and the subject moves out of the frame while waiting for a photo opportunity. That is, first, the subject is searched after zooming out by operating the zoom operation member. Then, after searching for the subject, the angle of view is adjusted by zooming until the desired angle of view is reached again.

  On the other hand, in the digital camera 100 having the manual search mode of the FA zoom function, when the subject is lost in a state in which the angle of view is adjusted before photographing (hereinafter referred to as a photographing preparation state), the photographer switches the FA zoom operation switch. Can be operated. This FA zoom operation switch is a switch assigned for the FA zoom function, and is a member different from the zoom operation member. By pressing the FA zoom operation switch, the camera is instructed to start the FA zoom function. The FA zoom control unit 122 stores each zoom position of the electronic zoom and the optical zoom in the memory 118 in response to an FA zoom start instruction from the FA zoom operation switch. Further, the FA zoom control unit 122 instructs the CZ control unit 119 or the electronic zoom control unit 120 to zoom out in the wide-angle direction according to the processing procedure described below, and the angle of view is zoomed out from the shooting preparation state. (Hereinafter referred to as subject search state).

  Next, with reference to FIG. 3, each angle of view in the shooting preparation state and the subject search state will be described. FIG. 3 is an explanatory diagram of the angle of view in the subject search state and the angle of view in the shooting preparation state. 3A and 3D show the angle of view in the zoom-in state (shooting preparation state), and FIGS. 3B and 3C show the angle of view in the zoom-out state (subject search state). Is shown.

  When the subject is out of frame as shown in FIG. 3A, the photographer presses the FA zoom operation switch to search for the subject. While the FA zoom operation switch is pressed, the zoom-out state is maintained, and the FA zoom frame 300 indicating the zoom-in position is displayed on the display unit 109 so as to be superimposed on the image.

  When a desired subject is found in the zoom-out state (subject search state) as shown in FIG. 3B, the subject is photographed so as to fit inside the FA zoom frame 300 as shown in FIG. Perform framing. Thereafter, the photographer releases the FA zoom operation switch to instruct the FA zoom control unit 122 to end the FA zoom. At this time, the FA zoom control unit 122 performs a zoom-in operation by electronic zoom or optical zoom up to the stored zoom position (zoom-in position) in the shooting preparation state. Thereby, the optimal framing state as shown in FIG. 3D is obtained.

  As shown in FIGS. 3B and 3C, the FA zoom frame control unit 121 calculates the size indicating the angle of view in the stored shooting preparation state, and the EVF center of the display unit 109 is calculated. The FA zoom frame 300 is displayed on the screen. The size of the FA zoom frame 300 is calculated based on the zoom magnification at the time of zooming out. For example, when the subject search state is entered by zooming out from the shooting preparation state at 2 × electronic zoom magnification and 3 × optical zoom magnification, the angle of view displayed on the EVF in the subject search state is (1 / 2) A FA zoom frame with a size of (1/3) = 1/6 times is displayed. By such processing, the photographer can shoot at a desired angle of view while re-framing the subject out of the frame with a simple operation.

  Also, when shooting a scene where the subject is likely to be out of frame, such as when shooting a moving subject, frame out can be more easily prevented by the automatic tracking mode in which the camera automatically changes the zoom position. In particular, when shooting in the telephoto state, since the angle of view is narrow, there is a case where the subject is out of frame even by a slight camera movement caused by camera shake or the like.

  The digital camera 100 of the present embodiment has an automatic tracking mode with an FA zoom function. For this reason, after setting the automatic tracking mode, the subject to be photographed may be designated by performing an operation of designating the subject on the touch panel or the like. Other than touch panel operation, the subject can be specified by specifying the subject near the center when a specific button is pressed, or automatically selecting the main subject from the subjects detected by the camera. Conceivable.

  The subject detection unit 123 calculates the position and size of the subject region designated from the image memory 108 on the image data. By continuously performing this on the sampled image data for each frame displayed as a live view, the movement of the subject can be tracked. When the tracking subject is detected in a zoom-out area described later, the FA zoom control unit 122 instructs the CZ control unit 119 or the electronic zoom control unit 120 to zoom out in the wide-angle direction. When the subject is detected in the zoom-in area of the FA zoom frame 300, the zoom-in operation is performed to the zoom position on the telephoto side indicated by the FA zoom frame 300. By such processing, the photographer only has to move the camera so that the subject is placed on the screen without worrying about the zoom operation. Even if the subject is about to be out of frame, the zoom position is automatically changed, so that the angle of view can be adjusted more easily. In the present embodiment, the photographer can easily perform framing by performing the zoom-out operation and the zoom-in operation in the automatic tracking mode at the optimal timing.

