JP2011217333A - Imaging apparatus and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that not only a cost increases when a sensor is loaded for tripod determination but also photographing is performed at a shutter speed not in consideration of a camera shake when fixed to a unipod or a tripod at an instable installation location, and while there is also an imaging apparatus which detects a camera shake amount using a motion vector obtained from video signals, there is the risk that it is not correctly determined whether or not to be fixed to a tripod in the state that a camera shake correction lens is mounted and lens camera shake correction sufficiently works.SOLUTION: When an imaging optical system includes a shake detection sensor, it is determined whether or not to be the state that the imaging apparatus is fixed to a tripod by output from the shake detection sensor. When the imaging optical system does not include the shake detection sensor, it is determined whether or not to be the state that the imaging apparatus is fixed to a tripod by a motion vector detected by a vector detection means.

Description

  The present invention relates to an imaging apparatus having a function of controlling Tv / Av / ISO / strobe with an appropriate value when shooting with a camera fixed to a tripod.

  Conventionally, when the subject is dark, it takes a long time to shoot, so it can be fixed on a tripod in consideration of camera shake, etc., the photographer can set the ISO sensitivity on the high sensitivity side, or open the aperture value of the lens. I was shooting. However, if the ISO sensitivity is increased, the higher the sensitivity, the easier the noise will be in the captured image, and the captured image will become rough, so there are cameras equipped with a noise reduction mode that removes noise components contained in the captured image. . However, when shooting in the noise reduction mode, there is a problem that the number of shots that can be taken decreases due to a decrease in resolution and an increase in image capacity. If the aperture of the lens is opened too much to reduce ISO sensitivity, the depth of field will be shallow and it will be difficult to take a picture that will focus on the background. In order to avoid these problems, Patent Document 1 automatically changes the ISO sensitivity when it detects that the camera is fixed to a tripod, and changes the shutter speed accordingly.

  In addition, as a technique for suppressing camera shake itself, for example, disclosed in Patent Document 2, camera shake correction is performed by detecting a motion of an imaging apparatus using a motion detection sensor or a motion vector obtained from a video signal, and shooting by camera shake or the like. There is a camera having a camera shake correction function for correcting image shake.

JP 2007-101860 A Special registration 4201809

  However, mounting a sensor for tripod determination not only increases the cost, but if it is fixed to a monopod or tripod in an unstable installation location, you can shoot at a shutter speed that does not consider camera shake. There was a case. In addition, when a tripod is attached to the lens, it is not determined as a tripod, and there is a possibility that a captured image with a lot of noise may be obtained with a high ISO setting.

  Another method is to detect the amount of camera shake using a motion vector obtained from the video signal, but when a camera shake correction lens is attached and the lens camera shake correction is fully effective, the tripod is fixed. There is a problem that the determination as to whether or not is not performed correctly.

  The present invention has been made paying attention to the above points. It is determined whether or not the camera is fixed to a tripod with a relatively inexpensive configuration, and Av / Tv / ISO / strobe is determined according to the scene analysis result. An object is to provide a high-quality image by controlling with an appropriate value.

  In order to solve the above-described problems and achieve the object, the present invention provides an imaging device that obtains a subject image by an imaging optical system, the imaging unit that captures the subject image, and a motion from the image captured by the imaging unit. Vector detection means for detecting a vector, a tripod determination unit for determining whether or not the imaging device is fixed to a tripod, and the imaging optical system includes at least one of a shake detection sensor and a correction optical system. A control unit that determines whether or not the image sensor has a shake detection sensor, and the tripod determination unit has a state in which the image pickup apparatus is fixed to a tripod by an output from the shake detection sensor. If the imaging optical system does not have a shake detection sensor, the imaging device is fixed to a tripod by the motion vector detected by the vector detection means. It has a feature that determines whether the state of being.

  As described above, since the possibility of camera shake is eliminated by fixing to a tripod, the shutter speed can be set to the low speed side. Therefore, even at the same brightness, the degree of freedom of exposure control is increased. For example, it is not necessary to squeeze to reduce the depth of field, to reduce noise, or to lower the ISO sensitivity or to not emit the strobe light. As a result, it is possible to provide a photographed image with less noise, in which the background is in focus, and the unnatural brightness of the strobe is suppressed.

