JP5594157B2 - Imaging apparatus and imaging method - Google Patents

Description

  The present invention relates to an imaging apparatus and an imaging method that perform appropriate focus adjustment even when a subject cannot be detected.

  In recent years, in an imaging apparatus such as a video camera, a subject detection function typified by face detection or the like has become widespread, and a technique using this subject detection function for focus control or the like has become common.

  Furthermore, when the imaging device stores the features of a specific person's face in advance and detects that person's face in the captured image, the face is automatically focused or displayed on the display screen of the imaging device. A technique has also been developed in which a user mainly specifies a subject to be imaged and performs focus control or the like by continuously focusing while tracking a subject touched by the user on a touch panel. In the following, a subject that the user wants to mainly capture, such as a person who stores such facial feature quantities or a touched subject, is referred to as a main subject.

  On the other hand, many of these recent general imaging devices have a situation in which the imaging device cannot detect the main subject, such as when a person who is the main subject for which face detection has been performed faces backward. Until now, the focus control has been switched to a non-related object.

  For example, when it is detected that the main subject that has been detected so far has fallen out of the range of the captured image, or when it is within the image range but the main subject cannot be detected, the auto subject There has been proposed a technique related to an imaging apparatus that allows a user to set in advance whether the focus function is turned off or kept on (for example, Patent Document 1).

  In addition to the uniform switching described above, there has been proposed a method of continuing tracking of the subject by estimating the position of the subject.

  For example, when the face image of the main subject can no longer be detected, the rough position of the current face is estimated based on the face position detected in the past, and a plurality of surrounding information corresponding to this rough position is acquired. To do. Then, a technique for continuously tracking the main subject by estimating the current face position based on the position where the surrounding information most similar to the surrounding information acquired in the past is acquired has been proposed (for example, Patent Document 2).

JP 2010-23087 A JP 2007-42072 A

  However, with the technique described in Patent Document 1 described above, the autofocus function can only be turned off uniformly as special focus control when the main subject cannot be detected. Therefore, for example, the imaging apparatus is in a state where it cannot detect the main subject, but since the main subject is not out of the frame, the user can visually recognize that the main subject is in the frame. Regardless of the user's intention, it is surmised that the imaging apparatus automatically turns off the autofocus function.

  Further, in the technique described in Patent Document 2 described above, the surrounding information (for example, the color of clothes) of the face of the main subject is distinguished from the information (for example, the color of other people's clothes or the background) that is unrelated to the main subject. The problem that continuous tracking is impossible in the first place is presumed.

  As described above, with the conventionally proposed techniques, when the main subject has become undetectable, it has not been possible to realize appropriate focus control reflecting the imaging situation and the user's intention.

  Therefore, in view of such a problem, the present invention provides an imaging apparatus and an imaging method capable of automatically adjusting a focus area and an iris appropriately reflecting an imaging situation and a user's intention even when a main subject cannot be detected. The purpose is to provide.

In order to solve the above problems, an imaging device (110, 510) according to the present invention includes an imaging unit (122) that captures a subject and generates video data, and a subject (main subject) identified in the video data. When the tracking section (186, 586) to be tracked and the subject being tracked become untrackable, imaging operation information indicating an imaging operation state is shown for each before tracking becomes impossible and after tracking becomes impossible. When the information generation unit (190) to generate and the state in which the subject cannot be tracked continues for a waiting time having a length corresponding to the imaging operation information, the depth of field of the imaging unit is based on the imaging operation information. And a focus determination unit (192) that changes the determined value.
In order to solve the above-described problem, another imaging device (110, 510) of the present invention includes an imaging unit (122) that captures an image of a subject and generates video data, and an identified subject (main subject) in the video data. ) And a tracking unit (186, 586) that tracks the image, and when the tracked subject becomes untrackable, an imaging operation that indicates an imaging operation state before and after tracking becomes impossible an information generation unit for generating information (190), wherein the subject is a non-tracking state, is continued length of waiting time according to the imaging operation information, the imaging target position in the angle of view to match the focal And a focus determination unit (192) that moves the center of the range.
In order to solve the above-described problem, another imaging device (110, 510) of the present invention includes an imaging unit (122) that captures an image of a subject and generates video data, and an identified subject (main subject) in the video data. ) And the tracking unit (186, 586) that tracks the image, and when the tracked subject becomes untrackable, the imaging operation that indicates the imaging operation state before and after tracking becomes impossible an information generation unit for generating information (190), wherein the subject is a non-tracking state, is continued length of waiting time according to the imaging operation information, the imaging target position in the angle of view to match the focal A focus determination unit (192) for moving to a face detected near the center of the range.

In order to solve the above-described problem, the imaging method of the present invention images a subject to generate video data, tracks the specified subject in the video data, and the tracked subject becomes untrackable. In this case, imaging operation information indicating a change in imaging operation state is generated before and after tracking is disabled, and the state in which the subject cannot be tracked is a length corresponding to the imaging operation information. continuing the waiting time, and changing the value determined on the basis of the depth of field of the imaging section in the imaging operation information.
In order to solve the above-described problem, another imaging method of the present invention images a subject to generate video data, tracks the specified subject in the video data, and the tracked subject cannot be tracked. In this case, before the tracking becomes impossible and after the tracking becomes impossible, imaging operation information indicating a change in imaging operation state is generated, and the state in which the subject cannot be tracked corresponds to the imaging operation information. continuing the length of waiting time, and wherein the moving the position of the view angle to align the focal point in the center of the range to be imaged.
In order to solve the above-described problem, another imaging method of the present invention images a subject to generate video data, tracks the specified subject in the video data, and the tracked subject cannot be tracked. In this case, before the tracking becomes impossible and after the tracking becomes impossible, imaging operation information indicating a change in imaging operation state is generated, and the state in which the subject cannot be tracked corresponds to the imaging operation information. continuing the length of waiting time, and wherein the moving the position of the view angle to align the focal point on the face detected in the vicinity of the center of the range to be imaged.

  As described above, the present invention enables automatic adjustment of the focus area and the iris appropriately reflecting the imaging situation and the user's intention even when the main subject cannot be detected.