  Next, with reference to FIG. 4, the start conditions for the zoom-out operation and the zoom-in operation will be described. FIG. 4 is an explanatory diagram of processing for preventing a subject from being out of the frame.

  In FIG. 4, reference numeral 400 denotes a subject tracking frame for tracking the subject. The subject tracking frame is displayed on the EVF of the display unit 109 so as to surround the subject so that the subject designated by the photographer can be seen. The position and size of the subject tracking frame on the screen are calculated by the subject detection unit 123 based on face information and color information, and are updated at a frame rate cycle.

  FIG. 4A shows a peripheral area outside a predetermined ratio as a zoom-out area ZO with respect to the entire angle of view (entire screen) displayed in EVF. For example, when the center point of the screen is set to 0%, the entire screen is set to 100%, and a position that is 80% of the entire screen is set as the boundary of the zoom-out area ZO, the area of 80 to 100% in the entire screen is zoomed. It becomes the out area ZO. When a part of the tracking frame 400a enters the zoom-out area ZO in the image, the zoom-out operation is started. Further, the zoom position (zoom-in angle of view) before zoom movement is stored in the memory 118. The zoom magnification and zoom speed during the zoom-out operation are preset according to the size and moving speed of the subject. Further, the zoom magnification and the zoom speed may be appropriately calculated according to the size and moving speed of the subject. The zoom-out operation is executed according to the magnification and zoom speed. Thereby, it is possible to effectively prevent the subject from being out of frame.

  FIG. 4B shows an angle of view obtained by zooming out from the angle of view of FIG. 4A by a predetermined zoom drive amount. In FIG. 4B, an area inside a predetermined ratio with respect to the zoom-in angle of view indicated by the FA zoom frame 300 in the subject search state is shown as a zoom-in area ZI. For example, the center point of the screen is set to 0%, the FA zoom frame 300 (zoom-in angle of view) is set to 100%, and a position that is 70% of the zoom-in angle of view is set as the boundary of the zoom-in area ZI. In this case, an area of 0 to 70% in the entire FA zoom frame 300 becomes the zoom-in area ZI. At this time, when the zoom-out magnification is 1/2, for example, the FA zoom frame 300 is 50% of the entire screen. Therefore, it can be said that the zoom-in area ZI is an area of 0 to 35% (= 70% × (1/2)) with respect to the entire screen. When the photographer changes the orientation of the camera so that the tracking frame 400b fits inside the zoom-in area ZI, the zoom-in operation starts.

  Next, the overall processing of the FA zoom function will be described with reference to FIG. The FA zoom function in FIG. 5 is performed based on a command from the FA zoom control unit 122 unless otherwise specified. The process of the flowchart of FIG. 5 is started when the photographer sets the FA zoom function to be valid via the camera menu setting screen, the operation unit 117, or the like.

  First, in step S500, the FA zoom control unit 122 determines whether or not the FA zoom operation switch of the operation unit 117 is pressed. When the FA zoom operation switch is pressed, the process proceeds to step S501, and the FA zoom control unit 122 measures the pressing time of the FA zoom operation switch.

  In step S501, the FA zoom control unit 122 determines whether or not the FA zoom operation switch is released within a predetermined time A after the FA zoom operation switch is pressed. That is, the FA zoom control unit 122 determines whether the FA zoom operation switch is pressed long or short. When the FA zoom operation switch is not released within the predetermined time A, that is, when the FA zoom operation switch is pressed for a long time, the process proceeds to step S502, and the above-described manual search mode is set. On the other hand, when the FA zoom operation switch is released within the predetermined time A, that is, when the FA zoom operation switch is pressed for a short time, the process proceeds to step S507 and the above-described automatic tracking mode is set.

  When the process proceeds to step S507 and the automatic tracking mode is set, in step S508, processing for designating a subject to be tracked is performed. Here, the system control unit 114 automatically selects a subject by a photographer using a touch panel, a cross key, or the like, which is a member of the operation unit 117, or the size or position of the detected subject. You may specify it.

  In step S509, the FA zoom control unit 122 determines whether the subject tracking frame of the subject to be tracked has entered the zoom-out area ZO (first predetermined area) described above. When the tracking frame enters the zoom-out area ZO, that is, when the possibility that the subject is out of the frame is high, the process proceeds to step S510, and automatic FA zoom determination is performed.

