JP2011215199A - Photographing device, and method for correcting shake of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a panoramic image from being unrealistically seen which is obtained by photographing while panning or tilting a photographing device equipped with a function which corrects the shake of the device.SOLUTION: A panning direction component and a tilting direction component of a shake are detected to output a panning-direction shake signal and a tilting-direction shake signal. It is determined whether panning and/or tilting occurs. These signals are inputted directly or after integration to two high-pass filters 162A, 162B, 167A and 167B. When either a tilting operation or a panning operation is performed, the cutoff frequency of one high-pass filter to a shake signal in a non-operational direction is set for a frequency which is lower than the cutoff frequency of the other high-pass filter, and a shake which is generated at a photographing device 1 is corrected on the basis of the signals which pass through the high-pass filters 162A, 162B, 167A and 167B.

Description

  The present invention relates to a photographing apparatus having a camera shake correction function and a camera shake correction method thereof. More specifically, the present invention relates to a photographing apparatus capable of shooting a moving image while performing panning or tilting, and creating a panoramic image by synthesizing each frame image obtained by moving image shooting, and a camera shake correction method thereof.

  2. Description of the Related Art Conventionally, an imaging apparatus having a camera shake correction function has been proposed. The camera shake correction function detects the amount of camera shake from an angular velocity signal from an angular velocity sensor or the like, and drives a camera shake correction unit consisting of a correction lens or the like based on the angular velocity signal that has passed through processing such as a high-pass filter. Prevents camera shake.

  Here, there are camera shakes that occur due to camera shake and those that occur when the user intentionally pans and / or tilts the camera.

  Patent Document 1 proposes a technique for correcting camera shake immediately after panning or tilting by acquiring angular acceleration information from an angular velocity signal and switching the time constant of a high-pass filter using this angular acceleration information. Yes.

  In Patent Document 2, panning (or tilting) and camera shake are discriminated. When camera shake is discriminated, the cutoff frequency of the high-pass filter is lowered to improve the camera shake correction capability, and panning (or tilting) is performed. ), A technique has been proposed that suppresses camera shake correction capability by increasing the cutoff frequency.

JP 2009-75532 A JP-A-7-203285

  2. Description of the Related Art In recent years, it has been popular to shoot moving images while panning or tilting a photographing apparatus, and to create a panoramic image by combining images obtained for each frame.

  However, if the camera shake correction capability during movie shooting is equivalent to the correction capability when the user confirms the composition while visually recognizing the through image, the frame image obtained by movie shooting is particularly panning or tilting. The blur in the direction that is not the direction of movement becomes larger. On the other hand, if the camera shake correction capability during moving image shooting is inadvertently improved, the movement in the panning or tilting direction becomes unnatural because the correction operation is performed despite panning or tilting. As a result, there is a possibility that the position shift at the joint of each frame image becomes large, and the panoramic image may look unnatural.

  In view of the above circumstances, an object of the present invention is to provide a photographing apparatus capable of effectively correcting camera shake and eliminating an unnatural appearance of a panoramic image in moving image photographing while panning or tilting. .

  In order to solve the above-described problem, the image capturing apparatus of the present invention detects a panning direction component and a tilting direction component of blur generated in the image capturing apparatus, and outputs a panning direction blur signal and a tilting direction blur signal. Panning and / or tilting based on the two high-pass filters that are input directly or after integrating the panning direction blur signal and the tilting direction blur signal, respectively, and the panning direction blur signal and the tilting direction blur signal. The pan / tilt discrimination means for discriminating whether or not, and when only one of the operations of panning and tilting has occurred, the cutoff frequency of the high-pass filter that inputs a blur signal that is not in the operation direction is set to the other high-pass filter. Lower than the cut-off frequency And a blur correction mechanism that corrects a blur generated in the photographing apparatus based on the panning direction blur signal and the tilting direction blur signal that have passed through the two high pass filters. To do.

  Here, “lower than the cut-off frequency of the high-pass filter” means lower than the cut-off frequency of the normal high-pass filter. This is when the composition is confirmed while visually recognizing. “Low” means that the cutoff frequency is lowered from the normal cutoff frequency to the cutoff frequency at the time of still image shooting. Specifically, this means that the cut-off frequency at the time of moving image shooting at about 0.1 Hz to about 0.5 Hz or at the time of live view display is lowered to the cut-off frequency at the time of still image shooting at 0.05 Hz or less. .

  In addition, the photographing apparatus of the present invention has two coring means for coring each of the panning direction blur signal and the tilting direction blur signal, and only one of the operations of panning and tilting occurs. And a coring setting means for setting the threshold value of the coring means for the shake signal that is not in the operation direction to be smaller than the threshold value of the other coring means.

