JP2010250156A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic camera which takes an optical image at shutter speed and in imaging timing suitable for panning. <P>SOLUTION: The electronic camera includes: an imaging unit; a decision unit that detects an image area having an image surface moving amount different from an image surface moving amount generated by movement of the electronic camera in an imaging screen based on a camera moving amount and an image surface moving amount as a subject image area, and decides whether the image surface moving amount of the detected subject image area follows the camera moving amount; and a control signal generation unit that generates a first control signal for allowing the imaging unit to perform imaging in first exposure time if the decision unit decides that the image surface moving amount follows the camera moving amount, and generates a second control signal for allowing the imaging unit to perform imaging in second exposure time shorter than the first exposure time if the decision unit decides that the image surface moving amount does not follow the camera moving amount, and then outputs the first control signal and the second control signal to the imaging unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic camera.

Conventionally, there is a method called panning as one of the methods for taking a photograph. When taking a picture taking advantage of the effect of panning, it is necessary for the electronic camera to take an object that moves at high speed while focusing on the object and securing a longer exposure time than usual. As a result, it is possible to capture a photograph in which a subject other than the subject is blurred and the subject is clear.
For example, there is a technique that secures an exposure time suitable for panning by calculating a shutter speed from the moving speed of an electronic camera (see Patent Document 1).

JP-A-5-232562

  However, when the electronic camera cannot follow the movement of the subject, both the subject and the background are blurred, and there is a problem that an unclear photograph is taken. For example, this is because the imaging timing of the electronic camera is turned on in a state that does not correspond to the movement of the electronic camera and the subject, so that the subject is exposed while moving.

  The present invention has been made in consideration of such circumstances and has been made to solve the above-described problems, and an object thereof is to provide an electronic camera that captures an optical image at a shutter speed and imaging timing suitable for panning. There is to do.

In order to solve the above problems, an electronic camera according to the present invention forms an optical image by an optical system on an image sensor and generates an image signal based on the optical image, and an electronic device including the imaging unit. A detection unit that detects a camera movement amount of a camera; an analysis unit that calculates an image plane movement amount of an image in an imaging screen of the image signal based on the camera movement amount detected by the detection unit; and the detection unit The image plane movement amount that is different from the image plane movement amount caused by the movement of the electronic camera within the imaging screen is calculated based on the camera movement amount detected by the analysis unit and the image plane movement amount calculated by the analysis unit. A determination unit that detects an image area having the detected image area as a subject image area, and determines whether the detected image plane movement amount of the subject image area follows the camera movement amount; First control for causing the imaging unit to capture the optical image in a first exposure time when the determination unit determines that the image plane movement amount of the subject image area follows the camera movement amount. A signal is generated, and when the determination unit determines that the image plane movement amount of the subject image area does not follow the camera movement amount, the second exposure time is shorter than the first exposure time. And a control signal generation unit that generates a second control signal for causing the imaging unit to capture the optical image.

  According to the present invention, it is possible to realize panning for clearly capturing an image of a subject.

It is a block diagram which shows an example of a structure of the electronic camera by one Embodiment of this invention. It is the schematic for demonstrating the condition where a panning is taken with the electronic camera by one Embodiment of this invention. It is a figure which shows an example of the continuous image imaged with the electronic camera by one Embodiment of this invention. It is a figure which shows an example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is a figure which shows the other example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is a figure which shows the other example of the continuous image imaged with the electronic camera by one Embodiment of this invention. It is a figure which shows the other example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is a flowchart which shows the operation example of the automatic imaging | photography process by the electronic camera by one Embodiment of this invention. It is a flowchart which shows the operation example of the automatic imaging | photography process by the electronic camera by one Embodiment of this invention. It is a figure which shows the other example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is the schematic for demonstrating the movement amount of the electronic camera by one Embodiment of this invention. It is a figure which shows the other example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is a figure which shows the other example of the relationship between the continuous image imaged with the electronic camera by one Embodiment of this invention, and the to-be-photographed object in the said image. It is a figure which shows the other example of the continuous image imaged with the electronic camera by one Embodiment of this invention.

  FIG. 1 is a block diagram illustrating a configuration of an electronic camera 100 according to the present embodiment. The electronic camera 100 includes an imaging unit 10, a nonvolatile memory 11, a buffer memory 12, an operation detection circuit 13, a monitor control circuit 14, a monitor 15, a memory control circuit 16, a memory 17, and a control unit 20.

The imaging unit 10 includes an optical system 1, an angular velocity sensor (detection unit) 2, an optical system control circuit 3, an image sensor control circuit 7, an image sensor 8, and a video circuit 9. Output a signal.
The optical system 1 opens and closes an optical element that corrects exposure to the image sensor 8, for example, a focus lens that has a function of adjusting the focus, an anti-shake lens that has a function of correcting image shake due to camera shake, and a shutter. And a shutter having a function of adjusting the exposure time.
The angular velocity sensor 2 detects a movement amount (camera movement amount) including the movement speed and movement direction of the electronic camera 100. In addition, as shown in FIG. 2, when the electronic camera 100 that images the automobile A traveling from the point P toward the point Q is moved following the movement of the automobile A, the angular velocity sensor 2 is connected to the electronic camera 100. The pan direction and pan angle θ are detected. Here, the pan direction refers to a position fixed by the photographer, for example, from a point P as shown in FIG. 2 by swinging the direction of the electronic camera 100 (direction in which the optical system 1 is directed) in a certain direction. The direction in which the direction of the optical system 1 of the electronic camera 100 is changed in accordance with the subject (car A) moving toward the point Q. The pan angle θ is an angle at which the orientation of the electronic camera 100 can be changed with the imager as the center when panning in the pan direction, and the orientation of the electronic camera 100 before the panned electronic camera 100 is moved. It is an angle between the direction of the electronic camera 100 after movement.