  Here, the automatic FA zoom determination in step S510 will be described with reference to FIGS. FIG. 6 is a flowchart showing the automatic FA zoom determination process in step S510.

  In step S600, the FA zoom control unit 122 determines whether or not an automatic FA zoom determination timer (hereinafter referred to as a determination timer) is counting. If the timer is being counted, the process proceeds to step S602. If the timer is not being counted, the timer starts counting in step S601 and then proceeds to step S602.

  In step S <b> 602, the FA zoom control unit 122 acquires the camera motion amount based on the signal output from the shake detection unit 124. In step S <b> 603, the FA zoom control unit 122 acquires the amount of movement of the tracking subject detected by the subject detection unit 123. As a method for detecting the amount of motion of a subject, a known motion vector technique, for example, a matching method that compares and contrasts an image of the current frame with an image of the immediately preceding frame for each predetermined representative point or pixel is detected. There is a way. Any means other than the motion vector technique based on the matching method may be used as long as it can detect the amount of motion of the subject.

  In step S604, the FA zoom control unit 122 determines whether the camera motion amount acquired in step S602 is greater than the threshold value X1. If the camera motion amount is larger than the threshold value X1, the process proceeds to step S605. If the camera motion amount is less than the threshold value X1, the process proceeds to step S609.

  When the process proceeds to step S605, the FA zoom control unit 122 determines whether the subject motion amount acquired in step S603 is greater than the threshold Y1. If the subject movement amount is larger than the threshold Y1, the process proceeds to step S606, and if it is equal to or smaller than the threshold Y1, the process proceeds to step S608.

  In step S606, the FA zoom control unit 122 sets the automatic FA zoom to “valid”. In step S607, the determination timer is reset and the process ends.

  On the other hand, when the subject movement amount is equal to or smaller than the threshold Y1 and the process proceeds to step S608 in the determination in step S605, the FA zoom control unit 122 determines whether or not the determination timer exceeds the predetermined time B. If the determination timer exceeds the predetermined time B, the process proceeds to step S606, and the automatic FA zoom is set to “valid” as described above. On the other hand, if the determination timer is within the predetermined time B, the process proceeds to step S610. In step S610, the FA zoom control unit 122 sets the automatic FA zoom to “invalid” and ends the process.

  On the other hand, when the camera motion amount is equal to or smaller than the threshold value X1 in step S604 and the process proceeds to step S609, the FA zoom control unit 122 determines whether the subject motion amount acquired in step S603 is larger than the threshold value Y1 as in step S605. Determine whether. If the subject movement amount is larger than the threshold value Y1, the process proceeds to step S608, where it is determined whether or not the determination timer exceeds the predetermined time B as described above. If the subject motion amount is equal to or smaller than the threshold Y1, the process proceeds to step S610, the automatic FA zoom is set to “invalid”, and the process ends.

  In FIG. 6, the elapsed time since the subject tracking frame entered the zoom-out area ZO was used for the determination, but the number of times that the subject tracking frame has entered the zoom-out area ZO may be used. . In this case, the number of times the subject tracking frame has entered the zoom-out area ZO is counted instead of the timer, and it is determined in step S608 whether the count has exceeded a predetermined number.

  Here, FIGS. 7A to 7D are diagrams illustrating the amount of movement of the subject acquired in step S603 and the amount of movement of the camera acquired in step S602. That is, it represents how much the subject is moving and how much the camera is moved.

  FIG. 7A shows an example (area A) where the amount of movement of the subject and the amount of movement of the camera are both small. Specifically, this corresponds to the case where the camera motion amount is equal to or less than the threshold value X1 (second threshold value) and the subject motion amount is equal to or less than the threshold value Y1 (first threshold value or less). In this case, even if the subject tracking frame enters the zoom-out area, there is a low possibility that the subject will immediately go out of the view angle (or the photographer can easily return the subject to the vicinity of the center of the view angle). If automatic zoom-out is performed here, the angle of view changes unnecessarily, which may be annoying for the photographer. Accordingly, in the case of FIG. 7A, the automatic FA zoom is set to “invalid”.