  Here, “smaller than the threshold value of the coring means” means to make it smaller than the threshold value of the coring means at the normal time. The term “small” means that the threshold value is reduced from a normal threshold value to a threshold value for still image shooting. Specifically, the coring threshold for still image shooting, which is about 0 to 0.5% from the coring threshold at the time of moving image shooting or through image display, which is about 10% of the range of the blur signal that can be input. It means to make it small.

  The camera shake correction method of the present invention detects a panning direction component and a tilting direction component of a blur generated in a photographing apparatus, outputs a panning direction blur signal and a tilting direction blur signal, and outputs a panning direction blur signal and a tilting direction. Based on the blur signal, it is determined whether panning and / or tilting has occurred, and the panning direction blur signal and the tilting direction blur signal are directly or integrated, respectively, and then input to the two high-pass filters. When only one of the two operations is occurring, set the cutoff frequency of the high-pass filter for the blur signal that is not in the operating direction to be lower than the cutoff frequency of the other high-pass filter, and pass through the high-pass filter. Panning direction blur signal and Based on the tilting direction blur signal, and corrects the blur occurring in the imaging apparatus.

  Further, the camera shake correction method of the present invention correlates each of the panning direction blur signal and the tilting direction blur signal, and when only one of the panning and tilting operations occurs, the motion direction The coring threshold for a non-blurred signal may be set to be smaller than the coring threshold for the other blurred signal.

  According to the photographing apparatus and the camera shake correction method of the present invention, the panning direction component and the tilting direction component of the blur generated in the photographing apparatus are detected and the panning direction blur signal and the tilting direction blur signal are output, and the panning direction When the blur signal and tilting direction blur signal are either directly or integrated and then input to two high-pass filters, and only one of panning and tilting operations occurs, the high-pass filter for blur signals that are not in the operating direction Set the cut-off frequency to be lower than the cut-off frequency of the other high-pass filter, and correct the blur generated in the photographing apparatus based on the panning direction blur signal and the tilting direction blur signal that have passed through the high-pass filter. By panning or chilty Can be improved than in the direction of the camera shake correction performance operation direction of the camera shake correction ability is not the direction of movement of the grayed. As a result, the frame image obtained by moving image shooting while panning or tilting is taken with a large positional shift in a direction other than the operation direction, and the movement in the panning or tilting direction is not improved by improving the correction capability. Since it is possible to avoid becoming natural, it is possible to eliminate the unnatural appearance of a panoramic image obtained by combining these frame images.

The block diagram which shows the internal structure of the digital camera which is 1st Embodiment. 1 is a block diagram illustrating a camera shake correction unit, a gyro sensor, and a camera shake correction control unit according to a first embodiment. Diagram showing panning and tilting applied to a digital camera The figure which shows the change of the cutoff frequency of a 1st high pass filter Flowchart of camera shake correction method according to first embodiment The block diagram which shows the camera-shake correction part in 2nd Embodiment, a gyro sensor, and the camera-shake correction control part. The figure which shows the change of the cutoff frequency of a 2nd high pass filter Flowchart of a camera shake correction method according to the second embodiment The block diagram which shows the camera-shake correction part in 3rd Embodiment, a gyro sensor, and the camera-shake correction control part. Flowchart of camera shake correction method according to third embodiment The block diagram which shows the camera-shake correction part in 4th Embodiment, a gyro sensor, and the camera-shake correction control part. The figure which shows the change of the coring threshold of the coring circuit Flowchart of a camera shake correction method according to the fourth embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the internal configuration of a digital camera according to the first embodiment of the present invention. As shown in FIG. 1, the digital camera 1 includes an operation unit 2 including a release button, a mode dial, and the like, and a photographing unit 10 that photographs a subject.

  The photographing unit 10 includes a photographing lens 12 including a focus lens and a zoom lens. A focus lens and a zoom lens constituting the photographing lens 12 can be moved in the optical axis direction by a lens driving unit 13.

  The camera shake correction unit 14 corrects a deviation of the optical axis due to camera shake, and includes a correction lens and a correction mechanism that drives the correction lens in the X and Y directions perpendicular to the optical axis. The gyro sensors 15A and 15B detect camera shakes in the X direction and Y direction that occur in the digital camera 1, and output angular velocity signals in the X direction and Y direction as shake signals. The camera shake correction control unit 16 controls the camera shake correction unit 14 based on signals from the gyro sensors 15A and 15B. Details of the camera shake correction unit 14, the gyro sensors 15A and 15B, and the camera shake correction control unit 16 will be described later.

  The diaphragm 17 is driven by a diaphragm driver 18. The aperture drive unit 18 adjusts the aperture diameter based on aperture value data output from an AE / AWB processing unit 31 described later.

