JP2010048994A - Image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device capable of detecting a face and focusing on the face even in low luminance. <P>SOLUTION: The image pickup device comprises: an imaging optical system including a focusing optical system; an image pickup means; a monitor; a strobe means; a control means for controlling monitor mode photographing in which images photographed by the image pickup means at constant time intervals are displayed on the monitor; a focusing means having a focus search function of detecting a focusing state based on the photographed images; and a face detection means for detecting a face image of a character from the image photographed in the monitor mode. When the face detection means detects a face image, the control means sets the area including the face image as a focus area. When the face detection means does not detect a face image, the control means moves the focusing optical system to the distance for photographing a part above the bust, causes the strobe means to produce luminescence with a preluminescence amount to give correct exposure, causes the image pickup means to photograph an image, causes the face detection means to detect the face image of the character from the photographed image, and causes the focus detection means to set the area including the detected face image as a focus area and perform focus search. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image pickup apparatus including a focus adjustment device that performs face adjustment by performing face detection (face recognition), and particularly relates to an image pickup apparatus effective at low luminance.

In a digital camera equipped with a conventional focus detection device based on an image contrast method, a focus adjustment using a face detected by face detection as a focus detection region is known (Patent Document 1). This Patent Document 1 describes a technique for detecting a face during strobe pre-light emission because face detection is difficult in a low-luminance environment such as a night scene. In close-up photography, an invention is known in which an approximate distance is obtained from a deviation between the strobe light irradiation center position in the image area and the center position of the image area, and the focus search range is limited to a range including the approximate distance ( Patent Document 2).
JP 2005-184508 A JP 2006-258970 A

  When adjusting the focus for a detected face, if face detection is performed during monitor mode shooting, it is not necessary to detect the face again when the shutter button is pressed. It is preferable because the time lag can be shortened. However, since face detection uses photographed image data, the image data obtained by monitor mode photography has an output of image data that is too low when the luminance is low, and accurate face detection cannot be performed. There is a problem similar to that at low luminance when backlit.

  In monitor mode shooting, the focus adjustment lens group is located at the hyperfocal distance or an arbitrary focal length in the previous shooting state. It was difficult to detect and face detection was severe.

  Accordingly, an object of the present invention is to provide an imaging apparatus capable of detecting a face and focusing on the face even when the luminance is low.

  The present invention that solves such a problem is an imaging optical system including a focus adjustment optical system, an imaging unit, a monitor that displays an image captured by the imaging unit, a strobe unit, and an image captured by the imaging unit at regular time intervals. The control means for controlling the monitor mode photographing for displaying the image on the monitor and the imaging means while photographing the focus adjusting optical system within the movable range from the near position to the far position, and focusing based on the photographed image. A focus adjustment unit having a focus search function for detecting a state; and a face detection unit for detecting a face image of a person from the monitor mode imaged image, wherein the control unit detects the face image. When the focus detection unit performs the focus search by setting an area including the face image as a focus area, the face detection unit detects the face image. When this occurs, the focus adjustment unit moves the focus adjustment optical system to a bust-up shooting distance, and the strobe unit emits light with a pre-emission amount that provides an appropriate exposure at the bust-up shooting distance, and the imaging unit shoots. And causing the face detection means to detect a face image of a person from the captured image, and causing the focus detection means to set a region including the detected face image as a focus area and perform a focus search. .

  Further, the control means of the present invention determines whether or not the brightness of the photographed image is saturated if the face detection means fails to detect the face even if the pre-flash is used for imaging, and the saturation is so large that the image is saturated. If it is determined that the pre-emission amount is smaller than the first pre-emission amount, the focus adjustment optical system is moved closer to the bust-up position, and the flash unit is pre-emission to take a picture. The face is detected by the face detecting means. Even when a person is located at a closer distance than the bust-up position, the face can be detected and focused.