It is sectional drawing which shows the structure of the camera which concerns on the form of a present Example. It is a block diagram which shows the internal structure of the camera which concerns on the form of a present Example. It is a figure regarding description of the motion vector which concerns on the form of a present Example. It is a figure regarding description of the face information detection which concerns on the form of a present Example. It is a flowchart which shows operation | movement of the camera which concerns on the form of a present Example. It is a flowchart which shows the detailed control of step S505 of FIG. 5 among operation | movement of the camera which concerns on the form of a present Example. It is a flowchart which shows the detailed control of FIG.5 S506 among operation | movement of the camera which concerns on the form of a present Example.

  FIG. 1 is a central sectional view of a single-lens reflex camera according to the present invention, and the configuration will be described below.

  An interchangeable lens 2 (lens portion) that can be attached to and detached from the camera 1 (main body portion) of FIG. 1 is fixed by a camera mount portion 5 and a lens mount portion (not shown), and a camera contact portion and a lens contact portion (not shown). The electrical connection is made by contact. Via this contact point, power supply from the camera 1 to the interchangeable lens 2 and communication for controlling the lens are performed. The light beam that has passed through the photographing lens 3 (imaging optical system) of the interchangeable lens 2 enters the main mirror 6 of the camera 1. The main mirror 6 is a half mirror, and the reflected light beam is guided to the finder, and the transmitted light beam is reflected downward by the sub mirror 7 and guided to the focus detection device 8. The focus detection device 8 detects the defocus amount of the photographic lens 3 and calculates a lens driving amount for driving the photographic lens 3 so that the photographic lens is in focus. When the lens driving amount is sent to the interchangeable lens 2 through the contact portion, the lens controls a motor (not shown) to drive the photographing lens 3 to adjust the focus. The diaphragm 4 controls the amount of light by changing the diameter of the diaphragm.

  The light beam guided to the finder by the main mirror 6 forms a subject image on the focus plate 9, and the photographer observes the subject image on the focus plate via the pentaprism 10 and the eyepiece 11. The The focus plate 9 is supported by a focus plate holder (not shown), and is configured so that it can be attached and detached as appropriate. The photometric lens 12 disposed above the rear part of the pentaprism 10 uses the subject image on the focusing plate 9 as a secondary light source and projects the reduced image on a photometric sensor (light receiving element) 13. The photometric lens 12 and the photometric sensor (light receiving element) 13 are known light receiving means for exposure.

  A shutter unit 14 is disposed behind the sub-mirror 7, and an optical filter 15 that integrates an optical low-pass filter and an infrared cut filter is further provided behind the shutter unit 14. At the time of shooting, the light beam that has passed through the optical filter 15 is incident on the image sensor 16 disposed further rearward than the optical filter 15. The image pickup device 16 is a two-dimensional image pickup device such as a CCD or a CMOS, and picks up a subject image formed by the photographing lens 3 and converts it into an electric signal. The image sensor 16 also has a so-called electronic shutter function (electronic shutter means) that controls the accumulation time (in shutter seconds) of charges accumulated in each photosensor. Reference numeral 17 denotes an image display monitor configured to display a captured image, a shooting menu, and the like. The tripod seat 18 is a mechanism for attaching a tripod or a monopod, and is, for example, a screw hole. The operation member 25 is, for example, a button, a dial switch, or a touch panel, and is disposed on the upper surface or the back surface of the imaging apparatus. In addition, it may consist of a plurality of types or a plurality of operation members. The operation member 25 can perform settings relating to shooting such as menu operation. In this embodiment, the main SW that is turned on / off by the main switch operation of the camera, an electronic dial that can switch the shooting mode, It has a release button for shooting. The release button performs photometry control and focusing control when SW1 is turned on by the first stroke, and the release operation is started when SW2 is turned on by the second stroke.

  FIG. 2 is a block diagram showing an internal configuration of the imaging apparatus of FIG. 1 according to the embodiment of the present invention.