  FIG. 7B shows an example (B region) where the amount of motion of the subject is small but the amount of motion of the camera is large. Specifically, this corresponds to a case where the amount of motion of the subject is equal to or less than the threshold Y1 and the amount of motion of the camera is greater than the threshold X1. In this case, the subject may be out of frame from the angle of view due to the camera shake of the photographer. However, since the movement of the subject is small, the possibility that the photographer can return the subject to the vicinity of the center of the angle of view is relatively high. Therefore, even if the subject tracking frame enters the zoom-out area, the automatic FA zoom is set to “invalid” until the predetermined time B elapses, and the automatic zoom-out is limited. If the subject tracking frame has entered the zoom-out area even after the predetermined time B has elapsed, the automatic FA zoom is set to “valid”.

  FIG. 7C shows an example (C region) where the camera movement amount is small but the subject movement amount is large. Specifically, this corresponds to a case where the amount of motion of the camera is less than or equal to the threshold value X1 and the amount of motion of the subject is greater than the threshold value Y1. In this case, the subject may move out of the angle of view because the subject moves so much, but the effect of camera movement such as camera shake is small, and the photographer is relatively likely to return the subject to the vicinity of the center of the angle of view. . Therefore, as in the case of FIG. 7B described above, even if the subject tracking frame enters the zoom-out area, the automatic FA zoom is set to “invalid” for a predetermined time B and the automatic zoom-out is limited. If the subject tracking frame has entered the zoom-out area even after the predetermined time B has elapsed, the automatic FA zoom is set to “valid”.

  FIG. 7D shows an example (D region) where both the amount of movement of the subject and the amount of movement of the camera are large. Specifically, this corresponds to the case where the amount of movement of the subject is larger than the threshold Y1 and the amount of movement of the camera is larger than X1. In this case, there is a high possibility that the subject will frame out of the angle of view, and it will be difficult for the photographer to return the subject to near the center of the angle of view. Therefore, in this case, the automatic FA zoom is set to “valid”.

  In the flow of FIG. 6, the threshold value X1 is set as the camera motion amount and the threshold value Y1 is set as the subject motion amount. However, the number of threshold values is not limited to this. For example, as shown in FIG. 7, a threshold value X2 (> X1) may be provided for the camera motion amount, and a threshold value Y2 (> Y1) may be provided for the subject motion amount. In this case, if the camera motion amount exceeds the threshold value X2 or the subject motion amount exceeds the threshold value Y2, the automatic FA zoom may be set to “valid” regardless of the determination timer.

  Returning to the description of FIG. When the automatic FA zoom determination described above is performed in step S510, the process proceeds to step S511. In step S511, the FA zoom control unit 122 refers to the automatic FA zoom determination result in step S510. If the automatic FA zoom determination is valid, the process proceeds to step S512. If the automatic FA zoom determination is invalid, the process returns to step S509.

  In step S512, the FA zoom control unit 122 performs an FA zoom-out operation. Details of the FA zoom-out operation will be described later with reference to FIG. After the FA zoom-out operation, in step S513, the FA zoom control unit 122 determines whether or not the FA zoom operation switch has been pressed. If the button has been pressed, the process proceeds to step S514. If the button has not been pressed, the process returns to step S509.

  In step S514, the FA zoom control unit determines whether or not the FA zoom operation switch pressed in step S513 is released within a predetermined time A. If it is released within the predetermined time A, the FA zoom process is terminated. On the other hand, when the button is pressed for a predetermined time A or longer, that is, when the FA zoom operation switch is pressed for a long time, the process proceeds to step S502, and the manual search mode is set.

  On the other hand, if the subject tracking frame has not entered the zoom-out area ZO in step S509, the process proceeds to step S515. In step S515, the FA zoom control unit 122 resets the automatic FA zoom determination timer described above.

  In step S516, the FA zoom control unit 122 determines whether the process is after the FA zoom-out operation in the automatic tracking mode in step S512. If it is after the automatic FA zoom-out operation, the process proceeds to step S517; otherwise, the process proceeds to step S513.

  In step S517, the FA zoom control unit 122 determines whether or not the subject tracking frame is included in the zoom-in area ZI (second predetermined area) described above. When the subject tracking frame is included in the zoom-in area ZI, the process proceeds to step S518, and when it is not included, the process proceeds to step S513.

  In step S518, the FA zoom control unit 122 performs an FA zoom-in operation. Details of the FA zoom-in operation will be described later with reference to FIG. After the FA zoom-in operation, the process proceeds to step S513.

  On the other hand, when the manual search mode is set in step S502, the process proceeds to step S503, and the FA zoom control unit 122 performs an FA zoom-out operation. Details of the FA zoom-out operation will be described later with reference to FIG. 8 as in step S512.

