JP2004228644A - Image blur correction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image blur correction apparatus capable of excellently correcting an image blur for both of still picture photographing and moving picture photographing. <P>SOLUTION: The image blur correction apparatus uses a camera-shake detection means 7 employing a vibration gyro sensor to detect a camera-shake and to drive a correction optical system 2 thereby performing correction operations in the case of still picture photographing. Further, the image blur correction apparatus uses a motion vector detection section 9a to detect a camera-shake and to allow an image segmentation circuit 13 to revise a segmented position in accordance with a motion vector for correcting the camera-shake thereby correcting the image blur without being affected by a drift of the vibration gyro sensor in the case of moving picture photographing. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a blur correction device that corrects image blur in a photographing device that electronically photographs still images and moving images.
[0002]
[Prior art]
Conventionally, in an image pickup apparatus having an optical system and a CCD, a still image and a moving image equipped with a shake correction device that detects an image blur due to a camera shake by detecting a camera shake using a vibration gyro and displacing a part of the optical system. Cameras capable of recording are known.
[0003]
[Patent Document 1]
JP-A-6-22205 [Patent Document 2]
JP 2000-278588 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2001-218104
[Problems to be solved by the invention]
However, in the above-described conventional blur correction device, although image blur can be satisfactorily corrected at the time of recording a still image, the correction optical system moves due to drift of the output of the vibrating gyroscope during the recording of a moving image, and a recorded image flows ( Move). For example, when shooting a video with the camera fixed on a tripod, the output of the vibrating gyroscope drifts and the output signal changes, causing the originally stationary subject to move slowly and be shot. I was
[0005]
An object of the present invention is to provide a blur correction device that can satisfactorily correct image blur in both still image shooting and moving image shooting.
[0006]
[Means for Solving the Problems]
The present invention solves the above problem by the following means. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this. That is, the first aspect of the present invention provides an imaging optical system (1, 2), a first shake detection unit (7) that detects a shake, and outputs a first shake detection signal according to the shake, A second shake detection unit (9a) that detects shake by a method different from the first shake detection unit and outputs a second shake detection signal corresponding to the shake, and an image obtained by the imaging optical system. By moving at least a part of an imaging system including the imaging optical system and the imaging unit based on the first shake detection signal from the first shake detection unit; An optical blur correction unit (2, 3, 5) for correcting image blur, and an image blurring unit that captures a moving image from an image captured by the imaging unit based on the second shake detection signal from the second shake detection unit. Video blur to correct image blur by changing the clipping position Tadashibu (13), a motion compensation device comprising a.
[0007]
According to a second aspect of the present invention, in the blur correction device according to the first aspect, the moving image blur correction unit (13) is configured to control the image pickup unit based on the first shake detection signal in addition to the second shake detection signal. And changing a cut-out position from an image taken by the camera.
[0008]
The invention according to claim 3 is an imaging optical system (1, 2), a first shake detection unit (7) that detects a shake, and outputs a first shake detection signal according to the shake, and the first shake detection unit (7). A second shake detection unit (9a) that detects shake by a method different from the shake detection unit and outputs a second shake detection signal corresponding to the shake, and electronically converts an image obtained by the imaging optical system. Image blurring by moving at least a part of an imaging system including the imaging optical system and the imaging means based on the first shake detection signal from the first shake detection unit. And an optical blur correction unit (2, 3, 5) that corrects image blur, and corrects image blur by the optical blur correction unit based on the first shake detection signal when capturing a still image (S210, S220). When capturing a moving image, the frequency of the detected shake is set to a predetermined value. Compared with the value (0.1 Hz), a shake component having a frequency higher than the threshold is detected by the first shake detector (S250), and a shake component having a frequency lower than the threshold is detected by the second shake detector. A shake correction apparatus characterized in that a shake is detected by a shake detection unit (S270).
[0009]
According to a fourth aspect of the present invention, in the shake correction apparatus according to the third aspect, the threshold (0.1 Hz) is a frequency at which a drift component of the first shake detecting unit can be detected. This is a shake correction device.
[0010]
According to a fifth aspect of the present invention, there is provided an image pickup optical system, a first shake detection section for detecting a shake and outputting a first shake detection signal according to the shake, and the first shake detection section. A second shake detection unit (9a) that detects shake by a method different from the shake detection unit and outputs a second shake detection signal corresponding to the shake, and electronically converts an image obtained by the imaging optical system. Image blurring by moving at least a part of an imaging system including the imaging optical system and the imaging means based on the first shake detection signal from the first shake detection unit. And an optical blur correction unit (2, 3, 5) that corrects image blur, and corrects image blur by the optical blur correction unit based on the first shake detection signal when capturing a still image (S210, S220). When capturing a moving image, a blur correction is performed based on the first shake detection signal. While performing the operation (S340, S350), the second shake detection signal is monitored (S360), and when a drift component is detected from the second shake detection signal, the drift component is corrected. Performing a blur correction operation (S380).