  The shutter 19 is a mechanical shutter and is driven by a shutter driving unit 20. The shutter drive unit 20 performs opening / closing control of the shutter 19 according to a signal generated when a release button (not shown) is pressed and a shutter speed output from an AE / AWB processing unit 31 described later.

  Behind the shutter 19 is a CCD 21 which is an image sensor. The CCD 21 has a photoelectric surface in which a large number of light receiving elements are two-dimensionally arranged, and subject light that has passed through the photographing lens 12 or the like forms an image on the photoelectric surface and is subjected to photoelectric conversion. In front of the photocathode, a microlens array for condensing light on each pixel and a color filter array in which filters of R, G, and B colors are regularly arranged are arranged.

  The CCD 21 outputs the charges accumulated for each pixel as a serial analog photographing signal line by line in synchronization with the vertical transfer clock and the horizontal transfer clock supplied from the CCD controller 22. The time for accumulating charges in each pixel, that is, the exposure time is determined by an electronic shutter drive signal given from the CCD controller 22. The gain of the CCD 21 is adjusted by the CCD control unit 22 so that an analog photographing signal having a predetermined size can be obtained.

  The analog photographing signal captured from the CCD 21 is input to the analog signal processing unit 23. The analog signal processing unit 23 includes a correlated double sampling circuit (CDS) that removes noise from the analog signal, an auto gain controller (AGC) that adjusts the gain of the analog signal, and an A / D that converts the analog signal into a digital signal. It consists of a converter (ADC). The processing performed by the analog signal processing unit 23 is referred to as analog signal processing. The image data converted into the digital signal is CCD-RAW data having R, G, and B density values for each pixel.

  The timing generator 24 generates a timing signal. By supplying the timing signal to the shutter driving unit 20, the CCD control unit 22, and the analog signal processing unit 23, the release button is operated, the shutter is opened and closed, and the CCD 21 is operated. The charge capture and the processing of the analog signal processing unit 23 are synchronized.

  The image input controller 25 writes the CCD-RAW data input from the analog signal processing unit 23 in the frame memory 26. The frame memory 26 is a working memory used when various image processing (signal processing) described later is performed on the image data. For example, an SDRAM (Synchronous) that performs data transfer in synchronization with a bus clock signal having a fixed period. Dynamic Random Access Memory) is used.

  The display control unit 27 displays the image data stored in the frame memory 26 on the monitor 28 as a through image, or displays a still image or a moving image stored in the recording medium 35 during reproduction.

  The AF processing unit 30 and the AE / AWB processing unit 31 determine shooting conditions based on the pre-image. Here, the pre-image refers to the image data stored in the frame memory 26 as a result of the CPU 39 having detected a half-press signal generated by half-pressing a release button (not shown) causing the CCD 21 to perform pre-photographing. It is an image that is represented.

  The AF processing unit 30 detects the focal length based on the pre-image and outputs focus drive amount data (AF processing). As a focus position detection method, for example, a passive method that detects the focus position using the feature that the contrast of the image is high when the desired subject M is in focus can be considered.

  The AE / AWB processing unit 31 measures the subject brightness based on the blurred image, and based on the measured subject brightness, the ISO sensitivity, the aperture value, the shutter speed, and the like so that the captured image has a desired brightness. And ISO sensitivity data, aperture value data, and shutter speed data are determined as exposure setting values (AE processing), and white balance at the time of shooting is automatically adjusted (AWB processing).

  The image processing unit 32 performs image quality correction processing such as gradation correction, sharpness correction, and color correction on the image data, and Y data that is a luminance signal for CCD-RAW data, and Cb data and red that are blue color difference signals. YC processing is performed for conversion to YC data composed of Cr data which is a color difference signal. The image processing unit 32 also performs necessary processing on moving image data obtained by moving image shooting.

  The compression / decompression processing unit 33 performs compression processing on the image data of the main image processed by the image processing unit 32 in a compression format such as JPEG to create an image file. A tag storing incidental information such as shooting date and time is added to the image file based on the EXif format or the like. Further, at the time of shooting in the moving image shooting mode, the compression / decompression processing unit converts motion image data obtained by moving image shooting into motion JPEG, MPEG1, 2, 4 and H.264. The image is compressed by a compression method such as H.264 to create a moving image file.

  The media control unit 34 controls the writing and reading of an image file including a moving image file by accessing the recording medium 35. In addition, the media control unit 34 acquires the capacity of the recording medium 35.

  The internal memory 36 records various constants set in the digital camera 1, programs executed by the CPU 39, and the like.

  The moving image setting unit 37 sets a resolution, a frame rate, and the like for the image data of each moving image from the image capturing unit 10 when the digital camera 1 performs moving image shooting.

  The digital camera 1 can create a panoramic image from a moving image obtained by moving image shooting. The panorama synthesizing unit 38 separates the data of each frame image from the moving image data captured by the imaging unit 10 and aligns the overlapping portions of the frame images with the adjacent frame image data. Thus, image processing for creating a panoramic image is performed.

