JP5067475B2 - Imaging apparatus and program thereof - Google Patents

Description

  The present invention relates to an imaging apparatus and a program thereof, and more particularly to an imaging apparatus that corrects image blurring and a program thereof.

In recent years, in an imaging apparatus, for example, a digital camera, there are a number of blur correction methods for correcting image blur.
For example, a camera shake is detected by an angular velocity sensor such as a gyro sensor, and an image pickup device such as a CCD or a photographing lens is moved in accordance with the detected camera shake amount to optically correct an image blur. There is a method of suppressing image blur by increasing the sensitivity and increasing the shutter speed. There is also a technique (hybrid) that corrects image blur by combining a plurality of blur correction methods.
Patent Document 1 relates to a technique (hybrid system) that controls a mechanical vibration isolator and an electronic vibration isolator in combination, and when the battery becomes a predetermined value or less, the mechanical power consumption is large. The image stabilizer is eliminated and only the electronic image stabilizer with low power consumption is used to suppress image blurring.

Japanese Patent Laid-Open No. 2001-311976

However, in the method of correcting blur using a gyro sensor or the like, it is possible to correct image blur due to camera shake of the photographer, but it is not possible to correct subject blur caused by movement of the subject.
In addition, in the method of suppressing blur by increasing the sensitivity and increasing the shutter speed, both camera shake and subject blur can be suppressed. However, in order to increase the sensitivity, the noise of the captured image increases and the image quality deteriorates. I was doing it.
In addition, there has been no hybrid system that can correct such a problem by appropriately suppressing blur according to the blur condition.

  Therefore, the present invention has been made in view of such conventional problems, and an object of the present invention is to provide an imaging apparatus capable of appropriately suppressing blurring according to the blurring state and a program thereof.

In order to achieve the above object, an image pickup apparatus according to the first aspect of the present invention includes an image pickup means for picking up an image of a subject,
Image stabilization means for correcting image blur due to camera shake;
Blur reduction means for reducing image blur due to camera shake and subject blur,
A setting unit for the user to set a ratio between the strength of the degree of blur correction by the blur correction unit and the strength of the amount of blur reduction by the blur reduction unit;
Control means for executing blur correction by the blur correction means and blur reduction by the blur reduction means according to the ratio set by the setting means;
It is provided with.

Further, for example, as described in claim 2 , the blur correction unit includes:
Optical blurring may be corrected optically.

Further, for example, as described in claim 3 , the blur reduction means includes:
Image blur may be reduced by increasing the sensitivity and increasing the shutter speed accordingly.

Further, for example, as described in claim 4 , a light amount calculating means for calculating a light amount based on the light of the subject,
A light amount determination means for determining whether or not the light amount calculated by the light amount calculation means is a sufficient light amount necessary for photographing;
With
The control means includes
If it is determined by the light amount determination means that the light amount is necessary and sufficient, execution of blur reduction by the blur reduction means may be prohibited and only blur correction by the blur correction means may be executed.

Further, for example, as described in claim 5 , shutter speed calculation means for calculating a proper exposure and calculating a shutter speed based on the calculated proper exposure;
Shutter speed determining means for determining whether or not the shutter speed calculated by the shutter speed calculating means is faster than a predetermined shutter speed;
With
The control means includes
If the shutter speed determination means determines that the shutter speed is faster than a predetermined shutter speed, the blur reduction by the blur reduction means may be prohibited and only the blur correction by the blur correction means may be executed.

To achieve the above object, a program according to a sixth aspect of the invention includes an imaging process for imaging a subject,
Blur correction processing to correct image blur due to camera shake,
Blur reduction processing to reduce image blur due to camera shake and subject blur,
Detection processing for detecting subject blur based on image data captured by the imaging processing in which blur correction has been performed by the blur correction processing;
Control processing for controlling the amount of blur reduction by the blur reduction processing according to the detection result by the detection processing;
And each of the above processes is executed by a computer.

According to the first aspect of the present invention, an imaging unit that captures an image of a subject, a blur correction unit that corrects image blur due to camera shake, a blur reduction unit that reduces blur of an image due to camera shake and subject blur, and a user A setting unit for setting a ratio between the strength of the degree of blur correction by the blur correction unit and the strength of the amount of blur reduction by the blur reduction unit, and the blur according to the use ratio set by the setting unit. Since the blur correction by the correction unit and the blur reduction by the blur reduction unit are executed, it is possible to suppress the blur reflecting the user's intention.

According to the second aspect of the present invention, since the blur correction unit optically corrects the blur of the image, it is possible to correct camera shake and the like without deteriorating the image quality.

According to the third aspect of the present invention, since the blur reducing means reduces the blur of the image by increasing the sensitivity and increasing the shutter speed accordingly, the camera shake, camera shake, subject blur, etc. Can reduce blurring. Further, since the amount of blur reduction is controlled according to the detection result, the blur reduction is not performed unnecessarily, and the image quality is not unnecessarily degraded.

According to the fourth aspect of the present invention, the light amount calculating means for calculating the light amount based on the light of the subject, and the light amount for determining whether or not the light amount calculated by the light amount calculating means is a sufficient light amount necessary for photographing. Determining means, and the control means prohibits execution of blur reduction by the blur reduction means when the light quantity determination means determines that the necessary and sufficient light quantity is obtained, and blur correction by the blur correction means. Therefore, it is possible to suppress deterioration in image quality due to blur reduction.

According to the fifth aspect of the present invention, the shutter speed calculating means for calculating the appropriate exposure and calculating the shutter speed based on the calculated appropriate exposure, and the shutter speed calculated by the shutter speed calculating means are predetermined. Shutter speed determining means for determining whether or not the shutter speed is higher than a predetermined shutter speed. When the shutter speed determining means determines that the shutter speed is faster than a predetermined shutter speed, Since the execution of the reduction is prohibited and only the shake correction by the shake correction unit is executed, it is possible to suppress the deterioration of the image quality due to the execution of the shake reduction.