  In step S504, the FA zoom control unit 122 controls the FA zoom frame control unit 121 to display the FA zoom frame on the display unit 109. The FA zoom frame displayed here corresponds to the FA zoom frame 300 described above with reference to FIG.

  In step S505, the FA zoom control unit 122 determines whether or not the FA zoom operation switch that has been pressed for a long time has been released. If the FA zoom operation switch is released, the process proceeds to step S506, and the FA zoom control unit 122 performs an FA zoom-in operation. Details of the FA zoom-in operation will be described later with reference to FIG. 8 as in step S518. When the FA zoom-in operation is completed, the FA zoom process is terminated.

  Next, the FA zoom-out operation and the FA zoom-in operation will be described with reference to FIG. FIG. 8A is a flowchart of the FA zoom-out operation performed in steps S503 and S512 of FIG.

  First, in step S800, the FA zoom control unit 122 acquires the optical zoom position from the CZ control unit 119, and acquires the electronic zoom position from the electronic zoom control unit 120. Further, the FA zoom control unit 122 stores the data of the optical zoom position and the electronic zoom position in the memory 118. The optical zoom position represents the position of the zoom lens corresponding to the zoom magnification that can be changed by the optical zoom function. The electronic zoom position represents a control position corresponding to the magnification of image enlargement and reduction that can be changed by the electronic zoom function. In the present embodiment, the zoom position stored here is set as the zoom return position during the FA zoom-in operation.

  Subsequently, in step S801, the FA zoom control unit 122 acquires a zoom-out drive amount. The zoom-out drive amount is a predetermined drive amount stored in the memory 118. The driving amount may be changed by the photographer by an operation from the setting menu.

  In step S802, the FA zoom control unit 122 determines whether the zoom state is an electronic zoom state. In the zoom operation of this embodiment, when the zoom lever of the operation unit 117 is pressed, the optical zoom is driven by the CZ control unit 119 when the optical zoom position is between the wide end and the tele end. When the optical zoom position is at the telephoto end and an operation instruction is further given in the telephoto direction, the electronic zoom control unit 120 drives the electronic zoom to enable super telephoto shooting. In order to maintain consistency between the zoom operation by the operation of the zoom lever and the FA zoom operation, even in the FA zoom operation, when the zoom state is the electronic zoom state, the electronic zoom is driven first. That is, it is determined whether or not the zoom position stored in the memory 118 is within the zoom area in the zoom state to be prioritized. In this embodiment, since electronic zoom is prioritized, it is determined in step S802 whether the zoom position is in the electronic zoom area. If the zoom position at the start of FA zoom is in the electronic zoom area, the process proceeds to step S803. If the zoom position is not in the electronic zoom area (in the optical zoom area), the process proceeds to step S805.

  In step S803, the FA zoom control unit 122 calculates the zoom-out position of the electronic zoom based on the electronic zoom position acquired in step S800 and the zoom-out drive amount acquired in step S801, and the electronic zoom control unit. Set to 120. The FA zoom control unit 122 instructs the electronic zoom control unit 120 to perform the scaling process up to the set zoom-out position of the electronic zoom. In step S804, the electronic zoom control unit 120 starts a zoom-out operation using the electronic zoom. When the zoom-out operation of the electronic zoom is stopped in step S804, the process proceeds to step S805.

  In step S805, the FA zoom control unit 122 determines whether further zoom-out by optical zoom is necessary. That is, if the electronic zoom alone is not sufficient for the zoom drive of the set zoom-out drive amount, it is necessary to supplement the remaining zoom-out drive amount with the optical zoom. If it is determined that zoom-out by optical zoom is necessary, the process proceeds to step S806. If it is determined that zoom-out is unnecessary, the FA zoom-out operation is terminated.

  In step S806, the FA zoom control unit 122 calculates the zoom-out position of the optical zoom based on the optical zoom position and the zoom-out drive amount, and sets the calculated zoom-out position in the CZ control unit 119. The FA zoom control unit 122 instructs the CZ control unit 119 to perform zoom driving to the set zoom-out position of the optical zoom. In step S807, the CZ control unit 119 controls the zoom lens driving unit 113 to start an optical zoom zoom-out operation. When the zoom-out operation of the optical zoom is finished, the FA zoom-out operation is finished.

  Next, the FA zoom-in operation will be described. FIG. 8B is a flowchart of the FA zoom-in operation performed in steps S506 and S518 in FIG.