It is explanatory drawing for demonstrating the focus control by the conventional video camera when the to-be-focused object is lost and lost. 1 is an external view illustrating an example of an imaging apparatus according to a first embodiment. 1 is a functional block diagram illustrating a schematic configuration of an imaging apparatus according to a first embodiment. It is a flowchart which shows the flow of a process of the imaging method in 1st Embodiment. It is a flowchart which shows the flow of a process of the imaging method in 1st Embodiment. It is a flowchart which shows the flow of a process of the imaging method in 1st Embodiment. FIG. 6 is a functional block diagram illustrating a schematic configuration of an imaging apparatus according to a second embodiment. It is a flowchart which shows the flow of a process of the imaging method in 2nd Embodiment. It is a flowchart which shows the flow of a process of the imaging method in 2nd Embodiment. It is a flowchart which shows the flow of a process of the imaging method in 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is an explanatory diagram for explaining focus control by a conventional video camera when a main subject to be focused is lost and when the subject is lost. As shown in FIG. 1A, in the imaging screen 100 of the video camera, a person 102 is at a relatively close position on the left side of the screen, and a person 104 is at a relatively far position on the right side of the screen. Here, when a face is detected in the imaging screen 100, a focus area representing a position within the angle of view to be focused is set at the position of the face, and imaging is performed in a mode for tracking the face. It shall be.

  For example, the user designates the right person 104 with the touch sensor provided on the imaging screen 100, or the feature amount indicating the facial features of the right person 104 is registered in the video camera in advance and registered. For example, in the situation where the face tracking is performed or the child priority mode is set, for example, the face of the right person 104 is like a child and the face of the left person 102 is an adult face feature amount. Assume that the right person 104 (main subject) is imaged in focus. At this time, for example, the frame 106 is superimposed on the face of the person 104 on the right side.

  Then, as shown in FIG. 1B, if the right person 104 moves and the face faces in the opposite direction to the video camera during video recording, the video camera moves the face of the right person 104 It becomes impossible to detect and tracking becomes impossible (lost). In this case, the conventional video camera, as a preset process, fixes the standby time, focus area, stops the autofocus function at the position where the face is lost, stops the face of the person 102 on the left side, etc. The process of moving the focus area to the detected position and focusing on the face of the person 102 on the left side is performed uniformly. In FIG. 1B, the face 106 of the person 102 on the left side is focused and a frame 106 is superimposed.

  Therefore, even if the user wants to continue focusing on the person 104 on the right side, the processing is different from the user's intention, and the video data with the focus in an unintended area is generated. It was happening.

  In addition, after the right person 104 is lost, the right person 104 turns his face to the video camera side again, and the user respecifies the right person 104 with the touch sensor provided on the imaging screen 100. Can be resumed. However, since the right person 104 has to be designated again every time it is lost, the user may feel troublesome.

  In the following embodiments, an imaging device 110 capable of automatically adjusting a focus area and an iris in accordance with the user's intention without requiring troublesome work for the user will be described, and an imaging method using the imaging device 110 will be described in detail. To do.

(First embodiment: imaging device 110)
FIG. 2 is an external view illustrating an example of the imaging device 110 according to the first embodiment. 2A shows a digital still camera as the imaging device 110, and FIG. 2B shows a video camera as the imaging device 110. FIG. 3 is a functional block diagram illustrating a schematic configuration of the imaging device 110 illustrated in FIG. The imaging device 110 includes an operation unit 120, an imaging unit 122, a data processing unit 124, a video holding unit 126, a display unit 128, a compression / decompression unit 130, a storage reading unit 132, and an external input / output unit 134. A storage unit 136, a motion detection unit 138, and a central control unit 140.

  The operation unit 120 includes operation keys including a release switch, a cross key, a joystick, and the like, and accepts a user operation input. In addition, a touch panel may be provided on the display surface of the display unit 128 described later to serve as the operation unit 120.

  The imaging unit 122 is configured to receive an imaging lens 150, a zoom lens 152 used for changing the angle of view, a focus lens 154 used for focus adjustment, an iris (aperture) 156 used for exposure adjustment, and a light beam incident through the imaging lens 150. An image sensor 158 that photoelectrically converts video data, and a drive unit 160 that drives the zoom lens 152, the focus lens 154, the iris 156, and the image sensor 158 in accordance with a control signal from an image capture control unit, which will be described later, are configured. Then, the subject is imaged to generate video data, which is output to the data processing unit 124.

  The data processing unit 124 performs predetermined processing such as white balance adjustment, noise reduction processing, level correction processing, A / D conversion processing, and color correction processing (gamma correction processing, knee processing) on the video data output from the imaging unit 122. Processing is performed, and the processed video data is output to the video holding unit 126. Further, the data processing unit 124 extracts a high-frequency component of the video data by a BPF (Band Pass Filter) provided in the data processing unit 124 and outputs it to the imaging control unit for contrast evaluation. The contrast evaluation will be described in detail later.

  The video holding unit 126 includes a RAM (Random Access Memory), a flash memory, an HDD (Hard Disk Drive), and the like, and receives video data input from the data processing unit 124, the compression / decompression unit 130, and the external input / output unit 134. Hold temporarily.

  The display unit 128 includes a liquid crystal display, an organic EL (Electro Luminescence) display, and the like. The display unit 128 is linked to the video data output from the data processing unit 124 and the compression / decompression unit 130 and held in the video holding unit 126 and the operation unit 120. Display instruction items.

  The compression / decompression unit 130 outputs the video data output from the data processing unit 124 via the video holding unit 126 to M-JPEG (motion JPEG), MPEG (Moving Picture Experts Group) -2, H.264, and so on. The encoded data is encoded by a predetermined encoding method such as H.264 / AVC, and the encoded data is output to the storage / reading unit 132. In addition, the compression / decompression unit 130 outputs video data obtained by decoding the code data encoded by a predetermined encoding method read by the storage reading unit 132 from the storage medium 170 to the video holding unit 126.

  The storage reading unit 132 stores the code data encoded by the compression / decompression unit 130 in an arbitrary storage medium 170. As the arbitrary storage medium 170, an optical disk medium such as a DVD (Digital Versatile Disc) and a BD (Blu-ray Disc), a medium such as a RAM, an EEPROM, a nonvolatile RAM, a flash memory, and an HDD can be applied. Here, the storage medium 170 is detachable, but may be integrated with the imaging device 110. Further, the storage / reading unit 132 reads encoded data from an arbitrary storage medium 170 in which encoded data obtained by encoding video data using a predetermined encoding method is stored, and outputs the encoded data to the compression / decompression unit 130.

  The external input / output unit 134 outputs the video data held in the video holding unit 126 to, for example, the display device 172 connected to the imaging device 110 and displaying the video. Further, the external input / output unit 134 receives a video signal from an external device (not shown) and stores it in the video holding unit 126.

  The storage unit 136 includes a RAM, a flash memory, an HDD, and the like, and stores the facial feature amount derived by the face detection unit according to the control of the face detection unit described later. Here, the feature amount of the face is the relative position of each feature point of the face (representative point of the feature part such as eyes, mouth, nose, ears, etc.), the distance between the feature points, the size of the feature part, the outline of the face Information that characterizes the face, such as skin color. The storage unit 136 stores imaging operation information indicating an imaging operation state described later.