According to the sixth aspect of the invention, the image pickup apparatus of the present invention can be realized by being read by a digital camera, a personal computer or the like.

1 is a block diagram of a digital camera according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the digital camera of 1st Embodiment. It is a figure which shows the mode of the utilization ratio table | surface currently recorded on the memory. It is a flowchart which shows operation | movement of the digital camera of 2nd Embodiment. It is a flowchart which shows operation | movement of the digital camera in a modification. It is a figure which shows the mode of the image which is displayed on the flowchart and operation | movement of the digital camera in the modification, and the display part. It is a figure which shows the mode of the utilization ratio corresponding to the detected contrast component.

Hereinafter, the present embodiment will be described in detail with reference to the drawings as an example in which the imaging apparatus of the present invention is applied to a digital camera.
[First Embodiment]
A. Configuration of Digital Camera FIG. 1 is a block diagram showing a schematic electrical configuration of a digital camera 1 that implements the imaging apparatus of the present invention.
The digital camera 1 includes a photographic lens 2, a correction lens 3, a lens driving block 4, a shutter / aperture 5, a CCD 6, a vertical driver 7, a TG (timing generator) 8, a unit circuit 9, a DMA controller (hereinafter referred to as DMA) 10, CPU 11, key input unit 12, memory 13, DRAM 14, DMA 15, motion vector calculation unit 16, blur detection unit 17, DMA 18, image generation unit 19, DMA 20, DMA 21, display unit 22, DMA 23, compression / decompression unit 24, DMA 25, flash A memory 26 and a bus 27 are provided.

The photographic lens 2 includes a focus lens and a zoom lens that are composed of a plurality of lens groups.
The lens driving block 4 includes a driving circuit (not shown), and the driving circuit moves the focus lens and the zoom lens in the optical axis direction in accordance with a control signal from the CPU 11.

The correction lens 3 is a lens for correcting image blur due to camera shake, and the lens driving block 4 is connected to the correction lens 3.
The lens driving block 4 corrects the blur by moving the correction lens 3 in the yaw direction and the pitch direction. The lens drive block 4 includes a motor that moves the correction lens 3 in the yaw direction and the pitch direction, and a motor driver that drives the motor.

The aperture / shutter 5 includes a drive circuit (not shown), and the drive circuit operates the aperture / shutter 5 in accordance with a control signal sent from the CPU 11. The diaphragm / shutter 5 functions as a diaphragm and a shutter.
The diaphragm means a mechanism for controlling the amount of light incident on the CCD 6, and the shutter means a mechanism for controlling the time for which light is applied to the CCD 6, and the time for which light is applied to the CCD 6 (exposure time). Depends on the shutter speed.
The exposure amount is determined by the aperture value (aperture level) and the shutter speed.

  The CCD 6 is scanned and driven by the vertical driver 7, photoelectrically converts the intensity of light of each color of the RGB value of the subject image for every fixed period, and outputs it to the unit circuit 9 as an imaging signal. The operation timings of the vertical driver 7 and the unit circuit 9 are controlled by the CPU 11 via the TG 8.

  A TG 8 is connected to the unit circuit 9, a CDS (Correlated Double Sampling) circuit that holds the imaged signal output from the CCD 6 by correlated double sampling, and an AGC that performs automatic gain adjustment of the imaged signal after the sampling. (Automatic Gain Control) circuit and an A / D converter that converts the analog signal after the automatic gain adjustment into a digital signal. The image pickup signal obtained by the CCD 6 passes through the unit circuit 9 and is then Bayered by the DMA 10 The data is stored in the buffer memory (DRAM 14).

The CPU 11 has a function of performing AE processing, AF processing, and the like, and is a one-chip microcomputer that controls each unit of the digital camera 1.
In particular, the CPU 11 sets a utilization ratio between sensitivity-type blur reduction and mechanical / electronic blur correction according to the shooting situation.
Sensitivity-type blur reduction is to suppress blur by increasing the sensitivity of an image sensor such as a CCD and increasing the shutter speed. Here, “increased sensitivity” refers to the action of brightening the image, and is a method of increasing sensitivity by increasing the gain or a method of increasing sensitivity by driving the CCD 6 to add pixels. There may be. Here, the sensitivity is increased by increasing the gain.

The mechanical / electronic blur correction referred to here is a blur correction method other than the sensitivity blur reduction.
For example, based on the blur amount of a gyro sensor such as an angular velocity sensor or a motion vector of image data, a correction lens, a photographing lens, or a method of correcting blur by shifting an image sensor (mechanical blur correction), There is a method of correcting blur by trimming an image of image data based on a blur amount of a gyro sensor or a motion vector of a frame (electronic blur correction). Here, blurring is corrected by shifting the correction lens (mechanical blur correction is adopted).

The key input unit 12 includes a plurality of operation keys such as a shutter button, a mode switching key, a cross key, and a SET key that can be pressed halfway down, and outputs an operation signal corresponding to a user key operation to the CPU 11.
The memory 13 stores a control program (for example, a program necessary for AE and AF processing) necessary for the CPU 11 to control each part of the digital camera 1 and necessary data (for example, a utilization ratio table). The CPU 11 operates according to the program.

  The DRAM 14 is used as a buffer memory for temporarily storing image data picked up by the CCD 6 and also as a working memory for the CPU 11.