  The CPU 39 controls each unit of the digital camera 1 in accordance with signals from various processing units. Further, the CPU 39 receives settings such as an instruction for moving image shooting mode, an instruction for panorama image creation, and the like from the operation unit 2 such as ON / OFF setting of the camera shake correction mode. The camera shake correction unit 14 and the camera shake correction control unit 16 operate when the camera shake mode is ON and stop when the camera shake mode is OFF. The camera shake correction mode can be set for both still image shooting and moving image shooting. This setting result is stored in the internal memory 36.

  The data bus 40 is connected to various processing units, the frame memory 26, and the CPU 39, and exchanges image data and various instructions.

  Next, the configuration of the camera shake correction unit 14, the gyro sensors 15A and 15B, and the camera shake correction control unit 16 in the first embodiment will be described. FIG. 2 is a block diagram illustrating a camera shake correction unit, a gyro sensor, and a camera shake correction control unit according to the first embodiment, and FIG. 3 is a diagram illustrating panning and tilting applied to the digital camera.

  As shown in FIG. 2, the camera shake correction unit 14 detects the positions of the correction lens 141, the correction lens 141 in the X direction and the Y direction, and outputs position signals. The X direction includes a hall sensor 142A, 142B and a servo motor. And a Y-direction correction mechanism 143.

  The correction mechanism 143 drives the correction lens 141 in the X and Y directions perpendicular to the optical axis, so that the correction lens 141 moves in the X and Y directions perpendicular to the optical axis. It should be noted that when there is no camera shake, the correction lens 141 is at a position where its optical axis coincides with the optical axis of the photographing lens 12, and this position is driven as a reference position.

  The hall sensors 142A and 142B generate voltages according to the positions of the correction lens 141 in the X direction and the Y direction. The hall sensors 142A and 142B output a reference voltage when the correction lens 141 is at the reference position, and when the correction lens 141 moves in the X direction and the Y direction, the current of the correction lens 141 centered on the reference voltage is output. Output position signal.

  The gyro sensors 15A and 15B are fixed inside the digital camera 1, detect angular velocities including the direction of the digital camera 1 due to blurring in the X direction and the Y direction, and output analog angular velocity signals in the X direction and the Y direction. . The angular velocity signal becomes a reference value when no blur occurs, and becomes a value corresponding to the blur amount around the reference value when blur occurs. Here, when panning as shown in FIG. 3 occurs in the digital camera 1, the gyro sensor 15A outputs an angular velocity signal in the + X direction or −X direction corresponding to the panning direction for a predetermined time or more. Similarly, when tilting as shown in FIG. 3 occurs in the digital camera 1, the gyro sensor 15B outputs an angular velocity signal in the + Y direction or −Y direction corresponding to the tilting direction for a predetermined time or more.

  Returning to FIG. 1 and FIG. The camera shake correction control unit 16 includes first A / D converters 161A and 161B that convert analog angular velocity signals in the X direction and Y direction from the gyro sensors 15A and 15B into digital angular velocity signals, respectively.

  The digitized angular velocity signal is input to the first high-pass filters 162A and 162B and the pan / tilt determination unit 163. The first high-pass filters 162A and 162B have high-pass filter coefficients set by a filter coefficient setting unit 164 described later. The first high-pass filters 162A and 162B have a cut-off frequency based on the high-pass filter coefficient, thereby removing low-frequency components below the cut-off frequency from the input angular velocity signal. That is, only the angular velocity signal generated when the operation of the digital camera 1 changes suddenly is passed, and the angular velocity signal generated when the operation changes slowly is removed. As a result, an angular velocity signal equal to or lower than the cutoff frequency of the input angular velocity signal is not transmitted to the correction mechanism 143. A method for setting the high-pass filter coefficient by the filter coefficient setting unit 164 will be described later.

  The angular velocity signal from which the low frequency component has been removed is input to the phase compensation circuits 165A and 165B. The phase compensation circuits 165A and 165B compensate the phase with respect to the phase lag from the time of occurrence of blurring to the time of output of the angular velocity signals of the gyro sensors 15A and 15B.

  The phase-compensated angular velocity signal is input to integrating circuits 166A and 166B. The integrating circuits 166A and 166B integrate the angular velocity signal and output an angle signal.

  The angle signal is input to the second high-pass filters 167A and 167B and the pan / tilt determination unit 163. The second high-pass filters 167A and 167B have a cut-off frequency based on the high-pass filter coefficient, thereby removing a low frequency component equal to or lower than the cut-off frequency from the angle signal. That is, the angle signal when the posture of the digital camera 1 is suddenly changed is passed, and the angle signal when the posture is slowly changed is removed. By providing the second high-pass filters 167A and 167B, the angle signal is gradually reset, the correction mechanism 143 is returned to the reference position, and the centering speed when the correction mechanism 143 is corrected to the reference position is increased. Be controlled.