  First, in step S808, the FA zoom control unit 122 acquires a zoom-in drive amount. The zoom-in drive amount is a drive amount for zooming in to the zoom return position stored in the memory 118 in step S800 of FIG.

  In step S809, the FA zoom control unit 122 determines whether the zoom position is in the optical zoom area. If the zoom position is in the optical zoom area, the process proceeds to step S810 to perform zoom-in with priority on optical zoom. On the other hand, when the zoom position is not in the optical zoom area (in the electronic zoom area), the process proceeds to step S812 in order to perform zoom-in only with the electronic zoom.

  In step S810, the FA zoom control unit 122 calculates the zoom-in position of the optical zoom based on the optical zoom position and the zoom-in driving amount acquired in step S808, and sets it in the CZ control unit 119. The FA zoom control unit 122 instructs the CZ control unit 119 to perform zoom driving to the zoomed-in position of the set optical zoom. In step S813, the CZ control unit 119 controls the zoom lens driving unit 113 to start an optical zoom zoom-in operation. When the zoom-in operation of the optical zoom is stopped, the process proceeds to step S812.

  In step S812, the FA zoom control unit 122 determines whether it is necessary to further zoom in by electronic zoom. If zooming in by electronic zoom is necessary, the process proceeds to step S813. On the other hand, when zoom-in by electronic zoom is unnecessary, the FA zoom-in operation is terminated.

  In step S813, the FA zoom control unit 122 calculates the zoom-in position of the electronic zoom based on the zoom-in driving amount acquired in step S808, and sets it in the electronic zoom control unit 120. The FA zoom control unit 122 instructs the electronic zoom control unit 120 to perform the scaling process up to the set zoom-in position of the electronic zoom. In step S814, the electronic zoom control unit 120 starts a zoom-in operation using the electronic zoom. When the electronic zoom-in operation is stopped, the FA zoom-in operation is terminated.

  Next, a method for calculating the zoom-out position of the electronic zoom and optical zoom set in steps S803 and S806 in FIG. 8 will be described with reference to FIG. FIG. 9A is a diagram illustrating a zoom-out operation example when the zoom-out drive amount is set as a continuous amount based on the zoom magnification. In this example, when the focal length of the optical zoom is in the range of 24 to 840 mm, the optical zoom magnification is set to a maximum of 35 times, the electronic zoom magnification is set to a maximum of 4 times, and the zoom-out drive amount is converted to a zoom magnification to 1/8 times. It is said that. In the figure, “optical wide end” and “optical tele end” indicate the wide end (focal length 24 mm) and tele end (focal length 840 mm) in the optical zoom operation, respectively, and represent the boundaries of the optical zoom region. “Electronic wide end” and “electronic tele end” indicate a wide end (focal length 840 mm) and a tele end (corresponding to a focal length 3340 mm) in the electronic zoom operation, respectively, and represent the boundaries of the electronic zoom region. The optical telephoto end position matches the electronic wide end position.

  Pattern 1 shows a zoom-out position when the zoom position in the shooting preparation state is a focal length of 840 mm at the optical telephoto end position. Since the zoom state in the shooting preparation state is the optical zoom state, the electronic zoom position remains at the electronic wide end position. When the optical zoom position is changed with the zoom-out drive amount corresponding to the zoom magnification of 1/8, the position corresponding to the focal length of 840 mm × (1/8 times) = 105 mm is the zoom-out position.

In pattern 2, the zoom position in the shooting preparation state is the optical middle position and the focal length is 192 mm.
The zoom out position at the time of is shown. The zoom-out position of the optical zoom at this time is the zoom-out position at the optical wide end position corresponding to a focal length of 192 mm × (1/8 ×) = 24 mm.

  Pattern 3 shows the zoom-out position when the zoom position in the shooting preparation state is the optical middle position and the focal length is 72 mm. The calculation result of the zoom-out position of the optical zoom is 72 mm × (1/8 times) = 9 mm, which is a position on the wide angle side from the optical wide end position. In this case, the optical wide end position is set as the zoom-out position.

  Pattern 4 shows the zoom-out position when the zoom position in the shooting preparation state is the electronic telephoto end position. Since the electronic zoom magnification is a maximum of four times, the zoom-out position of the electronic zoom is set to the electronic wide end position, and the zoom-out operation with the optical zoom is performed for the remaining two times. Therefore, the zoom-out position by the optical zoom is a position corresponding to a focal length of 840 mm × (½ times) = 420 mm.