The DMA 15 reads out Bayer data or luminance / chrominance signal image data stored in the buffer memory and outputs the data to the motion vector calculation unit 16.
The motion vector calculation unit 16 calculates a motion vector of a frame (image data), and calculates a motion vector of the image data using a representative point matching method, a block matching method, or the like. In order to calculate this motion vector, the motion vector is calculated based on the image data of the frame to be calculated and the previously captured frame, and therefore a memory circuit that holds the previous frame for a certain period of time is also provided. Including.

The blur detection unit 17 includes an angular velocity sensor such as a gyro sensor (not shown), and detects a camera shake amount of the photographer.
The blur detection unit 17 includes a gyro sensor that detects a blur amount in the Yaw direction and a gyro sensor that detects a blur amount in the Pitch (pitch) direction.
The blur amount detected by the blur detection unit 17 is sent to the CPU 11.

The DMA 18 reads out image data of Bayer data stored in the buffer memory and outputs it to the image generation unit 19.
The image generation unit 19 performs processing such as pixel interpolation processing, γ correction processing, and white balance processing on the image data sent from the DMA 18 and also generates a luminance color difference signal (YUV data). That is, it is a portion that performs image processing.
The DMA 20 stores, in a buffer memory, image data (YUV data) of a luminance / color difference signal that has been subjected to image processing by the image generation unit 19.

The DMA 21 outputs image data of YUV data stored in the buffer memory to the display unit 22.
The display unit 22 includes a color LCD and its drive circuit, and displays an image of the image data output from the DMA 21.

The DMA 23 outputs the YUV data image data and compressed image data stored in the buffer memory to the compression / decompression unit 24, and buffers the image data compressed by the compression / decompression unit 24 and the decompressed image data. It is stored in memory.
The compression / decompression unit 24 is a part that performs compression / decompression of image data (for example, compression / decompression in JPEG or MPEG format).
The DMA 25 reads compressed image data stored in the buffer memory and records it in the flash memory 26, or stores the compressed image data recorded in the flash memory 26 in the buffer memory.

B. Hereinafter, the function of each configuration of the digital camera 1 which is a feature of the present invention will be described.
The operation of the digital camera 1 in the first embodiment will be described with reference to the flowchart of FIG.

  When the hybrid shooting mode is set by the user operating the mode switching key of the key input unit 12, the CPU 11 starts imaging the subject by the CCD 6, and the image data of the luminance color difference signal generated from the captured image data. Is stored in the buffer memory, and so-called through image display is started to display the stored image data on the display unit 22 (step S1). Further, when the user sets the hybrid shooting mode, the CPU 11 also starts camera shake detection by the blur detection unit 17.

  Next, the CPU 11 starts mechanical blur correction (step S2). Specifically, the amount of blur (the amount of blur in the yaw direction and the amount of blur in the pitch direction) detected by the blur detection unit 17 is acquired, and the operation of driving the correction lens 3 based on the acquired blur amount is started. . Thereby, the image of the image data output from the CCD 6 becomes an image without camera shake.

  Next, the CPU 11 acquires a frame by storing the image data (Bayer data) of one frame output from the CCD 6 at the start of the through image display in the buffer memory (step S3). Further, the CPU 11 causes the image generation unit 19 to output the acquired Bayer data image data via the DMA 18, and causes the image generation unit 19 to perform white balance processing and luminance color difference signal (YUV data) generation processing. The image data of the luminance / color difference signal is stored in the buffer memory via the DMA 20.

  Next, the CPU 11 performs AE processing (step S4). That is, the exposure amount is calculated based on the luminance component of the acquired image data, and the shutter speed, aperture value, gain amount, etc. are set based on the calculated exposure amount. The setting of the shutter speed and the like is performed based on the AE program diagram for the through image.

Next, the CPU 11 causes the motion vector calculation unit 16 to acquire the image data of the Bayer data (or YUV data) stored in the buffer memory in step S3 via the DMA 15, thereby causing the motion vector calculation unit 16 to acquire the frame. The motion vector of the image data is calculated (step S5), and the calculated motion vector is acquired. This calculated motion vector becomes the blur vector of the subject as it is. This is because since mechanical blur correction is executed, the image captured by the CCD 6 is already in a state in which camera shake has been corrected, and thus the detected blur vector becomes the blur vector of the subject as it is.
Note that the calculation of the motion vector requires the current frame data (the frame from which the motion vector is to be calculated) and the previous frame data, so the motion vector of the first captured frame must be calculated. Therefore, the motion vector is not calculated.

Next, the CPU 11 determines whether or not the magnitude of the acquired motion vector (subject blur amount) is larger than a predetermined value (step S6). This predetermined value is recorded in the memory 13 in advance.
If it is determined in step S6 that the blur amount of the subject is not larger than the predetermined value, that is, it is small, there is almost no subject blur and the camera shake correction can be handled only. The reduction use ratio is set to 0% (step S7), and the process proceeds to step S9. That is, blur correction is performed only by mechanical blur correction. The set utilization ratio is stored in the utilization ratio storage area of the internal memory of the CPU 11.

On the other hand, if it is determined in step S6 that the blur amount of the subject is greater than the predetermined value, the mechanical blur correction for performing the blur correction and the use ratio of the sensitivity type blur reduction are recorded in the calculated blur amount of the subject and the memory 13. Is set based on the usage ratio table (step S8), and the process proceeds to step S9.
This set use ratio is used for blur suppression in still image shooting.

FIG. 3A shows the state of the usage ratio table recorded in the memory 13.
As can be seen from the figure, it can be seen that as the subject blur amount becomes larger than a predetermined value, the use ratio of the sensitivity-type blur reduction increases. On the contrary, if the subject blur amount is smaller than the predetermined value, it can be seen that the utilization ratio of the sensitivity-type blur reduction is 0%.