As shown in FIG. 11, the angular velocity sensor 2 detects the vertical movement X (referred to as pitching) and the horizontal rotational movement Y (referred to as yawing) of the electronic camera 100. Further, as shown in FIG. 2, the pan angle θ is generally 90 ° at most, and the vehicle A coming toward the electronic camera 100 is imaged from the front at 0 ° and passes at 45 °. The side of the automobile A is imaged, and the rear of the automobile A that passes by at 90 ° is imaged. Therefore, in order to avoid taking an image of the rear of the automobile A passing by, the pan angle θ is preferably 45 ° or less, for example.
Further, the angular velocity sensor 2 detects a movement amount of the electronic camera 100 that represents that the electronic camera is in a stopped state based on the detected angular velocity.

The optical system control circuit 3 includes an imaging control circuit 31 and a camera shake correction drive circuit 32.
The imaging control circuit 31 automatically adjusts the exposure by controlling the focus lens to automatically adjust the focus (hereinafter referred to as AF), the shutter control function for controlling the opening and closing of the shutter, and the aperture. The AE (Automatic Exposure) control function is provided, and the optical system 1 is driven in accordance with a control signal from the control unit 20 to correct exposure to the image sensor 8. Further, the imaging control circuit 31 uses the shutter control function to open the shutter at the imaging timing corresponding to the control signal output from the control unit 20, for example, and after the shutter speed corresponding to the control signal has elapsed. Control to close the shutter. Here, the shutter speed corresponds to the time from when the shutter is opened and the exposure time for capturing a single image elapses until the shutter is closed. If the exposure time is short, the speed is high. The longer the exposure time, the slower the speed.

The camera shake correction drive circuit (optical system correction unit) 32 controls the camera shake prevention lens according to the camera shake correction value calculated by the control unit 20 based on the angular velocity detected by the angular velocity sensor 2. The optical axis shift of the optical image formed on the optical image 8 is corrected. For example, the camera shake correction drive circuit 32 moves the camera shake prevention lens according to the moving amount (blur amount) of the camera calculated based on the angular velocity detected by the angular velocity sensor 2, and transmits light from the subject to the image sensor 8. An image is formed at an appropriate position on the light receiving surface.
Further, when the VR panning mode is set, the camera shake correction drive circuit 32 does not perform camera shake correction in the pan direction of the electronic camera 100 and corrects camera shake in directions other than the pan direction. When the VR normal mode is set, the camera shake correction is performed for all movement directions of the electronic camera 100. Note that the camera shake correction drive circuit 32 does not control camera shake correction when camera shake correction is not set.
Note that the camera shake correction control according to the VR panning mode by the camera shake correction drive circuit 32 is the same as the camera shake correction method used in a general electronic camera capable of panning. The technique described in Japanese Patent Laid-Open No. 5-216104 can be used.

The image pickup device 8 is a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like, and has a light receiving surface on which an optical image exposed from the optical system 1 is formed. It converts to an electrical signal and outputs an analog image signal. Further, the image sensor 8 outputs a captured image signal based on an optical image incident when the shutter is released by the imaging control circuit 31, and outputs a through image signal based on the optical image incident before the shutter is released. .
The video circuit 9 amplifies the image signal output from the image sensor 8 and converts it into a digital signal.
The image sensor control circuit 7 drives the image sensor 8 and controls operations such as conversion of an optical image formed on the image sensor 8 into an image signal and output of the converted image signal. For example, the image sensor control circuit 7 controls the exposure time for forming an optical image on the image sensor 8 with the exposure time based on the control signal input from the control unit 20 or the image sensor 8 at intervals of a fixed time t. A through image generation control for generating a plurality of through image signals is performed. Note that the interval of the fixed time t is, for example, 1/60 seconds.

The nonvolatile memory 11 stores a program for operating the control unit 20 and information such as various settings and imaging conditions input by the user. The non-volatile memory 11 includes, for example, information on camera shake correction values in the VR panning mode, information on camera shake correction values in the VR normal mode, presence / absence of normal shooting mode setting for shooting under normal shooting conditions, presence / absence of setting of the panning mode, In addition, information indicating that the automatic release setting is valid or invalid, information indicating that the automatic release setting is valid, and a condition value when the automatic release setting is valid are stored as the panning mode setting information. The VR panning mode is a camera shake correction that is used when the control signal generation unit 25 generates a correction control signal to be output to the camera shake correction drive circuit 32 when the panning mode setting is enabled. This is a setting in which information related to values is stored, and the panning mode setting information refers to information related to these. On the other hand, the VR normal mode is a camera shake correction value used when the control signal generator 25 generates a correction control signal to be output to the camera shake correction drive circuit 32 when the normal shooting mode setting is valid. This is a setting in which information related to is stored.
The buffer memory 12 is a temporary information storage area used for the control processing of the control unit 20, for example, a through image signal output from the image sensor 8 or a captured image signal image-processed by the control unit 20. Etc. are temporarily stored by the control unit 20.