  Since the first high-pass filters 162A and 162B cut the low frequency component of the angular velocity signal in this way, the angular velocity signal that changes slowly is not input to the integrating circuits 166A and 166B, whereas the angular signal does not change directly. By providing the second high-pass filters 167A and 167B, the angle signal is gradually reset, so that a later-described target position of the correction mechanism 143 changes directly. For example, if the cut-off frequency of the first high-pass filters 162A and 162B is extremely high, the correction mechanism 143 remains at the current position, whereas the cut-off frequency of the second high-pass filters 167A and 167B is extremely high. The correction mechanism 143 continues to stay at the reference position.

  The angle signal from which the low frequency component is removed is input to the correction sensitivity circuits 168A and 168B. The correction sensitivity circuits 168A and 168B calculate a displacement signal for displacing the correction lens 141 by multiplying the angle signal by a mechanical coefficient. The mechanical coefficient is a value corresponding to the focal length. The larger the focal distance, the larger the mechanical coefficient. The correction sensitivity circuits 168A and 168B add a reference voltage to the displacement signal and output a target position signal for the correction lens 141. Further, the target position signal is input to the limit circuits 174A and 174B, and when the angle due to the blur exceeds the correctable limit, the excess portion is cut.

  The second A / D converters 169A and 169B convert the analog current position signal of the correction lens 141 from the hall sensors 142A and 142B into a digital current position signal.

  The target position signal and the current position signal of the correction lens 141 are input to the subtraction circuits 170A and 170B. The subtraction circuits 170A and 170B subtract the current position signal from the target position signal of the correction lens 141 and output a feedback signal.

  The feedback signal is input to the servo control circuits 171A and 171B. The servo control circuits 170A and 170B move the correction lens 141 to the target position by PWM control of the servo motor of the correction mechanism 143 based on the feedback signal.

  The pan / tilt determination unit 163 will be described. The pan / tilt discrimination unit 163 discriminates whether or not the blur generated in the digital camera 1 is caused by panning and / or tilting, and supplies the discriminated information to the filter coefficient setting unit 164.

  As described above, the angular velocity signal and the target position signal are input to the pan / tilt determination unit 163. The pan / tilt determination unit 163 determines that panning has occurred in the digital camera 1 when an angular velocity signal in the X direction exceeding a predetermined threshold is detected in a predetermined direction for a predetermined time or more. The pan / tilt determination 163 also determines that panning has occurred in the digital camera 1 even when the target position signal in the X direction is detected in a fixed direction for a predetermined time or longer with a correctable limit value. As described above, the X direction corresponds to the panning direction.

  Similarly, the pan / tilt determination unit 163 determines that tilting has occurred in the digital camera 1 when an angular velocity signal in the Y direction exceeding a predetermined threshold is detected in a predetermined direction for a predetermined time or more. The camera shake correction control unit 16 also determines that tilting has occurred in the digital camera 1 even when the target position signal in the Y direction is detected in a fixed direction and at a predetermined time for a predetermined time or longer. To do. As described above, the Y direction corresponds to the tilting direction.

  The filter coefficient setting unit 164 is supplied with the discrimination information from the pan / tilt discrimination unit 163. When the camera shake correction mode is turned ON, the filter coefficient setting unit 164 applies normal high-pass filter coefficients (hereinafter referred to as normal coefficients) to the first and second high-pass filters 162A, 162B, 167A, and 167B. Set. Here, the normal time refers to a time when the user confirms the composition while visually recognizing the through image, including during moving image shooting. The first and second high-pass filters 162A, 162B, 167A, 167B have a cutoff frequency based on the high-pass filter coefficients. Specifically, the cut-off frequency is about 0.1 Hz to 0.5 Hz at the time of moving image shooting that is normal and when a through image is displayed.

  When the discrimination information from the pan / tilt discrimination unit 163 is either panning or tilting, the filter coefficient setting unit 164 changes the coefficient of the high-pass filter that inputs the angular velocity signal in the direction other than the operation direction from the normal coefficient. Set.

  In this case, as shown in FIG. 4, the filter coefficient setting unit 164 has the cut-off frequency of the first high-pass filter that inputs an angular velocity signal that is not in the operation direction, as in the first embodiment. The filter coefficient is set to be lower than the cutoff frequency of the first high-pass filter that inputs. Here, “lower” means lowering from the normal cutoff frequency to the cutoff frequency at the time of still image shooting. Specifically, the frequency is lowered to a cutoff frequency of 0.05 Hz or less during still image shooting. Thereby, the correction capability with respect to the change in the angular velocity in the direction other than the motion direction is improved more than the correction capability in the motion direction.