  In other words, if the subject blur amount is smaller than the predetermined value, it is considered that the subject blur is small, so only mechanical blur correction can be used, and if the subject blur amount is larger than the predetermined value, the subject blurring is likely to occur. Accordingly, the degree of sensitivity-type blur reduction is increased and the degree of mechanical blur correction is decreased accordingly. As a result, it is not necessary to perform sensitivity-type blur reduction unnecessarily, and the image quality is not unnecessarily degraded.

  In step S9, the CPU 11 causes the display unit 22 to display the frame image data (YUV data) stored in the buffer memory acquired in step S3 via the DMA 21.

Next, the CPU 11 determines whether or not the shutter button has been half-pressed by the user (step S10). This determination is made based on whether or not an operation signal corresponding to half-pressing of the shutter button has been sent from the key input unit 12.
If it is determined in step S10 that the shutter button is not half-pressed, the process returns to step S3 to acquire image data of the next captured frame and repeat the above-described operation.

On the other hand, if it is determined in step S10 that the shutter button is half-pressed, the shutter speed, aperture value, and gain amount are set based on the luminance component of the through-image data captured immediately before and the most recently used usage ratio. (Step S11). The setting of the shutter speed and the like is performed based on an AE program diagram that takes into account the utilization ratio for still image shooting.
Note that a shutter speed or the like may be set based on the AE process, and the set shutter speed or the like may be reset according to the usage ratio. The setting of the shutter speed and the like in the AE process at this time is performed based on a normal AE program diagram that does not take into account the utilization ratio for still image shooting.

  Next, the CPU 11 performs AF processing (step S12). Here, since AF processing by contrast detection is performed as the AF processing method, the focus lens is moved from the lens end (the lens position where the subject closest to the photographer is in focus) to the other lens end. Then, the AF evaluation value of the AF area at each lens position is calculated to detect the peak of the AF evaluation value of the AF area. When the peak is detected, the search movement is stopped and the peak is detected. The subject is brought into focus by moving the focus lens to the lens position where is detected.

Next, the CPU 11 determines whether or not the user has fully pressed the shutter button (step S13). This determination is made based on whether or not an operation signal corresponding to the full press of the shutter button has been sent from the key input unit 12.
If it is determined in step S13 that the shutter button is not fully pressed, the process stays in step S13 until the shutter button is fully pressed. If it is determined that the shutter button is fully pressed, exposure starts at the shutter speed and aperture value set in step S11 (step S13). S14). That is, the light of the subject is projected onto the CCD 6 via the taking lens 2 or the like.

  Next, the CPU 11 acquires the shake amount (the shake amount in the yaw direction and the shake amount in the pitch direction) detected by the shake detection unit 17 (step S15), and drives the correction lens 3 based on the acquired shake amount. As a result, blur correction is performed (step S16).

  At this time, the drive amount for driving the correction lens 3 is changed in accordance with the utilization ratio of mechanical blur correction. For example, when the mechanical blur correction utilization ratio is 100%, the blur is corrected by moving the detected blur amount within the driving range of the correction lens 3, but the utilization ratio is not 100% (sensitivity). In the case of performing the image blur reduction), the detected blur amount is decreased according to the mechanical blur correction use ratio and the correction lens 3 is moved, or the driving range of the correction lens 3 is set to the mechanical blur correction. The blurring is corrected by gradually limiting according to the usage ratio.

  That is, when the mechanical blur correction utilization ratio is 100%, the camera shake can be dealt with only by the mechanical blur correction, but when the mechanical blur correction is not 100%, the mechanical blur correction and the sensitivity blurring are performed. Since the blur is suppressed by the reduction, the mechanical blur correction is performed by reducing the detected blur amount according to the usage ratio, and the usage ratio of the mechanical blur correction is 0% (the usage ratio of the sensitivity-type blur reduction is 100). %), The correction lens 3 is not driven.

Next, the CPU 11 determines whether or not the exposure has been completed (step S17). That is, the determination is made based on whether or not the exposure time set in step S11 has elapsed.
If it is determined in step S17 that the exposure has not ended, the process returns to step S15 and the above-described operation is repeated.
On the other hand, if it is determined in step S17 that the exposure has been completed, the CPU 11 reads out the charges (still image data) accumulated in the CCD 6 and stores them in the buffer memory via the DMA 10, and the image generator 19 performs image processing. The compressed still image data (YUV data) is compressed by the compression / decompression unit 24, and the compressed still image data is recorded in the flash memory 26 via the DMA 25 (step S18).
At this time, the still image data read from the CCD 6 is subjected to automatic gain adjustment based on the gain amount set in step S11 by the unit circuit 9.

C. As described above, in the first embodiment, the blur amount of a subject is calculated, and when the calculated blur amount of the subject is smaller than a predetermined value, the utilization ratio of mechanical blur correction is set to 100%. Since it is set and shake correction is performed, it is possible to perform shake correction appropriate for the nature and state of the shake. In this case, since sensitivity-type blur reduction is not performed, it is not necessary to unnecessarily deteriorate image quality.
If the calculated blur amount of the subject is greater than a predetermined value, the usage ratio between the degree of blur correction by mechanical blur correction and the degree of blur suppression by sensitivity-type blur reduction is set according to the blur amount of the subject. As a result, it is not necessary to unnecessarily reduce sensitivity-type blurring, and image quality degradation can be minimized.

[Second Embodiment]
Next, a second embodiment will be described.
In the first embodiment, a blur amount of a subject is calculated, and a blur correction is performed by setting a mechanical blur correction and a sensitivity blur reduction usage ratio according to the calculated subject blur amount. However, in the second embodiment, the distance of the subject is calculated, and the use ratio of mechanical blur correction and sensitivity blur reduction is set according to the distance of the subject. This is because as the subject is farther away, the blurring of the subject is not a problem and the camera shake becomes a problem. The closer the subject is, the more the subject blurring becomes a problem.