  The camera 1 has a lens control unit 122 that controls the interchangeable lens 2 attached to the camera via a mount (not shown). The lens control unit 122 changes the size and position of the image formed on the image sensor 16 and the light amount of the optical image on the image sensor 16 by driving the photographing lens 3 and the diaphragm 4 through a lens I / F (not shown). . 2 includes a plurality of lenses including a shake detection sensor 151 as a shake detection unit and a shift lens 152 as a correction optical system for a camera shake correction function. The shake detection sensor 151 is an angular velocity sensor such as a gyro sensor or an acceleration sensor, for example. However, a single focal length (fixed focus) lens or a variable focal length lens may be used.

  The lens CPU 154 is a central processing unit that controls the interchangeable lens 2. The lens CPU 154 can communicate with the control unit 117 through the lens control unit 122 and the lens control unit 122 through a lens communication I / F (not shown) provided between the interchangeable lens 2 and the camera 1. In addition, a camera shake correction start command is issued from the control unit 117 or the lens control unit 122 in synchronization with half-press (SW1) ON of the release switch in the operation member 25, and camera shake is synchronized with half-press (SW1) OFF. A correction stop command is sent to the lens CPU 154. The lens CPU 154 monitors the state of a shake correction SW (switch) 153 provided in the interchangeable lens 2. If the shake correction SW 153 is ON, camera shake correction control is performed. If the shake correction SW 153 is OFF, the camera shake correction start command from the lens control unit 122 is ignored and no shake correction is performed.

  The subject image formed on the light receiving surface of the image sensor 16 by the optical system of the interchangeable lens 2 is converted into an amount of signal charge corresponding to the amount of incident light by each photosensor, and sequentially read out as an imaging output signal. Thereafter, the analog signal processing unit 101 is supplied.

  The analog signal processing unit 101 includes a CDS clamp circuit, a gain adjustment circuit, and the like, and appropriately processes an imaging output signal (analog electrical signal) input from the imaging device 16 based on control of the control unit 117. The signal output from the analog signal processing unit 101 is converted into a digital signal by the A / D converter 102 and then sent to the main signal processing unit 103.

  The main signal processing unit 103 includes a gain adjustment unit 104, an offset unit 105, a digital signal processing unit 106, a histogram generation unit 107, and the like. Data output from the A / D converter 102 is input to the gain adjustment unit 104 and the histogram generation unit 107.

  The histogram generation unit 107 generates a histogram indicating the distribution of the integrated value of the image sensor signal with respect to the signal level from the data for one screen sent from the A / D converter 102. Based on the histogram calculation of the histogram generation unit 107, the gain value changed by the gain adjustment unit 104 and the offset value changed by the offset unit 105 are determined and changed. Then, the signal that has passed through the gain adjustment unit 104 and the offset unit 105 is sent to the digital signal processing unit 106.

  The digital signal processing unit 106 includes a luminance (Y) signal generation circuit and a color difference (C) signal generation circuit, and performs Y / C signal processing on the signal input from the offset unit 105. The signal-processed image data is temporarily stored in the memory 108. The image data stored in the memory 108 is processed for various images, which will be described later, decoded, converted to an analog signal by a D / A converter 109, and displayed on an image display such as a liquid crystal monitor as an image display means. It is supplied to the monitor 17. Thus, the subject image formed on the image sensor 16 is displayed on the image display monitor 17 as an image or video. The signal converted into an analog signal by the D / A converter 109 can be output as an image from the external image output unit 111 such as a video output terminal.

  On the other hand, the image data stored in the memory 108 is guided to the recording control unit 112, where it is compressed according to a predetermined format (for example, JPEG) and recorded on the recording medium 114. Note that the recording medium can be in various forms such as a built-in memory or a smart media inserted in a memory slot (not shown) or an IC card. The image data recorded on the recording medium 114 can be called up via the control unit 117, and the called image data is decompressed and reproduced by the recording control unit 112, and then the memory 108, D / A conversion The image is output to the image display monitor 17 via the device 109. Alternatively, it is supplied to the external video output unit 111 and can be output to another external device.

