JP2016031380A - Blur correction system, blur correction method and computer program, and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which an interchangeable lens type imaging device cannot have sufficient camera shake correction performance desired by a user when vibration isolation performance of optical vibration isolation means of a lens is deficient.SOLUTION: A blur correction system comprises: first blur detection means of detecting a blur amount from magnitude of an applied angular velocity, second blur detection means of detecting a blur amount from a movement amount of a picked-up image; first blur correction means of making optical blur corrections; second blur correction means of making electronic blur corrections on the picked-up image; and control means of acquiring a correctable amount of the first blur correction means, determining a first blur correction amount of the first blur correction means and a second blur correction amount of the second blur correction means on the basis of the blur amount detected by the first blur detection means and the blur amount detected by the second blur detection means, and driving the first and second blur correction means according to the first and second blur correction amounts.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shake correction system, and more particularly to a shake correction system suitable for shake correction of an imaging apparatus.

  2. Description of the Related Art In recent years, interchangeable-lens imaging devices have mainly been provided with a camera shake correction function, and there is a demand for a high level of vibration suppression performance. Hereinafter, these imaging devices will be described.

  FIG. 1 is a block diagram of a conventional interchangeable lens type imaging apparatus. In the figure, reference numeral 301 denotes an interchangeable lens having a photographing optical system composed of a zoom lens group, a diaphragm, a focus lens, and the like. Reference numeral 304 denotes an optical blur correction unit including a shift lens. By driving the optical blur correction unit 304, the optical axis of the photographing optical system of the interchangeable lens 301 can be changed. An image pickup unit 102 includes an image pickup device such as a CCD, a sample / hold circuit (S / H circuit), and a preprocess circuit. Reference numeral 103 denotes a signal processing unit, 104 denotes a motion detection unit, and 105 denotes a signal recording unit. Reference numeral 106 denotes a recording medium such as a flash memory, an optical disk, or a tape. Reference numeral 107 denotes a display unit for confirming an image signal and the state of the imaging apparatus. Reference numeral 110 denotes an operation unit, and 109 denotes a control microcomputer for controlling the imaging apparatus main body. Reference numeral 303 denotes a shift lens control unit, and reference numeral 305 denotes an angular velocity detection unit. The angular velocity detection unit 305 includes an angular velocity sensor 306, a high pass filter 307, an amplifier 308, and an A / D converter 309. In the angular velocity detection unit 305, the angular velocity sensor 306 detects and outputs vibration applied to the imaging apparatus, and the output is amplified by the amplifier 308 through the high-pass filter 307 and then digitized by the A / D converter 309. It is output to the lens microcomputer 302.

  302 is a lens microcomputer for controlling the interchangeable lens, 101 is a mount for connecting the interchangeable lens to the imaging apparatus main body, and 108 is a communication unit for communication between the imaging apparatus main body and the interchangeable lens 301. . Reference numeral 109 denotes a control microcomputer that controls each part of the imaging apparatus main body by loading and executing a control program stored in a memory (not shown), and also controls communication with the lens microcomputer 302 via the communication unit 108. is there. For example, the control microcomputer 109 receives an instruction from the user via the operation unit 110 and instructs the signal processing unit 103 and the signal recording unit 105 to start / end recording and change various settings.

  The light from the subject received by the photographing optical system of the interchangeable lens 301 is adjusted in light amount by the diaphragm, and is imaged on the surface of the image pickup device such as a CCD of the image pickup unit 102. In the imaging unit 102, the formed subject image is photoelectrically converted and accumulated as an imaging signal. An image signal output from an image pickup device such as a CCD is sample-held by a sample-hold circuit, and then supplied to a pre-process circuit where AGC processing, black balance processing, white balance processing, gamma correction processing, etc. are performed. It is supplied to the processing unit 103. The signal processing unit 103 executes processing / correction on the image signal based on an instruction from the control microcomputer 109.

  The signal recording unit 105 records an image signal on the recording medium 106 and outputs an image signal to the display unit 107 based on an instruction from the control microcomputer 109. The motion detection unit 104 included in the signal processing unit 103 detects, for example, a motion vector from an image signal to detect the amount of motion of the subject, extracts vibration applied to the imaging device body and the motion of the subject itself, and The applied vibration is output to the control microcomputer 109.