The operation detection circuit 13 includes input units such as a power switch 13a, a release switch 13b,... 13n, and outputs operation information input by the user to the input unit to the control unit 20 as a control signal. In addition, the operation detection circuit 13 is configured to perform automatic release setting (for example, a setting for controlling the imaging control circuit 13 so as to release the shutter at the imaging timing determined by the control unit 20 after the release switch 13b is pressed by the user and capturing an image. ) And the input automatic release setting is stored in the nonvolatile memory 11 by the control unit 20.
For example, the monitor control circuit 14 performs display control such as turning on / off of the monitor 15 and brightness adjustment, and processing for displaying the image signal image-processed by the control unit 20 on the monitor 15. The monitor 15 is a display that displays an image according to an image signal, and is a liquid crystal display such as an LCD (Liquid Crystal Display).

The memory control circuit 16 controls input / output of information between the control unit 20 and the memory 17. For example, the memory control circuit 16 stores the image signal image-processed by the control unit 20 in the memory 17 or is stored in the memory 17. A process of reading information such as an image signal and outputting the information to the control unit 20 is performed.
The memory 17 is a storage medium that can be inserted into and removed from the electronic camera 100 such as a memory card, for example, and stores an image signal subjected to image processing by the control unit 20.

The control unit 20 is a microcomputer, a CPU (Central Processing Unit), or the like that controls the operation of each unit of the electronic camera 100 based on a program stored in the nonvolatile memory 11.
For example, the control unit 20 turns on the power to the electronic camera 100 according to operation information from the user input to the operation detection circuit 13, drive control of the optical system 1 via the optical system control circuit 3, image sensor The drive control of the image sensor 8 via the control circuit 7 and the display control of the monitor 15 via the monitor control circuit 14 are performed. The control unit 20 includes an image processing unit 21, a live view output unit 22, an analysis unit 23, a determination unit 24, and a control signal generation unit 25.

The image processing unit 21 performs image processing on the image signals (captured image signal and through image signal) output from the image sensor 8 to the video circuit 9. For example, the image processing unit 21 performs image processing on the through image signal so as to be displayed on the monitor 15 as a moving image, and stores it in the buffer memory 12.
The live view output unit 22 reads the live view image signal stored in the buffer memory 12 and subjected to image processing by the image processing unit 21, and outputs it to the monitor 15 in real time.

  The analysis unit 23 analyzes a plurality of through image signals input to the control unit 20 based on the movement amount of the electronic camera 100 detected by the angular velocity sensor 2, and moves the images of each through image signal in the imaging screen. The amount (image plane movement amount) is detected. For example, the analysis unit 23 moves and moves the image in the imaging screen based on a difference between two through image signals having continuous imaging timings among the plurality of through image signals input to the control unit 20. A motion vector corresponding to is calculated.

  The determination unit 24 calculates a movement amount different from the movement amount in the imaging screen caused by the movement amount of the electronic camera 100 detected by the angular velocity sensor 2 based on the movement amount of the image in the imaging screen calculated by the analysis unit 23. The detected image area is detected as a target object image (object image area). For example, the determination unit 24 is based on the motion vector calculated from the through image signal and the pan direction of the electronic camera 100 detected by the angular velocity sensor 2, and the motion different from the motion vector in the imaging screen caused by the movement of the electronic camera 100. An image area having a vector is detected as a target subject image.

  Here, an example in which the determination unit 24 detects the automobile A as a target subject image will be described in detail with reference to FIGS. FIG. 3 shows a plurality of through image signals generated by the image sensor 8 when the electronic camera 100 is panned following the movement of the automobile A traveling from the point P toward the point Q as shown in FIG. It is the schematic which shows the some through images D1-D5 based, the picked-up image D6 based on the image pick-up image imaged with the electronic camera 100, etc. FIG. The difference image DD45 is a schematic diagram for explaining a difference between the through image signals of the through images D4 and D5 calculated by the determination unit 24. The through images D1 to D5, the captured image D6, and the difference image DD45 are live view images displayed on the monitor 15, and the screen L side is in the direction of the point P at the rear end of the car A, and the screen R side is the car A. The point Q direction at the tip of Here, the imaging screen means an image plane based on an image signal generated by the imaging element 8 and corresponds to a live view image.

As shown in FIG. 3, the plurality of through images D1 to D5 are captured in time series, and the through image D1 is captured first, and the through image D5 is captured last. Comparing the through images D1 to D3, the tip of the car A traveling in the direction of the point Q moves from the L side to the R side in the imaging screen, and the coordinate position of the car A in the imaging screen is N1 to N3. It has changed. Further, when the through images D3 to D4 are compared, the tip of the automobile A does not change in the imaging screen and remains at the coordinate position N3 in the imaging screen. This indicates that the car A is a target subject image having a motion vector different from the motion vector in the imaging screen caused by the panning of the electronic camera 100. In the through image D3, the electronic camera moves to the movement of the car A. It means that 100 pans have followed.
On the other hand, when the house B in the background of the car A compares the through images D1 to D5, the top of the roof moves from the R side, which is the opposite direction to the car A, to the L side in the image pickup screen. The coordinate position inside is changed to M1 to M5. Therefore, the house B is an image area having a motion vector in the imaging screen caused by panning of the electronic camera 100, which means that the house B is not a target subject image. The difference image DD45 shows the car A at a certain position and the house B moving within the imaging screen, and the house B is the amount of movement α (indicated by the coordinate position M5-M4). It moves within the imaging screen.