  The control unit 117 is connected to each switch of the photometric sensor 13, the focus detection device 8, the main signal processing unit 103, the memory 108, the recording medium 114, and the operation member 25. Further, the face detection unit 161, the scaling unit 162, the motion vector calculation unit 163, the tripod determination unit 164, the image processing unit 165, the shake determination unit 166, and the scene determination unit 167 are connected. The output signal of the photometric sensor 13 is sent to the control unit 117, and the control unit 117 calculates an exposure control value indicating the exposure time. Then, based on the obtained exposure control value, the control unit 117 performs control such as automatic exposure control, autofocus, auto strobe, auto white balance, and overall control of the drive circuit of the image sensor 16. to manage. For example, in the electronic shutter control mode, the charge accumulation time of the image sensor 16 is controlled. In the mechanical shutter control mode, the opening / closing timing of the shutter unit 14 is controlled, and the aperture 4 is controlled during exposure through a lens communication I / F (not shown). To do. The control unit 117 controls a corresponding circuit based on various signals input from the operation member 25 such as a release button or a shooting mode selection button.

  The face detection unit 161 acquires information on the position and size of the face from the image data output from the memory 108 or the image processing unit 165. This facilitates detection of a subject that is a user's shooting target, and enables detection of the subject together with focusing information and the like. The scaling unit 162 performs scaling processing if scaling is necessary. The motion vector calculation unit 163 is for calculating a motion vector from the correlation between images. The direction and magnitude of the motion vector is detected directly from the temporally continuous image processing unit 165 or from two image data written in the memory 108 for each predetermined block. The tripod determination unit 164 detects whether or not the camera is fixed to a tripod.

  The image processing unit 165 performs image processing such as white balance, contrast correction, noise reduction, and sharpness on the captured image data once stored in the memory 108 based on parameters set in advance through the GUI. The shake determination unit 166 calculates a motion vector amount from the amount of camera shake based on the acquired lens information, or detects whether the lens is compatible with camera shake information. The scene determination unit 167 determines a scene such as portrait / landscape / sport / flower macro / snow / person + landscape / night view / night view + person / fireworks. Accordingly, appropriate Tv / Av / ISO / strobe control values are automatically set, and shooting according to the scene is possible. This scene may be selected by the user in the scene setting unit of the operation member 25, or the image processing unit 165, the face detection unit 161, the motion vector calculation unit 163, the histogram generation unit 107, the tripod determination unit 164, and the photometric sensor 13. Or from clock information (not shown).

<Motion vector detection>
FIG. 3 illustrates a description regarding a motion vector acquired by the motion vector calculation unit 163.

  The motion vector calculation unit 163 detects a motion vector from the image data, and calculates a motion vector between two images in each block as illustrated. First, a correlation calculation is performed by comparing the captured image with the previous image stored in the memory 108. Correlation calculation is performed, for example, according to a block matching method, in which an image area based on image data is divided into blocks of a predetermined size such as 7 pixels × 5 pixels as shown in FIG. 3, and the correlation calculation between the current field and the previous field is performed for each block. Do. Next, a motion vector for each block is detected from the correlation value calculated by the correlation calculation. Specifically, the block of the previous field that minimizes the correlation value is searched, and the relative shift is used as a motion vector.

  The detected motion vectors for each block are classified into groups based on the motion vector values. First, the supplied blocks are classified into groups based on respective motion vector values in the X direction (horizontal direction of the screen) and the Y direction (vertical direction of the screen). Next, a representative motion vector is obtained for each classified group. As the representative motion vector, for example, the class value of the class having the maximum frequency in the group when the histogram of the appearance frequency of the motion vector value is taken can be used. However, the present invention is not limited to this, and an average value of motion vector values detected in all vector detection regions belonging to a group can be used as a representative motion vector as a group.

  Using the representative motion vector for each group and the face detection information from the face detection unit 161, the control unit 117 calculates a motion vector (referred to as an overall motion vector) for the entire screen, that is, the entire image. The calculated overall motion vector can be subjected to camera shake correction (electronic camera shake correction) by controlling reading of image data stored in the memory 108 based on the overall motion vector.

