JP2015152830A - Imaging device and control method thereof, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of detecting the position of a subject in a screen with high accuracy regardless of a frame rate.SOLUTION: The imaging device includes: a position information acquisition part for acquiring the position information of a subject on the basis of an image signal output from an imaging element; a moving amount acquisition part for acquiring the information of the relative moving amount of a subject by using a plurality of image signals whose photographic time is different; an area setting part for setting a focus detection area by using at least either the position information or the information of the relative moving amount; a switching part for switching a time interval at which the signal is output by the imaging element from a first time interval to a second time interval shorter than the first time interval; and a focus adjustment part for adjusting the focal state of the subject image. The area setting part is configured to, when the imaging element outputs the signal at the first time interval, set the focus detection area by using at least the position information, and to, when the imaging element outputs the signal at the second time interval, and the focus adjustment part performs focus adjustment, set the focus detection area by using only the information of the relative moving amount.

Description

  The present invention relates to a technique for setting a focus detection frame when focus detection is performed using an image signal acquired by an image sensor.

  In digital cameras and video cameras, a contrast detection type autofocus (hereinafter referred to as AF) that uses an output signal from an image sensor such as a CCD or CMOS sensor to detect and focus a signal corresponding to a contrast evaluation value of a subject. ) The method is common. In this method, the contrast evaluation value of the subject is sequentially detected (AF scan operation) while moving the focus lens in the optical axis direction over a predetermined movement range, and the focus lens position where the contrast evaluation value is maximized is detected as the in-focus position. To do.

  Also, using the output signal from the image sensor, face detection processing is performed to detect the face of a person included in the shooting range, and focus control is performed so that the detected face is in focus as the focus detection area. An imaging device for performing is known. According to such an imaging apparatus, it is possible to perform focusing control while reducing the influence of movement of the subject at the time of shooting and camera shake of the photographer.

  Patent Document 1 discloses a method of tracking a focus detection area with movement of a subject by combining face detection processing and pattern matching processing. Thereby, the focus detection area can be set with higher accuracy. As disclosed in Patent Document 1, the detection accuracy of a subject can be improved by a method of detecting the absolute position of the subject, such as face detection processing, or a method of detecting the relative movement amount of the subject, such as pattern matching processing. it can. On the other hand, in order to improve the detection accuracy of a subject with respect to the situation of the subject that changes from moment to moment, it is also effective to shorten the detection time interval and detect a large number of subjects per unit time.

  Patent Document 2 discloses a focus detection method using an imaging surface of a contrast detection method. During focus detection, the frequency of obtaining the output waveform of the photoelectric conversion unit is increased, that is, the frame rate is changed to a higher frame rate. Has been. As disclosed in Patent Document 2, if not only focus detection is performed at a high frame rate but also subject detection is performed, detection can be performed with higher accuracy.

JP 2010-96964 A JP 2013-25107 A

  However, when applying the subject position detection method disclosed in Patent Document 1 to the method of changing the frame rate before and after focus detection disclosed in Patent Document 2, the following method is used. There was a problem.

  The method for detecting the absolute position of a subject such as face detection processing disclosed in Patent Document 1 has a large amount of calculation processing and takes a long time to process, so the detection result of the subject position in accordance with a high-speed frame rate is updated. Difficult to do.

  On the other hand, methods for detecting the relative movement amount of a subject such as pattern matching processing can reduce the calculation processing load by narrowing the calculation range for detecting the movement amount. However, since the relative amount of movement is detected from two signals arranged in chronological order, if the time interval between the two signals is long, the probability that the subject's picture will change increases, and the pattern (subject's picture) Detection (matching) accuracy is reduced. Further, when the time interval between the two signals is long, it is necessary to widen the calculation range for detecting the movement amount, and the calculation processing load increases. For these reasons, when the frame rate is low before the focus detection process as disclosed in Patent Document 2, the subject detection accuracy is lowered.

  As described above, the subject detection method has characteristics related to the detection result update interval. However, Patent Document 1 does not disclose an optimal subject detection method associated with a change in the frame rate.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an imaging apparatus that can detect the position of a subject in a screen with high accuracy regardless of the frame rate. .

  An imaging apparatus according to the present invention captures a subject image formed by a photographing optical system having a focus lens for focus adjustment, outputs an image signal, and acquires subject position information based on the image signal. At least one of position information acquisition means, movement amount acquisition means for acquiring information on the relative movement amount of the subject using a plurality of the image signals having different imaging times, and information on the position information and the relative movement amount. Area setting means for setting a focus detection area, and switching means for switching a time interval for signal output of the image sensor to a first time interval and a second time interval shorter than the first time interval, Focus adjustment means for adjusting the focus state of the subject image by moving the focus lens, and the area setting means is configured to output the signal at the first time interval. When the focus detection area is set using at least the position information, the image sensor outputs a signal at the second time interval, and the focus adjustment is performed. Is characterized in that the focus detection area is set using only the information of the relative movement amount.

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which enabled the position detection of the to-be-photographed object in a screen with high precision irrespective of a frame rate can be provided.

1 is a block diagram illustrating a configuration of an imaging apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a scan AF processing circuit in FIG. 1. 5 is a flowchart showing an AF operation procedure in the first embodiment. The figure which shows the focus detection area (AF evaluation range) in 1st Embodiment. 6 is a flowchart showing an operation of setting a focus detection area in the first embodiment. 6 is a flowchart illustrating operations for acquiring a relative movement amount and setting a focus detection region in the first embodiment. The figure which shows the example of the line peak evaluation value in 1st Embodiment. The figure which shows an example of the timing of acquisition of the positional information on a to-be-photographed object and acquisition of a relative movement amount in 1st Embodiment. The figure which shows an example of the timing of acquisition of the positional infomation on a to-be-photographed object and acquisition of relative movement amount in the modification of 1st Embodiment. 9 is a flowchart showing an AF operation procedure in the second embodiment.

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

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration example of an imaging apparatus having a focus adjustment apparatus according to the first embodiment of the present invention. The imaging device includes, for example, a digital still camera and a digital video camera, but is not limited thereto. For example, the present invention can be applied as long as an incident optical image is acquired as an electrical image by photoelectric conversion using a two-dimensionally arranged image sensor such as an area sensor.