  The motion detection unit 138 detects a motion such as panning or tilting of the imaging device 110. Specifically, the motion detection unit 138 includes, for example, an angular velocity sensor, measures the angular velocity of the imaging device 110, and outputs the measured value to the information generation unit 190 described later.

  The central control unit 140 manages and controls the entire imaging apparatus 110 by a semiconductor integrated circuit including a central processing unit (CPU), a ROM storing programs, a RAM as a work area, and the like. The central control unit 140 also functions as a face detection unit 180, a face identification unit 182, a peripheral information generation unit 184, a tracking unit 186, an imaging control unit 188, an information generation unit 190, and a focus determination unit 192.

  The face detection unit 180 detects a face from the video data generated by the imaging unit 122, and generates face information indicating the position, size, inclination, and the like of the detected face. Specifically, the face detection unit 180 detects a face by template matching based on, for example, the outline of the entire face or face components such as eyes, mouth, nose, and ears. The face detection unit 180 may detect an area close to the skin color and detect the area as a face. Further, the face detection unit 180 may perform learning using a teacher signal using a neural network, detect an area determined to be a face as a face, or use another existing technique for detecting a face.

  Then, the face detection unit 180 derives the detected face feature amount. Further, when there is a user operation input to register the detected face, the face detection unit 180 causes the storage unit 136 to store the derived feature amount.

  The face identifying unit 182 derives a similarity by comparing the derived feature amount with the feature amount stored in advance in the storage unit 136 for the face detected by the face detection unit 180. The similarity indicates the degree of similarity between the detected face and the person whose feature quantity is stored in the storage unit 136 (hereinafter referred to as “registered person”). Then, when the similarity exceeds a predetermined threshold, the face identification unit 182 determines that the face detected by the face detection unit 180 is the face of the same person as the registered person.

  The peripheral information generation unit 184 uses the position, size, and inclination of the face output from the face detection unit 180 to estimate a region corresponding to the human torso of the face, Peripheral information indicating position and color is generated.

  The tracking unit 186 tracks the face detected by the face detection unit 180 in the video data or the peripheral information corresponding to the face. The tracking unit 186 acquires the face information generated by the face detection unit 180 and the peripheral information generated by the peripheral information generation unit 184 at a predetermined cycle (for example, a frame cycle). When a plurality of faces are detected from the video data, the tracking unit 186 acquires face information and peripheral information for each detected face.

  Then, the tracking unit 186 starts from the position A ′ in the video area in the latest frame corresponding to the position A where the face in the video area in the frame immediately before the latest frame is detected based on the face information. It is determined whether or not a face is detected within a predetermined distance. A face is detected at position B within a predetermined distance, and the face size detected at position A in the video area of the previous frame and the position B in the video area of the latest frame are detected. When the change in the size of the face is equal to or smaller than the predetermined value, the tracking unit 186 determines that the two faces are faces of the same person and the faces can be tracked. Then, the tracking unit 186 derives a velocity vector by taking the difference between the position B and the position A ′.

  In addition, the tracking unit 186 performs tracking using peripheral information when a face is not detected within a predetermined distance, or when a change in the size of the face exceeds a predetermined size even if it is detected. I do. Specifically, the tracking unit 186, when the position indicated by the peripheral information corresponding to the position D in the video area of the previous frame is the position D ′, the position D in the video area in the latest frame. Within a predetermined distance from ', a search is made as to whether there is a color histogram area similar to the color histogram shown in the peripheral information. At this time, the tracking unit 186 determines similarity based on whether or not the value of the histogram intersection, which is an index indicating the degree of color similarity, is equal to or less than a predetermined threshold.

  When a region where the value of the histogram intersection is equal to or smaller than a predetermined threshold is detected, the tracking unit 186 determines that the information is peripheral information of the same person. The tracking unit 186, when a region where the histogram intersection is equal to or less than a predetermined threshold is not detected, or when a plurality of regions (for example, a plurality of human torso wearing clothes of the same color) are detected, It is determined that the peripheral information of the same person has been lost. In addition, the index of the degree of similarity between colors is not limited to the histogram intersection, and Euclidean distance or the like may be used.

  When it is determined that the face determined to be the same person's face in the latest frame is not detected and the peripheral information of the same person is also lost, the tracking unit 186 determines that the person has been lost and tracking is impossible.

  The tracking unit 186 temporarily stores face information, peripheral information corresponding to the face information, and ID (IDentification) for identifying the face information regardless of whether tracking is possible. The tracking unit 186 gives a different ID for each face when a face is detected. However, when the face can be tracked, the tracking unit 186 takes over the ID assigned to the face information of the face to be tracked in the previous frame for the face information of the face being tracked, and the same Is stored with the ID, and the derived velocity vector is also stored. At this time, when the face of a person who has become unable to track is detected again within a predetermined time, the ID assigned to the face may be taken over. Thus, the tracking unit 186 basically tracks all the faces detected by the face detection unit 180.

  The imaging control unit 188 performs imaging control including focus adjustment and exposure adjustment. The imaging control unit 188 outputs a control command for performing imaging control to the driving unit 160, and the driving unit 160 adjusts the focus lens 154 and the iris 156 according to the control command output from the imaging control unit 188.

  The imaging apparatus 110 according to the present embodiment uses a contrast method as an autofocus method. The contrast method is a method of focusing by using the fact that there is a correlation between the degree of blur of the image on the image sensor 158 and the contrast, and the contrast of the image is maximized when the image is focused. The contrast can be evaluated by the magnitude of the energy of the high frequency component of the video data generated by the imaging unit 122.

  Specifically, the imaging control unit 188 performs autofocus calculation using the integral value of the absolute value of contrast output from the data processing unit 124 as an evaluation value. Then, the imaging control unit 188 adjusts the focus by causing the drive unit 160 to adjust the position of the focus lens 154 so that the contrast is maximized according to the result of the autofocus calculation. Further, the imaging device 110 is not limited to the contrast method, and may adjust the position of the focus lens 154 according to the subject distance measured by infrared light, or may apply various other methods for focusing. Also good.

  At this time, the imaging control unit 188 sets any area within the angle of view on the imaging element 158 as a focus area, and sets partial video data corresponding to the focus area as a target for contrast evaluation. The autofocus method in the imaging apparatus 110 is classified into the following modes, for example, by the focus area selection unit.