  Now, (a) and (b) in FIGS. 3A to 3C are two images captured continuously in time, and (c) represents the calculated motion vector. (1, 1) to (7, 5) of (c) are indicated by arrows as movement amounts of the two images (a) and (b). By accessing the motion vector calculation unit 163, each of (1, 1) to (7, 5) as the motion vector amount calculated for each block can be acquired.

  FIG. 3A illustrates a state of a motion vector when a subject near the center is moving when there is almost no camera shake.

  FIG. 3B illustrates the state of the motion vector when the entire screen moves in the same direction due to camera shake in a state where the subject hardly moves and the depth of field is deep. As shown in FIG. 3B, when the motion vectors of most blocks on the screen are directed in substantially the same direction, it can be determined that camera shake has occurred.

  FIG. 3C illustrates the state of the motion vector when there is no camera shake and there is no movement in all blocks.

  FIG. 4 is an example illustrating information on the position and size of the face acquired from the face detection unit 161. By using the face recognition as shown in FIG. 4 together, it is easy to separate the moving subject, and the motion detection accuracy is improved by separately handling the moving body moving speed and the moving amount of the camera shake.

  The face detection unit 161 detects the center coordinates and radius of the face while reading image data output from the image processing unit 165 or image data read via the memory 108. In this embodiment, since the face area is circular, the center coordinates and radius of the face are detected. However, the face area may be elliptical, and if the face area is regarded as a rectangle, the coordinates of the four corners may be used. The coordinates of one vertex and the length of each side may be detected.

  By accessing the face detection unit 161, the number of detected faces and the center coordinates and radius of each face can be acquired. For example, from the image data in FIG. As a result of detection, the detection result of FIG. 4D can be obtained from the image data of FIG.

<Shooting flow>
The shooting flow of the camera 1 in the present embodiment will be described based on the flowchart of FIG.

  First, in step S501, the luminance of the subject image formed on the focusing screen (not shown) by the interchangeable lens 2 or the luminance of the image data output from the memory 108 or the image processing unit 165 is measured by the photometric sensor 13. . Next, the face detection unit 161 acquires information regarding the position and size of the face from the image data output from the memory 108 or the image processing unit 165 (step S502).

  In step 503, the motion vector calculation unit 163 detects the direction and magnitude of the motion vector for each predetermined block directly from the output of the image processing unit 165 at different consecutive times or from two image data written in the memory 108. Thus, moving object recognition information is acquired. That is, the motion vector calculation unit 163 also serves as a moving object recognition unit.

  In step S504, in addition to the photometric result obtained by the photometric sensor 13, the face recognition information obtained by the face detection unit 161, the moving object recognition information obtained in step 503, the histogram information obtained by the histogram generation unit 107, information such as color distribution information and photographing time. Perform scene determination. The scene determination is to determine what kind of scene the captured image is, for example, a scene such as portrait / landscape / sports / flower macro / snow / person + landscape / night view / night view + person / fireworks. . In step S505, mode determination is performed, and in S506, shooting control is performed. Details thereof will be described later with reference to FIGS.

  Thereafter, it is monitored whether or not the release button SW2 of the operation member 25 is turned on (step S507). When the release button is turned on, the photographing process is performed with the photographing control setting calculated in step S507 (step S507). Step S508). If shooting is completed in step S508, or if SW2 is not turned on in step S507, the process returns to step S501 again.

<Mode judgment>
Next, an example of mode determination in step S505 will be described based on the flowchart of FIG.

  First, in step S601, the control unit 117 acquires lens information of the interchangeable lens 2 attached to the camera 1 through a lens mount (not shown). In step S <b> 602, the shake determination unit 166 determines whether the camera shake information can be acquired based on the acquired lens information, that is, the interchangeable lens 2 includes the shake detection sensor 151. It is determined whether or not information can be communicated to the camera 1. When it is detected from the determination result in step S602 that the interchangeable lens 2 can acquire camera shake information, the process proceeds to step S603, and in the case of a non-compatible lens, the process proceeds to step S609.