  When the interchangeable lens 301 is connected to the imaging apparatus main body via the mount 101, power is supplied to the interchangeable lens 301 via a power supply terminal installed on the mount, and the control microcomputer 109 is connected to the lens microcomputer via the communication unit 108. 302 performs initial communication. In this initial communication, the control microcomputer 109 confirms whether or not the interchangeable lens 301 has an optical image stabilization mechanism. When the interchangeable lens 301 includes an optical image stabilization mechanism, the control microcomputer 109 transmits vibration applied to the imaging apparatus main body detected by the motion detection unit 104 to the lens microcomputer 302 via the communication unit 108. The lens microcomputer 302 derives the driving amount of the shift lens based on the vibration applied to the imaging device detected by the angular velocity sensor 306 and the vibration applied to the imaging device detected by the motion detection unit 104 transmitted from the imaging device body. Then, control parameters are set in the shift lens control unit 303. The shift lens control unit 303 drives the optical blur correction unit 304 based on the set control parameter.

  At this time, since the angular velocity sensor 306 can respond at high speed to the update period of the imaging signal, sampling is performed with a high frequency component as a center. On the other hand, the motion detection unit 104 responds in synchronization with the update cycle of the image signal, but by performing sampling around the low frequency component attenuated by the high pass filter 307, it is possible to realize camera shake correction for a wide frequency component. it can.

JP 2002-107787 A

  However, in the above-described conventional example, if the image stabilization performance of the entire imaging apparatus depends on the performance of the light learning correction unit 304 mounted on the interchangeable lens 301, the higher the image stabilization performance when the user needs higher image stabilization performance. It was necessary to prepare an interchangeable lens with anti-vibration performance.

  Patent Document 1 discloses a digital camera that does not perform electronic shake correction when the imaging apparatus main body has an electronic shake correction function and an interchangeable lens having the shake correction function is attached. Also in this case, the image stabilization performance of the entire imaging apparatus depends on the performance of the optical blur correction unit mounted on the interchangeable lens.

  Accordingly, an object of the present invention is to provide a user with a desired image stabilization performance without depending on the image stabilization performance of the entire image pickup apparatus depending on the performance of the optical image stabilization section mounted on the interchangeable lens. A correction system and an imaging apparatus are provided.

  In order to achieve the above object of the present invention, according to the present invention, a shake correction system includes a first shake detection unit that detects a shake amount from the magnitude of an applied angular velocity, and a shake amount from a motion amount of a captured image. Second blur detection means for detecting, first blur correction means for performing optical blur correction, second blur correction means for performing electronic blur correction on the captured image, and first blur correction The correction amount of the means is acquired, and the first shake correction means of the first shake correction means is based on the shake amount detected by the first shake detection means, the shake amount detected by the second shake detection means, and the correctable amount. Control means for determining one shake correction amount and a second shake correction amount of the second shake correction means, and driving the first and second shake correction means according to the first and second shake correction amounts, respectively. Prepare.

  According to the present invention, an image stabilization system capable of providing a user with a desired image stabilization performance without depending on the image stabilization performance of the entire imaging apparatus depending on the performance of the optical image stabilization unit mounted on the lens. An imaging device can be provided. In addition, according to the performance of the light learning correction unit mounted on the interchangeable lens, an imaging device having an image stabilization function that can flexibly change the operation range of the electronic shake correction unit of the imaging device main body and has little image quality degradation. It can be configured.

Processing block diagram of a conventional imaging apparatus having a blur correction function 1 is a block diagram of an image pickup apparatus to which a shake correction system according to a first embodiment of the present invention is applied. The figure which shows the structure of the vibration-proof correction amount in the shake correction system concerning the 1st Example of this invention. The figure which shows the flowchart of the blurring correction | amendment operation | movement in the imaging device to which the blurring correction system concerning 1st Example of this invention is applied.

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

<First embodiment>
FIG. 2 is a block diagram of an interchangeable lens type imaging apparatus to which the shake correction system according to the first embodiment of the present invention is applied. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless particularly required.

  In the figure, 201 is an electronic shake correction unit, and 202 is an image stabilization correction amount calculation unit. The electronic shake correction unit 201 is configured to change the angle of view by changing the cutout position of the image signal, and provides an electronic shake correction function by changing the angle of view with a phase opposite to that of the camera shake. The image stabilization correction amount calculation unit 202 is based on the shake detection output of the angular velocity detection unit 305 based on the angular velocity detected by the angular velocity sensor 306 and the detection output based on the motion vector of the motion detection unit 104 ( Hereinafter, the vibration compensation amount is calculated. The electronic shake correction unit 201 has a configuration in which the readout position of the captured image stored in the memory is changed according to the shake correction amount, and a configuration in which the pixel area of the image sensor that reads the imaging signal is changed in accordance with the shake correction amount. It is not limited to the change of the cutout position. For example, you may have the structure which eliminates blurring by the image composition by image signal processing.