[0011]
According to a sixth aspect of the present invention, in the blur correction device according to any one of the first to fifth aspects, the optical blur correction unit (2, 3, 5) includes the imaging optical system (1, 2). The blur correction device is characterized in that a blur correction operation is performed by moving a blur correction optical system (2) that forms at least a part of (2).
[0012]
According to a seventh aspect of the present invention, in the shake correction apparatus according to the sixth aspect, the blur correction optical system (2) is a shift optical system that corrects image blur by moving in a direction substantially orthogonal to an optical axis. And a blur correction device.
[0013]
According to an eighth aspect of the present invention, in the shake correction apparatus according to any one of the first to seventh aspects, the first shake detecting section (7) has a vibration gyro sensor, The second shake detection unit (9a) is a shake correction device, which detects shake by performing image processing on an image captured by the imaging unit.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings and the like.
(1st Embodiment)
FIG. 1 is a block diagram showing a first embodiment of a blur correction device according to the present invention. The blur correction device according to the present embodiment includes a main optical system 1, a correction optical system 2, a correction optical system moving actuator 3, a CCD 4, an actuator drive circuit 5, a CCD drive circuit 6, a shake detection means 7, an amplifier 8, a CPU 9, an AD It includes a converter 10, a mode changeover switch (SW) 11, a field memory 12, an image cutout circuit 13, a memory 14, and the like.
[0015]
The main optical system 1 is a lens group that does not move due to a blur correction operation by a correction optical system 2 described later.
The correction optical system 2 is a lens group that forms a photographing optical system together with the main optical system 1, and is movably held in a plane substantially orthogonal to the optical axis. The correction optical system 2 is driven by a correction optical system movement actuator 3 described later, and its position is detected by a position detection device (not shown).
[0016]
The correction optical system moving actuator 3 is an optical blur correction unit that drives the correction optical system 2, and is formed by a voice coil motor. The correction optical system moving actuator 3 is connected to the CPU 9 via the actuator drive circuit 5, and is driven in accordance with an instruction from the CPU 9. The correction optical system moving actuator 3 moves the correction optical system 2 in two directions orthogonal to each other with the optical axis as an intersection. Although two sets are provided, only one direction is shown here for simplicity.
[0017]
The CCD 4 is an imaging unit that electronically captures an image obtained by the imaging optical system including the main optical system 1 and the correction optical system 2. The CCD 4 is connected to the CPU 9 via the CCD drive circuit 6, and performs imaging according to an instruction from the CPU 9.
[0018]
The shake detection means 7 is a first shake detection unit that detects a shake of the camera and outputs a first shake detection signal according to the shake. The shake detecting means 7 detects the shake by the vibration gyro sensor, and the first shake detection signal output from the shake detecting means 7 is sent to the CPU 9 via the amplifier 8 and the AD converter 10.
[0019]
The CPU 9 is a control unit that controls various operations of the camera, and includes a motion vector detection unit 9a as a part related to the present invention. The motion vector detection unit 9a is a second shake detection device that detects a motion vector corresponding to the amount of shake between fields obtained from the CCD 4 by image processing. The motion vector detection unit 9a outputs a motion vector corresponding to the shake to the image cutout circuit 13 as a second shake detection signal.
[0020]
The mode switch SW11 is a switch for the photographer himself to arbitrarily switch between still image shooting and moving image shooting. The switching result of the mode switching SW 11 is transmitted to the CPU 9.
[0021]
The field memory 12 is a storage unit for temporarily storing a field-based image obtained by the CCD 4.
[0022]
The image cutout circuit 13 is a moving image blur correction unit that corrects image blur by cutting out a necessary range from an image stored in the field memory 12 according to the motion vector obtained by the motion vector detection unit 9a. By changing the cutout position according to the motion vector between consecutive fields, image blur can be corrected.
[0023]
The memory 14 is a storage unit that stores a captured image. In the present embodiment, the memory 14 is an external storage unit such as a so-called memory card that is detachable from the camera.
[0024]
Next, a camera shake correction operation of the camera according to the present embodiment will be described.
FIG. 2 is a flowchart illustrating the flow of the shake correction operation according to the first embodiment.
Since the camera according to the present embodiment can shoot a still image and a moving image, the photographer specifies which one to shoot by switching the mode switch SW11.