FIG. 4 is a diagram illustrating a position change in the imaging screen of the automobile A in the plurality of through images D1 to D5 illustrated in FIG. The horizontal axis in FIG. 4 represents time, the vertical axis represents the screen position (LR) of the through image, and the black line for each frame represents the car A in the imaging screen.
As described above, the vehicle A shown in FIG. 4 moves from the L side to the R side in the same direction as the pan direction of the electronic camera 100 in the through images D1 to D3. Since the pan of the electronic camera 100 follows the movement of the automobile A, a change in the movement amount of the automobile A is reduced.
For example, the determination unit 24 detects a subject that moves in the imaging screen in a direction different from the movement that occurs in the imaging screen due to the movement of the electronic camera 100, and the movement amount of the subject is within a certain range in the imaging screen. If S1, the subject is recognized as the target subject image (see FIG. 4). For example, when the pan angle θ of the electronic camera 100 is smaller than a certain threshold, the determination unit 24 detects a subject that moves in the imaging screen in a direction different from the movement that occurs in the imaging screen due to the movement of the electronic camera 100. Even if the movement amount of the subject is not within a certain range S1 in the imaging screen, the subject may be recognized as the target subject image (see FIG. 7).

Further, when the determination unit 24 detects the target subject image, the movement of the electronic camera 100 follows the movement of the target subject image in the image plane based on the motion vector of the target subject image calculated by the analysis unit 23. Determine whether or not. For example, the determination unit 24 determines whether or not the target subject image is continuously detected for a certain time T1 or longer (first determination). The determination unit 24 determines that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane when the target subject image is continuously detected for a certain time T1 or more, and the imaging timing. Judge that.
On the other hand, when the determination unit 24 does not detect the target subject image continuously for a certain time T1 (for example, for 10 frames) or more, whether or not the movement amount of the electronic camera 100 detected by the angular velocity sensor 2 is a certain value or more. Is determined (second determination). For example, the determination unit 24 determines whether or not the pan angle θ detected by the angular velocity sensor 2 is equal to or greater than a certain threshold (for example, 30 °). Here, FIG. 5 is a diagram for explaining the second determination of the determination unit 24, and shows the relationship between the position of the detected target subject image (car A) in the imaging screen and the pan angle θ.

As shown in FIG. 5, when the pan angle θ detected by the angular velocity sensor 2 is equal to or greater than a threshold value (30 °), the determination unit 24 has not detected the target subject image continuously for a certain time T1 or more. However, it is determined that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane, and it is determined that it is an imaging timing.
In addition, based on the motion vector in the image plane calculated by the analysis unit 23, the determination unit 24 determines that the movement of the target subject image is within a certain range S1 in the image plane for a certain time or longer. It is determined that the movement follows the movement of the target subject image in the image plane, and it is determined that it is an imaging timing.
When the determination unit 24 determines that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane, the determination unit 24 validates the automatic release setting in the panning mode setting information of the nonvolatile memory 11.

  When the determination unit 24 detects the target subject image based on the amount of movement of the subject in the imaging screen calculated by the analysis unit 23, the determination unit 24 calculates the time until the target subject image protrudes from the imaging screen. It is determined whether or not an optical image including the target subject image can be captured with the high-speed shutter before the subject image protrudes from the imaging screen (third determination). Here, the third determination of the determination unit 24 will be described with reference to FIGS. FIG. 6 shows an imaging device when the electronic camera 100 is panned while following the movement of the automobile A as the automobile A passing through the electronic camera 100 approaching from the direction far from the electronic camera 100 (the back side of the imaging screen). 8 is a schematic diagram showing a plurality of through images D11 to D15 based on a plurality of through image signals generated by No. 8, and a screen D10 showing an imaging situation indicating a situation of a subject imaged as these through images. FIG. 7 is a diagram showing a change in position in the imaging screen of the car A in the plurality of through images shown in FIG.

For example, as illustrated in FIG. 6, when the pan angle θ of the electronic camera 100 is smaller than a certain threshold, the determination unit 24 indicates that a certain motion vector (for example, less movement in the imaging screen) is present in the imaging screen. An image region having a motion vector within a certain range) is recognized as a certain subject and the vehicle A is detected. The determination unit 24 is based on the movement amount of the electronic camera 100 detected by the angular velocity sensor 2 and the motion vector in the imaging screen calculated by the analysis unit 23, and a direction different from the direction represented by the motion vector generated by the pan of the electronic camera 100. A vehicle A having a motion vector of is detected as a target subject image.
Further, when the determination unit 24 detects the car A as a target subject image, the determination unit 24 determines whether or not the detected car A gradually increases in the imaging screen, and detects the gradually increasing target subject image. In this case, a third determination is made as to whether or not the target subject image deviates from the imaging screen (hereinafter referred to as a predicted shot). For example, as shown in FIG. 7, the determination unit 24 detects the size of the target subject image (hereinafter referred to as a horizontal size) in the horizontal axis direction (LR direction) in the imaging screen, and the horizontal size is constant. (For example, indicated by a dotted line BL in FIG. 7), the time when the target subject image contacts the edge of the imaging screen based on this ratio (the n + 6 frame through image in FIG. 7 is captured). Hour). The time calculated at this time is referred to as a frame-out time. When the determination unit 24 calculates the frame-out time, the determination unit 24 determines that the target subject image is in contact with the end of the imaging screen. As a result, the prediction is established.
When the determination unit 24 determines that the prediction is satisfied, the automatic release setting in the panning mode setting information of the nonvolatile memory 11 is validated.