  In the case of a camera shake information compatible lens, in step S603, the shake determination unit 166 acquires camera shake information from the shake detection sensor 151, and the tripod determination unit 164 acquires tripod information from the interchangeable lens 2. In step S604, the tripod determination unit 164 determines whether the camera 1 is fixed to a tripod based on information from the interchangeable lens 2. Incidentally, “fixed to a tripod” in the present embodiment means that a shake applied to the camera 1 or the interchangeable lens 2 is less than a predetermined value, and the tripod is not necessarily fixed. It is sufficient that the vibration is less than that of the hand-held state, and it is possible to detect whether it is placed on the ground or an object, or to fix the tripod if the hand-held state is extremely small. There is no problem to judge. The tripod determination may be any method using the amplitude and frequency of shake, for example, determining that the tripod is fixed to the tripod if the amplitude and frequency of shake are lower than a predetermined value for a predetermined time.

  If it is fixed to a tripod (Yes in step S604), in step S605, the control unit 117 determines the tripod fixing mode and switches to the exposure control table in the tripod fixing mode. Then, the mode determination ends. In the tripod fixing mode, camera shake correction is stopped. Here, the tripod fixing is determined based on the lens information, but it is determined that the tripod seat 18 of FIG. 1 has a sensor and a switch, and the tripod determination unit 164 is fixed to the tripod by detection from the sensor of the tripod seat 18. You may do it.

  If the determination result is non-tripod fixation (No in step S604), in step S606, the control unit 117 determines whether the interchangeable lens 2 is in-lens camera shake correction function effective. If the in-lens camera shake correction function is valid (Yes in step S606), it is determined as the camera shake correction mode, and in step S607, the control unit 117 switches to the exposure control table in the mode for camera shake correction. When the in-lens camera shake correction function is invalid (No in step S606), in step S608, the control unit 117 switches to the exposure control table in the non-camera shake correction mode, and ends the mode determination.

  If the lens is not compatible with camera shake information (No in step S602), in step S609, the control unit 117 determines whether the interchangeable lens 2 attached to the camera 1 has the in-lens camera shake correction function enabled. I do. That is, it is determined whether or not the interchangeable lens 2 has a shift lens 152 as an optical camera shake correction unit, and whether or not the camera shake correction function is currently valid.

  If the determination result in step S609 is that the in-lens camera shake correction function is valid (Yes in step S609), the control unit 117 cancels the lens camera shake correction mode in step S610. This is because when the shift lens 152 is driven in the interchangeable lens 2 based on the output of the shake detection sensor 151, the subject image acquired by the camera 1 becomes an image after shake correction, and the shake is correctly detected when the motion vector is acquired. This is because it cannot be detected. The canceling method can be performed by the control unit 117 communicating a shake correction cancel command to the lens CPU 154 through the lens communication I / F and setting the shake correction SW 153 to be shake correction OFF.

  In step S611, the motion vector calculation unit 163 calculates a motion vector amount from the correlation between the images for a predetermined period. In step S612, the tripod determination unit 164 determines whether the tripod is fixed from the calculation result of the motion vector amount. As a tripod determination method, for example, there is a method that uses the amplitude or frequency of the shake, for example, a method that determines that the shake amplitude and frequency are fixed to the tripod when a time lower than a predetermined value is continued for a predetermined time. . If it is determined that the tripod is fixed (Yes in step S612), the control unit 117 switches to the exposure control table in the tripod fixing mode (step S613) and ends the mode determination. In the tripod fixing mode, camera shake correction is stopped. In this embodiment, when it is determined that the tripod is fixed, the camera shake correction remains OFF even after the tripod mode is determined in order to prevent battery consumption and image quality deterioration. The correction mode may be returned to ON.

  In step S614, when it is determined that the tripod is not fixed (No in step S612), the control unit 117 returns the lens camera shake correction mode to ON. In step S615, the exposure control table is switched to the camera shake correction mode, and the mode determination is terminated.