D. Operation of Digital Camera 1 The second embodiment also implements the imaging device of the present invention by using the digital camera 1 having the same configuration as that shown in FIG.
Hereinafter, the operation of the digital camera 1 according to the second embodiment will be described with reference to the flowchart of FIG.

When the hybrid shooting mode is set by the user operating the mode switching key of the key input unit 12, the CPU 11 starts imaging by the CCD 6, and displays a through image of the sequentially captured subject on the display unit 22. The through image display is started (step S31).
Next, the CPU 11 starts a continuous AF process (step S32). This continuous AF processing refers to performing AF processing continuously. Here, since AF processing using a contrast detection method is adopted, AF processing using a contrast detection method is continuously performed. It becomes.

Next, the CPU 11 performs an AE process (step S33). That is, the exposure amount is calculated based on the luminance component of the captured image data, and the shutter speed, aperture value, gain amount, and the like are set based on the calculated exposure amount. The setting of the shutter speed and the like is performed based on the AE program diagram for the through image.
Next, the CPU 11 determines whether or not the focus position (focus lens position) has been detected by the continuous AF process (step S34).
If it is determined in step S34 that the focus position has not been detected, the process proceeds to step S39. If it is determined that the focus position has been detected, the distance of the subject (subject distance) is calculated based on the focus position (step S35).

Next, the CPU 11 determines whether or not the calculated subject distance is smaller than a predetermined value (predetermined distance) (step S36). This predetermined value is recorded in the memory 13 in advance. Note that it may be determined whether the distance is smaller than a predetermined value based on the focus position without calculating the subject distance.
If it is determined in step S36 that the subject distance is not smaller than the predetermined value (the subject is not closer than the predetermined value), that is, the subject distance is larger (the subject is farther than the predetermined value), the subject is at a far position and the subject blur is noticeable. Since the camera shake is conspicuous, the mechanical blur correction utilization ratio is set to 100% (sensitivity blur reduction utilization ratio 0%) (step S37), and the process proceeds to step S39. The set utilization ratio is stored in the utilization ratio storage area of the built-in memory of the CPU 11.

On the other hand, if it is determined in step S36 that the subject distance is smaller than the predetermined value, the utilization ratio of mechanical blur correction for performing blur correction and sensitivity-type blur reduction is used for the calculated subject distance and the usage recorded in the memory 13. Set based on the ratio table (step S38), and proceed to step S39.
FIG. 3B shows a usage ratio table recorded in the memory 13 according to the second embodiment.

As can be seen from the figure, as the subject distance increases, the sensitivity blur reduction usage ratio decreases, and when the subject distance reaches a predetermined value, the sensitivity blur reduction usage ratio becomes 0%.
In other words, when the subject distance is smaller than the predetermined value, the subject blur is conspicuous, so the degree of sensitivity-type blur reduction is reduced according to the size (length) of the subject distance, and the subject distance is larger than the predetermined value. In such a case, the blurring of the subject is hardly noticeable, so that only the mechanical blur correction is used.

In step S39, the CPU 11 determines whether or not the shutter button is half-pressed by the user.
If it is determined in step S39 that the shutter button is not half-pressed, the process returns to step S33 and the above-described operation is repeated.
On the other hand, if it is determined in step S39 that the shutter button has been half-pressed, the shutter speed, aperture value, and gain amount are set based on the luminance component of the through image data captured immediately before and the most recently used usage ratio. (Step S40). The setting of the shutter speed and the like is performed based on an AE program diagram that takes into account the utilization ratio for still image shooting.
Note that a shutter speed or the like may be set based on the AE process, and the set shutter speed or the like may be reset according to the usage ratio. The setting of the shutter speed and the like in the AE process at this time is performed based on a normal AE program diagram that does not take into account the utilization ratio for still image shooting.

Next, the CPU 11 performs an AF process using a contrast detection method (step S41).
Next, the CPU 11 determines whether or not the shutter button has been fully pressed by the user (step S42).
If it is determined in step S42 that the shutter button is not fully pressed, the process stays in step S42 until the shutter button is fully pressed. If it is determined that the shutter button is fully pressed, exposure starts at the shutter speed and aperture value set in step S40 (step S42). S43).

Next, the CPU 11 acquires a camera shake amount (a shake amount in the yaw direction, a shake amount in the pitch direction) detected by the shake detection unit 17 (step S44), and drives the correction lens 3 based on the acquired camera shake amount. Thus, the blur is corrected (step S45).
At this time, the drive amount for driving the correction lens 3 is changed in accordance with the utilization ratio of mechanical blur correction. For example, when the use ratio of mechanical shake correction is 100%, the shake is corrected by moving the detected camera shake amount within the driveable range of the correction lens 3, but the use ratio is not 100% ( In the case where sensitivity-type blur reduction is also performed), the detected camera shake amount is decreased according to the mechanical blur correction use ratio and the correction lens 3 is moved, or the driving range of the correction lens 3 is mechanical blur correction. The blur correction is performed by gradually restricting according to the use ratio.

  That is, when the mechanical blur correction utilization ratio is 100%, the camera shake can be dealt with only by the mechanical blur correction, but when the mechanical blur correction is not 100%, the mechanical blur correction and the sensitivity blurring are performed. Since the blur is suppressed by the reduction, the mechanical blur correction is performed by reducing the detected blur amount according to the utilization ratio. Therefore, when the mechanical blur correction usage ratio is 0% (sensitivity blur reduction usage ratio is 100%), the correction lens 3 is not driven.

Next, the CPU 11 determines whether or not the exposure is completed (step S46). That is, the determination is made based on whether or not the exposure time set in step S40 has elapsed.
If it is determined in step S46 that the exposure has not ended, the process returns to step S44 and the above operation is repeated.