  Next, with reference to FIGS. 3 and 4, the blur correction operation in the image pickup apparatus in the present embodiment will be described. FIG. 3 is a diagram illustrating a configuration of an image stabilization amount generated by the shake correction system according to the present embodiment, and FIG. 4 is a flowchart of a shake correction operation in the imaging apparatus to which the shake correction system according to the present embodiment is applied. FIG.

  First, when the user operates the operation unit 110 to turn on the power of the image pickup apparatus, the control microcomputer 209 starts the initialization operation of the image pickup apparatus, and each unit such as the image pickup unit 102, the signal processing unit 203, and the signal recording unit 105 is started. Instruct to start operation.

  Next, when the interchangeable lens (lens unit) 301 is detachably connected to the imaging apparatus body via the mount 101, the control microcomputer 209 and the lens microcomputer 302 execute the control shown in step S401 in FIG. In step S401, the control microcomputer 109 turns on the interchangeable lens 301, and the lens microcomputer 302 starts a lens initialization operation. When the lens initialization operation is completed, the control microcomputer 209 and the lens microcomputer 302 shift control to step S402.

  In step S402, the control microcomputer 209 and the lens microcomputer 302 execute initial communication. In the initial communication, the control microcomputer 209 requests the lens microcomputer 302 to transmit information such as the number of aperture steps, zoom width, and focus state of the connected interchangeable lens 301, and the lens microcomputer 302 sends information to the lens microcomputer 302 accordingly. Send. On the other hand, the lens microcomputer 302 requests the imaging apparatus body (imaging unit) to transmit information such as the shutter speed and the operation mode, and the control microcomputer 209 transmits information to the control microcomputer 209 accordingly. As a result, the light from the subject received by the photographing optical system of the interchangeable lens 301 is adjusted in light quantity by the diaphragm, and is imaged on the surface of the image pickup device such as a CCD of the image pickup unit 102. In the imaging unit 102, the formed subject image is photoelectrically converted and accumulated as an imaging signal. When the initial communication is completed, the control microcomputer 209 and the lens microcomputer 302 shift the control to step S403.

  In step S403, the control microcomputer 209 requests the lens microcomputer 302 to transmit the correctable amount of the optical blur correction unit 304. In response to this, the lens microcomputer 302 transmits the correctable amount of the optical shake correction unit 304 to the control microcomputer 209. At this time, if the mounted interchangeable lens 301 does not include the optical shake correction unit 304, the amount that can be corrected by the optical shake correction unit is transmitted as zero. When the control microcomputer 209 receives the correctable amount of the optical shake correction unit 304, the control microcomputer 209 and the lens microcomputer 302 shift the control to step S404.

  In step S404, the control microcomputer 209 monitors whether or not the interchangeable lens 301 is continuously connected. When the interchangeable lens 301 is connected, the control microcomputer 209 starts loop control from step S405.

  In the loop control, in step S405, the control microcomputer 209 requests the lens microcomputer 302 to transmit the angular velocity applied to the interchangeable lens 301 detected by the angular velocity detection unit 305. In response to this, the lens microcomputer 302 transmits the angular velocity detected by the angular velocity detector 305 to the control microcomputer 209. When the control microcomputer 209 acquires the angular velocity detected by the angular velocity detection unit 305, the control microcomputer 209 proceeds to step S406.

  In step S406, the control microcomputer 209 determines an image stabilization correction amount based on the received angular velocity detected by the angular velocity detection unit 305 and the vibration applied to the imaging device detected by the motion detection unit 104. At this time, the high frequency component focuses on the angular velocity detected by the angular velocity detection unit 305, and the low frequency component focuses on the vibration applied to the imaging device detected by the motion detection unit 104, and the shake correction amount of the entire imaging device is determined. calculate. Thereafter, the control microcomputer 209 shifts the control to step S407.

  In step S <b> 407, the control microcomputer 209 compares the received correction amount of the optical shake correction unit 304 with the calculated shake correction amount, and determines that the correction amount of the optical shake correction unit (shift lens) 304 is the image stabilization. If it is equal to or greater than the correction amount, the control proceeds to step S408. If the correctable amount of the optical shake correction unit 304 is smaller than the image stabilization correction amount, the control proceeds to step S409.