  That is, as the focus area, the “center focus” using the center area within the angle of view, and the area within the angle of view corresponding to the position where the user touches the touch sensor arranged on the display surface of the display unit 128 is used. ”Touch focus”, “Touch tracking autofocus” using the tracking result area by tracking the tracking object using the color information of the area within the angle of view corresponding to the vicinity of the touched position, detected by the face detection unit 180 `` Face detection focus '' that uses the area within the angle of view corresponding to the position of the face of the largest area of the face, tracking the face touched by the user among one or more faces of the face detection result, “Face tracking focus” using an area within the angle of view corresponding to the position of the face being tracked, determined to be the face of a person whose feature quantity is stored in the storage unit 136 in the imaging device 110 Tracking the a modes "personal tracking focus" as used an area within the angle corresponding to the position of the face that the tracking. In the case of “face tracking focus”, the feature amount of the face touched by the user may be temporarily stored.

  The peripheral information generation processing by the peripheral information generation unit 184 and the tracking processing by the tracking unit 186 described above are executed at least in the “face tracking focus” and “personal tracking focus” modes. Note that the face that is the target of the peripheral information extraction by the peripheral information generation unit 184 and the face that is the target of tracking by the tracking unit 186 are all the faces detected by the face detection unit 180, but the focus area is moved. The target face is “identified face”.

  The “specified face” is, for example, a face designated by the user with the touch sensor provided on the display surface of the display unit 128 if “face tracking focus” is selected, and if “face tracking focus” is specified, The face is determined to be the face of the same person as the registered person by the identification unit 182.

  In the former case, if the “specified face” specified by the touch sensor is lost, tracking of the “specified face” cannot be resumed unless the touch sensor is specified again. In the case of a configuration that temporarily stores the feature amount of the face specified by the user with the touch sensor, if the face of the person appears again on the screen after losing sight of the “specified face”, tracking is performed. You can resume. This is because the face identification unit 182 compares the temporarily stored facial feature quantity with the detected facial feature quantity to determine whether or not they are the same person's face. This is because when the face determined to be is detected, the tracking is resumed as “specified face”.

  In the latter case, since the face registered in the storage unit 136 is used in advance, when the face of the person appears again on the screen after losing sight of the “specified face”, the face identifying unit 182 registers the face. It is determined that the face is the same person as the person, and the tracking unit 186 can resume tracking.

  In the present embodiment, the “specified face” is exemplified by one face, but the “specified face” may be a plurality of faces. In that case, the imaging control unit 188 performs focus adjustment so that all the “specified faces” are focused most comprehensively.

  When imaging starts in one of the above two modes, the information generation unit 190 causes the storage unit 136 to store imaging operation information (described later) acquired for each frame period, for example.

  The information generation unit 190 stores the imaging operation information in the first location of the storage unit 136 until the tracking unit 186 determines that tracking is not possible for the “specified face” being tracked. The imaging operation information stored in the storage unit 136 is the latest first predetermined time, and old data is overwritten with new data. Therefore, even when tracking becomes impossible, the storage unit 136 stores the imaging operation information immediately before tracking becomes impossible.

  Then, when the “specified face” being tracked becomes untrackable, the information generation unit 190 generates imaging operation information for the second predetermined time immediately after the tracking becomes impossible, and the storage unit 136 in a second location.

  As described above, the information generation unit 190 generates imaging operation information indicating the imaging operation state for each of the first predetermined time immediately before tracking becomes impossible and the second predetermined time immediately after tracking becomes impossible. ,Remember.

  This imaging operation state is, for example, the size of pan or tilt, and the information generation unit 190 generates information indicating the size of pan or tilt as the imaging operation state. Specifically, the information generation unit 190 derives the angular velocity immediately before the tracking becomes impossible and the angular velocity immediately after the tracking becomes impossible as the size of pan and tilt based on the output value from the motion detection unit 138, respectively. . The magnitude of pan and tilt is not limited to speed, and may be, for example, the amount of displacement or angular speed in the pan or tilt direction.

  In the imaging apparatus 110 of the present embodiment, by grasping the size of pan and tilt, it is possible to know how the user moved the orientation of the imaging apparatus 110 to capture the main subject at the angle of view. The estimation accuracy of the user's intention such as how to capture the main subject is improved, and the focus area and the iris that appropriately reflect the imaging situation and the user's intention can be adjusted.

  Further, the imaging operation state is, for example, the zoom size, and the information generation unit 190 generates information indicating the zoom size as the imaging operation state. Specifically, the information generation unit 190 derives the position of the zoom lens and the moving speed of the zoom lens (hereinafter referred to as zoom speed) as the zoom size.

  In the imaging apparatus 110 according to the present embodiment, by grasping the zoom size, it can be determined whether the user has zoomed in or zoomed out with respect to the main subject. The estimation accuracy of the user's intention such as how to capture the main subject is improved, and the focus area and the iris that appropriately reflect the imaging situation and the user's intention can be adjusted.

  Further, the imaging operation state may be a focus state. In this case, when the fluctuation of the energy of the high-frequency component of the video data for each frame is smaller than a predetermined threshold, it is determined that the in-focus state is achieved.

  Further, the imaging operation state may be the characteristics of the “specified face” and its peripheral information and their positions, and all the other facial characteristics and their peripheral information and their positions. The imaging operation state may be a velocity vector derived by the tracking unit 186.

  When the imaging operation state is the peripheral information, the information generation unit 190 obtains the peripheral information of the “specified face” from the peripheral information of the “specified face” being tracked and the peripheral information of all other faces. It is determined whether it can be distinguished from other peripheral information. For example, when the peripheral information is the color of the upper body clothes, it is determined that the color histogram of the person who is tracking “identified face” is different from the color histograms of the clothes of all other face persons. And are determined to be identifiable. Whether the color histograms are different is determined based on whether the value of the histogram intersection is larger than a predetermined threshold value.

  The focus determination unit 192 selects the focus area (within the angle of view for focusing) based on the imaging operation information for the first predetermined time immediately before tracking becomes impossible and the second predetermined time immediately after tracking becomes impossible. ), Or the depth of field of the imaging unit 122, in this embodiment, the iris. Then, the focus adjustment unit 192 outputs the determined focus area and iris value to the imaging control unit 188. The imaging control unit 188 controls the driving unit 160 according to the focus area and the iris value. A specific example in which the focus adjustment unit 192 determines the focus area and the iris value will be described in detail in a flowchart described later.

  The imaging apparatus 110 according to the present embodiment is located at a position inside or outside the angle of view immediately after the main subject that cannot be tracked immediately after the main subject that cannot be tracked according to the imaging operation information immediately before and after the main subject becomes untrackable. , And whether the photographer continues to consider the main subject as the main subject, and determines the focus area and depth of field (iris in the present embodiment) when tracking becomes impossible. Therefore, imaging that reflects the user's intention such as whether tracking is still possible or whether the tracking is abandoned becomes possible, and the imaging device 110 operates against the user's intention, and the user corrects it. The troublesome situation that must be avoided can be avoided.