On the other hand, if it is determined in step S46 that the exposure has been completed, the CPU 11 reads out the charge (image data) accumulated by the CCD 6, causes the image generation unit 19 to perform image processing, and then compresses it by the compression / decompression unit 24. The still image data is recorded in the flash memory 26 (step S47).
At this time, the still image data read from the CCD 6 is subjected to automatic gain adjustment based on the gain amount set in step S40 by the unit circuit 9.

E. As described above, in the second embodiment, the subject distance is calculated, and when the calculated subject distance is larger than a predetermined value (when camera shake is more conspicuous than subject blur), mechanical blur correction is used. Since blur correction is performed with the ratio set to 100%, it is possible to perform blur correction appropriate to the nature of the blur. In this case, since sensitivity-type blur reduction is not performed, it is not necessary to unnecessarily deteriorate image quality.
When the calculated subject distance is smaller than a predetermined value (when the subject blur is noticeable together with the camera shake), the degree of the blur correction by the mechanical blur correction and the degree of the blur suppression by the sensitivity-type blur reduction according to the subject distance. Since the use ratio is set, it is not necessary to reduce sensitivity-type blurring unnecessarily, and degradation of image quality can be minimized.

[Modification]
Each of the above embodiments can be modified as follows.
(1) In the first and second embodiments described above, the mechanical blur correction and sensitivity blur reduction use ratios are simply set according to the subject blur amount and subject distance. When the set shutter speed is faster than the predetermined shutter speed, the mechanical blur correction utilization ratio may be set to 100% regardless of the subject blur amount and subject distance.

Hereinafter, the operation will be described with reference to the flowchart of FIG.
First, when it is determined that the shutter button is half-pressed in step S10 in FIG. 2 or step S39 in FIG. 4, the process proceeds to step S61 in FIG. 5A, and the CPU 11 performs AE processing. The setting of the shutter speed and the like in the AE process at this time is performed based on a normal AE program diagram that does not take into account the utilization ratio for still image shooting.
Next, the CPU 11 determines whether or not the shutter speed set by the AE process is faster than a predetermined shutter speed (step S62). This predetermined shutter speed is recorded in the memory 13.

If it is determined in step S62 that the shutter speed is faster than the predetermined shutter speed, the CPU 11 resets the mechanical blur correction usage ratio to 100% (the sensitivity blur reduction usage ratio is set to 0%). (Step S63), the process proceeds to Step S12 in FIG. 2 or Step S41 in FIG.
On the other hand, if it is determined in step S62 that the shutter speed is not faster than the predetermined shutter speed, the CPU 11 determines the shutter speed, aperture value, and gain amount set in step S61 according to the most recently used usage ratio. After resetting (step S64), the process proceeds to step S12 in FIG. 2 or step S41 in FIG.

In other words, if the sensitivity-type blur reduction is performed when the shutter speed set by the AE process is equal to or higher than a predetermined speed (high speed), the shutter speed must be further increased and the sensitivity must be increased. Since deterioration becomes conspicuous, when the appropriate shutter speed is equal to or higher than a predetermined speed, the use ratio of mechanical blur correction is set to 100% and sensitivity blur reduction is not performed. Thereby, degradation of image quality can be suppressed.
That is, in the modified example (1), the operation as shown in FIG. 5A is performed instead of the operation in step S11 in FIG. 2 or step S40 in FIG.

  (2) In the first and second embodiments, the use ratio of mechanical blur correction and sensitivity blur reduction is simply set according to the blur amount and subject distance of the subject. When the calculated LV value is equal to or greater than a certain value, the mechanical blur correction usage ratio is set to 100% regardless of the subject blur amount and subject distance. You may make it set.

The operation will be described below with reference to the flowchart of FIG.
First, when it is determined that the shutter button is half-pressed in step S10 of FIG. 2 or step S39 of FIG. 4, the process proceeds to step S71 of FIG. 5B, and the CPU 11 calculates an LV value indicating the brightness of the subject. I do. This calculation is performed based on the luminance component of the image data.
Next, the CPU 11 performs an AE process based on the calculated LV value (step S72). The setting of the shutter speed and the like in this AE process is performed based on a normal AE program diagram.
Next, the CPU 11 determines whether or not the calculated LV value is larger than a certain value (step S73). This constant value is recorded in the memory 13.

If it is determined in step S73 that the calculated LV value is greater than a certain value, the CPU 11 resets the mechanical blur correction usage ratio to 100% (the sensitivity blur reduction usage ratio is set to 0%). Then (step S74), the process proceeds to step S12 in FIG. 2 or step S41 in FIG.
On the other hand, if it is determined in step S73 that the calculated LV value is not greater than a certain value, the CPU 11 determines the shutter speed, aperture value, gain set in step S72 according to the most recently used usage ratio. The amount is reset (step S75), and the process proceeds to step S12 in FIG. 2 or step S41 in FIG.

In other words, when the calculated LV value is equal to or greater than a certain value, a sufficient amount of light necessary for photographing can be secured. In such a case, if sensitivity-type blur reduction correction is performed, the shutter speed is further increased and sensitivity is increased. If the LV value is a certain value or more, the mechanical blur correction usage ratio is set to 100% to reduce sensitivity blurring. Is not performed. Thereby, degradation of image quality can be suppressed.
That is, in the modified example (2), the operation shown in FIG. 5B is performed instead of the operation in step S11 in FIG. 2 or step S40 in FIG.

(3) In the first and second embodiments, the ratio of use of mechanical blur correction and sensitivity blur reduction is set during through image display (before halfway pressing of the shutter button). The utilization ratio may be set after half-pressing the shutter.
The specific operation in this case will be described separately for the first and second embodiments.