  When the digital camera 1 is panned, the filter coefficient setting unit 164 sets the cutoff frequency of the high-pass filter 162B to be lower than that of the high-pass filter 162A, so that the correction capability for blur in the Y direction is higher than normal. Improve. When the panning is completed, the filter coefficient setting unit 164 returns the high-pass filter coefficient of the high-pass filter 162B to the normal coefficient. When the digital camera 1 is tilted, the filter coefficient setting unit 164 sets the cutoff frequency of the high-pass filter 162A to be lower than that of the high-pass filter 162B, thereby improving the correction capability for blurring in the X direction from the normal time. Also improve. When the tilting is completed, the filter coefficient setting unit 164 returns the high-pass filter coefficient of the high-pass filter 162A to the normal coefficient.

  Next, the camera shake correction method according to the first embodiment will be described. FIG. 5 is a flowchart of the camera shake correction method according to the first embodiment. Wait until the camera shake correction mode of the digital camera 1 is turned on (ST11). The cutoff frequencies of the first and second high-pass filters are set to normal cutoff frequencies (ST12).

  The X direction component and the Y direction component of the occurring blur are detected, and it is determined whether or not the blur is caused by panning or tilting (ST13). If the occurring blur is not due to panning or tilting, the current cutoff frequency of the first and second high pass filters is maintained.

  It is determined whether or not panning or tilting is occurring (ST14). If it is either one, the cutoff frequency of the first high-pass filter for the angular velocity signal in the direction other than the operating direction is set lower than that of the first high-pass filter for the angular velocity signal in the operating direction (ST15). Further, when both panning and tilting have occurred, the current cutoff frequency of the first high-pass filter is maintained. It is determined whether panning or tilting is completed (ST16). If completed, the cutoff frequency of the first high-pass filter that is not in the operating direction is returned to the normal cutoff frequency, and if not completed, the current cutoff frequency of the first high-pass filter is maintained.

  As described above, according to the first embodiment, it is determined whether or not the blurring being generated is due to panning or tilting, and when either panning or tilting is occurring, the operation direction is determined. By making the cut-off frequency of the first high-pass filter to which the angular velocity signal in the non-directional direction is input lower than that of the first high-pass filter to which the angular velocity signal in the operational direction is input, the correction capability for the angular velocity change in the operational direction is usually It is possible to improve the correction capability with respect to the change in angular velocity in the direction other than the operation direction as compared with the normal time while maintaining the correction capability at the time. As a result, since the correction operation is performed in spite of panning or tilting, it is possible to avoid unnatural movement in the panning or tilting direction. Can also reduce blurring and eliminate unnatural panoramic images.

  Next, a second embodiment will be described. FIG. 6 is a block diagram illustrating a camera shake correction unit, a gyro sensor, and a camera shake correction control unit according to the second embodiment of the present invention. Note that the digital camera 1 according to the second embodiment is the first in that the filter coefficient setting unit 164 sets the high-pass filter coefficients of the second high-pass filters 167A and 167B according to the determination information from the pan / tilt determination unit 163. Since it is different from the embodiment, only the difference will be described, and the other description will be omitted.

  When the discrimination information from the pan / tilt discrimination unit 163 is either panning or tilting, the filter coefficient setting unit 164 uses the coefficients of the second high-pass filters 167A and 167B for inputting angle signals that are not in the operation direction as normal coefficients. Change and set from.

  In this case, as shown in FIG. 7, the filter coefficient setting unit 164 has a cutoff frequency of the second high-pass filter that inputs an angle signal that is not in the operating direction, as compared with the second high-pass filter that inputs the angle signal in the operating direction. Is set to be lower. Thereby, the correction capability with respect to the angle change in the direction other than the operation direction is improved more than the correction capability in the operation direction. Note that FIG. 7 shows an addition of an integral characteristic, and the extent to which the cut-off frequency is lowered is the same as in the first embodiment.

  Next, a camera shake correction method according to the second embodiment will be described. FIG. 8 shows a flowchart of a camera shake correction method according to the second embodiment. Wait until the camera shake correction mode of the digital camera 1 is turned on (ST21). The cut-off frequencies of the first and second high-pass filters are set to normal coefficients (ST22).

  The X direction component and the Y direction component of the occurring blur are detected, and it is determined whether or not the blur is caused by panning or tilting (ST23). If the occurring blur is not due to panning or tilting, the current cutoff frequency of the first and second high pass filters is maintained.