  When the camera shake correction function in the lens is invalid, that is, when the shake correction SW 153 of the interchangeable lens 2 is OFF, when the information of the shake detection sensor 151 cannot be acquired, the interchangeable lens 2 has both the shake detection sensor 151 and the shift lens 152. If not, the process of step S616 is performed. In step S616, the motion vector calculation unit 163 calculates a motion vector amount from the correlation between images. In step S617, the tripod determination unit 164 determines whether the tripod is fixed from the calculation result of the motion vector amount. As a tripod determination method, for example, there is a method that uses the amplitude or frequency of the shake, for example, a method that determines that the shake amplitude and frequency are fixed to the tripod when a time lower than a predetermined value is continued for a predetermined time. . If it is determined that the tripod is fixed (Yes in step S617), in step S618, the control unit 117 switches to the exposure control table in the tripod fixing mode. If it is determined that the tripod is not fixed (No in step S617), in step S619, the control unit 117 switches to the exposure control table when the camera shake correction mode is not set, and ends the mode determination.

<Shooting preparation control after mode judgment>
Next, the flow of shooting preparation control in step S506 will be described based on the flowchart of FIG.

  First, in step S701, the mode determination result in step S505 is referred to. If the tripod mode is set in the mode determination in step S505, the tripod fixed mode exposure control table is read in step S702. In the camera shake correction mode, the camera shake correction mode exposure control table is read in step S703. In the camera shake non-correction mode, the camera shake non-correction mode exposure control table is read in step S704. Hereinafter, photographing control in each mode will be described.

  First, in the tripod mode, it is determined in step S705 whether or not a moving object exists using the moving object recognition result in step S503. If there is no moving object as a result of the moving object recognition in step S503 (No in step S705), the moving object speed is set to zero from the tripod fixed mode exposure control table in step S706, and the result obtained by the scene recognition in step S504 is set. The lower limit Tv value is selected. On the other hand, if a moving object exists as a result of the moving object recognition in step S503 (Yes in step S705), the moving object speed for each block is detected from the amount of movement between frames in step S707. For example, when calculating from the movement amount of two images taken at 60 FPS (60 frames per second), the interval between frames is about 16 msec, and if no moving block is found between them, the shutter speed is about 1/16. Will be acceptable. Here, when the moving amount (motion vector) of the image at 60 FPS is equivalent to 4 pixels of the image sensor, the shutter speed is equivalent to 4 pixels at 1/15, 1 pixel at 1/60, and 0 at 1/250. .Equivalent to 24 pixels. Therefore, the higher the shutter speed, the less influence the shake has on the image.

  In step S708, conditions such as the total number of pixels of the image sensor, the shooting scene, and whether the main subject is moving are added, and the lower limit Tv value of the moving object that does not affect the shot image is calculated. In step S709, the shutter speed is calculated from the tripod fixed mode exposure control table by selecting the moving body speed + the lower limit Tv value corresponding to the result obtained by the scene recognition in step S504.

  In the case of the camera shake correction mode or the camera shake non-correction mode, it is determined in step S710 whether or not a moving object exists from the moving object recognition result in step S503. If there is no moving object (No in step S710), in step S711, the motion vector calculation unit 163 calculates the amount of movement for each block from the correlation of the images, and calculates the amount of camera shake from the amount of motion vector. . In step S712, the control unit 117 adds the total number of pixels of the image sensor, the shooting scene, the angle of view, the subject distance, and the amount of camera shake, and calculates the lower limit Tv value due to camera shake that does not affect the captured image. . In step S713, the control unit 117 sets the moving body speed to zero from the camera shake correction / camera non-correction mode exposure control table, and in addition, the lower limit Tv value corresponding to the result obtained by the scene recognition in step S504. Make a selection and calculate the shutter speed.

  On the other hand, when a moving body exists in step S710, the motion vector calculation part 163 detects the moving body speed for every block from the moving amount | distance between frames in step S714. In step S715, the control unit 117 adds conditions such as the total number of pixels of the image sensor, the shooting scene, and whether the main subject is moving, and calculates a lower limit Tv value of the moving object that does not affect the shot image. The shutter speed is calculated. In step S716, the motion vector calculation unit 163 calculates a movement amount for each block from the correlation between the images, and calculates a camera shake amount from the motion vector amount. In step S717, the control unit 117 adds the total number of pixels of the image sensor, the shooting scene, the angle of view, the subject distance, and the amount of camera shake, and calculates a lower limit Tv value due to camera shake that does not affect the captured image.