  Here, the image stabilization correction amount calculated by the control microcomputer 209 will be described with reference to FIG. In FIG. 3, the horizontal axis represents the image stabilization correction amount calculated by the control microcomputer 209, and the vertical axis represents the breakdown of the image stabilization correction amount corresponding to each shake correction unit included in the imaging apparatus. When the image stabilization correction amount can take a value up to 4 °, when the optical blur correction unit 304 can correct the amount 2 °, and when the image stabilization correction amount is 2 ° (below the correctable amount). Performs only camera shake correction (change in the optical axis of incident light) by optical shake correction in accordance with the image stabilization correction amount. When the image stabilization amount exceeds 2 °, electronic shake correction is executed in addition to optical shake correction. When the correctable amount of the optical shake correcting unit changes according to the type of the interchangeable lens 301, the electronic shake correction is executed based on the correctable amount of the optical shake correcting unit 304 of the connected interchangeable lens 301. Increase or decrease the vibration compensation amount. As a result, the image pickup apparatus as a whole can provide a user with a certain amount of vibration isolation performance.

  Returning to the flowchart of FIG. 4, in step S <b> 408, the control microcomputer 209 instructs the electronic shake correction unit 201 to stop operating. At this time, the lens microcomputer 302 is notified that the electronic shake correction is stopped, and the lens microcomputer 302 executes control so that low-frequency camera shake can be sufficiently removed. Instead of stopping the operation of the electronic shake correction unit 201, the correction amount of the electronic shake correction unit 201 may be set to zero.

  In step S409, as shown in FIG. 3, the control microcomputer 209 calculates a difference between the calculated image stabilization correction amount and the optical shake correction correction amount for the entire imaging apparatus as an electronic shake correction amount, and step S410. Transfer control to.

  In step S410, the control microcomputer 209 instructs the electronic camera shake correction unit 201 to execute electronic camera shake correction based on the calculated electronic camera shake correction amount. The electronic shake correction unit 201 performs electronic shake correction based on the instructed electronic shake correction amount. At this time, the control microcomputer 209 transmits the execution of electronic shake correction to the lens microcomputer 302, and the lens microcomputer 302 places more emphasis on higher frequency components on the assumption that the electronic shake correction is executed. You may make it perform control which performs optical blurring correction.

  In step S411, the control microcomputer 209 monitors whether or not the interchangeable lens 301 is continuously connected. If the interchangeable lens 301 is continuously connected, the loop control after step S405 is continued. When the interchangeable lens 301 is not attached, the control is terminated and the process waits until the interchangeable lens 301 is connected again.

  When the image stabilization correction amount allocated to the electronic image stabilization unit 201 according to the correction amount of the shift lens, which is the optical image stabilization unit 304, is larger than the amount that can be corrected. Generates a warning of insufficient anti-vibration performance and stops the motion compensation operation. Alternatively, the above-described warning may be issued and control may be performed so that the electronic shake correction unit 201 is driven with the image stabilization correction amount of the electronic shake correction unit 201 as the correctable amount.

  By configuring the shake correction system as described above, the image stabilization performance of the entire image pickup apparatus does not depend on the performance of the optical shake correction unit 304 mounted on the interchangeable lens mounted on the image pickup apparatus body. It is possible to achieve the desired vibration isolation performance.

  In addition, an image pickup apparatus that can flexibly change the operation range of the electronic shake correction according to the performance of the optical shake correction unit 304 mounted on the interchangeable lens 301 and has an image stabilization function with little image quality deterioration. Can be configured.

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined.

  Also, when a software program that realizes the functions of the above-described embodiments is supplied from a recording medium directly to a system or apparatus having a computer that can execute the program using wired / wireless communication, and the program is executed Are also included in the present invention.

  Accordingly, the program code itself supplied and installed in the computer in order to implement the functional processing of the present invention by the computer also realizes the present invention. That is, the computer program itself for realizing the functional processing of the present invention is also included in the present invention.

  In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS.

  The recording medium for supplying the program may be, for example, a magnetic recording medium such as a hard disk or a magnetic tape, an optical / magneto-optical storage medium, or a nonvolatile semiconductor memory.

  As a program supply method, a computer program that forms the present invention is stored in a server on a computer network, and a connected client computer downloads and programs the computer program.