  In FIG. 1, 1 is an imaging device. Reference numeral 2 denotes a zoom lens group, and reference numeral 3 denotes a focus lens group for focus adjustment, which constitutes a photographing optical system. Reference numeral 4 denotes a light amount adjusting means for controlling the amount of the light beam that has passed through the photographing optical system, and an aperture that is an exposure means. Reference numeral 31 denotes a lens barrel that houses the zoom lens group 2, the focus lens group 3, the diaphragm 4, and the like.

  Reference numeral 5 denotes an image sensor such as a CCD that photoelectrically converts a subject image that has passed through the photographing optical system. The image sensor that photoelectrically converts the subject image formed by the photographing optical system 5 having a focus adjusting unit that adjusts the focus state of the subject image may be a CMOS sensor. Reference numeral 6 denotes an image pickup circuit that receives an electric signal photoelectrically converted by the image pickup device 5 and performs various image processing to generate a predetermined image signal. Reference numeral 7 denotes an A / D conversion circuit that changes an analog image signal generated by the imaging circuit 6 into a digital image signal.

  Reference numeral 8 denotes a memory (VRAM) such as a buffer memory for temporarily storing the digital image signal output from the A / D conversion circuit 7. Reference numeral 9 denotes a D / A conversion circuit that reads out an image signal stored in the VRAM 8, converts it into an analog signal, and converts it into an image signal in a form suitable for reproduction output.

  Reference numeral 10 denotes an image display device (hereinafter, LCD) such as a liquid crystal display device (LCD) for displaying image signals. Reference numeral 12 denotes a storage memory that stores image data including a semiconductor memory or the like. 11 is a compression circuit that performs compression processing and coding processing of image data and performs decoding processing and decompression processing in order to read out the image signal temporarily stored in the VRAM 8 and put it into a form suitable for storage in the storage memory 12. It is a compression / decompression circuit comprising an expansion circuit. The compression / decompression circuit 11 takes an optimum form for reproducing and displaying the image data stored in the storage memory 12.

  Reference numeral 13 denotes an AE processing circuit that receives an output from the A / D conversion circuit 7 and performs automatic exposure (AE) processing. Reference numeral 14 denotes a scan AF processing circuit that receives an output from the A / D conversion circuit 7 and performs autofocus (AF) processing. The scan AF processing circuit 14 has a function as a focus evaluation value calculation processing unit that calculates a focus evaluation value by extracting a specific frequency component from an image signal output from the image pickup area of the image pickup element corresponding to the focus detection region. In the present embodiment, the focus detection area and the AF evaluation range are used synonymously. Further, the scan AF processing circuit 14 calculates various evaluation values used for in-focus position calculation. Details of these evaluation values will be described later. Reference numeral 15 denotes a CPU with a built-in memory for controlling the image pickup apparatus. Reference numeral 16 denotes a timing generator (hereinafter referred to as TG) that generates a predetermined timing signal. The CPU 15 calculates a focus position using various evaluation values calculated by the scan AF processing circuit 14.

  Reference numeral 17 denotes an image sensor driver. Reference numeral 21 denotes an aperture drive motor that drives the aperture 4. Reference numeral 18 denotes a first motor driving circuit for driving and controlling the diaphragm driving motor 21. A focus drive motor 22 drives the focus lens group 3. The focus lens group 3 and the focus drive motor 22 correspond to focus adjustment means. Reference numeral 19 denotes a second motor drive circuit that drives and controls the focus drive motor 22. A zoom drive motor 23 drives the zoom lens group 2. Reference numeral 20 denotes a third motor drive circuit for driving and controlling the zoom drive motor 23. The CPU 15 controls the focus drive motor 22 through the second motor drive circuit 19 using the focus evaluation value calculated by the scan AF processing circuit 14.

  Reference numeral 24 denotes an operation switch composed of various switch groups. An EEPROM 25 is an electrically rewritable read-only memory in which programs for performing various controls, data used for performing various operations, and the like are stored in advance. Reference numeral 26 denotes a battery, 28 denotes a strobe light emitting unit, 27 denotes a switching circuit that controls flash light emission of the strobe light emitting unit 28, and 29 denotes a display element such as an LED for displaying OK / NG of AF operation.

  A storage memory, which is a storage medium for image data, is a fixed semiconductor memory such as a flash memory, and has a card shape or a stick shape. In addition to a semiconductor memory such as a card type flash memory that is detachably formed in the apparatus, various forms such as a magnetic storage medium such as a hard disk and a flexible disk are applied.

  The operation switch 24 includes a main power switch, a release switch, a reproduction switch, a zoom switch, a switch for turning on / off the display of the focus evaluation value signal on the monitor, and the like. The main power switch is for starting up the imaging apparatus 1 and supplying power.

  The release switch starts a shooting operation (storage operation) and the like. The reproduction switch starts a reproduction operation. The zoom switch moves the zoom lens group 2 of the photographing optical system to perform zooming. The release switch then performs a first stroke (hereinafter referred to as SW1) for generating an instruction signal for starting an AE process and AF operation performed prior to the photographing operation and a second stroke (hereinafter referred to as an instruction signal for starting an actual exposure operation). SW2) and a two-stage switch.

  30 detects a face from the object scene using the image signals processed by the imaging circuit 6 and the A / D conversion circuit 7, and detects one or more pieces of detected face information (position, size, reliability, face). Is a subject detection circuit that sends to the CPU 15. The subject detection circuit 30 is position information acquisition means. Note that the face detection method is not the main point of the present embodiment, and thus detailed description thereof is omitted.

  FIG. 2 is a block diagram showing the internal configuration of the scan AF processing circuit 14 in FIG. With reference to FIG. 2, various AF evaluation values calculated using the CPU 15 and the scan AF processing circuit 14 of FIG. 1 will be described.

  When the digital signal converted by the A / D conversion circuit 7 is input to the scan AF circuit 14, the AF evaluation signal processing circuit 401 converts the luminance signal Y and emphasizes the low luminance component to increase the luminance. A gamma correction process for suppressing the component is performed.

  A method for calculating the Y peak evaluation value will be described. The luminance signal Y subjected to gamma correction is input to a line peak detection circuit 402 for detecting a line peak value for each horizontal line. With this circuit, the Y line peak value for each horizontal line within the AF evaluation range set by the area setting circuit 413 is obtained. Further, the output of the line peak detection circuit 402 is input to the vertical peak detection circuit 405. By this circuit, peak hold is performed in the vertical direction within the AF evaluation range set by the region setting circuit 413, and a Y peak evaluation value is generated. The Y peak evaluation value is effective for determining a high-luminance subject or a low-illuminance subject.