  The focus determination unit 192 changes the depth of field (iris in the present embodiment) to the determined value when the state in which the main subject cannot be tracked continues for a length of the standby time according to the imaging operation information. May be. For example, when the imaging operation information is a pan or tilt speed, the focus determination unit 192 determines a standby time or an iris according to the speed.

  As described above, the imaging apparatus 110 according to the present embodiment can change the depth of field after waiting for an appropriately set waiting time. In this embodiment, the waiting time until the iris is changed is referred to as iris waiting time.

  When the main subject cannot be tracked and the standby time of the length corresponding to the imaging operation information continues, the focus determination unit 192 determines the position within the angle of view to be focused in the center of the range to be imaged (hereinafter simply referred to as an image). You may move to the center of the corner. For example, when the imaging operation information is a pan or tilt speed, the focus determination unit 192 determines the standby time according to the speed. When the tracking impossible state continues for the standby time, the focus determination unit 192 moves the position within the angle of view for focusing to the center of the range to be imaged. At this time, the focus determination unit 192 sets the standby time to a length according to the imaging operation information. For example, when the possibility that the main subject is out of frame is high, the standby time is relatively short, and when the possibility that the main subject is out of frame is low, the standby time is relatively long.

  As described above, the imaging apparatus 110 according to this embodiment can wait for the appropriately set waiting time to elapse and set the focus area at the center of the range to be imaged. In this embodiment, the waiting time until the focus area is changed is referred to as an area waiting time.

  In addition, the focus determination unit 192 performs pan and tilt sizes, zoom sizes, focus states, all detected facial features and their surrounding information immediately before and after the main subject becomes untrackable. The area standby time and the iris standby time are continuously changed according to an output value of a predetermined function that receives any one or a plurality of values of the imaging operation information such as the position and velocity vector. It may be.

  As described above, when the imaging apparatus 110 according to the present embodiment is used, the focus area and the iris are adjusted according to the imaging operation information. Therefore, even if tracking becomes impossible during autofocus that tracks the face, the user's intention is achieved. It is possible to automatically adjust the focus area and the iris.

(Imaging method)
4 to 6 are flowcharts illustrating the processing flow of the imaging method according to the first embodiment. When imaging is started in at least one of the above two modes, the imaging unit 122 generates video data (S300), the face detection unit 180 detects a face from the video data (S302), and uses the face information. A feature amount is derived (S304). The face identifying unit 182 compares the derived feature amount with the feature amount stored in advance in the storage unit 136 to determine whether the face is the same person as the registered person (S306).

  The peripheral information generation unit 184 estimates a region corresponding to the detected human torso of all the faces, and generates peripheral information indicating the position and color of the estimated region (S308). The tracking unit 186 tracks the face detected by the face detection unit 180 in the video data or peripheral information corresponding to the face (S310). The information generation unit 190 stores the latest imaging operation information in the storage unit 136 (S312).

  Immediately before the “specified face” tracked by the tracking unit 186 becomes untrackable, the information generation unit 190 stores the imaging operation information in the first location of the recording unit 136. The first location stores imaging operation information for the number of frames corresponding to the first predetermined time (here, N frames, where N is a natural number). The imaging operation information of the latest frame is overwritten with the information of the oldest frame among the information for N frames. Accordingly, imaging operation information for N frames immediately before tracking becomes impossible is stored in the first location.

  Immediately after the “specified face” tracked by the tracking unit 186 becomes untrackable, the information generating unit 190 stores the imaging operation information in the second location of the recording unit 136. The second location stores imaging operation information for the number of frames corresponding to the second predetermined time (here, M frames, where M is a natural number) from the frames that cannot be tracked. When the tracking impossible state continues, imaging operation information for M frames from the frame that cannot be tracked is stored in the second location. As described above, the imaging operation information for the N frames immediately before and after the tracking becomes impossible is stored in the first place and the second place of the storage unit 136.

  The stored photographing information includes pan and tilt sizes, zoom sizes, focus states, all detected facial features and their peripheral information, their positions, and velocity vectors.

  The information generation unit 190 determines whether or not the “specified face” tracked by the tracking unit 186 has become untrackable (S314). When tracking becomes impossible (YES in S314), the information generation unit 190 determines whether tracking is disabled even in the frame immediately before the latest frame (S316). If tracking is not possible in the previous frame, that is, if the latest frame is the first frame that cannot be tracked (NO in S316), the “measured face” is reset after resetting the time measurement counter. Starts measuring the elapsed time from when it is determined that tracking is impossible (S318).

  Next, focus area and iris setting determination processing is performed (S320). The setting determination step S320 will be described in detail later with reference to FIGS. The focus determination unit 192 indicates that the area flag indicating whether or not the area standby time has been set in the setting determination step S320 is 1 and that the area standby time has elapsed since it was determined that tracking is impossible. It is determined whether or not (S322). If the area flag is 1 and the area standby time has elapsed (YES in S322), the imaging control unit 188 controls the drive unit 160 so that the center of the angle of view becomes the focus area (S324). When the area flag is 0 indicating that the area standby time is not set or the area standby time has not elapsed (NO in S322), the focus determination unit 192 sets the iris standby time in the setting determination step S320. It is determined whether the iris flag indicating whether or not it is set to 1 indicating that it has been set and whether or not the iris standby time has elapsed (S326). When the iris flag is 1 and the iris standby time has elapsed (YES in S326), the imaging control unit 188 controls the drive unit 160 so that the set iris value is obtained (S328). If the iris flag is 0 indicating that the iris flag is not set or if the iris waiting time has not elapsed (NO in S326), the focus adjustment and the iris adjustment are both fixed. To do.

  In the tracking impossibility determination step S314, when tracking is not impossible (NO in S314), the imaging control unit 188 sets a focus area based on the face information or the peripheral information of the “specified face” being tracked and sets the focus. (S330).

  Then, the central control unit 140 determines whether or not there is an imaging end instruction from the user (S332), and if there is an end instruction (YES in S332), the imaging process is ended and there is no end instruction. If (NO in S332), the process returns to the video data generation step S300.

  Next, details of the setting determination step S320 will be described with reference to FIG. The information generation unit 190 can identify the peripheral information of the “specified face” from the other peripheral information from the information for N frames immediately before the tracking becomes impossible, which is stored in the first location of the storage unit 136. It is determined whether or not (S350). If it is discriminable (YES in S350), peripheral information that can be regarded as the same as the peripheral information of the “specified face” is detected from the latest frame information stored in the second location of the storage unit 136. It is determined whether or not it has been done (S352). When peripheral information that can be regarded as the same is detected (YES in S352), the focus determination unit 192 sets the focus area to the position indicated by the peripheral information, and the imaging control unit 188 drives the drive unit 160 (S354). The tracking unit 186 tracks the peripheral information from the next frame. The focus determination unit 192 sets the area flag and the iris flag to 0 (S356).