  When it is determined that the brightness of the captured image is not so high that the control means is saturated, it is determined whether the brightness of the image is low. If it is determined that the brightness is low, a pre-light emission amount greater than the first pre-emission amount is determined. A light emission amount is set, the focus adjustment optical system is moved farther than the bust-up position, the strobe unit is pre-flashed and imaged, and the face is detected by the face detection unit. Even when a person is located farther than the bust-up position, the face can be detected and focused.

  If it is not determined that the control means is small, the pre-emission amount for proper exposure is set at the hyperfocal distance, the focus adjustment optical system is moved to the hyperfocal distance, and the strobe is pre-flashed for imaging. The face is detected by the face detecting means. Even when a person is far away from the within-depth face detection range at the bust-up shooting distance, the face can be detected and focused.

  Actually, when the focus detection unit sets the focus image with the face image detected by the face detection unit as a focus area and starts the focus search, the focus detection unit starts the focus search from the near position and detects the in-focus position. The focus search is terminated and the focus adjustment optical system is moved to the in-focus position. When the in-focus position is detected, the focus search is terminated and in-focus is performed, so that the focus adjustment time can be shortened. When the face detection means does not detect a face image, a focus search is performed from a near position to a far position, so that it is possible to focus even when a subject other than a person is a subject.

  It is preferable that a shooting magnification at which the bust-up shooting distance is obtained is set in advance, and the bust-up shooting distance is calculated from the focal length at the time of shooting and the preset shooting magnification. Based on the focal length at the time of shooting, the bust-up shooting distance can be easily obtained.

  As described above, according to the imaging apparatus of the present invention, when a face cannot be detected during monitor mode shooting, the strobe unit is pre-flashed to detect the face. Therefore, when the face has low brightness, for example, the subject is dark and the face Even if the face cannot be detected due to backlight failure, the face can be detected even when the face is too dark to detect the face, and the face can be focused.

  The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a block diagram showing a main configuration of an embodiment applied to a digital camera having an image contrast AF type AF imaging device as an imaging device. This digital camera is a compact digital camera that uses a CCD image sensor 11 to photograph a subject image formed by a photographing lens block L as a photographing optical system. The photographing lens block L includes a zooming variable power lens group LZ and a focus adjusting focus lens group LF, and a diaphragm / shutter unit 31 that functions as a mechanical shutter and a diaphragm in the middle of the optical path. The aperture / shutter unit 31 is driven by an aperture / shutter control circuit 33, the focus lens group LF is driven by a focus motor MF via a focus control circuit 35, and the zoom lens group LZ is zoomed by a zoom control circuit 37. Driven by MZ. The focus lens group LF is movable from a near position that is the shortest shooting distance to a far position that is the infinite focus position. The digital camera includes a zoom button, and the control unit 15 drives the zoom motor MZ according to the operation of the zoom button to move the zoom lens group LZ for zooming.

  The CCD image sensor 11 performs monitor mode photographing and still photographing operation by a CCD driving circuit 13 that operates under the control of the control unit 15. The control unit 15 includes a CPU, and further includes a flash ROM 15a for storing various data and a RAM 15b for temporarily storing AE data.

  The image signal captured and output by the CCD image sensor 11 is subjected to noise removal by a correlated double sampling circuit (CDS) 17, converted into a digital signal by an A / D converter 19, and RAW data by a RAW data circuit 21. Is generated and sent to the image processing circuit 23 and the AE data processing circuit 25. The image processing circuit (DSP) 23 performs predetermined image signal processing (white balance adjustment, gamma correction, etc.) on the RAW data, converts it into video data for monitor display, displays it on the monitor 44, and displays the RAW data. As it is, or converted into JPEG data or the like and written in the memory 43. The memory 43 is generally a removable flash memory card.