In step (hereinafter, referred to as S) 100, CPU 9 determines whether still image mode or moving image mode is selected by mode switching SW11. When the still image mode is selected, the process proceeds to S110, and when the moving image mode is selected, the process proceeds to S140.
[0025]
In S110, since the still image mode is selected, the shake amount and the shake correction amount for the shake amount are calculated based on the signal from the shake detection means 7.
In S120, the blur correction is performed by driving the actuator 3 and moving the correction optical system 2 according to the blur correction amount calculated in S110 so that the image formed on the CCD 4 stops blurring. In this case, the image cutout circuit 13 does not operate or always cuts out from a fixed position.
In S130, it is determined whether or not the shooting is to be ended. If the shooting is to be ended, END is set. If the shooting is to be continued, the process returns to S110.
In the above-described shake correction operation in the still image mode, it is possible to satisfactorily correct a camera shake frequency (for example, 30 Hz), and to obtain a good shake correction effect in a still image. In still image shooting, since the shutter speed is short, there is no influence of the drift of the vibration gyro sensor used in the shake detecting means 7.
[0026]
When the moving image mode is selected, in S140, a blur correction amount by image clipping is calculated according to the motion vector obtained from the motion vector detection unit 9a.
In S150, the image cutout circuit 13 cuts out a necessary range from the image stored in the field memory 12 according to the blur correction amount calculated in S140. At this time, the image blur between consecutive frames (fields) is corrected by changing the cutout position according to the motion vector. In the case of the moving image mode, since the blur detecting means 7 is not used, the photographing can be performed without being affected by the drift of the vibration gyro sensor.
In S160, it is determined whether or not the shooting is to be ended. If the shooting is to be ended, END is set. If the shooting is to be continued, the process returns to S140.
[0027]
According to the present embodiment, at the time of shooting a still image, the shake is detected by the shake detecting means 7 using a vibration gyro sensor and the correction optical system 2 is driven to perform the shake correction operation. The shake is detected by the section 9a and the image cutout position is changed by the image cutout circuit 13 in accordance with the motion vector to perform the shake correction. Therefore, the image shake is not affected by the drift in both the still image shooting and the moving image shooting. Can be satisfactorily corrected.
[0028]
(2nd Embodiment)
The second embodiment and a third embodiment to be described later are the same as the first embodiment except that the specific mode of the blur correction operation is different. , The same reference numerals are given, and overlapping description will be omitted as appropriate.
FIG. 3 is a flowchart showing the flow of the shake correction operation in the second embodiment.
In S200, the CPU 9 determines whether the still image mode or the moving image mode is selected by the mode switch SW11. When the still image mode is selected, the process proceeds to S210, and when the moving image mode is selected, the process proceeds to S240.
Steps S210 to S230 are the same as steps S110 to S130 in the first embodiment, and a description thereof will be omitted.
[0029]
In S240, among the shakes applied to the camera, the shake having a frequency of 0.1 Hz or more is detected by the shake detecting means 7, and the shake having a frequency of less than 0.1 Hz is detected by the motion vector detecting section 9a.
The signal generated by the drift of the vibration gyro sensor used in the shake detecting means 7 is a very low frequency signal. Therefore, in the present embodiment, regardless of whether or not drift has occurred, the low-frequency signal (signal corresponding to a shake of less than 0.1 Hz) obtained from the shake detecting means 7 is not used, and this low-frequency signal is used. The frequency component is detected by the motion vector detection unit 9a, so that the influence of the drift of the blur detection means 7 is eliminated.
In the present embodiment, 0.1 Hz is set as a threshold to separate the high-frequency component and the low-frequency component. However, this threshold takes into account the frequency characteristics of the drift component of the shake detecting means 7 in the present embodiment. The threshold value needs to be set to an optimum value according to the frequency characteristics of the drift component of the sensor to be used.
[0030]
In S250, an amount of shake correction by driving the correction optical system 2 is calculated based on the shake component of 0.1 Hz or more detected by the shake detection means 7.
In S260, the correction optical system 2 is driven to execute blur correction.
In S270, a shake correction amount by image clipping is calculated based on a shake component of less than 0.1 Hz detected by the motion vector detection unit 9a.
In S280, the image is cut out by the image cutout circuit 13, and the blur correction of the low frequency component is performed.
In S290, it is determined whether or not the shooting is to be ended. If the shooting is to be ended, END is set. If the shooting is to be continued, the process returns to S240.
[0031]
According to the present embodiment, since the low-frequency component which may include the drift component is detected by the motion vector detecting unit 9a without using the blur detecting means 7, the drift component is included in the detection signal. Therefore, an accurate blur correction operation can be always performed.