  Further, when the determination unit 24 calculates the frame-out time, after the release instruction is issued by the control unit 20 to the imaging control circuit 31 (release point: t1 in FIG. 7), the shutter is released (opened / closed). The optical image is exposed to the release time T2 until the optical image is exposed to the image sensor 8 (exposure start time: t2 in FIG. 7) and the image sensor 8 controlled by the image sensor control circuit 7. A release time lag T4 including the exposure time T3 is calculated. Further, when the frameout time is calculated, the determination unit 24 calculates, as the predicted shutter time by subtracting the release time lag time from the frameout time, assuming that the prediction is satisfied, and when the predicted time is reached, It is determined that it is an imaging timing. In this case, the control signal generation unit 25 controls the imaging control circuit 31 to release the shutter with a high-speed shutter. Here, the high-speed shutter is a setting for imaging at a shutter speed (second exposure time) that is extremely fast (short) as compared to the shutter speed (first exposure time) in the panning mode, and the image sensor control circuit 7. The exposure time T3 controlled by is corresponding to this shutter speed.

When the determination unit 24 determines that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane, the control signal generation unit 25 emits the subject light at the first exposure time in the panning mode. When a control signal to be imaged is generated and the determination unit 24 determines that the movement of the electronic camera 100 does not follow the movement of the target subject image in the image plane, the second exposure shorter than the first exposure time. A control signal for imaging subject light over time is generated. Further, when the imaging timing is determined, the control signal generation unit 25 outputs the control signal at the imaging timing to the imaging control circuit 31 and the imaging element control circuit 7. Further, when the determination unit 24 determines that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane, the imaging time setting unit 25 sets the amount of movement of the target subject image in the imaging screen. A corresponding first exposure time is calculated.
In addition, the imaging time setting unit 25 reads information indicating that the automatic release setting is valid or invalid as information of the panning mode setting stored in the nonvolatile memory 11 and is valid. In this case, the first control signal for imaging the subject light at the first shutter speed in the panning mode is generated. If invalid, the second control signal for imaging the subject light at the second shutter speed, which is a high-speed shutter, is used. Generate a control signal.

In addition, when the determination unit 24 determines that the movement of the electronic camera 100 follows the movement of the target subject image in the image plane, the control signal generation unit 25 performs the predetermined movement of the electronic camera 100 according to the VR panning mode. Generating a first correction control signal (hereinafter referred to as a first camera shake correction control signal) for correcting a shift of the optical axis of the optical system 1 caused by a movement in a direction other than the direction (for example, pan direction). This is output to the shake correction drive circuit 32.
Further, when the determination unit 24 determines that the movement of the electronic camera 100 does not follow the movement of the target subject image in the image plane, the control signal generation unit 25 performs all movement directions of the electronic camera 100 according to the VR normal mode. A second correction control signal (hereinafter referred to as a second camera shake correction control signal) for correcting the optical axis shift of the optical system 1 caused by the movement of the optical system 1 is generated and output to the camera shake correction drive circuit 32.

That is, the control signal generation unit 25 detects the target subject image detected in the predetermined range S1 within a certain range continuously for a certain time T1 (first determination), or the continuous detection time. Even if the time does not reach the predetermined time T1, the amount of movement detected by the angular velocity sensor 2 when the amount of movement of the electronic camera 100 detected by the angular velocity sensor 2 is not less than a certain amount (second determination). A first shutter speed (first exposure time) suitable for panning according to the above is calculated.
On the other hand, the control signal generation unit 25 does not detect the target subject image continuously for a certain time T1 or more by the determination unit 24, and the movement amount of the electronic camera 100 detected by the angular velocity sensor 2 is not a certain value or more. When the target object image is deviated from the imaging screen and “expected prediction” is established (third determination), imaging is performed at the second shutter speed (second exposure time) in the high-speed shutter mode. Note that the second shutter speed is extremely faster than the first shutter speed and the shutter speed in the normal shooting mode.

Further, the control signal generation unit 25 generates a camera shake correction value to be output to the camera shake correction drive circuit 32 according to the shooting mode stored in the nonvolatile memory 11. For example, when information indicating that the normal shooting mode setting is selected (valid) is stored in the nonvolatile memory 11, the control signal generation unit 25 performs manual operations for all moving directions of the electronic camera 100. A camera shake correction value for performing camera shake correction is generated.
In addition, when the panning mode is set in the nonvolatile memory 11, the control signal generation unit 25 does not generate a camera shake correction value for the camera shake in the pan direction of the electronic camera 100, and the direction other than the pan direction. A camera shake correction value for the camera shake is generated. The camera shake correction value generation unit 26 does not generate a camera shake correction value when camera shake correction is not set.

Next, an operation example in which automatic photographing (automatic release imaging) by the electronic camera 100 is performed will be described with reference to the flowcharts of FIGS.
As shown in FIG. 8, when the user presses the power switch 13a in step ST100, the electronic camera 100 is turned on, and then when the release switch 13b is half-pressed, in step ST200, the control unit 20 AF control is performed. In step ST300, the control unit 20 performs auto white balance adjustment (AWB control). In step ST400, the control unit 20 performs AF control. Here, AWB is a process of measuring the subject color, adjusting the amplification factor for each color so that the image output to the monitor 15 becomes an optimum color, and setting the amplification factor for each color at the time of shooting. It is.

When the release switch 13b that has been half-pressed is further pressed in step ST500, the control unit 20 reads information related to the automatic release setting stored in the nonvolatile memory 11 in step ST600. In step ST600, when the read automatic release setting information indicates that automatic shooting is not performed, in step ST800, the shooting processing unit 26 immediately starts shooting processing and performs shooting. Next, in step ST900, the image signal processed by the image processing unit 21 is stored in the memory 17, and the process ends.
On the other hand, when the automatic release setting information read by the control unit 20 in step ST600 indicates that automatic shooting is performed, in step ST700, the control unit 20 performs shooting in the automatic release mode, and then ends the process.