  In the RAW data sent to the AE data processing circuit 25, the image area data used for the AE calculation is converted into the AE data, and the exposure value calculated by the AE calculation circuit 27 is controlled using the AE data. Sent to section 15. The control unit 15 sets the current exposure conditions such as the aperture value and the shutter speed according to the shooting mode, the exposure value, and the like. The operation mode includes a monitor mode and a still mode. In monitor mode shooting, a frame rate and an electronic shutter speed at an open aperture value are set, and the CCD image is passed through the CCD drive circuit 13 at the frame rate and the electronic shutter speed. The sensor 11 is driven to capture an image, and the captured image is displayed on the monitor 44 via the image processing circuit 23. In the case of still mode shooting, the aperture / shutter unit 31 is driven with the shutter speed and aperture value obtained during monitor mode shooting, and the CCD image sensor 11 is driven via the CCD drive circuit 13 to take an image. The image data is written into the memory 43 via the image processing circuit 23. In monitor mode shooting, it is preferable to hold the focus lens group LF at the hyperfocal distance position or the pan focus position. In addition, when the portrait (portrait shooting) mode is selected as the shooting mode, it is preferable to hold it at a bust-up position described later.

  The camera further includes a strobe light emitting unit 41 and a strobe control circuit 39 as a built-in strobe. The strobe control circuit 39 controls charging and light emission to the main capacitor according to a command from the control unit 15. The control unit 15 and the strobe control circuit 39 constitute strobe control means. The control unit 15 also has a selection and control function related to strobe light emission, such as a function for selecting a strobe light emission mode for setting a strobe light emission method.

  This digital camera has a face image recognition function for detecting whether or not an image signal related to a face image is included in the image signal based on the image signal captured and output by the CCD image sensor 11. In this embodiment, the image processing circuit 23 performs face detection processing (face image recognition and image region extraction processing) using RAW data obtained by imaging with the CCD image sensor 11. Based on a predetermined program written in the flash ROM 15a, the control unit 15 detects a person's face (face recognition, face image detection), and an area including the face image, that is, a face image area. Face image recognition and face image area extraction processing include skin color detection in the entire image, detection of feature points such as eyes, nose, and mouth in a human face from the skin color area, or face contour extraction. Etc., according to a conventionally known face and face image recognition method.

  When face detection (face image detection) is performed by the image processing circuit 23, information regarding the center position and size of the face image is communicated to the focus control circuit 35 as the face image information.

  The AF function of this digital camera is based on the so-called image contrast method. The AF processing of this digital camera will be described with reference to FIG. As shown in the shooting screen 51 in FIG. 2A, it is assumed that the person A is located in the lower left, the person B is located in the center right, and the tree C is located in the upper left from the short distance side. In the figure, reference numeral 53f indicates a fixed focus frame, reference numeral 55a indicates a face image area of the person A, and reference numeral 55b indicates a face image area of the person B.

  The digital camera 10 performs face detection processing in the image processing circuit 23 while performing monitor mode imaging in a state where the focus lens group LF is stopped at the hyperfocal distance position. Here, it is assumed that faces are detected for person A and person B. The face image information detected by the image processing circuit 23 is communicated to the control unit 15. This face image information includes pixel information about the center position and size of the face image on the shooting screen. The control unit 15 selects the face image area at the closest distance from the size (height) of the face image area whose face has been detected. That is, the face image area having the highest height is selected. Then, the search range limitation is selected. In the preferred embodiment, the search range limitation means that in the focus search process, the search range is limited to a range including the approximate shooting distance obtained from the selected face image area, and when a contrast peak is detected by searching from a near position, This means that the search process is ended even if the search is not performed to a far position. When the search process is ended, the focus lens group LF is moved to the lens position where the peak is obtained.

  The search range limiting process described above is executed when the first switch SW1 is turned on. When the first switch SW1 is turned on, the control unit 15 sets the face image area at the nearest distance as a focus area. In this embodiment, the face image area 55a of the person A is set as the focus area. Then, the focus lens group LF is moved to a close position (closest focus position) via the focus control circuit 35 and the focus motor MF, and is taken while moving in the direction of the farthest focus position. (Focus image area) Focus detection processing by the image contrast method for detecting the contrast of the image data in 55a is started.

  When the contrast peak of the image data in the focus area (face image area) 55a is detected, the position of the focus lens group LF at the time when the peak is obtained is set as the in-focus position, and the focus lens group LF is located at that position. To finish the AF processing by the image contrast method.