  In this way, peripheral information that is identifiable immediately before tracking of the “specified face” becomes impossible to track and immediately after tracking becomes impossible is detected as being the same as that of the person. In this case, the focus determination unit 192 determines the focus area at the position indicated by the peripheral information. If the peripheral information can be identified, that is, if the color histogram of the body clothes is different from that of other persons, the peripheral information that can be regarded as the same as the peripheral information is likely to be that of the same person. Accordingly, it is highly possible that the main subject can be focused by moving the focus area to the position of the peripheral information. On the other hand, when the peripheral information is not identifiable, it is considered that there are a plurality of persons with similar colored clothes. In such a case, since there is a possibility that a person different from the person intended by the user may be focused, the focus determination unit 192 refers to the peripheral information only when there is peripheral information that can be distinguished from others. Determine the focus area.

  When the peripheral information is not distinguishable from other peripheral information immediately before tracking becomes impossible (NO in S350), or when there is no peripheral information that can be regarded as the same in the latest frame (NO in S352), the information generation unit 190 derives the zoom speed as the imaging operation information immediately before and immediately after the tracking becomes impossible based on the imaging operation information stored in the storage unit 136 (S358). Then, the focus determination unit 192 determines from the zoom speed whether or not the zoom-in is performed at least one of immediately before and after the tracking becomes impossible (S360). When zoomed in (YES in S360), the focus determination unit 192 sets the area standby time to about 2 seconds, sets the area flag to 1, and sets the iris flag to 0 (S362).

  As described above, when the zoom-in operation is performed immediately before the tracking becomes impossible or immediately after the tracking becomes impossible, the focus determination unit 192 shortens the area waiting time to about 2 seconds, and then the imaging control unit 188 Then, the center focus step S324 is performed with the center of the angle of view as the focus area. This is because the zoom-in operation is often performed with the main subject positioned at the center of the angle of view. Further, after the area waiting time setting step S362, when a face of the same person is detected in the vicinity of the center of the angle of view for a plurality of frames (for example, 10 frames), the “specified face” in which the face cannot be tracked is detected. Even when the focus determination unit 192 cannot be considered as the focus area, the focus determination unit 192 may use the face position as the focus area. Furthermore, the focus determination unit 192 may shorten the area standby time as the zoom speed increases.

  When the zoom-in has not been performed (NO in S360), the focus determination unit 192 determines whether or not the zoom-out has been performed at least one of immediately before and after the tracking becomes impossible (S364). When zoomed out (YES in S364), the focus determination unit 192 sets the area standby time and the iris standby time to about 2 seconds, sets the area flag and the iris flag to 1 (S366), and after the iris standby time has elapsed, The iris is set to a narrow value (S368).

  When the zoom-out operation is performed immediately before tracking becomes impossible or immediately after tracking becomes impossible, the area waiting time is set to about 2 seconds, and then the imaging control unit 188 sets the center of the angle of view. A central focus step S324 is performed as the focus area. In the zoom-out operation, since the main subject is less likely to be at a specific position of the angle of view, the focus determination unit 192 sets the iris to be narrow and increases the depth of field. By increasing the depth of field, a focused image can be obtained regardless of the position of the main subject in the angle of view. Again, the focus determination unit 192 may shorten the area standby time as the zoom speed increases.

  If it is not zoomed out (NO in S364), a setting determination process is further performed (S370). The setting determination step S370 will be described with reference to FIG. Based on the imaging operation information stored in the storage unit 136, the information generation unit 190 derives the panning and tilting speed as imaging operation information for each immediately before and after the tracking is disabled (S400). Then, the focus determination unit 192 determines whether panning or tilting operation is performed instead of camera shake by comparing the panning and tilting speeds with a predetermined speed threshold value (S402). When panning and tilting operations are being performed (YES in S402), the focus determination unit 192 determines whether panning and tilting immediately before and after tracking become relatively fast (for example, 30 ° / sec or more). It is determined whether or not (S404). When both are high speed (YES in S404), the focus determination unit 192 sets the area standby time and the iris standby time to about 3 seconds, sets the area flag and the iris flag to 1 (S406), and the iris standby time has elapsed. Thereafter, the iris is set to a narrow value (S408).

  In this way, if panning and tilting is performed at a relatively high speed immediately before tracking becomes impossible, and if panning and tilting is performed at a relatively high speed immediately after tracking becomes impossible, the main subject is relatively It is thought that it is moving at high speed. In this case, since it is considered that imaging is performed so that the main subject is arranged in the center of the screen, the focus determination unit 192 sets the area waiting time to a short time of about 3 seconds, and then the imaging control unit 188 performs the center of the angle of view. The center focus step S324 is performed with the focus area. In this case, since the distance to the main subject also often changes, the focus determination unit 192 sets the iris narrow to increase the depth of field. By increasing the depth of field, a focused image can be obtained even if the estimation of the subject distance has failed. Further, the standby time may be shortened as the panning and tilting speed increases.

  If either the panning or tilting immediately before tracking becomes impossible or the panning or tilting immediately after that is not relatively fast (NO in S404), the focus determination unit 192 compares the panning and tilting immediately before tracking becomes impossible. It is determined whether or not panning and tilting immediately after the target becomes fast and tracking is relatively slow (for example, less than 30 ° / sec) (S410). If the tracking immediately before tracking is relatively fast and the tracking just after tracking is relatively slow (YES in S410), the focus determination unit 192 sets the area waiting time to about 15 seconds and the iris waiting time to about 4 seconds, Each of the area flag and the iris flag is set to 1 (S412), and the iris is set to a narrow value after the iris standby time has elapsed (S414).

  In this way, panning and tilting were performed at a relatively high speed immediately before tracking became impossible, but immediately after tracking became impossible, when panning and tilting were stopped, when the main subject became untrackable There is a high possibility of staying at the place where it was. In this case, there is a possibility that only the face is temporarily deviated and the image is directed again toward the imaging device 110 and tracking becomes possible. At this time, if the focus area is moved to the center of the angle of view in a relatively short time, the user has to specify the main subject again with the touch sensor or the like, and is troublesome and the focus area is often moved. , It will be difficult to see. Therefore, the focus determination unit 192 fixes the focus area for a relatively long period of about 15 seconds. On the other hand, since panning and tilting were performed at a relatively high speed immediately before tracking became impossible, there is a high possibility that the subject distance is not accurate, so the iris is narrowed.