  It is determined whether or not panning or tilting is occurring (ST24). If it is either one, the cutoff frequency of the second high-pass filter for the angle signal in the direction other than the operation direction is set lower than that of the second high-pass filter for the angle signal in the operation direction (ST25). Further, when both panning and tilting have occurred, the current cutoff frequency of the second high-pass filter is maintained. It is determined whether panning or tilting is completed (ST26). If completed, the cutoff frequency of the second high-pass filter that is not in the operating direction is returned to the normal cutoff frequency, and if not completed, the current cutoff frequency of the second high-pass filter is maintained.

  As described above, according to the second embodiment, the cutoff frequency of the second high-pass filter to which the angle signal in the direction other than the operation direction is input is set to the cutoff frequency of the second high-pass filter to which the angle signal in the operation direction is input. By lowering the value, the correction capability for the angle change in the operation direction can be made the normal correction capability, and the correction capability for the angle change in the direction other than the operation direction can be improved compared to the normal time. As a result, since the correction operation is performed in spite of panning or tilting, it is possible to avoid unnatural movement in the panning or tilting direction. In addition, it is possible to suppress misalignment and to eliminate the unnatural appearance of the panoramic image.

  Next, a third embodiment will be described. FIG. 9 is a block diagram showing a camera shake correction unit, a gyro sensor, and a camera shake correction control unit according to the third embodiment of the present invention. In the digital camera 1 according to the third embodiment, the filter coefficient setting unit 164 has both the filter coefficients of the first and second high-pass filters 162A, 162B, 167A, and 167B in accordance with the determination information from the pan / tilt determination unit 163. Is different from the first and second embodiments, and a detailed description of the configuration is omitted.

  Next, a camera shake correction method according to the third embodiment will be described. FIG. 10 shows a flowchart of a camera shake correction method according to the third embodiment. The filter coefficient setting unit 164 waits until the camera shake correction mode is turned on (ST31). The cutoff frequencies of the first and second high pass filters are set to normal values (ST32).

  The X component and the Y component of the occurring blur are detected, and it is determined whether or not the blur is caused by panning or tilting (ST33). If the occurring blur is not due to panning or tilting, the current cutoff frequency of the first and second high pass filters is maintained.

  It is determined whether or not panning or tilting is occurring (ST34). In either case, the cut-off frequency of the first and second high-pass filters for the angular velocity signal and the angle signal in the direction other than the operation direction is lower than that of the first and second high-pass filters for the angular velocity signal and the angle signal in the operation direction. (ST35). When both panning and tilting are occurring, the current cutoff frequencies of the first and second high-pass filters are maintained. It is determined whether panning or tilting is finished (ST36). If completed, the cutoff frequencies of the first and second high-pass filters that are not in the operating direction are returned to normal values. If not completed, the current cutoff frequencies of the first and second high-pass filters are maintained. .

  As described above, according to the third embodiment, the cut-off frequency of the first and second high-pass filters to which the angular velocity signal and the angle signal in the direction other than the operation direction are input is set to the cutoff frequency of the first and second high-pass filters. By making it lower than the input first and second high-pass filters, the correction ability for the angular velocity change and the angular change in the operation direction is set as the normal correction ability, and the correction for the angular velocity change and the angle change in the direction other than the operation direction is performed. Ability can be improved compared to normal times.

  Next, a fourth embodiment will be described. FIG. 11 is a block diagram showing a camera shake correction unit, a gyro sensor, and a camera shake correction control unit according to the fourth embodiment of the present invention. The digital camera 1 according to the fourth embodiment is different from the first embodiment in that the camera shake correction control unit 16 includes the coring circuits 172A and 172B and the coring setting unit 173. Explain and omit other explanations.

  In the fourth embodiment, the angular velocity signals output from the first A / D converters 161A and 161B are input to the coring circuits 172A and 172B. The coring circuits 172A and 172B output the reference value when the absolute value of the amount of change from the reference value of the input angular velocity signal is equal to or less than the coring threshold value. That is, the change in the angular velocity signal within the coring threshold does not perform camera shake correction as a fine blur within a so-called dead zone.

  The coring setting unit 173 sets a normal coring threshold value (hereinafter referred to as a normal threshold value) of the coring circuits 172A and 172B when the camera shake correction mode is turned on. Specifically, a coring threshold value of about 10% is set with respect to the range of angular velocity signals that can be input during moving image shooting or through-image display.

  The coring setting unit 173 changes the coring threshold value of the coring circuit for inputting the angular velocity signal that is not in the operation direction from the normal threshold value when the discrimination information from the pan / tilt discrimination unit 163 is either panning or tilting. To set.

  In this case, as shown in FIG. 12, the coring setting unit 173 is configured such that the coring threshold of the coring circuit that inputs the angular velocity signal that is not in the operating direction is smaller than that of the coring circuit that inputs the angular signal in the operating direction. Set. Here, the term “decrease” refers to a reduction from the normal coring threshold value to the level of the coring threshold value during still image shooting. Specifically, it is reduced to a coring threshold value of about 0 to 0.5 percent with respect to the range of input angular velocity signals at the time of still image shooting. That is, since the so-called dead zone is smaller than normal, camera shake correction is performed even for finer blur. The fourth embodiment can be applied to the second and third embodiments.