  If face detection (face image detection) is not performed in monitor mode shooting, normal focus search processing is executed. The normal focus search process is a process for searching the image in the fixed focus area 53f by step-driving the focus lens group LF over the entire movable region from the near position to the far position (FIG. 2A, ( C)).

  Here, when face detection is not possible in monitor mode shooting, for example, there may be no person in the scene, but even if there is a person in the scene, the scene is dark or backlit. In some cases, the face of a person is too dark to be detected. According to the present invention, when face detection cannot be performed under the above-mentioned adverse conditions in monitor mode shooting, an environment in which face detection can be performed by strobe pre-light emission when the first switch SW1 is turned on is performed. It has a special feature. The configuration will be described with reference to FIGS.

  FIG. 3 is a graph showing the relationship between the shooting distance (distance to the subject) and the image signal level (luminance) when shooting with a strobe light so as to achieve proper exposure at the bust-up shooting distance. In this graph, the horizontal axis represents the shooting distance, and the vertical axis represents the image signal level. When the subject is a person, set the appropriate flash emission amount as the pre-emission amount at a distance (hereinafter referred to as “bust-up shooting distance”) that makes the person's upper body full of the shooting screen (bust-up). . Then, the flash is emitted with the pre-emission light quantity and photographed, and the face is detected from the photographed image.

  At the time of pre-flash shooting, the focus lens group LF is moved to the shooting distance d at which the person image is bust up at the current focal length f of the shooting lens block L. In this embodiment, the focus lens group LF is moved to a position where the upper body of a person (average adult male) is photographed fully up and down on the photographing screen 51. For example, when the focal length f of the photographing lens block L is 10 mm, the effective height h of the image sensor is 5 mm, and the height H of the upper body of the person is 500 mm, the focus lens group LF is moved to a position where the photographing distance d is 1000 mm. To do.

  This bust-up shooting distance is set within a shooting distance range in which an image signal level capable of detecting a face image is obtained in the pre-flash dimmable range of the strobe light emitting unit 41. When the photographing lens block L is a zoom lens, the bust-up photographing distance is set according to the set focal length f.

"Bust-up shooting distance"
FIG. 4 is a schematic diagram for obtaining a shooting distance d in a state of bust-up shooting, that is, when the upper body of the person is fully captured in the height (vertical) direction of the shooting screen. The shooting magnification m in the case of bust-up shooting can generally be approximated by the following equation depending on the proportion of the person in the screen.
Shooting magnification m = focal length f / shooting distance d
= Height of the image sensor h / maximum height H at which a person appears at a certain shooting distance
If the shooting magnification m can be set in advance, the bust-up shooting distance d is
d = f / m.

  In addition, the maximum height at which a person's upper body appears on the shooting screen at a certain shooting distance can be obtained by calculating backward from a preset average length of the face and a screen ratio that can be said to be bust-up. For example, the ratio between the average length of the face and the maximum height H of the subject captured at a certain shooting distance is set to 1: 2.5, and the average length of the face is set to about 20 cm. . The height H is 50 cm.

  The above parameters (shooting magnification m) are set in advance and written in the flash ROM 15a. Thus, since the focal length f is determined at the time of shooting, the bust-up bust-up shooting distance d is determined.

  When the photographing lens block L has a single focal length, the bust-up photographing distance is calculated in advance and written in the flash ROM 15a. When the photographic lens block L is a zoom lens, a configuration may be obtained by calculation based on the set focal length f. However, in the case of step zoom, the photographic distance that is bust up for each step focal length is calculated in advance. It is also possible to obtain the table data, write it in the flash ROM 15a, and read the shooting distance corresponding to the focal length set by the step zoom from the table data when necessary.