  If the tracking immediately before tracking is relatively fast and the tracking immediately after tracking is not relatively slow (NO in S410), the focus determination unit 192 determines that panning and tilt immediately before tracking becomes impossible and tracking is impossible. It is determined whether or not the panning and tilting after the shift is relatively fast (S416). When the tracking just before tracking is relatively slow and the tracking just after tracking is relatively fast (YES in S416), the focus determination unit 192 sets the area waiting time to about 0 seconds and the iris waiting time to about 0 seconds, The area flag is set to 1, the iris flag is set to 1 (S418), and the iris is set to a narrower value (S420).

  In this way, if panning or tilting is not performed immediately before tracking becomes impossible or it is performed at a relatively low speed, but panning or tilting starts at a relatively high speed immediately after tracking is impossible, for some reason the face Is difficult, or the user has switched the “specified face” to another person's face. Accordingly, the focus determination unit 192 quickly sets the focus on the face near the center of the screen and sets the iris to be relatively large. In addition, when a face is detected in the vicinity of the center of the angle of view over a plurality of frames (for example, 10 frames or more), even if the face cannot be regarded as a “specified face” that cannot be tracked. The focus determination unit 192 sets the face position as the focus area.

  The focus is determined when the tracking immediately before tracking is relatively slow and the tracking immediately after tracking is not relatively fast (NO in S416), that is, when pan and tilt are relatively slow immediately before and immediately after tracking becomes impossible. The unit 192 sets the area standby time to about 15 seconds, sets the area flag to 1, and sets the iris flag to 0 (S422).

  In this way, if panning and tilting are performed at a relatively low speed immediately before and after tracking becomes impossible, the “specified face” cannot be tracked for some reason, but it is actually in that place. Conceivable. For this reason, the focus determination unit 192 fixes the focus area at a position immediately before the tracking becomes impossible for about 15 seconds, and the iris is set to keep the same value as that immediately before the tracking becomes impossible.

  Furthermore, the position of the “specified face” and its surrounding information immediately before tracking becomes impossible is near the center of the angle of view, the velocity vector is small (for example, less than 5 ° / sec in terms of angle of view), and the in-focus state And the change in the focal length is small, the position of the other face is far from the position of the “specified face”, the velocity vector is small (for example, less than 5 ° / sec in terms of angle of view), and tracking If the change in the position of the other face is small immediately after the failure, the focus determination unit 192 fixes the focus area for a longer time. This is because there is a higher possibility that the person of the “specified face” is in the place.

  If no panning or tilting operation has been performed in the significance determination step S402 (NO in S402), the focus determination unit 192 has not been in focus before the tracking becomes impossible or immediately after the tracking becomes impossible. Or the change in focal length is large, or the moving speed of the “specified face” being tracked and its surrounding information is fast (for example, 20 ° / sec or more in terms of angle of view) and immediately after tracking is impossible It is determined whether panning or tilting is not performed or the speed is relatively low (for example, less than 20 ° / sec), and whether any of the conditions is satisfied (S424). If applicable (YES in S424), the focus determination unit 192 sets the area standby time and the iris standby time to a relatively short time of about 5 seconds, sets the area flag and the iris flag to 1 (S426), and the iris standby time has elapsed. Thereafter, the iris is set to a narrow value (S428). If any of the conditions is met in the condition determination step S424, it is considered that the “specified face” is not in focus, so the focus area is moved to the center of the angle of view relatively quickly. If none of the conditions are met (NO in S424), the focus determination unit 192 sets the area standby time and the iris standby time, which are the default settings, to about 10 seconds, and sets the area flag and the iris flag to 1 respectively ( S430).

  As described above, according to the imaging method using the imaging apparatus 110 of the present embodiment, it is possible to automatically adjust the focus area and the iris in accordance with the user's intention.

(Second Embodiment)
In the first embodiment described above, it is assumed that a person's face is tracked. In the second embodiment, a description will be given of an imaging apparatus 510 that performs processing immediately after the inability to track following the intention of the user on the premise of more versatile tracking that is not limited to a human face. In the present embodiment, a case where imaging is performed in the above-described “touch tracking autofocus” mode will be described. In addition, about the component substantially equivalent to 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

(Imaging device 510)
FIG. 7 is a functional block diagram illustrating a schematic configuration of the imaging apparatus 510. The imaging device 510 includes an operation unit 120, an imaging unit 122, a data processing unit 124, a video holding unit 126, a display unit 128, a compression / decompression unit 130, a storage reading unit 132, and an external input / output unit 134. , A storage unit 136, a motion detection unit 138, and a central control unit 540.

  The central control unit 540 is configured by a semiconductor integrated circuit including a central processing unit and a signal processing unit, and manages and controls the entire imaging apparatus 510 using a predetermined program. The central control unit 540 also functions as a color extraction unit 580, a tracking unit 586, an imaging control unit 188, an information generation unit 190, and a focus determination unit 192.

  The operation unit 120, the imaging unit 122, the data processing unit 124, the video holding unit 126, the display unit 128, the compression / decompression unit 130, the storage reading unit 132, and the external input / output unit 134, which have already been described as the constituent elements in the first embodiment. The storage unit 136, the motion detection unit 138, the imaging control unit 188, the information generation unit 190, and the focus determination unit 192 are substantially the same in function, and thus redundant description is omitted. Here, the central control unit 540 having a different configuration is omitted. The color extraction unit 580 and the tracking unit 586 will be mainly described.

  When the user designates a position with the touch sensor provided on the display surface of the display unit 128, the color extraction unit 580 extracts color information of an area corresponding to the position in the video data. This color information is for specifying the tracking object. Thereafter, when an area is designated from the tracking unit 586, the color extracting unit 580 extracts the color information of the designated area.

  The display unit 128 displays the image being captured as a through image. When the user touches an arbitrary place in the through image, a subject image (tracking target) in the video data is designated. The position information touched by the user is read by a touch sensor arranged on the display surface of the display unit 128 and stored in the storage unit 136. The color extraction unit 580 reads the video data of the area corresponding to the position information stored in the storage unit 136 from the video data stored in the video holding unit 126, and extracts the color information from the video data. The extracted color information is stored in the storage unit 136.

  After the next frame, the movement of the tracking target within the angle of view is tracked. The tracking unit 586 determines a search range based on the position information stored in the storage unit 136. The search range is, for example, an area having a predetermined distance in the vertical and horizontal directions from the position information position. The color extraction unit 580 reads the video data in the search range from the video holding unit 126, and extracts color information from the video data in a small area that is sufficiently smaller than the search area.

  Subsequently, the tracking unit 586 derives the similarity between the extracted color information and the color information stored in the storage unit 136 using a histogram intersection, and changes the similarity while changing the position of the small region within the tracking region. Calculate and derive the position of the small region with the highest similarity. The position of the small area having the highest similarity is the position of the tracking result. The tracking unit 586 updates the position information stored in the storage unit 136. Hereinafter, the imaging control unit 188 uses the position of the tracking result as a focus area, and adjusts the focus as in the first embodiment.