  A method for calculating the Y integral evaluation value will be described. The luminance signal Y subjected to gamma correction is input to a horizontal integration circuit 403 for detecting an integrated value for each horizontal line. With this circuit, an integral value of Y for each horizontal line is obtained within the AF evaluation range set by the area setting circuit 413. Further, the output of the horizontal integration circuit 403 is input to the vertical integration circuit 406. By this circuit, integration is performed in the vertical direction within the AF evaluation range set by the area setting circuit 413, and a Y integral evaluation value is generated. The Y integral evaluation value can determine the brightness of the entire AF evaluation range.

  A method for calculating the Max-Min evaluation value will be described. The gamma-corrected luminance signal Y is input to the line peak detection circuit 402, and the Y line peak value for each horizontal line is obtained within the AF evaluation range. Further, the luminance signal Y subjected to gamma correction is input to the line minimum value detection circuit 404. This circuit detects the minimum value of Y for each horizontal line within the AF evaluation range of the luminance signal Y. The detected Y line peak value and minimum value for each horizontal line are input to the subtractor, and (line peak value−minimum value) is calculated and input to the vertical peak detection circuit 407. By this circuit, peak hold is performed in the vertical direction within the AF evaluation range, and a Max-Min evaluation value is generated. The Max-Min evaluation value is effective for determination of low contrast and high contrast.

  A method for calculating the region peak evaluation value will be described. A specific frequency component is extracted from the gamma-corrected luminance signal Y through the BPF 408 to generate a focus signal. This focus signal is input to a line peak detection circuit 409 which is a peak hold means for detecting a line peak value for each horizontal line. The line peak detection circuit 409 obtains a line peak value for each horizontal line within the AF evaluation range. The obtained line peak value is peak-held within the AF evaluation range by the vertical peak detection circuit 411, and an area peak evaluation value is generated. Since the area peak evaluation value changes little even when the subject moves within the AF evaluation range, it is effective for restart determination for shifting from the focused state to the process of searching for the focused point again.

  A method for calculating the total line integral evaluation value will be described. Similar to the area peak evaluation value, the line peak detection circuit 409 obtains a line peak value for each horizontal line within the AF evaluation range. Next, the line peak value is input to the vertical integration circuit 410 and integrated with respect to the number of all horizontal scanning lines in the vertical direction within the AF evaluation range to generate an all-line integration evaluation value. The high-frequency all-line integration evaluation value is effective as the main evaluation value of AF for detecting the in-focus position because the integration effect has a wide dynamic range and high sensitivity. In this embodiment, the evaluation value changes according to the defocus state, and the total line integral evaluation value used for focus adjustment is referred to as a focus evaluation value.

  A method for calculating the line peak evaluation value will be described. Similar to the area peak evaluation value, the line peak detection circuit 409 obtains a line peak value (unit evaluation value) for each horizontal line within the AF evaluation range. Next, the line peak value is held and stored for all horizontal scanning lines in the vertical direction within the AF evaluation range, and a line peak evaluation value (unit evaluation value group) is generated. The line peak evaluation value indicates the distribution state of the peak value of the information of the specific frequency component for each row within the AF evaluation range, and is used for detecting a change in the subject position in the vertical direction in this embodiment. .

  In order to detect a change in the position information of the subject, it is also conceivable to detect a change in the subject position in the vertical direction using the integral value of Y for each row calculated in the process of calculating the Y integral evaluation value. However, since the integral value of Y for each row is an integral value, there is a case where subject information is subjected to low-pass and accurate detection cannot be performed.

  It is also conceivable to detect subject position information using the Y peak signal of each row. However, when the Y peak signal is saturated or the change in luminance peak in the vertical direction is poor, the detection accuracy of the subject position information deteriorates.

  In this embodiment, since the peak value of the information on the specific frequency component in each row is used as the line peak evaluation value, the feature amount of the subject in each row can be detected with high accuracy. Even when the luminance signal is saturated, the subject information can be obtained because the information is acquired from the contour with the luminance change. Even when the change in the luminance peak in the vertical direction is poor, subject information can be obtained if the contour shape with a change in luminance changes.

  In this embodiment, the peak value of the information on the specific frequency component in each row is used as the line peak evaluation value, but the integrated value of the information on the specific frequency component in each row may be used. Although there is a concern that the subject moves in the horizontal direction, information with a larger S / N ratio can be acquired.

  In the present embodiment, when performing AF evaluation in the horizontal direction, a change in the position of the subject in the vertical direction is detected based on the line peak evaluation value, and the focus detection area is updated. In other words, the update of the focus detection area is equivalent to the update of the range in which the line peak value is integrated when the above-described total line integration evaluation value is calculated.

  On the other hand, the integration of a predetermined region of the line peak evaluation value becomes the total line integration evaluation value, and the focus evaluation value is used for detection of the in-focus position. Therefore, detecting the amount of movement of the subject based on the line peak evaluation value directly uses the feature amount constituting the information called the focus evaluation value, and the accuracy of detecting the amount of movement of the subject and the detection of the focus position It leads to improvement. In addition, since the line peak evaluation value is configured using the line peak value obtained in the process of calculating the focus evaluation value, it is possible to detect the amount of movement of the subject without greatly increasing the calculation amount.

  The area setting circuit 413 generates an AF evaluation range gate signal for selecting a signal at a predetermined position in the screen set by the CPU 15. The gate signal is input to each circuit of the line peak detection circuit 402, the horizontal integration circuit 403, the line minimum value detection circuit 404, the line peak detection circuit 409, the vertical integration circuits 406 and 410, and the vertical peak detection circuits 405, 407, and 411. The Then, the timing at which the luminance signal Y is input to each circuit is controlled so that each focus evaluation value is generated by the luminance signal Y within the AF evaluation range. The area setting circuit 413 can set a plurality of areas in accordance with an AF evaluation range, a movement amount information acquisition area described later, and the like.

  The AF control unit 151 takes in each focus evaluation value, controls the focus lens drive motor 22 through the second motor drive circuit 19, and moves the focus lens group 3 in the optical axis direction to perform AF control. In the present embodiment, various AF evaluation values are calculated in the horizontal line direction, but may be calculated in either the horizontal direction or the vertical direction, or in both directions.