The features of the face detection AF process by the digital camera 10 will be described with reference to FIGS. In FIG.
Symbol d is the bust-up shooting distance,
Reference sign d1 is a distance range closer to the shortest distance of the first pre-light emission dimmable range,
Reference sign d2 is within the first pre-emission dimmable range but is closer to the distance range within the depth of field face detectable range,
Reference sign d3 is a face detectable range within the depth of field,
Reference sign d4 is within the first pre-flash dimmable range, but is a distance range farther than the in-depth-of-field face detectable range d3,
Reference sign d5 is a distance range farther than the first pre-emission dimmable range,
d1 + d2 + d3 + d4 = d5
It is.
The bust-up shooting distance d usually falls within the face detectable range d3 within the depth of field. The in-depth-of-field face detectable range d3 is a variable that varies depending on the focal length f, the aperture value, and the hyperfocal length.

Under the above conditions, the first pre-flash is photographed and face detection processing is executed based on the photographed image data.
The first pre-emission amount can be set to an emission amount that provides an appropriate output (appropriate exposure) at the hyperfocal distance.
Approximate distance = hyperfocal distance x (appropriate output / pre-flash output) ^1/2

  If the face cannot be detected during monitor mode shooting, the flash lens 41 is pre-flashed after moving the focus lens group LF to the bust-up shooting position, and a face image is detected from the obtained image data.

  Next, the face detection imaging operation of this digital camera will be described in detail with reference to the flowchart shown in FIG. FIG. 6 is a flowchart showing the main sequence of this digital camera. This main sequence is entered when the power switch is turned on.

"Main sequence"
When entering the main sequence, first, in step S101, initialization of software and hardware such as internal RAM, variables, and ports is executed.

  Next, the monitor is turned on (S103), monitor mode imaging is started, and a subject image is displayed (through display) on the monitor (S105). That is, the image sensor is driven by the monitor frame, and the image data output from the image sensor is converted into an image signal for monitor display and displayed on the monitor.

  It is detected whether or not a face image is included in the image data obtained by the monitor mode photographing (S107). Subsequently, it is checked whether or not the first switch (photometry switch) SW1 is turned on (S109), and if not turned on, the process returns to step S103 (S109: NO). When the first switch SW1 is on (S109: YES), the following processing is executed.

  A focus search range is determined according to the result of the face detection process in step S107 (S111), a focus search by the image contrast method is executed, and an AE calculation is executed (S113). Then, it is checked whether or not the first switch SW1 is turned on (S115). If it is not turned on, the process returns to step S103 (S115: NO, S103). If the first switch SW1 is on (S115: YES), it is checked whether the second switch (release switch) SW2 is on (S117). If not (S117: NO), the first switch The process returns to the check (S115) of whether SW1 is on.

  When the second switch SW2 is turned on (S117: YES), the image signal obtained by photographing with the exposure value set in step S113 is written in the flash memory in the set format (S119). If the power is not turned off (S121: YES), the process returns to step S103. If the power is off (S121: YES), the main flow is terminated. When this main flow is finished, a so-called standby mode is entered, and a check is repeated whether the power switch is turned on every predetermined time.

"Face detection discrimination & focus search range determination process"
Next, details of the face detection determination & focus search range determination process executed in step S111 will be described with reference to the flowchart shown in FIG.

  If this flowchart is entered, it is first checked whether or not a face has already been detected in the monitor mode (S201). If the face is detected (S201: YES), the process jumps to the focus search range limit setting (S221). If the face is not detected (S201: NO), the focus lens group LF is moved to the bus-up shooting distance. (S203).

  In the focus search range limited setting, the focus area is set to the face detection area corresponding to the nearest distance, the focus search is performed on the detected face, and when the contrast peak is detected, the focus search is stopped and the focus lens group LF is based on the contrast peak position. In this mode, the lens is moved to the in-focus position.

  When the focus lens group LF is moved to the bust-up shooting distance (S203), the strobe light emitting unit 41 is pre-flashed with the pre-flash amount, and the face is detected from the captured image data (S205). Whether or not a face has been detected is checked (S207). If a face can be detected (S207: YES), the process jumps to step S219, and if a face cannot be detected (S207: NO), the following processing is executed (S207: NO). S209 to S219).