  When the zoom-out drive amount is set based on the zoom position, the size of the FA zoom frame in the subject search state is constant except when the zoom-out position exceeds the optical wide end position as in pattern 3. That is, there is an advantage that the zoomed out angle of view becomes the same magnification.

  FIG. 9B is a diagram illustrating a zoom-out operation example when the zoom-out drive amount is set based on the number of zoom steps. The number of zoom steps refers to the number of stop-division zooms in the step zoom function that stops only at zoom positions determined in stages, and the zoom position is represented by a discrete amount. In this example, the number of steps of optical zoom is 13 steps of optical W (wide), optical M1 to M11, and optical T (tele). The optical W corresponds to the optical M0, and the optical T corresponds to the optical M12. The number of steps of the electronic zoom is four steps of electron W (wide), electrons M1 and M2, and electron T (tele). The electron W corresponds to the electron M0, and the electron T corresponds to the electron M3. The zoom-out drive amount is 6 steps.

  Pattern 5 shows the zoom-out position when the zoom position in the shooting preparation state is the optical telephoto end position (= electronic wide end position). Since the zoom state in the shooting preparation state is the optical zoom state, the electronic zoom remains at the electronic wide end position. The optical zoom position is optical T (M = 12), and the position of M12-6 (step) = M6 is the zoom-out position.

  Pattern 6 represents a zoom-out position when the zoom position in the shooting preparation state is the optical middle position M6. The zoom-out position of the optical zoom at this time is M6-6 (step) = M0, and the optical wide end (optical W) position is the zoom-out position.

  Pattern 7 shows the zoom-out position when the zoom position in the shooting preparation state is the optical middle position. When the zoom-out position of the optical zoom is calculated, M4-6 (step) = M (−2), which is a position on the wide angle side with respect to the optical wide end position. In this case, the optical wide end (optical W) position is set as the zoom-out position.

  Pattern 8 shows the zoom-out position when the zoom position in the shooting preparation state is the electronic telephoto end position (electronic T). Since the maximum number of electronic zoom steps is four, the zoom-out position of the electronic zoom is the electronic wide end position, and the zoom-out operation is performed with the optical zoom for the remaining two steps. Therefore, the zoom-out position of the optical zoom is M12-2 (step) = M10.

  When the zoom-out drive amount is set based on the number of zoom steps as described above, the zoom-out position can be basically calculated only by subtraction, so that there is an advantage that the arithmetic processing becomes easy. Note that the calculation of the zoom-in position performed in steps S810 and S813 in FIG. 8 is performed in the same manner as described above except that the optical zoom is prioritized, and thus the description thereof is omitted.

  In the present embodiment, in the automatic tracking mode, the zoom-out drive amount (zoom movement amount) set in step S801 in FIG. 8 may be set according to the camera movement amount and the subject movement amount. For example, the zoom-out drive amount may be set larger as one or both of the camera motion amount and the subject motion amount increases. In the case of the D area described above with reference to FIG. 7, the subject is more easily out of the frame than in the case of the B area or the C area. Also good. Also, considering that the higher the zoom magnification, the greater the effect of camera movement due to camera shake on the subject's angle of view change, the zoom-out drive amount is changed according to the zoom magnification in the shooting preparation state. May be. For example, as the zoom magnification becomes higher, the zoom-out drive amount in the B region or D region where the camera motion amount is larger than a predetermined value may be set larger.

  In this embodiment, an example of switching whether to allow automatic FA zoom-out by comparing the amount of movement of the camera or the amount of movement of the subject with a threshold value is shown, but the present invention is not limited to this. is not. In addition to the example described above, the degree to which automatic FA zoom-out is limited may be changed according to the amount of movement of the camera and the amount of movement of the subject. In this case, the degree of limiting automatic FA zoom-out is increased as the camera movement amount or subject movement amount decreases. As a method for limiting automatic FA zoom-out, for example, it is assumed that the predetermined time B is increased, the zoom-out area ZO is narrowed (more limited to the area around the image), and the like.

  As described above, according to the present embodiment, in the control for automatically zooming out according to the position where the subject is detected, the execution of the automatic zoom-out is limited according to the amount of movement of the camera and the amount of movement of the subject. . With such a configuration, it is possible to suppress unnecessary changes in the angle of view in a situation where the shooter can easily adjust the framing by moving the camera for a subject that is likely to be out of the frame, and more comfortable shooting Operation can be realized.