  Next, FIG. 3 is a flowchart of the AF operation in the present embodiment, and FIG. 4 is a diagram showing a focus detection area in the present embodiment. A focus adjustment process (AF operation) using subject detection in the imaging apparatus of the present embodiment will be described with reference to FIGS. 3 and 4.

  In step S1, main subject determination is performed based on subject information (position, size, number of detected subjects) such as a human face obtained from the subject detection circuit 30, and a focus detection area is set. The focus detection area is set by the area setting unit 413 in the scan AF circuit 14, and the area setting unit 413 is a focus detection area setting unit.

  Here, the features of the focus detection region setting method in the present embodiment will be described with reference to FIG. As shown in FIG. 4A, the focus detection area is set inside the detection area of the subject in the screen detected by the subject detection circuit 30. 4A corresponds to the image sensor 5, and the scan AF processing circuit 14 calculates the contrast information as the focus evaluation value with the X direction in the figure as the AF evaluation direction.

  An area for acquiring the position information of the subject is set as a position information acquisition area 301 (first area) for the person 300 in the shooting screen 500. In FIG. 4, the position information acquisition area 301 is smaller than the shooting screen 500, but may be equal to the shooting screen 500. FIG. 4 shows an example of an area set by referring to information on the position where the subject exists in advance.

  Similarly, a movement amount information acquisition region 302 (second region), which is a region for acquiring relative movement amount information of a subject within a predetermined time, is set. The position information acquisition area 301 is set to include the movement amount information acquisition area 302. The subject detection area 304 is an area representing the position, size, inclination, etc. of the subject detected in the position information acquisition area 301.

  Then, the focus detection area 303 is set inside the subject detection area 304. This is because if the contour portion of the subject exists inside the focus detection area 303, it is influenced by the background pattern. However, when the size of the subject is small, the subject detection area 304 and the focus detection area 303 may be the same size or larger. Details of how to use information obtained in each area will be described later.

  In the present embodiment, as will be described later, the movement amount of the subject is detected using the line peak evaluation value obtained in the movement amount information acquisition region 302. The movement direction of the movement amount detected at this time is the vertical direction. Since the focus detection area 303 is set using this movement amount, it is necessary to set the movement amount information acquisition area 302 so that unnecessary information is not obtained in the horizontal direction with respect to the focus detection area. In the present embodiment, as shown in FIG. 4A, the movement amount information acquisition area 302 is set to be an area in which the X direction is substantially equal to the focus detection area 303. However, since the subject may move in the horizontal direction, the size in the X direction of the movement amount information acquisition region 302 relative to the focus detection region 303 may be changed as appropriate. When it is detected that the movement of the subject is large, the movement amount information acquisition area 302 may be set larger in the X direction.

  FIG. 4B shows the movement amount information acquisition area 302 when the Y direction in the figure is the AF evaluation direction. For the reason described above, the focus detection area 303 and the Y direction are set to be substantially equal. As described above, the movement amount information acquisition area 302 may be changed and set in accordance with the AF evaluation direction. Details of the method of detecting the subject movement amount will be described later.

  The procedure of step S1 will be described later with reference to FIG. In step S2, the subject detection area 304 set in step S1 is displayed on the LCD 10 to notify the photographer. The size of the area to be displayed is appropriately set to an appropriate size, shape, and color scheme in consideration of ease of visual recognition by the photographer.

  In step S3, the on / off state of SW1, which is a switch indicating the start of shooting preparation, is detected. If it is not detected in step S3 that SW1 is turned on, the process returns to step S1 to set the focus detection area 303 as needed.

  If it is detected in step S3 that SW1 is on, the process proceeds to step S4 to perform a frame rate switching process. In order to control the focus adjustment at high speed, the driving of the image sensor is switched so that focus detection data can be acquired at a second time interval shorter than the first time interval performed before step S3. In response to this, live view display displayed on the LCD 10 is also performed using the image data obtained at the second time interval. The update interval of the live view display may be performed at the second time interval, or may be performed at the first time interval by thinning out or adding image data.

  Next, in step S5, driving of the focus lens group 3 is started at a predetermined speed in a predetermined direction, and AF scanning (focus detection operation) is performed. In the AF scan, various evaluation values at each focus lens position are stored in the CPU 15 while moving the focus lens group 3 by a predetermined amount from the scan start position to the scan end position. The scan end position may be set at the end of the driveable range of the focus lens group 3. Further, when it is determined from the previous focus adjustment result that focus adjustment is possible in the vicinity of the current position of the focus lens group 3, the position may be set to a position driven by a predetermined amount from the current position. Further, the driving of the focus lens group 3 may be continued or stopped while acquiring various evaluation values.

  Next, using the signal output from the image sensor 5 in step S6, acquisition of the relative movement amount of the subject and setting of the focus detection area are performed. In the present embodiment, after setting the focus detection area using the position information of the subject before the SW1 is turned on, the relative movement amount of the subject is detected using the signal output from the image sensor having different acquisition time (imaging time), The focus detection area is updated. Acquisition of subject position information using the degree of coincidence such as face detection or two-dimensional pattern matching requires a large amount of calculation and takes time. On the other hand, when the frame rate is switched at a high speed for speeding up the focus adjustment, various AF evaluation values are calculated at a short time interval (second time interval). At that time, if the focus detection area that is the target of calculation of various AF evaluation values is not updated and focus detection is performed in the focus detection area based on past subject position information, the influence of subject position changes, camera shake, etc. As a result, the focus detection accuracy deteriorates. In the present embodiment, even after the frame rate is switched at a high speed, in order to set the focus detection area appropriately, the relative movement amount of the subject is calculated, and the focus detection area is updated using the information. Therefore, it is possible to reduce the influence of the movement of the subject and the camera shake of the photographer during the AF scan operation, and to perform highly accurate focus detection. Details of the processing performed in step S6 will be described later.

  Next, in step S7, the above-described various AF evaluation values are calculated, and the process proceeds to step S8. In step S8, it is determined whether or not the focus evaluation value has decreased by a predetermined amount or more with respect to the previously acquired value. If not decreased by a predetermined amount or more, it is determined that the peak (maximum value) of the focus evaluation value has not been detected and the process proceeds to step S14. In step S14, it is determined whether it is a scan end position. If the preset scan end position has not been reached, the process returns to step S5 in order to continue the AF scan. On the other hand, if the scan end position has been reached, the process proceeds to step S15, where it is determined that focus detection is impossible, and the focus lens group 3 is moved to a predetermined position. The predetermined position may be set using a subject distance that is assumed from a position where the existence probability of the subject is high or the size of the face of a person. Next, in step S16, an out-of-focus frame is displayed on the image display unit of the LCD 10, and the process proceeds to step S13. Here, the out-of-focus frame is a frame that is displayed in a region where a subject is present or a predetermined region in the image area when the image is out of focus. Sets a frame of a different color (for example, yellow).