  In step S209, it is checked whether or not the pre-light emission output is inappropriate. If the pre-light emission is not inappropriate (S209: NO), the search range is not limited (the search range is set to the entire range). (S221), AF processing is started.

If the pre-emission output is inappropriate (S209: YES), an approximate distance based on the pre-emission output is calculated (S211), the pre-emission amount and the focus position are recalculated (S213), and the recalculated focus position is set. The focus lens group LF is moved, the flash emission unit 41 is pre-flashed with the pre-flash amount, and the face is detected using the captured image data (S217).
Note that the approximate distance is the above-described formula,
Approximate distance = hyperfocal distance x (appropriate output / pre-flash output) ^1/2
However, the hyperfocal distance may be set.

  If the face can be detected (S217: YES), the search range is limited (S219), and AF processing is started. If the face cannot be detected (S217: NO), the search range is not limited (S221). Start.

"Pre-flash amount & focus position recalculation process"
The pre-emission amount & focus position recalculation process in step S213 will be described in detail with reference to the flowchart shown in FIG.
First, it is checked whether or not a face can be detected by the first pre-flash (S301). If a face can be detected, the process returns as it is (S301: YES, RET). Here, when the face can be detected, the person is usually located within the face detectable range d3 within the depth of field.

If the face cannot be detected (S301: NO), input the output data when the first pre-emission is made (input the flash emission light quantity data from the flash control circuit 39?) (S303) The first pre-emission quantity is the distance It is checked whether d1 is large enough to be saturated (S305). If the first pre-emission light amount is large enough to be saturated (S305: YES), a pre-emission amount smaller than the first time is set (S307), and the focus position closer to the first time (from the bust-up position). Set near side (S309) and return. For example, the pre-emission amount smaller than the first time is 1/8 times, and the focus position closer to the first time is d1. )
By the processes in steps S307: YES, S307, and S309, face detection is possible even when the person is closer than the bust-up shooting distance d, and the person can be focused. .

If it is not so large as to be saturated (S305: NO), it is checked whether the pre-emission amount is small (whether the brightness of the image data is low) (S311). If it is smaller (S311: YES), a pre-emission amount (for example, 8 times) larger than the first time is set (S313), a focus position d5 farther than the first time is set (S315), and the process returns.
Through the processes in steps S311: YES, S313, and S315 described above, even if a person is far away from the bust-up shooting distance d, the face can be detected and focused.

If it is not small (S311: NO), it is considered that the first pre-emission amount is appropriate and the subject is blurred at the bust-up position. That is, it is considered that the subject is located outside the face detectable range d3 within the depth of field. Therefore, a pre-emission amount that provides appropriate exposure is set at the approximate shooting distance obtained by the approximate distance calculation in step S211 (S317), the focus position at the approximate shooting distance is set (S319), and the process returns.
By the processes in steps S311: NO, S317, and S319 described above, even if a person is outside the face detectable range d3 within the depth of field, the face can be detected and focused.

  As described above, according to the embodiment of the present invention, when face detection cannot be performed during monitor mode shooting, the focus lens group LF is moved to the bust-up shooting distance, and the strobe flashing unit 41 is caused to emit light with a pre-flash amount. Since AF processing is performed on the detected face image after face detection, even if the face is dark or the face of the person is too dark to detect the face, the face is detected and detected. Can be focused.

  The pre-flash processing according to the present invention is preferably executed only when a specific shooting mode, for example, a portrait mode is set, and is not executed when another shooting mode is set. This is because, in cases other than the portrait mode, it can be assumed that there are many cases where a person is not photographed up or a person at a long distance is photographed.