  The tracking unit 586 calculates the moving speed of the tracking target object. The moving speed of the tracking object is a value obtained by calculating the moving distance from the position within the angle of view of each of the previous frame and the latest frame of the tracking object and dividing by the time interval between the frames. However, if the time interval between frames does not change during tracking, the movement distance may be used as it is without division. The tracking unit 586 outputs the derived movement speed to the information generation unit 190. The focus determination unit 192 may use the moving speed as the imaging operation state described in the first embodiment.

  Even when shooting in the “touch tracking autofocus” mode, for example, the tracking target is hidden behind other objects, or the tracking target color is different between the front and back, and the back In some cases, the tracking target may be out of frame, the light may be reflected on the tracking target and the color may change, and the tracking target may be unable to be tracked.

(Imaging method)
Furthermore, an imaging method using the above-described imaging device 510 is also provided. 8 to 10 are flowcharts illustrating the flow of processing of the imaging method according to the second embodiment. When imaging is started in the “touch tracking autofocus” mode, the imaging unit 122 generates video data (S300). It is determined whether or not the designation of the position in the video data through the touch panel has been accepted (S604). If the designation has already been accepted (YES in S604), the color extracting unit 580 has color information of the area corresponding to the designated position. (S606), and the tracking unit 586 starts tracking the tracking target based on the color information (S608).

  Hereinafter, the processing from the tracking impossibility determination step S314 to the end determination step S332 is substantially the same as that of the first embodiment except for the setting determination step S620, and thus a duplicate description is omitted. Next, details of the setting determination step S620 will be described with reference to FIG.

  In FIG. 9, the processing from the zoom speed deriving step S358 to the iris setting step S368 is substantially the same as that of the first embodiment, and therefore redundant description is omitted. However, in the area standby time setting step S362, the tracking unit 586 sets the search range for tracking based on the color information to be near the center of the angle of view. This is because the zoom-in operation is often performed when the main subject is at the center of the angle of view. In the zoom-out determination step S364, when the zoom-out is not performed (NO in S364), a setting determination process is further performed (S670). The setting determination step S670 will be described with reference to FIG.

  In FIG. 10, the processes from the pan / tilt speed deriving step S400 to the iris setting step S414 are substantially the same as those in the first embodiment, and thus redundant description is omitted. In the speed determination step S410 before and after the tracking is impossible, if the pan or tilt immediately before the tracking becomes impossible is relatively fast and the pan or tilt immediately after the tracking becomes impossible is not relatively slow (NO in S410), the focus The determination unit 192 determines whether panning and tilting immediately before and after the tracking becomes impossible are relatively slow (S680). When the speed is relatively low (YES in S680), the focus determination unit 192 has a low moving speed (for example, less than 5 ° / sec in terms of field angle) of the tracking target immediately before the tracking becomes impossible, and the focus It is determined whether or not the change in the focal length is small in the in-focus state (S682). When the moving speed of the tracking object is low and the change in the focal length is small (YES in S682), the focal point determination unit 192 sets the area standby time to about 20 seconds, sets the area flag to 1, and the iris flag to 0. (S684).

  The moving speed of the tracking object described above is the moving speed within the angle of view. In fact, even if the tracking object is moving at a relatively high speed, if the movement of the tracking object is followed by panning or tilting, the tracking object within the angle of view is The moving speed of an object becomes small. In this case, it is considered that the user follows the movement of the tracking target object by panning or tilting even after tracking becomes impossible, and the tracking target object does not move so as to change the focal length. Therefore, the focus determination unit 192 fixes the focus area for a relatively long time, so that the user can continue imaging while the tracking target is in focus.

  Hereinafter, the processing from the condition determination step S424 to the area standby time and iris standby time setting step S430 is substantially the same as that of the first embodiment, and therefore, a duplicate description is omitted.

  According to the imaging method using the imaging apparatus 510 of the present embodiment, it is possible to automatically adjust the focus area and the iris in accordance with the imaging situation and the user's intention.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  Note that each step in the imaging method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include parallel or subroutine processing.

  The present invention can be used in an imaging apparatus and an imaging method that perform appropriate focus adjustment even when a subject cannot be detected.

110, 510 ... imaging device 122 ... imaging units 186, 586 ... tracking unit 190 ... information generation unit 192 ... focus determination unit

Claims (6)

An imaging unit that images a subject and generates video data;
A tracking unit that tracks a specified subject in the video data;
When the subject that has been tracked becomes untrackable, an information generation unit that generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible,
A focus determination unit that changes the depth of field of the imaging unit to a value determined based on the imaging operation information when the state in which the subject cannot be tracked continues for a waiting time having a length according to the imaging operation information; ,
An imaging apparatus comprising: An imaging unit that images a subject and generates video data;
A tracking unit that tracks a specified subject in the video data;
When the subject that has been tracked becomes untrackable, an information generation unit that generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible,
The subject is unavailable tracking state and continues the length of the waiting time according to the imaging operation information, a focus determination unit to move the position of the angle at the center of a range to be imaged to adjust the focus point
An imaging apparatus comprising: An imaging unit that images a subject and generates video data;
A tracking unit that tracks a specified subject in the video data;
When the subject that has been tracked becomes untrackable, an information generation unit that generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible,
The subject is unavailable tracking state and continues the length of the waiting time according to the imaging operation information, is moved to a position in the angle of view to match the focal point is detected in the vicinity of the center of the range to be imaged face A focus determination unit;
An imaging apparatus comprising: Capture the subject, generate video data,
Track the identified subject in the video data,
When the tracked subject becomes untrackable, it generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible.
The subject is unavailable tracking state and continues the length of the waiting time according to the imaging operation information, and characterized by changing the depth of field of the imaging section to a value determined on the basis of the imaging operation information Imaging method. Capture the subject, generate video data,
Track the identified subject in the video data,
When the tracked subject becomes untrackable, it generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible.
Imaging the subject is unavailable tracking state, to the continuing length of waiting time according to the imaging operation information, and moving the position of the view angle to align the focal point in the center of the range to be imaged Method. Capture the subject, generate video data,
Track the identified subject in the video data,
When the tracked subject becomes untrackable, it generates imaging operation information indicating an imaging operation state for each of the tracking before and after tracking becomes impossible.
The subject is unavailable tracking state and continues the length of the waiting time according to the imaging operation information, is moved to a position in the angle of view to match the focal point is detected in the vicinity of the center of the range to be imaged face An imaging method characterized by the above.

Images