  In step S8, when the focus evaluation value has decreased by a predetermined amount or more with respect to the previously acquired value, it is determined that the peak of the focus evaluation value is detected, and the process proceeds to step S9. In step S9, from the relationship between the position of the focus lens group 3 and the focus evaluation value, interpolation calculation or the like is performed to calculate the position of the focus lens group 3 at which the focus evaluation value has a maximum value. Furthermore, the reliability of the change curve of the focus evaluation value near the maximum value is evaluated. This reliability evaluation is performed in order to determine whether the obtained focus evaluation value takes the maximum value because the optical image of the subject is formed on the image sensor or takes the maximum value due to other disturbances. .

  As a detailed method for determining the focus, for example, a method described in FIGS. 10 to 13 of JP 2010-078810 A may be used. That is, whether or not the focus evaluation value indicating the in-focus state has a mountain shape is determined by the difference between the maximum value and the minimum value of the focus evaluation value, and the length of the portion inclined with a slope equal to or greater than a certain value (SlopeThr). , And the slope of the inclined portion. Thereby, focus determination can be performed.

  Next, in step S10, it is determined whether or not the detected local maximum value of the focus evaluation value is a highly reliable focus position. If the reliability of the focus evaluation value is low, the process returns to step S14 and the focus adjustment is continued. On the other hand, if it is determined that the focus evaluation value is highly reliable and appropriate as the focus position, the process proceeds to step S11, and the focus lens group 3 is driven to the calculated focus position. Next, the process proceeds to step S12, and a focusing frame is displayed on the image display unit of the LCD 10. Here, the in-focus frame is a frame for indicating which region in the image region is in focus. For example, when the face is in focus, a frame is displayed in the face area. In addition, the frame is displayed with an in-focus color (for example, green) so that the state of being in focus can be easily identified.

  When the focus display is finished, the process proceeds to step S13, and the frame rate is changed from the second time interval to the first time interval. The purpose of this processing is that the power consumption is large when the image sensor is driven at the second time interval with a short update interval until after focusing. When the frame rate switching is finished, the AF operation is finished.

  As described above, the focus detection area displayed in step S2 of FIG. 3 is displayed based on the position information of the subject acquired in advance and is not updated during the AF scan. This is because when the focus adjustment time is sufficiently short, the photographer does not feel uncomfortable without updating the display position of the focus detection area. However, when the movement speed of the subject is high, the focus detection area moves based on the relative movement amount information of the subject during the AF scan as described above. At this time, the display of the focus detection area may be updated. With this configuration, although the processing content increases, it is possible to always display the focus detection area that follows the movement of the subject.

  Next, the focus detection area setting subroutine in step S1 of FIG. 3 will be described with reference to FIG. Here, various detection areas are set for the situation shown in FIG.

  First, in step S101, a position information acquisition area 301, which is an area for acquiring information such as the position of a subject, is set using the subject detection circuit 30. Here, when there is no prior subject position information, the shooting range 500 is set as the position information acquisition area 301. In a situation where the subject position information is included in advance and it is determined that there is little change in the subject, the position information acquisition area 301 is set in view of the prior subject position information. Information obtained by accumulating information on the relative movement amount described later may be used as the subject position information in advance. In this embodiment, the focus detection area is set by the relative movement amount during AF, but the accumulated relative movement amount is calculated every time the relative movement amount is detected, and the next position information is calculated using the accumulated relative movement amount. An acquisition area may be set. When both the position information and the accumulated relative movement amount are used, the accumulated relative movement amount is reset every time the position information is acquired.

  Next, in step S102, the detected subject information (detection number, position, size, inclination) is acquired from the subject detection circuit 30, and the process proceeds to step S103. In step S103, a variable i for counting the number of faces is initialized to 0, and the process proceeds to step S104.

  In step S104, the size of the focus detection area 303 with respect to the detected subject detection area 304 is calculated. In general, in human faces, the contrast of black portions such as hair, eyebrows, and eyes, and imprinted portions due to openings such as nose and mouth is high, and the focus evaluation value is large. Therefore, it is desirable to set the focus detection region so as to include such a high contrast portion.

  Also, when the contrast between the face portion and the background is high, the focus evaluation value of the face contour portion increases. However, when the focus detection area includes the outline of the face, perspective conflict may occur due to the influence of the background. Perspective conflicts in the focus detection area including the face and the surrounding background include focusing on the distant background pattern or focusing on the vicinity of the ear that is the outline of the face. It is possible that the subject is out of focus around the eyes.

  Therefore, by setting an area that does not include the face outline as the focus detection area, the influence of the face outline on the focus evaluation value can be reduced even when the face moves during AF scanning. However, this is not the case when the face size is smaller than the predetermined size. When the face is small, it is assumed that the shooting distance is relatively long, and the depth of field may be deep. There is also a concern that the S / N of the information amount in the focus detection area is deteriorated. In view of these situations, the focus detection region may be set as appropriate so as to include the outline of the face.

  Based on the information on the position, size, and tilt of the face, a focus detection area is set inside the i-th face, and the process proceeds to step S105. In step S105, i is incremented and the process proceeds to step S106. In step S106, it is checked whether i is equal to the number of detected faces. If i is not equal, the process returns to step S104. If i is equal, the process proceeds to step S107.

  In step S107, the face intended by the photographer as the main subject is estimated from the position and size of the face detection area, and the priority of the detected face is set. Here, a face closest to the center in the image area and having a face size of a predetermined size or more is set as a main face, and other detected faces are set as sub-faces. That is, the face selected as the main subject from the plurality of detected faces is the main face. The focus detection area of the main face is used for determining the focus position. Although the sub-face focus detection area is not used to determine the in-focus position, it is checked whether the peak position and the in-focus position of the main area of the sub-face are within a predetermined range at the time of in-focus display. When the in-focus position is within the predetermined range, the in-focus frame is also displayed in the sub-face area in the image area. The sub-face is used for determining the in-focus position when the main face is determined to be in-focus in the in-focus determination after AF scanning. For this reason, the priority of the sub-face is also determined based on the distance from the center in the image area and the face size.