  In step S718, the lower limit Tv value due to moving objects obtained in steps S715 and S717 is compared with the lower limit Tv value due to camera shake. However, although the Tv values are compared here, the shutter speeds may be compared. If the lower limit Tv value due to the moving object is faster, the process proceeds to step S719, and if the lower limit Tv value due to camera shake is faster, the process proceeds to step S713. In step S719, the control unit 117 selects the lower limit Tv value by the moving object according to the moving object speed and the result obtained by the scene recognition in step S504, from the camera shake correction / camera non-correction mode exposure control table.

  When the lower limit Tv value is selected in each of steps S706, 709, 713, and 719, in step S720, the control unit 117 determines an appropriate Tv / Av / ISO / strobe control value from the scene recognition result and the lower limit Tv value. Is calculated. When the process of step S720 ends, the process of step S505 ends.

In the present embodiment, for example, as an example of shooting a night scene without a moving object with a 50 mm lens attached,
For lenses that do not support image stabilization,
ISO3200, Av5.6, Tv1 / 60 seconds, no strobe,
In the case of lens for camera shake revision,
ISO 800, Av 5.6, Tv 1/15 seconds, no strobe,
When using a tripod,
ISO 200, Av 5.6, Tv 1/4 sec, no ISO effect such as no strobe, the effect of noise is reduced, exposure can be controlled according to the judgment result, and an appropriate image according to the scene can be obtained it can.

  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.

4 Aperture 14 Shutter

Claims (5)

An imaging device for obtaining a subject image by an imaging optical system,
Imaging means for imaging the subject image;
Vector detection means for detecting a motion vector from an image captured by the imaging means;
A tripod determination unit for determining whether or not the imaging device is fixed to a tripod;
A controller that determines whether or not the imaging optical system has at least one of a shake detection sensor and a correction optical system;
When the imaging optical system includes a shake detection sensor, the tripod determination unit determines whether the imaging device is fixed to a tripod based on an output from the shake detection sensor, and the imaging optical system An imaging apparatus characterized by determining whether or not the imaging apparatus is fixed to a tripod based on a motion vector detected by the vector detection means when no shake detection sensor is provided. The control unit further controls whether or not to perform camera shake correction by the imaging optical system when the imaging optical system has a correction optical system,
The control unit determines whether or not the tripod determination unit is fixed to the tripod when the imaging optical system does not have a shake detection sensor and the imaging optical system has a correction optical system. The image pickup apparatus according to claim 1, wherein control is performed so that camera shake correction by the correction optical system is not performed during the period.   3. The control unit according to claim 1, wherein when the tripod determination unit determines that the imaging apparatus is fixed to a tripod, the control unit stops camera shake correction by the correction optical system. The imaging device described. A scene setting unit that changes at least the shutter speed according to the scene to be imaged;
A moving object recognizing unit for recognizing whether there is a moving object moving relative to the imaging device in the captured image;
The control unit sets a shutter speed based on the speed of the moving body when the imaging device is fixed to a tripod, and when the moving body recognition unit recognizes that the moving body exists, the moving body 4. The imaging device according to claim 1, wherein the shutter speed is set based on a setting by the scene setting unit when it is recognized that there is no image. A control method for an image pickup apparatus having an image pickup means for picking up a subject image formed by an image pickup optical system,
A vector detection step of detecting a motion vector from an image captured by the imaging means;
A tripod determination step for determining whether or not the imaging device is fixed to a tripod;
A control step for determining whether the imaging optical system has at least one of a shake detection sensor and a correction optical system,
When the imaging optical system has a shake detection sensor, the tripod determination step determines whether the imaging device is fixed to a tripod based on an output from the shake detection sensor, and the imaging optical system A method for controlling an imaging apparatus, comprising: determining whether or not the imaging apparatus is fixed to a tripod based on a motion vector detected in the vector detection step when no shake detection sensor is provided.

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