  Next, a camera shake correction method according to the fourth embodiment will be described. FIG. 13 shows a flowchart of a camera shake correction method according to the fourth embodiment. Wait until the camera shake correction mode of the digital camera 1 is turned on (ST41). The cutoff frequency of the first high pass filter is set to a normal value (ST42). The coring threshold value of the coring circuit is set to the normal threshold value (ST43).

  The X direction component and the Y direction component of the occurring blur are detected, and it is determined whether or not the blur is caused by panning or tilting (ST44). If the occurring blur is not due to panning or tilting, the current first high-pass filter cutoff frequency and coring threshold of the coring circuit are maintained.

  It is determined whether or not panning or tilting is occurring (ST45). If it is either one, the cutoff frequency of the first high-pass filter for the angular velocity signal in the direction other than the operating direction is set lower than that of the first high-pass filter for the angular velocity signal in the operating direction (ST46). Further, the coring threshold of the coring circuit for the angular velocity signal in the direction other than the operation direction is set lower than that of the coring circuit for the angular velocity signal in the operation direction (ST47). Further, when both panning and tilting occur, the current cutoff frequency of the first high-pass filter and the coring threshold value of the coring circuit are maintained. It is determined whether panning or tilting is completed (ST48). If finished, the cutoff frequency of the first high-pass filter that is not in the operating direction and the coring threshold value of the coring circuit are returned to the normal coefficient and the normal threshold value. If not finished, the cut-off of the current first high-pass filter is done. Maintain off-frequency, coring threshold of coring circuit.

  As described above, according to the fourth embodiment, the cut-off frequency of the first high-pass filter to which the angle signal in the direction other than the operation direction is input is set to the cutoff frequency of the first high-pass filter to which the angular velocity signal in the operation direction is input. In addition, the coring threshold value of the coring circuit to which the angular velocity signal in the direction other than the operation direction is input is made lower than that of the coring circuit to which the angular velocity signal in the operation direction is input, so that the change in the angular velocity in the operation direction can be reduced. While the correction capability for a slight blur is a normal correction capability, the correction capability for a fine blur of a change in angular velocity in a direction other than the operation direction can be improved.

DESCRIPTION OF SYMBOLS 1 Digital camera 15A, 15B Gyro sensor 162A, 162B 1st high pass filter 167A, 167B 2nd high pass filter 163 Pan tilt discrimination means 164 Filter coefficient setting part 172A, 172B Coring circuit 173 Coring setting part

Claims (4)

Blur detecting means for detecting a panning direction component and a tilting direction component of blur generated in the photographing apparatus and outputting a panning direction blur signal and a tilting direction blur signal;
Two high-pass filters that are input directly or after integrating the panning direction blur signal and the tilting direction blur signal, respectively;
Pan / tilt determination means for determining whether panning and / or tilting has occurred based on the panning direction blur signal and the tilting direction blur signal;
When only one of the operations of panning and tilting occurs, the cutoff frequency of the high-pass filter that inputs a blur signal that is not in the operating direction is lower than the cutoff frequency of the other high-pass filter. High-pass filter setting means for setting
An imaging apparatus comprising: a blur correction mechanism that corrects a blur generated in the imaging apparatus based on a panning direction blur signal and a tilting direction blur signal that have passed through the two high-pass filters. Two coring means for coring each of the panning direction blur signal and the tilting direction blur signal;
A core that sets a threshold value of the coring means for a blur signal that is not in the operation direction to be smaller than a threshold value of the other coring means when only one of the operations of panning and tilting occurs. The photographing apparatus according to claim 1, further comprising a ring setting unit. Detect panning direction component and tilting direction component of blurring that occurred in the imaging device and output panning direction blur signal and tilting direction blur signal
Determine whether panning and / or tilting has occurred based on the panning direction blur signal and the tilting direction blur signal,
The panning direction blur signal and the tilting direction blur signal are each directly or integrated and then input to two high-pass filters.
When only one of the operations of panning and tilting occurs, the cutoff frequency of the high-pass filter with respect to the blur signal that is not in the operating direction is made lower than the cutoff frequency of the other high-pass filter. Set,
A camera shake correction method, comprising: correcting a shake that has occurred in the photographing apparatus based on a panning direction shake signal and a tilting direction shake signal that have passed through the high-pass filter. Coring each of the panning direction blur signal and the tilting direction blur signal,
When only one of the panning and tilting operations occurs, the coring threshold for the blur signal that is not in the operation direction is set to be smaller than the coring threshold for the other blur signal. The camera shake correction method according to claim 3.

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