  In step S108, the movement amount information acquisition area 302 is set. The movement amount information acquisition area 302 is set so as to include the focus detection area of the main face. The movement amount information acquisition area 302 is a range in which the movement amount of the subject during the AF scan is detected. Therefore, according to the movement state (speed, acceleration) of the subject optical image on the image sensor and the frame rate during the AF scan, the subject (main face) is set so as not to go out of the area during the AF scan. Is preferred. The movement state of the subject optical image on the image sensor may be estimated using information on subject movement and camera shake of the photographer. When step S108 ends, the focus detection area setting subroutine ends.

  Next, the subroutine for obtaining the relative movement amount and setting the focus detection area in step S6 of FIG. 1 will be described with reference to the flowchart of FIG. Here, the movement amount information acquisition area set in step S1 is used to detect the relative movement amount of the subject during the AF scan, and the focus detection area is updated based on the detected movement amount.

  In step S601, the line peak evaluation value in the movement amount information acquisition region is calculated and stored using the signal output from the image sensor 5. Next, in step S602, it is determined whether a plurality of line peak evaluation values including the previous line peak evaluation value are stored. If it is not stored, this subroutine is terminated.

  When the line peak evaluation values of a plurality of frames including the output signal from the previous image sensor 5 are stored in step S602, the relative movement amount is acquired in step S603. The relative movement amount is obtained by calculating the image shift amount of two line peak evaluation values that are temporally continuous by the CPU 15 as the correlation calculation means. The line peak evaluation value obtained from the signal of the nth frame is A (k) (first unit evaluation value group), and the line peak evaluation value obtained from the signal of the (n + 1) th frame is B (k). (Second unit evaluation value group). k indicates the row number in the vertical direction in the movement amount information acquisition region 302, and the line peak values in the k-th row are represented as A (k) and B (k). FIG. 7 shows examples of line peak evaluation values A (k) and B (k).

  In calculating the image shift amount, the correlation amount COR is calculated by the following equation while shifting the two signals (A (k) and B (k)).

... (1)
In equation (1), the shift amount is s1, and the shift range of the shift amount s1 is Γ1. By the shift process of the shift amount s1, the k-th first signal A (k) and the k-s1st second signal B (k-s1) are matched and subtracted to generate a shift subtraction signal. The absolute value of the generated shift subtraction signal is calculated, the number k is summed within the range W corresponding to the movement amount information acquisition area 302, and the correlation amount COR (s1) is calculated.

  Further, a real-valued shift amount at which the correlation amount becomes the minimum value is calculated from the correlation amount by sub-pixel calculation to obtain an image shift amount d1 as shown in the waveform of FIG. The image shift amount d1 calculated here corresponds to the relative movement amount of the subject in the vertical direction.

  Similarly, when the AF evaluation value can be calculated in the vertical direction, the horizontal relative movement amount d2 is calculated.

  In the above-described example, the line peak evaluation value calculated from the luminance signal Y is used. However, the line peak evaluation value may be calculated using RGB (red, green, blue) that are image sensor signals in the Bayer array. . In this case, since there are RG rows and GB rows, the line peak evaluation values are calculated separately for even rows and odd rows. As a result, the amount of image shift can be acquired in the same manner as the above-described processing.

  Next, in step S604, the CPU 15 as the reliability determination unit calculates the reliability of the pair of line peak evaluation values A (k) and B (k) used for calculating the image shift amount. As a reliability calculation method, a method used in phase difference detection type focus detection may be used. For example, the determination may be made using the S level disclosed in Japanese Patent Application Laid-Open No. 2007-52072. The reliability of the calculated image shift amount can be measured by the magnitude of the value of the S level. In the present embodiment, the image shift amount is calculated using the output signal of the image sensor 5 obtained while moving the focus lens group 3. Therefore, the relative movement amount is calculated using a pair of line peak evaluation values with different defocus states. Since it is difficult to calculate a highly reliable image shift amount from a pair of line peak evaluation values obtained in a largely defocused state, reliability determination is performed using the S level or the like.

  Next, in step S605, it is determined whether or not the obtained relative movement amount (image shift amount) is reliable. If there is no reliability, this subroutine is terminated. If there is reliability, the process proceeds to step S606, and the focus detection area 303 is updated. The update of the focus detection area performed here calculates the integration range of the line peak value in the vertical direction and the line peak value performed when calculating the horizontal focus evaluation value (total line integration evaluation value) in the focus detection area. It determines the horizontal range.

  FIG. 7 also shows a movement amount information acquisition region from which the line peak evaluation values A (k) and B (k) are acquired, a focus detection region before update, and a focus detection region after update. In the movement amount information acquisition area, when the focus evaluation value calculated in the focus detection area 303 before update is the integral value from the a-th line to the b-th line, the updated focus detection area 303 is the a + d1-th line. To b + d1 line. After the update, the focus evaluation value is calculated by integrating the line peak value in the range from the a + d1 line to the b + d1 line.

  When the horizontal relative movement amount d2 is calculated, the horizontal range of the focus detection area 303 is updated. When the focus detection area 303 before the update is from the c-th column to the d-th column, the updated focus detection area 303 integrates the line peak values in the range from the c + d2 column to the d + d2 column, and calculates a focus evaluation value. .

  In step S607, the movement amount information acquisition area 302 is updated. This is performed to prevent characteristic information in the movement amount information acquisition area from moving outside the area. This is used when various AF evaluation values are calculated from signals obtained from the image sensor 5 using the vertical and horizontal relative movement amounts d1 and d2.

  The update of the movement amount information acquisition area performed in step S607 may be omitted depending on the detected movement amount. That is, when a value smaller than the predetermined value is detected as the movement amount, the movement amount information acquisition area is not updated.

Further, the movement amount information acquisition area may be updated using the accumulated values of the vertical and horizontal relative movement amounts d1 and d2. When the cumulative relative movement amount (cumulative movement amount) is used, it is desirable to have information with higher resolution with respect to the relative movement amounts d1 and d2 used when setting the focus detection area described above. For example, when the image shift amount d1 is obtained as 3.2 pixels, the focus detection area may round off the image shift amount d1 and d1 = 3. On the other hand, when calculating the cumulative relative movement amount, errors generated due to rounding are also accumulated, so it is more accurate to calculate the cumulative relative movement amount using the image shift amount d1 = 3.2 pixels. A value can be calculated.
When step S607 ends, the subroutine for obtaining the relative movement amount and setting the focus detection area is ended, and the process proceeds to step S7.