Claims (15)

First blur detection means for detecting the blur amount from the magnitude of the applied angular velocity;
Second blur detection means for detecting the blur amount from the amount of motion of the captured image;
First blur correction means for performing optical blur correction;
Second shake correction means for performing electronic shake correction on the captured image;
A correctable amount of the first shake correcting means is acquired, and based on the shake amount detected by the first shake detecting means, the shake amount detected by the second shake detecting means, and the correctable amount. Determining a first blur correction amount of the first blur correction unit and a second blur correction amount of the second blur correction unit, and determining the first and second blur correction amounts according to the first and second blur correction amounts. Control means for driving each of the two blur correction means;
A shake correction system comprising:   The control means determines an image stabilization correction amount to be corrected by the first and second camera shake correction means from the camera shake amounts detected by the first and second camera shake detection means, and the image stabilization correction. 2. The blur correction system according to claim 1, wherein an amount is allocated to the first and second blur correction amounts according to the correctable amount.   When the image stabilization correction amount is larger than the correctable amount, the control unit sets the image stabilization correction amount as the first correction amount, and calculates a difference between the image stabilization correction amount and the correctable amount as the first correction amount. When the image stabilization correction amount is equal to or less than the correctable amount, the image stabilization correction amount is set as the first image stabilization amount and the second image stabilization amount is set to zero. 3. The shake correction system according to claim 2, wherein the driving of the second shake correction unit is stopped.   The control means acquires a correctable amount of the second shake correction means, and generates a warning if the second shake correction amount is larger than the correctable amount of the second shake correction means, 4. The shake correction system according to claim 3, wherein the driving of the first and second shake correction means is stopped.   The first shake detection means includes an angular velocity sensor, and the second shake detection means has means for detecting a motion vector from an image signal of the captured image and detecting a motion of the captured image. The shake correction system according to any one of claims 1 to 4.   The first blur correction unit includes a shift lens that changes an optical axis of incident light, and the second blur correction unit includes a unit that changes a field angle of a captured image of the image signal. The shake correction system according to any one of claims 1 to 5. A method for controlling a shake correction system, comprising: a first shake correction unit that performs optical shake correction; and a second shake correction unit that performs electronic shake correction on a captured image.
A first blur detection step of detecting a blur amount from the magnitude of the applied angular velocity;
A second blur detection step of detecting a blur amount from a motion amount of the captured image;
A correctable amount of the first shake correcting means is acquired, and based on the shake amount detected by the first shake detecting means, the shake amount detected by the second shake detecting means, and the correctable amount. Determining a first blur correction amount of the first blur correction unit and a second blur correction amount of the second blur correction unit, and determining the first and second blur correction amounts according to the first and second blur correction amounts. A control process for driving each of the two blur correction means;
A control method comprising:   A program for causing a computer to execute the control method according to claim 7.   A computer-readable recording medium storing a program for causing a computer to execute the control method according to claim 7. An imaging unit that captures a subject image formed by the imaging optical system and generates an image signal;
A lens unit that includes the imaging optical system and is detachable from the imaging unit;
First blur detection means for detecting the blur amount of the lens unit from the magnitude of the angular velocity applied to the lens unit;
Second blur detection means for detecting a movement amount of the subject image from the image signal and detecting a blur amount of the imaging unit from the movement amount;
First blur correction means for performing optical blur correction on the photographing optical system;
Second blur correction means for performing electronic blur correction on the image signal;
A correctable amount of the first shake correcting means is acquired, and based on the shake amount detected by the first shake detecting means, the shake amount detected by the second shake detecting means, and the correctable amount. Determining a first blur correction amount of the first blur correction unit and a second blur correction amount of the second blur correction unit, and determining the first and second blur correction amounts according to the first and second blur correction amounts. Control means for driving each of the two blur correction means;
An imaging apparatus comprising:   The control means determines an image stabilization correction amount to be corrected by the first and second camera shake correction means from the camera shake amounts detected by the first and second camera shake detection means, and the image stabilization correction. The imaging apparatus according to claim 10, wherein the first and second blur correction amounts are allocated according to the correctable amount.   When the image stabilization correction amount is larger than the correctable amount, the control unit sets the image stabilization correction amount as the first correction amount, and calculates a difference between the image stabilization correction amount and the correctable amount as the first correction amount. When the image stabilization correction amount is equal to or less than the correctable amount, the image stabilization correction amount is set as the first image stabilization amount and the second image stabilization amount is set to zero. The imaging apparatus according to claim 11, wherein driving of the second shake correction unit is stopped.   The control means acquires a correctable amount of the second shake correction means, and generates a warning if the second shake correction amount is larger than the correctable amount of the second shake correction means, The imaging apparatus according to claim 12, wherein driving of the first and second blur correction units is stopped.   11. The first blur detection unit includes an angular velocity sensor, and the second blur detection unit includes a unit that detects a motion vector from the image signal and detects a motion of a captured image. 14. The imaging device according to any one of 1 to 13.   The first blur correction unit includes a shift lens that changes an optical axis of incident light, and the second blur correction unit includes a unit that changes a field angle of a captured image of the image signal. The imaging device according to any one of claims 10 to 14.

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