It is a figure which shows the main structure of embodiment of the digital camera to which this invention is applied with a block. It is a figure explaining AF processing by the same digital camera, (A) is a figure explaining the relationship between an imaging | photography screen and a to-be-photographed object, (B) is a partial scan, (C) is a graph of the lens movement state in a whole scan. FIG. FIG. 6 is a graph illustrating the relationship between the shooting distance and the output of the image sensor when the strobe light is emitted so as to achieve proper exposure at the bust-up shooting distance in the digital camera. It is a figure explaining the relationship between a photographic lens and a to-be-photographed object in which a to-be-photographed object fills an image sensor. FIG. 3 is a diagram for explaining a relationship between a subject as a person and a distance in the digital camera. It is a figure which shows embodiment of the main sequence of the digital camera to which this invention is applied with a flowchart. It is a figure which shows the detail of embodiment of the face detection discrimination | determination & focus search range determination process performed in the main sequence with a flowchart. It is a figure which shows the detail of embodiment of the pre light emission amount & focus position recalculation process performed by face detection discrimination | determination & focus search range determination processing with a flowchart.

Explanation of symbols

11 CCD image sensor (imaging means)
13 CCD drive circuit 15 Control unit (control means, face detection means)
15a Flash ROM
15b RAM (image storage means)
17 Correlated Double Sampling Circuit (CDS)
19 A / D converter 21 RAW data circuit 23 Image processing circuit (DSP) (face detection means)
25 AE data processing circuit 31 Aperture / shutter unit 33 Aperture / shutter control circuit 35 Focus control circuit 37 Zoom control circuit 39 Strobe control circuit 41 Strobe light emitting unit 43 Memory 44 Monitor 51 Shooting screen 53f Fixed focus area 55a Focus area (face image area) )
55b Focus area (face image area)

Claims (6)

Shooting optical system including a focus adjustment optical system, imaging means, monitor for displaying images taken by the imaging means, strobe means, and monitor mode photography for displaying images taken by the imaging means at regular time intervals on the monitor And a focus search function for detecting a focus state based on the photographed image while the focus adjusting optical system is moved within a movable range from a near position to a far position while moving within the movable range. A focus adjustment means, and a face detection means for detecting a human face image from the monitor mode image,
When the face detection means detects a face image, the control means causes the focus detection means to set a region including the face image as a focus area and perform a focus search,
When the face detection means does not detect a face image, the focus adjustment optical system is moved to the focus adjustment means to the bust-up shooting distance, and the strobe means has a pre-flash that provides proper exposure at the bust-up shooting distance. The face detection means detects the person's face image from the captured image, and the focus detection means sets an area including the detected face image as a focus area. An imaging apparatus characterized by performing a focus search. 2. The imaging apparatus according to claim 1, wherein the control means determines whether or not the brightness of the photographed image is large enough to saturate when the face detection means cannot detect the face even when the pre-light emission is performed. If the pre-emission amount is smaller than the first pre-emission amount, the pre-emission amount is set, the focus adjustment optical system is moved closer to the bust-up position, and the strobe means is moved. An imaging device that performs pre-flash photography and detects the face by the face detection means. 3. The image pickup apparatus according to claim 2, wherein if it is determined that the brightness of the image photographed by the control means is not so high that the image is saturated, it is determined whether the brightness of the image is small. A pre-emission amount larger than the first pre-emission amount is set, the focus adjustment optical system is moved to the far side from the bust-up position, the strobe unit is pre-flashed, and the face is detected by the face detection unit. An imaging device to detect. 4. The imaging apparatus according to claim 3, wherein if it is not determined that the control means is small, a pre-emission amount that provides appropriate exposure at an overfocal distance is set, and the focus adjustment optical system is moved to the overfocal distance. An image pickup apparatus for picking up an image by pre-flashing the strobe and detecting the face by the face detecting means. 5. The imaging apparatus according to claim 1, wherein the focus detection unit performs a focus search from a near position when performing a focus search by setting the face image detected by the face detection unit as a focus area. 6. When the focus search is started and the focus search is terminated, the focus adjustment optical system is moved to the focus position, and when the face detection means does not detect the face image, the focus position is far from the near position. An imaging device that performs a focus search. 6. The imaging apparatus according to claim 1, wherein an imaging magnification for obtaining a bust-up imaging distance is set in advance, and the control means includes a focal length at the time of imaging and the preset imaging magnification. An imaging device that calculates a bust-up shooting distance from an image.

Images