  In the present embodiment, a contrast detection type focus detection method is used as the focus detection method, but the focus detection method is not limited to this. For example, a phase difference detection type focus detection method in which focus detection pixels are arranged on the image sensor may be used. For example, a technique as disclosed in JP 2012-63396 A may be used. In that case, an image shift amount corresponding to the defocus amount is acquired by phase difference detection in step S7 in FIG. 3, and the process proceeds to step S10.

  Next, with reference to FIG. 8, an example of acquisition timing of the subject position information and acquisition of the relative movement amount when the AF operation described in FIG. 3 is performed will be described. In FIG. 8, the horizontal axis indicates time, and F1 to F16 indicate acquisition times of output signals of the image sensor 5. From F1 to F4, focus detection data is acquired at a first time interval. When the AF operation is started at F4, the focus detection data is acquired by changing to the second time interval having a shorter interval. In addition, when the AF operation is finished in F14, the state is changed again to the first time interval.

  In the present embodiment, the position information is acquired during the first time interval. The position information is acquired using information of the position information acquisition area 301 set in advance. As a method of acquiring position information, known face detection, motion vector calculation using color information, pattern matching, and the like are used. The feature here is that the amount of information detected for acquisition of position information is large, such as position, size, inclination, personal authentication, etc., but many calculations are required for detection and time is required. Therefore, in FIG. 8, the position information is updated once every two times of the first time interval.

  On the other hand, when acquiring focus detection data at the second time interval, the relative movement amount is acquired every frame. The feature of acquiring the relative movement amount is that a region narrower than the position information acquisition region 301 is used as the movement amount information acquisition region 302, and the calculation content is simplified, so that information can be calculated at higher speed. .

  In the present embodiment, when a plurality of frames are acquired after the AF operation starts, the relative movement amount is calculated (F5 and later). Thereby, the focus detection area 303 is updated by the relative movement amount using the position information obtained between F3 and F4 as an initial value. When performing a focus detection by acquiring a plurality of data in time series, it is desirable that the obtained time series data is a signal obtained from the same region of the subject. This is related to the accuracy of peak position detection in the case of contrast detection type focus detection, and to the accuracy of subject movement prediction processing in the case of phase difference detection type focus detection. In the present embodiment, the focus adjustment can be performed at a high speed by switching the frame rate at a high speed during focus detection, and the focus detection area can be made to follow the movement of the subject at a high speed. Thereby, highly accurate focus detection can be performed.

  When the AF operation is finished, after F14, the focus detection data acquisition interval is changed to the first time interval, and the position information is acquired again.

  In the above embodiment, the detection of the relative movement amount of the subject is performed using the temporal change (image shift amount) of the line peak evaluation value, but the detection method is not limited to this. For example, the line peak value of the luminance signal Y may be used. Further, as a representative row or column, for example, a central row or column in the focus detection region may be selected, and the image shift amount may be calculated using the luminance signal of that row or column. However, the advantage of detecting the relative movement amount using the line peak evaluation value is as described above.

  The detection of the relative movement amount of the subject may be properly used depending on the detection direction. For example, when performing AF evaluation only in the horizontal direction, the relative movement amount in the vertical direction of the subject is calculated using the line peak evaluation value calculated in the process of calculating the focus evaluation value in the horizontal direction, and the horizontal direction of the subject is calculated. The relative movement amount may be performed using a luminance signal. Thereby, it is possible to detect the relative movement amount of the subject in the horizontal and vertical directions while reducing the calculation load.

  In addition, when a focus detection pixel is arranged on the image sensor and phase difference detection type focus detection can be performed, the relative movement amount of the present embodiment is calculated using the output signal of the focus detection pixel. You may go. In this case, the line peak evaluation value and the luminance signal are calculated using one of the focus detection pixel pairs that receive light beams that have passed through different areas on the exit pupil of the photographing optical system, and the relative movement is calculated. The amount may be calculated.

  In the present embodiment, the acquisition of the relative movement amount is performed in step S6 of FIG. 3 every time a signal is acquired by the image sensor, but the acquisition of the relative movement amount may be omitted. For example, if the amount of defocus is assumed to be large, such as when the focus evaluation value obtained in advance is small, the calculation of the line peak evaluation value and the calculation of the relative movement amount can be omitted, and the focus detection accuracy can be improved. Does not affect. Thereby, the calculation load during focus adjustment can be reduced.

  As described above, according to the present embodiment, it is possible to detect the position of the subject in the screen with high accuracy regardless of the frame rate by changing the acquisition method of the subject information before and after the focus detection. To do. Thereby, the focus detection accuracy can be increased regardless of the focus detection method.

  Next, FIG. 8 shows an example of realizing the AF operation of FIG. 3, but FIG. 9 will be described as a modification. FIG. 9 is an example of the timing of acquisition of the position information of the subject and the acquisition of the relative movement amount when the AF operation described in FIG. 3 is performed, as in FIG. In FIG. 8, the horizontal axis indicates time, and F1 to F16 indicate acquisition times of output signals of the image sensor 5. From F1 to F4, focus detection data is acquired at a first time interval. When the AF operation is started at F4, the focus detection data is acquired by changing to the second time interval having a shorter interval. In addition, when the AF operation is finished in F14, the state is changed again to the first time interval.

  The difference from FIG. 8 is that the relative movement amount is acquired even while the focus detection data is acquired at the first time interval. Since acquisition of the position information takes time as described above, the position information is updated once every two times of the first time interval. On the other hand, since the relative movement amount can acquire information at a higher speed, in the example of FIG. 9, the relative movement amount is acquired even during the acquisition of the position information, and the position information of the subject is interpolated to obtain a higher accuracy. Enable detection. Thereby, since the relative movement amount is acquired even during the first time interval, the amount of calculation increases, but the AF start timing is separated from the position information acquisition timing, for example, between F2 and F3. Even in this case, it is possible to obtain highly accurate subject position information based on the relative movement amount.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The main difference from the first embodiment is that each time the relative movement amount is calculated, the cumulative relative movement amount is also calculated as a cumulative value, and the magnitude of the cumulative relative movement amount is determined. If the cumulative relative movement amount is large, it may be possible that the position information of the subject is erroneously detected or the relative movement amount calculation accuracy is poor. Therefore, focus adjustment is performed again. Thereby, when updating the focus detection area with the relative movement amount, it is possible to avoid focus detection when there is a concern about deterioration of focus detection accuracy, and it is possible to improve the focus detection accuracy finally obtained. .