[0032]
(Third embodiment)
FIG. 4 is a flowchart illustrating a flow of a shake correction operation according to the third embodiment of the present invention.
In S300, the CPU 9 determines whether the still image mode or the moving image mode is selected by the mode switching SW11. When the still image mode is selected, the process proceeds to S310, and when the moving image mode is selected, the process proceeds to S340.
Steps S310 to S330 are the same as steps S110 to S130 in the first embodiment, and a description thereof will be omitted.
[0033]
In S340, based on the signal from the shake detecting means 7, a shake amount and a shake correction amount for the shake amount are calculated.
In S350, the blur correction is performed by driving the actuator 3 and moving the correction optical system 2 according to the blur correction amount calculated in S340 so that the image formed on the CCD 4 stops blurring.
In S360, the motion of the image is monitored by the motion vector detection unit 9a. Here, if the drift component is included in the signal from the blur detection means 7, the image moves slowly as a whole, for example, despite the execution of the optical blur correction in S350. It is detected by the vector detector 9a. In this case, a drift component is included.
[0034]
In S370, it is determined whether or not the drift component has been detected in S360. If the drift component has been detected, the process proceeds to S380, and if the drift component has not been detected, the process proceeds to S390.
In S380, the image is cut out so as to correct the image movement due to the drift component detected in S360, and the image movement (image blur) due to the drift component is corrected.
In S390, it is determined whether or not the shooting is to be ended. If the shooting is to be ended, END is set. If the shooting is to be continued, the process returns to S340.
[0035]
According to the present embodiment, at the time of capturing a moving image, the motion of the image is monitored by the motion vector detecting unit 9a together with the detection of the shake by the blur detecting means 7. Therefore, when a drift occurs in the blur detecting means 7, the motion vector is detected. The drift component can be detected by the unit 9a, and a correction for canceling the drift component can be added. Therefore, a high-quality image can always be obtained.
[0036]
(Modified form)
Various modifications and changes are possible without being limited to the embodiments described above, and these are also within the equivalent scope of the present invention.
(1) In the first embodiment, an example in which the motion detection unit 7 is not used in the moving image mode has been described. However, the present invention is not limited to this. For example, both the motion vector detection unit 9a and the motion detection unit 7 are used in the moving image mode. Then, the shake amount may be calculated.
[0037]
(2) In the first embodiment, an example has been described in which the motion vector detecting unit 9a is used to calculate the blur amount in the moving image mode. However, the present invention is not limited to this. For example, only the blur detecting unit 7 is used in the moving image mode. The shake amount may be obtained, and the image cutout circuit 13 may perform the shake correction according to the result.
[0038]
(3) In the second embodiment, high-frequency components (components of 0.1 Hz or more) are corrected by optical blur correction by the correction optical system 2, and low-frequency components (components of less than 0.1 Hz) are corrected by image clipping. Although an example is shown, the present invention is not limited to this. For example, after separately detecting a high-frequency component and a low-frequency component, both the high-frequency component and the low-frequency component may be corrected by optical blur correction, Both the low-frequency component and the low-frequency component may be corrected by image clipping.
[0039]
(4) In the third embodiment, an example has been described in which the blur correction is performed using a combination of the optical blur correction and the blur correction based on the image clipping. However, the present invention is not limited to this. The shake correction may be performed, or both the normal shake and the drift component may be performed by the shake correction by cutting out the image.
[0040]
【The invention's effect】
As described above in detail, according to the present invention, the following effects can be obtained.
(1) an optical blur correction unit that corrects image blur by moving at least a part of an imaging system including an imaging optical system and an imaging unit based on a first shake detection signal from a first shake detection unit; A moving image blur correction unit that corrects image blur by changing a cutout position from an image captured by the imaging unit based on a second shake detection signal from the second shake detection unit during imaging; Image blur can be accurately corrected for both images and moving images.
[0041]
(2) The moving image blur correction unit changes the cutout position from the image captured by the imaging unit based on the first shake detection signal in addition to the second shake detection signal. The first and second shake detection signals are complemented with each other, so that more accurate shake detection can be performed, and a better imaging result can be obtained.
[0042]
(3) At the time of capturing a still image, the image blur is corrected by the optical blur correction unit based on the first shake detection signal. At the time of capturing a moving image, the frequency of the detected shake is compared with a predetermined threshold. The shake component having a higher frequency is detected by the first shake detector, and the shake component having a frequency lower than the threshold is detected by the second shake detector. Therefore, the shake is detected by the first shake detector. The second shake detecting unit can be used for the shake in the frequency region that is not suitable for the above, and the appropriate shake can always be detected.