  FIG. 9 is a flowchart showing the photographing operation in the automatic release mode. As shown in FIG. 9, in step ST701, when the electronic camera 100 is panned during standby in the automatic release mode, the control unit 20 determines that the electronic camera 100 is fixed based on the amount of movement detected by the angular velocity sensor 2. It is determined whether panning is performed in the pan direction (for example, the horizontal direction with respect to the electronic camera 100). If it is determined in step ST701 that the electronic camera 100 is panned in a certain pan direction, in step ST702, the analysis unit 23 detects the movement amount (movement speed or movement) of the electronic camera 100 detected by the angular velocity sensor 2. A plurality of through image signals input to the control unit 20 are analyzed, and a motion vector of an image on the imaging screen of the through image signals is calculated.

In step ST703, the determination unit 24 detects a target subject image based on the moving direction of the electronic camera 100 detected by the angular velocity sensor 2 in step ST701 and the motion vector calculated by the analysis unit 23 in step ST702. Determine whether or not. When a target subject image is detected in step ST703, in step ST704, the determination unit 24 determines whether or not the target subject image is continuously detected for a certain time T1 or more.
In step ST705, for example, as shown in FIG. 4, the moving amount of the target subject image within the imaging screen is within a certain range S1, and the car A that is the target subject image is detected continuously for a certain time T1 or more. When continuing, the determination unit 24 determines that the electronic camera 100 is following the automobile A. Then, the determination unit 24 validates the automatic release setting in the panning mode setting information stored in the nonvolatile memory 11 and determines that it is the imaging timing in the panning mode. In this way, when it is determined that it is the shooting timing in the panning mode, in step ST705, the control signal generation unit 25 calculates the first shutter speed according to the movement amount detected by the angular velocity sensor 2. In step ST706, the camera shake correction drive circuit 32 is controlled in accordance with the VR panning mode.

  Thereby, in step ST707, the control signal generation unit 25 generates a camera shake correction control signal for a direction other than the pan direction of the electronic camera 100 according to the VR panning mode, and according to the camera shake correction control signal. The blur correction drive circuit 32 forms an image of light from the subject at an appropriate position on the light receiving surface of the image sensor 8. Next, the control signal generation unit 25 controls the imaging of a control signal that releases the shutter at the first shutter speed calculated for the imaging control circuit 31 and the imaging element control circuit 7 and captures an optical image at the first exposure time. It outputs to the circuit 31 and the image pick-up element control circuit 7. Here, when the automatic release setting is validated by the determination unit 24, the imaging time setting unit 25 reads the condition value when the automatic release setting stored in the nonvolatile memory 11 is valid, and reads this condition value. A control signal based on the processed information may be generated.

The imaging control circuit 31 opens and closes the shutter at the set first shutter speed based on the control signal input from the control signal generation unit 25, and the optical image is displayed for the exposure time controlled by the imaging element control circuit 7. An image is formed on the image sensor 8. Thereby, a captured image signal of one frame is generated. In step ST708, the memory control circuit 16 stores the captured image signal captured in step ST707 in the memory 17.
On the other hand, when the target subject image detected by the determination unit 24 is not continuously detected for a certain time T1 or longer in step ST704, the determination unit 24 performs electronic detection by the angular velocity sensor 2 in step ST709. It is determined whether or not the movement amount of the camera 100 is a certain amount or more.
For example, as shown in FIG. 5, when the movement amount of the target subject image in the imaging screen is within a certain range S1, and the car A that is the target subject image is not detected continuously for a certain time T1 or more, The determination unit 24 determines whether or not the pan angle θ of the electronic camera 100 detected by the angular velocity sensor 2 is equal to or greater than a predetermined threshold (for example, 30 °).
In step ST709, when the pan angle θ is equal to or greater than the threshold (30 °) (the n + 6th frame in FIG. 5), the determination unit 24 captures the image by the electronic camera 100 following the vehicle A as described above. The automatic release setting in the panning mode setting information stored in the nonvolatile memory 11 is validated, the imaging timing is determined, and the process proceeds to step ST705.

In step ST709, when the pan angle θ is less than the threshold value, the determination unit 24 determines that the movement of the electronic camera 100 does not follow the movement of the target subject image in the image plane. Next, in step ST710, the determination unit 24 determines whether or not the detected target subject image is gradually enlarged in the imaging screen, and when the gradually increased target subject image is detected, It is determined whether the image is out of the imaging screen.
For example, as illustrated in FIG. 7, when the size of the target subject image is increased at a certain ratio, the determination unit 24 performs frame out in which the target subject image contacts an end portion in the imaging screen based on this ratio. It is determined whether time has been calculated. Then, when the frame-out time is calculated, the determination unit 24 determines that the prediction has been established. Further, in step ST711, the determination unit 24 calculates a release time lag T4, and calculates a time obtained by subtracting the release time lag time from the frame-out time as an expected time.

  Next, in step ST712, the determination unit 24 determines whether or not the expected time has been reached. When the predicted time has been reached, in step ST713, the determination unit 24 determines that it is an imaging timing and is non-volatile. The automatic release setting stored in the memory 11 is invalidated. Thereby, in step ST714, the control signal generation unit 25 outputs a control signal for imaging at a high shutter speed (second shutter speed) to the imaging control circuit 31, and the panning mode stored in the buffer memory 12 is output. (Including the VR panning mode setting) and the automatic release mode setting are canceled (disabled). In step ST715, the control signal generation unit 25 generates a VR normal mode camera shake correction value (for example, a camera shake correction value corresponding to all the movement directions of the electronic camera 100), and follows this camera shake correction control signal. The blur correction drive circuit 32 forms an image of light from the subject at an appropriate position on the light receiving surface of the image sensor 8. If the expected time is not reached in step ST712, in step ST716, the determination unit 24 determines whether or not the next through image signal is generated by the image sensor 8, and the next through image signal is input. In this case, the process returns to step ST701.