First, in the case of the first embodiment, when determining that the shutter button is half-pressed in step S10 of FIG. 2, the CPU 11 determines the latest through image based on the two through images captured immediately before. A motion vector is calculated. Then, it is determined whether or not the calculated magnitude of the motion vector is larger than a predetermined value. If it is not larger, the utilization ratio of mechanical blur correction is set to 100%, and if larger, mechanical blur correction and sensitivity are set. The use ratio of the expression blur reduction is set based on the calculated blur amount of the subject and the use ratio table recorded in the memory 13. Then, when the use ratio setting is completed, the process proceeds to step S11.
In this case, the operations in steps S5 to S8 in FIG. 2 are not performed.

  Next, in the case of the second embodiment, when it is determined in step S39 in FIG. 2 that the shutter button is half-pressed, the CPU 11 performs an AF process using a contrast detection method. Then, the subject distance is calculated based on the lens position of the focus position, and it is determined whether or not the calculated subject distance is smaller than a predetermined value (predetermined distance). If not, the mechanical blur correction utilization ratio is set to 100. When the ratio is small, the utilization ratio of mechanical blur correction and sensitivity blur reduction is set based on the calculated subject distance and the utilization ratio recorded in the memory 13. When the use ratio setting is completed, the process proceeds to step S42 after performing the process of step S40.

In this case, the operations in steps S34 to S38 in FIG. 4 are not performed.
In addition, the utilization ratio is set after being half-pressed. However, when the shutter button is fully pressed at once, it may be performed after the shutter button is fully pressed. In this case, the determination of half-pressing the shutter button in step S10 in FIG. 2 and step S39 in FIG. 4 is replaced with the determination of full-pressing the shutter button, and the operations in step S13 in FIG. 2 and step S42 in FIG. 4 are not performed. It becomes.

  (4) Moreover, you may make it combine the said modification (1) or (2) and the said modification (3). That is, in the modified example (3), instead of the operation in step S11 in FIG. 2 or step S40 in FIG. 4, an operation as shown in FIG.

(5) In the first and second embodiments, the mechanical blur correction and sensitivity blur reduction usage ratio is automatically set. However, the user may set the usage ratio. You may be able to do it.
For example, when shooting in a situation where there is little subject blurring, the user can reduce the usage ratio of sensitivity-type blur reduction (increase the usage ratio of mechanical blur correction), and the user wants to prioritize image quality Also, by reducing the use ratio of sensitivity-type blur reduction, it is possible to obtain an image with good image quality (an image with less noise). In addition, when there is a lot of subject blur, if you want to prioritize the reduction of subject blur over image quality, the user increases the subject ratio by increasing the use ratio of sensitivity blur reduction (decreasing the use ratio of mechanical blur correction). Can be obtained.

The operation will be described below with reference to the flowchart of FIG.
When the hybrid shooting mode is set by the user operating the mode switching key of the key input unit 12, the CPU 11 starts imaging by the CCD 6, and displays a through image of the sequentially captured subject on the display unit 22. The through image display is started (step S81).

Next, the CPU 11 determines whether or not the menu mode has been selected by the user (step S82). This determination is made based on whether or not an operation signal corresponding to the operation of the menu key is sent from the key input unit 12.
If it is determined in step S82 that the menu mode has been selected, the CPU 11 determines whether or not the usage ratio setting mode has been selected by the user (step S83).

When the menu mode is selected by the user, the CPU 11 causes the display unit 22 to display the menu together with the through image of the subject. The contents of the displayed menu include a sensitivity setting mode and a usage ratio setting mode.
Then, the usage ratio setting mode can be selected by operating the cross key and the SET key from the displayed menu.
If it is determined in step S83 that the usage ratio setting mode has not been selected, processing of the selected other mode is performed.

On the other hand, when determining in step S83 that the usage ratio setting mode has been selected, the CPU 11 sets the usage ratio specified by the user (step S84) and returns to step S82.
At this time, when the usage ratio setting mode is selected, the CPU 11 causes the display unit 22 to display a usage ratio setting bar as shown in FIG.
Then, the user can designate the utilization ratio by operating the cross key and the set key while looking at the utilization ratio setting bar.

  Image quality priority in the utilization ratio setting bar refers to mechanical blur correction, and blur reduction priority refers to sensitivity-based blur reduction. The triangular portion of the usage ratio setting bar indicates the current usage ratio, and the image quality improves as the triangular portion moves to the left (priority in image quality). That is, the use ratio of mechanical blur correction increases and the use ratio of sensitivity-type blur reduction decreases. In addition, the blurring is reduced as the triangular part goes to the right (priority reduction priority). That is, the utilization ratio of mechanical blur correction decreases and the utilization ratio of sensitivity-type blur reduction increases.

Further, the movement of the triangular portion is performed by the user's operation of the cross key. That is, the user can adjust the usage ratio by operating the cross key. For example, when the user operates the cross key “←”, the triangle moves to the left, and when the user operates the cross key “→”, the triangle moves to the right.
Then, the user can specify the usage ratio by adjusting the usage ratio and operating the SET key when it is determined that blur correction is to be performed at this usage ratio.

Returning to the flowchart of FIG. 6A, if it is determined in step S82 that the menu mode is not selected, it is determined whether or not the shutter button is half-pressed (step S85).
If it is determined in step S85 that the shutter button is not half-pressed, the process returns to step S82. If it is determined that the shutter button is half-pressed, the process proceeds to step S11 in FIG. 2 or step S40 in FIG.
Thereby, the user can select the image quality and the degree of blur reduction.