(Other embodiments)
The object of the present invention can also be achieved as follows. That is, a storage medium in which a program code of software in which a procedure for realizing the functions of the above-described embodiments is described is recorded is supplied to the system or apparatus. A computer (or CPU, MPU, etc.) of the system or apparatus reads out and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium and program storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a flexible disk, a hard disk, an optical disk, and a magneto-optical disk. Further, a CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD-R, magnetic tape, nonvolatile memory card, ROM, or the like can also be used.

  Further, by making the program code read by the computer executable, the functions of the above-described embodiments are realized. Furthermore, when the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, the following cases are also included. First, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

  Further, the present invention is not limited to a device mainly intended for shooting such as a digital camera, and includes an imaging device such as a mobile phone, a personal computer (laptop type, desktop type, tablet type, etc.), a game machine, or the like. Applicable to any device to be connected. Therefore, the “imaging device” in this specification is intended to include any electronic device having an imaging function.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. The scene to be applied may be performed not only during angle adjustment for still image shooting but also during angle adjustment during moving image recording.

DESCRIPTION OF SYMBOLS 100 Digital camera 102 Zoom lens 113 Zoom lens drive part 114 System control part 117 Operation part 118 Memory 119 CZ control part 120 Electronic zoom control part 122 FA zoom control part 123 Subject detection part 124 Shake detection part

Claims (15)

An imaging device,
Subject detection means for detecting a subject from the captured image;
Calculation means for calculating the amount of movement of the subject detected by the subject detection means;
Motion detection means for detecting the amount of motion of the imaging device;
When the subject is detected in the first predetermined region in the image by the subject detection means, a first zoom operation for changing the zoom magnification to the wide angle side is performed, and the amount of movement of the subject and the amount of movement of the imaging device And a control unit that restricts execution of the first zoom operation according to the image pickup apparatus.   The image pickup apparatus according to claim 1, wherein the control unit further restricts execution of the first zoom operation as the amount of movement of the subject or the amount of movement of the image pickup apparatus decreases.   The imaging apparatus according to claim 1, wherein the first predetermined area is a peripheral area of an image.   When the movement amount of the subject is less than or equal to a first threshold value and the movement amount of the imaging device is less than or equal to a second threshold value, the control means controls not to execute the first zoom operation. The imaging device according to any one of claims 1 to 3.   When the amount of motion of the subject is greater than the first threshold and the amount of motion of the imaging device is greater than the second threshold, the control unit permits execution of the first zoom operation. The imaging device according to claim 4.   When the zoom magnification before performing the first zoom operation is obtained by electronic zoom, the control means first executes the first zoom operation by the electronic zoom. Item 6. The imaging device according to any one of Items 1 to 5.   7. The control unit according to claim 1, wherein the control unit changes a zoom movement amount in the first zoom operation in accordance with a movement amount of the subject or a movement amount of the imaging device. The imaging device described.   The imaging apparatus according to claim 7, wherein the control unit sets the zoom movement amount in the first zoom operation to be larger as the movement amount of the subject or the movement amount of the imaging device increases.   9. The control unit according to claim 1, wherein the control unit changes a zoom movement amount in the first zoom operation according to a zoom magnification before the first zoom operation. The imaging device described.   When the movement amount of the imaging device is greater than a predetermined value, the control means sets the zoom movement amount in the first zoom operation to be larger as the zoom magnification before the first zoom operation is closer to the telephoto side. The imaging apparatus according to claim 9.   The control means performs, after the first zoom operation, a second zoom operation for changing the zoom magnification to the telephoto side when a subject is detected in a second predetermined area in the image. The imaging device according to claim 1.   The imaging apparatus according to claim 11, wherein the second predetermined area is an area set at a center of the image.   The imaging apparatus according to claim 1, wherein the motion detection unit is configured using a unit that detects angular velocity or acceleration. A method for controlling an imaging apparatus,
A subject detection step for detecting a subject from the captured image;
A calculation step for calculating a movement amount of the subject detected by the subject detection step, and a motion detection step for detecting a movement amount of the imaging device;
When the subject is detected in the first predetermined area in the image by the subject detection step, a first zoom operation for changing the zoom magnification to the wide angle side is performed, and the movement amount of the subject and the movement amount of the imaging device And a control step for restricting the execution of the first zoom operation according to the control method.   An image pickup apparatus control program configured to cause a computer to execute the image pickup apparatus control method according to claim 14.

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