If it is determined in step ST701 that the electronic camera 100 is not panned in a certain pan direction during standby in the automatic release mode, the operation detection circuit 13 determines in step ST715 that the release switch 13b has been pressed again. If NO in step ST706, the flow advances to step ST706 to cause the imaging unit 10 to capture an image at the imaging timing when the release switch 13b is pressed. For example, the control signal generation unit 25 outputs a control signal that causes the imaging unit 10 to capture an image at an arbitrary shutter speed set in advance to the imaging control circuit 31 and the imaging element control circuit 7.
On the other hand, when the release switch 13b is not pressed again in step ST717, in step ST718, the control unit 20 determines whether or not the automatic release mode setting is canceled. For example, when the release switch 13b is not pressed again for a certain time or more, the control unit 20 determines that the setting of the automatic release mode has been canceled and ends the imaging operation in the automatic release mode. On the other hand, for example, when the angular velocity sensor 2 detects the displacement of the electronic camera 100 within a predetermined time, the process returns to step ST701.

If the target object image is not detected by the determination unit 24 in step ST703, the determination unit 24 determines in step ST719 that the pan angle θ of the electronic camera 100 detected by the angular velocity sensor 2 is a predetermined threshold (for example, 45 °) or more. Note that, as described above, the predetermined threshold value is a preferred angle for avoiding the rear imaging of the target subject image, and can be arbitrarily determined according to the pan direction.
In step ST719, when the pan angle θ is equal to or larger than the threshold value, in step ST720, the determination unit 24 calculates the moving direction of the electronic camera detected by the angular velocity sensor 2 in step ST701 and the analysis unit 23 in step ST702. Based on the obtained motion vector, it is determined whether or not an image region (hereinafter referred to as a moving subject) in the imaging screen in which the same motion vector as the moving direction of the electronic camera 100 is calculated is detected. If a moving subject is detected in step ST720, the process proceeds to step ST713. On the other hand, if no moving subject is detected in step ST720, the imaging operation in the automatic release mode is terminated.

Note that FIG. 10 shows the subject in the imaging screen when the electronic camera 100 pans the subject light including the car A (subject 1) and the house B (subject 2) as shown in FIG. Represents a movement relationship. As shown in FIG. 10, at the start of the release operation t1, subject 1 is within a certain range in the imaging screen and the motion vector is almost 0 (a value indicating no motion in the screen), but subject 2 is a camera It moves in the imaging screen according to the pan. In this state, when the shutter is released and subject light based on the captured image signal is exposed to the image sensor 8 (exposure time: t2), the subject 2 moves in the image plane at the exposure time T3 (FIG. 3). The subject 1 is at a position within a substantially constant range S1. As a result, the subject 1 is focused by the AF control function of the imaging control circuit 31, so that the subject 1 is clear and the subject 2 is blurred in the captured image.
In the example shown in FIG. 12, although the electronic camera 100 is panned, the movement of the subject 3 within the image plane is merely moving within the image plane due to the panning of the electronic camera 100, and the actual subject. 3 indicates that the subject does not move in a direction corresponding to the pan direction of the electronic camera 100. That is, the subject 3 has a motion vector generated by the movement of the electronic camera 100. In this case, the subject 3 is not detected as the target subject image, and in step ST717, the angular velocity sensor 2 determines whether or not the pan angle θ of the electronic camera 100 is equal to or larger than a certain pan angle (for example, 45 °). To do. The electronic camera 100 may cancel shooting when the subject 3 does not reach a certain pan angle within a certain period (for example, n + 7 frames) as shown in FIG.

Furthermore, as illustrated in FIG. 13, the determination unit 24 detects the subject 4 having a motion vector different from the motion vector generated by panning the electronic camera 100 from the through image signal, as a target subject image. However, as shown in FIG. 13, the subject 4 has not been detected for a certain time T1 within a certain range S1 in the image plane, and the pan angle θ of the electronic camera 100 has not reached the predetermined threshold 30 °. Therefore, the determination unit 24 determines that the movement of the electronic camera 100 does not follow the movement of the target subject image in the image plane.
In this case, as shown in step ST717, the electronic camera 100 can capture an image of the subject without missing a photo opportunity by releasing the shutter before reaching the predetermined angle (45 °). In this case, as shown in FIG. 13, when the pan of the electronic camera 100 does not follow the movement of the target subject image, the image is captured at a shutter speed with a long exposure time suitable for the panning mode, as shown in FIG. However, not only the background but also the subject shakes, and there is a problem that a blurred image is captured.

  However, in the electronic camera 100 according to the present embodiment, when it is determined that the movement of the electronic camera 100 does not follow the movement of the target subject image in the image plane, the above problem is improved by imaging with a high-speed shutter. Thus, it is possible to prevent blurring of the subject and the background due to the slow shutter speed. In step ST712, the electronic camera 100 invalidates the setting of the panning mode, and at the same time, sets the camera shake correction setting mode of the camera shake correction value generation unit 26 to the normal imaging mode. Camera shake accompanying movement can be corrected.