(6) In the first and second embodiments, the still image shooting mode has been described. However, the blur correction according to the present invention may be performed during through image display and during moving image shooting.
For example, in the first embodiment, a usage ratio is set based on the captured frame, and mechanical blur correction and sensitivity-type blur reduction are performed based on the set usage ratio to obtain the next frame. You may make it image. In the second embodiment, a usage ratio is set every time the subject distance is calculated, and the next frame is picked up by performing mechanical and sensitivity reduction based on the set usage ratio. Also good.

(7) In the first and second embodiments, the use ratio is set. However, mechanical blur correction is constantly performed at 100% (the detected blur amount is corrected within the drivable range). The lens 3 may be driven), and only the degree of sensitivity-type blur reduction may be changed according to the blur amount and subject distance of the subject.
Alternatively, mechanical blur correction may be performed at 100%, and sensitivity blur reduction may be turned on 100% or turned off 100% in accordance with the subject blur amount and subject distance. In this case, when the sensitivity blur reduction is turned on, both mechanical blur correction and sensitivity blur reduction are performed at 100%, and when it is turned off, the blur correction is performed only by mechanical blur correction.
This method is particularly effective when camera shake cannot be corrected even by mechanical shake correction.

(8) In the first embodiment, mechanical blur correction is performed during through image display, and the blur amount (motion vector) of the subject is calculated based on the captured frame. While the image is displayed, the entire captured frame image is divided into a plurality of regions without performing mechanical blur correction, the motion vectors of the plurality of regions are calculated, and the size and direction of the motion vector of one region are different. If it is determined that there is a subject blur, the subject blur may be calculated based on the magnitude and direction of the different motion vectors.
Further, without performing mechanical shake correction during live view display, the detected shake amount (camera shake) is subtracted from the calculated motion vector (the motion vector in this case includes camera shake and subject shake). Thus, the subject blur may be calculated.

(9) In the first embodiment, the usage ratio is set based on the subject blur amount. However, the usage ratio may be set according to the value based on the contrast component of the image. Good.
The contrast component becomes higher as there is no blur, and the contrast component becomes lower as there is blur. Since the mechanical blur correction is performed during live view display, the subject blur becomes lower as the contrast component is lower. It will be big.

Therefore, the contrast component of the captured frame image is detected, and when the value (for example, the average value) based on the detected contrast component is higher than a predetermined value, the mechanical blur correction utilization ratio is set to 100%. When the value based on the contrast component is lower than the predetermined value, the utilization ratio is set according to the contrast component.
FIG. 7 is a diagram illustrating a usage ratio corresponding to the detected contrast component.
As shown in FIG. 7A, when the contrast component is high, the mechanical blur correction utilization ratio is set high, and when the contrast component is low as shown in FIG. Set a high usage ratio.

  (10) In the second embodiment, the subject distance is obtained based on the focus position detected by the contrast detection method. However, by providing a distance measuring sensor for measuring the distance to the subject. The subject distance may be obtained.

  (11) Moreover, the modification which combined the said modification (1) thru | or (10) freely may be sufficient.

  (12) Further, the digital camera 1 in each of the above embodiments is not limited to the above embodiment, but is a mobile phone with a camera, a PDA with a camera, a personal computer with a camera, an IC recorder with a camera, or a digital video. A camera or the like may be used. In short, any device that can shoot a subject may be used.

1 Digital Camera 2 Shooting Lens 3 Correction Lens 4 Lens Drive Block 5 Shutter / Shutter 6 CCD
7 Vertical driver 8 TG
9 Unit circuit 10 DMA
11 CPU
12 Key input part 13 Memory 14 DRAM
15 DMA
16 motion vector calculation unit 17 blur detection unit 18 DMA
19 Image generator 20 DMA
21 DMA
22 Display 23 DMA
24 Compression / Expansion Unit 25 DMA
26 Flash memory 27 Bus

Claims (6)

Imaging means for imaging a subject;
Image stabilization means for correcting image blur due to camera shake;
Blur reduction means for reducing image blur due to camera shake and subject blur,
A setting unit for the user to set a ratio between the strength of the degree of blur correction by the blur correction unit and the strength of the amount of blur reduction by the blur reduction unit;
Control means for executing blur correction by the blur correction means and blur reduction by the blur reduction means according to the ratio set by the setting means;
An imaging apparatus comprising: The blur correction means includes
The imaging apparatus according to claim 1, wherein the image blur is optically corrected. The blur reducing means is
The imaging apparatus according to claim 1, wherein blurring of an image is reduced by increasing sensitivity and increasing a shutter speed accordingly. A light amount calculating means for calculating a light amount based on the light of the subject;
A light amount determination means for determining whether or not the light amount calculated by the light amount calculation means is a sufficient light amount necessary for photographing;
With
The control means includes
2. When the light amount determination means determines that the necessary and sufficient amount of light is obtained, execution of blur reduction by the blur reduction means is prohibited, and only blur correction by the blur correction means is executed. The imaging device according to any one of 1 to 3. Shutter speed calculating means for calculating an appropriate exposure and calculating a shutter speed based on the calculated appropriate exposure;
Shutter speed determining means for determining whether or not the shutter speed calculated by the shutter speed calculating means is faster than a predetermined shutter speed;
With
The control means includes
2. When the shutter speed determining means determines that the shutter speed is faster than a predetermined shutter speed, execution of blur reduction by the blur reduction means is prohibited, and only blur correction by the blur correction means is executed. The imaging device according to any one of 1 to 4. Imaging processing for imaging a subject;
Blur correction processing to correct image blur due to camera shake,
Blur reduction processing to reduce image blur due to camera shake and subject blur,
A setting process for the user to set a ratio between the strength of the degree of blur correction by the blur correction unit and the strength of the amount of blur reduction by the blur reduction unit;
A control process for executing blur correction by the blur correction unit and blur reduction by the blur reduction unit according to the ratio set by the setting unit;
A program characterized by causing a computer to execute the processes described above.

Images