Here, by setting the threshold value to a frequency at which a drift component of the first shake detecting unit can be detected, the first shake detecting unit detects a shake of a frequency including a drift component generated in the first shake detecting unit. Accordingly, the second shake detection unit can be used, and blur correction of a still image and a moving image can be performed without being affected by drift.
[0043]
(4) When capturing a still image, the image blur is corrected by the optical blur correction unit based on the first shake detection signal, and when capturing a moving image, the second shake correction operation is performed based on the first shake detection signal. The shake detection signal is monitored, and when a drift component is detected from the second shake detection signal, a blur correction operation is performed so as to correct the drift component. Can be corrected.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a blur correction device according to the present invention.
FIG. 2 is a flowchart illustrating a flow of a shake correction operation according to the first embodiment.
FIG. 3 is a flowchart illustrating a flow of a shake correction operation according to a second embodiment.
FIG. 4 is a flowchart illustrating a flow of a shake correction operation according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main optical system 2 Correction optical system 3 Correction optical system moving actuator 4 CCD
5 Actuator drive circuit 6 CCD drive circuit 7 Shake detection means 8 Amplifier 9 CPU
10 AD converter 11 Mode switch SW
12 Field memory 13 Image cutout circuit 14 Memory

Claims (8)

An imaging optical system;
A first shake detection unit that detects a shake and outputs a first shake detection signal according to the shake;
A second shake detection unit that detects shake by a method different from the first shake detection unit and outputs a second shake detection signal corresponding to the shake,
Imaging means for electronically capturing an image obtained by the imaging optical system;
An optical blur correction unit that corrects image blur by moving at least a part of an imaging system including the imaging optical system and the imaging unit based on the first shake detection signal from the first shake detection unit;
At the time of capturing a moving image, a moving image blur correction unit that corrects image blur by changing a cutout position from an image captured by the imaging unit based on the second shake detection signal from the second shake detection unit,
A blur correction device comprising: The blur correction device according to claim 1,
The moving image blur correction unit changes a cutout position from an image captured by the imaging unit based on the first shake detection signal in addition to the second shake detection signal;
A blur correction device characterized by the above-mentioned. An imaging optical system;
A first shake detection unit that detects a shake and outputs a first shake detection signal according to the shake;
A second shake detection unit that detects shake by a method different from the first shake detection unit and outputs a second shake detection signal corresponding to the shake,
Imaging means for electronically capturing an image obtained by the imaging optical system;
An optical blur correction unit that corrects image blur by moving at least a part of an imaging system including the imaging optical system and the imaging unit based on the first shake detection signal from the first shake detection unit;
With
At the time of capturing a still image, image blur is corrected by the optical blur correction unit based on the first shake detection signal,
At the time of moving image capturing, the detected shake frequency is compared with a predetermined threshold, and a shake component having a frequency higher than the threshold is detected by the first shake detection unit, and a shake component having a frequency lower than the threshold is detected. Detecting a shake component by the second shake detection unit;
A blur correction device characterized by the above-mentioned. The blur correction device according to claim 3,
The threshold value is a frequency at which a drift component of the first shake detection unit can be detected,
A blur correction device characterized by the above-mentioned. An imaging optical system;
A first shake detection unit that detects a shake and outputs a first shake detection signal according to the shake;
A second shake detection unit that detects shake by a method different from the first shake detection unit and outputs a second shake detection signal corresponding to the shake,
Imaging means for electronically capturing an image obtained by the imaging optical system;
An optical blur correction unit that corrects image blur by moving at least a part of an imaging system including the imaging optical system and the imaging unit based on the first shake detection signal from the first shake detection unit;
With
At the time of capturing a still image, image blur is corrected by the optical blur correction unit based on the first shake detection signal,
At the time of capturing a moving image, the second shake detection signal is monitored while performing a blur correction operation based on the first shake detection signal, and when a drift component is detected from the second shake detection signal, Performing a blur correction operation so as to correct the drift component,
A blur correction device characterized by the above-mentioned. The blur correction device according to any one of claims 1 to 5,
The optical blur correction unit performs a blur correction operation by moving a blur correction optical system that forms at least a part of the imaging optical system,
A blur correction device characterized by the above-mentioned. The blur correction device according to claim 6,
The blur correction optical system is a shift optical system that corrects image blur by moving in a direction substantially orthogonal to the optical axis;
A blur correction device characterized by the above-mentioned. The blur correction device according to any one of claims 1 to 7,
The first shake detection unit has a vibration gyro sensor,
The second shake detection unit detects a shake by performing image processing on an image captured by the imaging unit;
A blur correction device characterized by the above-mentioned.

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