  Here, FIG. 14 shows a case where the vehicle A moving as shown in FIG. 3 is imaged by panning the electronic camera 100 corresponding to the movement of the vehicle A, and the electronic camera according to the present embodiment. It is a figure for demonstrating the image based on the captured image signal at the time of imaging with electronic cameras other than 100. FIG. The through images D′ 1, D′ 2, and D′ 3 shown in FIG. 14 correspond to the through images D1 to D3 in FIG. 3, respectively, and the difference between the through images D′ 4 and D′ 5 (not shown). A difference image DD′45 and a captured image D′ 6 are further shown. As shown in the difference image DD′45, it can be understood that the difference is detected in the car A even in the through image immediately before the captured image D′ 6 is captured, and the vehicle A does not remain at a certain position in the image plane. . When the captured image D′ 6 is captured in this state, as shown in FIG. 14, not only the house B in the background but also the car A is blurred, and an unclear image is captured.

With this configuration, the electronic camera 100 according to the present embodiment determines whether or not the movement of the electronic camera 100 follows the movement of the target subject image in the imaging screen and determines that the movement does not follow. In this case, the camera shake correction control based on the panning mode is canceled, and the image is taken with a high-speed shutter. Accordingly, in the state where the automatic release mode in the panning mode is set, the camera shake correction value generation unit does not generate the camera shake correction value for the camera shake in the pan direction of the electronic camera 100, so that not only the background It is possible to solve the problem that the target subject image is blurred and an unclear image is captured. In addition, in panning, an exposure time longer than usual is required, but when it is determined that the electronic camera 100 cannot sufficiently follow, imaging is performed at a high shutter speed. As a result, it is not possible to capture an image with a background that is captured by panning, but it is possible to prevent generation of an unclear image and to generate a captured image signal with a clear entire image.
In addition, electronic camera 100 according to the present embodiment determines that the target subject is not panned in step ST701 in FIG. 9 or the camera is panned in step ST702 in FIG. If no image is detected, no panning is performed. Therefore, it is possible to avoid performing the panning imaging at a timing not intended by the user. The electronic camera 100 can change the conditions for determining panning by arbitrarily selecting settings for detecting the pan direction and the target subject image. Can have a panning function.

  DESCRIPTION OF SYMBOLS 2 ... Angular velocity sensor (detection part), 8 ... Imaging element, 10 ... Imaging part, 20 ... Control part, 23 ... Analysis part, 24 ... Determination part, 25 ... Control signal generation part, 32 ... Camera shake correction drive circuit (Optical system correction unit), 100 ... electronic camera

Claims (4)

An imaging unit that forms an optical image by the optical system on an imaging device and generates an image signal based on the optical image;
A detection unit for detecting a camera movement amount of an electronic camera including the imaging unit;
Based on the camera movement amount detected by the detection unit, an analysis unit that calculates the image plane movement amount of the image in the imaging screen of the image signal;
The image plane different from the image plane movement amount caused by the movement of the electronic camera in the imaging screen based on the camera movement amount detected by the detection unit and the image plane movement amount calculated by the analysis unit. A determination unit that detects an image region having a movement amount as a subject image region, and determines whether or not the image plane movement amount of the detected subject image region follows the camera movement amount;
First control for causing the imaging unit to capture the optical image in a first exposure time when the determination unit determines that the image plane movement amount of the subject image area follows the camera movement amount. A signal is generated, and when the determination unit determines that the image plane movement amount of the subject image area does not follow the camera movement amount, the second exposure time is shorter than the first exposure time. An electronic camera comprising: a control signal generation unit that generates a second control signal that causes the imaging unit to capture the optical image. A storage unit that stores panning mode setting information related to panning mode control by the imaging unit;
The determination unit
In the panning mode setting information stored in the recording unit, the validity or invalidity of the automatic release setting is stored, and it is determined that the image plane movement amount of the subject image area does not follow the camera movement amount. In this case, the automatic release setting that is valid in the storage unit is invalidated,
The control signal generator is
When the automatic release setting is enabled in the panning mode setting information of the storage unit, the first control signal is generated, and the automatic release setting is invalid in the panning mode setting information of the storage unit 2. The electronic camera according to claim 1, wherein the second control signal is generated. The determination unit
When the subject image area is continuously detected for a certain period of time or when the subject image area is not continuously detected for a certain period of time and the movement of the electronic camera is constant by the detection unit 3. The electronic camera according to claim 1, wherein when it is detected that the above is detected, it is determined that the amount of movement of the image plane of the subject image region follows the amount of movement of the camera. An imaging unit that forms an optical image by the optical system on an imaging device and generates an image signal based on the optical image;
A detection unit for detecting a camera movement amount of an electronic camera including the imaging unit;
An optical system correction unit that corrects a deviation of an optical axis of an optical image formed on the image sensor by the optical system;
Based on the camera movement amount detected by the detection unit, an analysis unit that calculates the image plane movement amount of the image in the imaging screen of the image signal;
The image plane different from the image plane movement amount caused by the movement of the electronic camera in the imaging screen based on the camera movement amount detected by the detection unit and the image plane movement amount calculated by the analysis unit. A determination unit that detects an image region having a movement amount as a subject image region, and determines whether or not the image plane movement amount of the detected subject image region follows the camera movement amount;
When the determination unit determines that the image plane movement amount of the subject image area follows the camera movement amount, the optical axis shift caused by the movement of the electronic camera other than the predetermined movement direction is corrected. When the first correction control signal is output to the optical system correction unit, and the determination unit determines that the image plane movement amount of the subject image area does not follow the camera movement amount, the electronic camera An electronic camera, comprising: a control signal generation unit that outputs a second correction control signal for correcting a shift of the optical axis caused by movement in all movement directions to the optical system correction unit.

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