  In addition, a block diagram (FIG. 1) of the image pickup apparatus having the focus adjusting device in the first embodiment, an explanatory diagram of various AF evaluation values (FIG. 2), an explanatory diagram of setting a focus detection area (FIG. 4), an AF Regarding the subroutine in the operation (FIGS. 5 and 6) and the diagram showing the example of the paired line peak evaluation values (FIG. 7), the second embodiment has the same configuration and performs the same operation. Is omitted.

  The difference between the processing contents performed in the second embodiment and the first embodiment, that is, the difference from the flowchart of the AF operation of FIG. 3 will be described with reference to FIG. In FIG. 10, the same step numbers are assigned to portions that perform the same processing as in FIG.

  In step S21 of FIG. 10, the relative movement amount calculated in step S6 is accumulated. Next, in step S22, it is determined whether or not the cumulative relative movement amount is greater than a predetermined value. If it is less than or equal to the predetermined value, the process proceeds to step S7.

  If the accumulated relative movement amount is larger than the predetermined value, the process proceeds to step S23, and the focus lens group 3 is driven to the AF start position in order to perform focus adjustment again. For example, the focus lens group 3 is moved so that the subject at an infinite distance is in focus as the AF start position.

  Next, in step S24, the focus detection area 303 is set again. The process performed here is the same as the process performed in step S1. Thereafter, the accumulated relative movement amount is reset in step S25, and the process proceeds to step S5. Thereby, when the accumulated relative movement amount is large, the focus detection area can be set again after the position information is acquired again. This is because the calculation of the relative movement amount includes a detection error every time it is calculated, and the accumulation of the error may cause the photographer to perform focus detection in a region different from the subject to be focused. This process is performed because of As another object, in order to prevent the movement amount of the subject from being large and the region including the main feature amount for calculating the focus evaluation value from deviating from the movement amount information acquisition region 302 and the focus detection region 303. This is the process to be performed.

  For the above reasons, in order to perform focus adjustment again, whether or not to perform focus adjustment again based not only on the amount of accumulated relative movement amount but also on the basis of the number of times of calculation of relative movement amount and the reliability determination at the time of relative movement calculation. It may be determined.

  As described in the first embodiment, the cumulative relative movement amount preferably has information with higher resolution than the relative movement amounts d1 and d2 used when setting the focus detection area described above. .

  By performing the processing as described above, high-precision focus adjustment can be performed without being affected by an error in calculating the relative movement amount or movement of the subject.

  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.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (12)

An image sensor that captures a subject image formed by a photographing optical system having a focus lens for focus adjustment and outputs an image signal;
Position information acquisition means for acquiring position information of a subject based on the image signal;
A movement amount acquisition means for acquiring information of a relative movement amount of a subject using a plurality of the image signals having different imaging times;
An area setting means for setting a focus detection area using at least one of the position information and the information of the relative movement amount;
Switching means for switching a time interval for performing signal output of the image sensor between a first time interval and a second time interval shorter than the first time interval;
Focus adjusting means for adjusting the focus state of the subject image by moving the focus lens,
The area setting means sets the focus detection area by using at least the position information when the image sensor outputs a signal at the first time interval, and the image sensor An imaging apparatus characterized in that, when signal output is performed at time intervals and focus adjustment is performed, the focus detection area is set using only information on the relative movement amount.   The imaging apparatus according to claim 1, wherein the position information acquired by the position information acquisition unit is information regarding a position having a high degree of coincidence with a predetermined pattern in the image signal.   The information on the relative movement amount acquired by the movement amount acquisition unit is information on a shift amount of a waveform of an output signal obtained from the same region of the image pickup device of the image signal having a different image pickup time. Item 2. The imaging device according to Item 1.   A first area that is an area on the image sensor that acquires the position information is wider than a second area that is an area on the image sensor that acquires the information on the relative movement amount. The imaging apparatus according to claim 1, wherein the imaging device is wider than the focus detection region.   2. The information processing apparatus according to claim 1, further comprising an accumulating unit that accumulates a plurality of temporally continuous information on the relative movement amount to calculate a cumulative movement amount, and changes the first area based on the cumulative movement amount. 5. The imaging device according to 4.   The imaging apparatus according to claim 5, wherein the cumulative movement amount is reset every time the focus detection area is set using position information of the subject.   Accumulating means for accumulating a plurality of time-sequential information on the relative movement amount and calculating the accumulated movement amount, further comprising: first position information acquired at a first time by the position information acquisition means; Subject position information obtained by using the cumulative movement amount calculated between the first time and the second time after the first time, and the second time by the position information acquisition means. The imaging apparatus according to claim 1, wherein the focus adjustment unit performs the focus adjustment again when the difference from the second position information acquired in the step is larger than a predetermined value.   Display means for notifying a photographer of the position of the focus detection area is further provided, and when the image sensor outputs a signal at the second time interval, the display means obtains the subject obtained in advance. The image pickup apparatus according to claim 1, wherein the position of the focus detection area is displayed based on the position information.   Display means for notifying a photographer of the position of the focus detection area is further provided, and when the image sensor outputs a signal at the second time interval, the display means obtains the subject obtained in advance. The image pickup apparatus according to claim 1, wherein the position of the focus detection area is displayed based on the position information of the image and the relative movement amount. A method for controlling an imaging device including an imaging device that captures a subject image formed by a photographing optical system having a focus lens for focus adjustment and outputs an image signal,
A position information acquisition step for acquiring position information of a subject based on the image signal;
A movement amount acquisition step of acquiring information on the relative movement amount of the subject using the plurality of image signals having different imaging times; and
A region setting step of setting a focus detection region using at least one of the position information and the information of the relative movement amount;
A switching step of switching a time interval for performing signal output of the image sensor between a first time interval and a second time interval shorter than the first time interval;
A focus adjustment step of adjusting the focus state of the subject image by moving the focus lens,
In the region setting step, when the image sensor is outputting a signal at the first time interval, the focus detection region is set using at least the position information, and the image sensor is A method for controlling an imaging apparatus, wherein the focus detection area is set using only information on the relative movement amount when signal output is performed at time intervals and focus adjustment is performed.   The program for making a computer perform each process of the control method of Claim 10.   A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 10.

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