JPH07177418A - Image blur preventing device - Google Patents

Abstract

PURPOSE:To effectively correct an image blur by increasing a ratio in the entire image shake correction occupied by a first correction device capable of correcting the image blur of large amplitude when an instantaneous blur amount is large and increasing the ratio of a second correction device capable of correcting the image blur of small amplitude when the blur amount is small. CONSTITUTION:An arithmetic and logic circuit 20 calculates the deviation from a reference position of images at the moment based on motion vector signals and apex signals. Then, by hanging a feedback loop to a variable apex prism VAP based on the deviation, drive-controlling the VAP 1 to a prescribed state through a VAP driving device 2 and bending an optical axis, the image blur is corrected. Further, the image blur of the small amplitude of high frequencies which can not be corrected by the drive-control of the VAP 1 is corrected. That is, by controlling the read position of a second field memory 22 in a memory read control circuit 21 based on control signals from the circuit 20, the image blur is corrected and the images are converted to a desired size in an electronic zooming circuit 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image shake preventing device for preventing an image of an image pickup means from shaking due to camera shake, etc., and particularly to an image pickup having a magnetic recording / reproducing function represented by a portable video camera or the like. The present invention relates to an image blur prevention device suitable for the means.

[0002]

2. Description of the Related Art Generally, in image pickup means such as a video camera,
Whether it is for industrial use or for consumer use, the shake at the time of shooting makes it difficult to see the image and causes various malfunctions. In particular, when shooting from a walking or moving vehicle, or shooting in a place with a lot of vibration, image shake is likely to occur. Therefore, various types of image shake preventive devices that conventionally correct image shake have been proposed. Has been done.

(A) The image signal output from the image pickup device (CCD) is stored in an image memory or the like, the image shake is detected from the information, and the displacement amount of the image is obtained, and the read address of the image memory is correspondingly obtained. Of a pure electronic image blur correction device for correcting image blur by shifting
3-166370).

(B) An inertial pendulum type anti-shake lens having a biaxial gimbal structure is arranged around the master lens, and the anti-shake lens cancels camera shake.
Inertial pendulum type image blur prevention device for correcting image blur (US Pat. No. 2,959,088 and US Pat. No. 2,822,955).
No. 7).

(C) A variable apex angle prism for changing the optical axis of the lens (front lens) is provided at the tip of the lens (front lens) to detect the motion from the image signal output from the image sensor, or the motion is detected by the acceleration sensor. A variable apex prism type image shake preventing device for detecting an image shake by driving the variable apex angle prism according to the detected signal.

(D) Using a large-area image pickup device having a larger area than usual, detecting a motion by an acceleration sensor or the like, and controlling the read-out start position of the image stored in the field memory by using the detection signal without using the memory. A large-area image sensor image blur prevention device that corrects image blur.

However, in the above-mentioned conventional apparatus (a), there is a problem that the image deteriorates, and in (b) to (d), the image deteriorates. However, as long as the shake detection is performed based on the image, it has a feedback loop, so that there is a problem that the high frequency characteristics are inferior.

For this reason, in recent years, a so-called hybrid correction type image blur preventing device has been proposed which takes advantage of the above-mentioned (a) device and (b) to (d) device.

[0009]

However, for example, in the conventional image stabilization apparatus of the hybrid correction system in which the image stabilization system having the feedback loop and the image stabilization system using the image memory are simply combined, When the shake frequency is high or when the image is taken on the wide-angle side where the image shake width is small, the deterioration of the high-frequency characteristics due to the delay of the feedback control is noticeable due to the effect of the image shake correction method with a feedback loop. In the case of shooting on the telephoto side where the image shake width is large, there is a problem that the correction range is easily exceeded due to the influence of the image shake correction method using the image memory.

The present invention has been made in view of the above-mentioned problems of the above-mentioned conventional technique, and an object thereof is to combine a plurality of image blur correction methods, but to have a high frequency characteristic. SUMMARY OF THE INVENTION It is an object of the present invention to provide an image blur preventing device capable of easily and reliably performing fine image blur correction according to a shooting condition without deteriorating the image quality or exceeding the correction range.

[0011]

In order to achieve the above object, the first invention of the present invention is, in an image blur preventing apparatus for detecting a motion vector from an image signal and correcting the image blur in real time, in time series. A motion vector detecting means for performing a correlation operation between consecutive images to detect a motion vector between the images; and a shake frequency calculating means for calculating a shake frequency of the image based on the motion vector detected by the motion vector detecting means. A first correction unit that has a feedback loop and corrects the image shake; a second correction unit that has a field memory and corrects the image shake by using an image delayed by the field memory; and the shake frequency The ratio of the first correction means and the second correction means in the total image shake correction is changed based on the shake frequency of the image calculated by the calculation means. It is characterized in that it has and a ratio changing means for.

In order to achieve the same object, a second invention of the present invention is to provide an image blur preventing apparatus for detecting a motion vector from an image signal and correcting the image blur in real time,
First correction means having a feedback loop and correcting the image shake, second correction means having a field memory and correcting the image shake by using an image delayed by the field memory, and a focus of the optical system A focal length reading unit for reading the distance, and the first correcting unit and the second unit based on the focal length information read by the focal length reading unit.
The present invention is characterized by including a correction unit and a ratio changing unit that changes a ratio of the entire image blur correction.

In order to achieve the same object, a third aspect of the present invention is an image blur prevention apparatus for detecting a motion vector from an image signal and correcting the image blur in real time,
A motion vector detecting means for detecting a motion vector between the images by performing a correlation calculation between the images continuous in time series, and a motion vector detected by the motion vector detecting means are added to obtain a motion vector from a reference point of the current image. The image deviation is corrected by using an absolute deviation calculating means for calculating an absolute deviation, a first correction means having a feedback loop and correcting the image shake, and an image having a field memory and delayed by the field memory. The second correction means and the ratio of the first correction means and the second correction means to the total image shake correction based on the absolute deviation value from the reference point of the current image calculated by the absolute deviation calculation means. And a ratio changing means for changing.

Further, in order to achieve the same object, a fourth invention of the present invention is an image blur preventing apparatus for detecting a motion vector from an image signal and correcting the image blur in real time,
A motion vector detecting means for performing a correlation calculation between images which are consecutive in time series to detect a motion vector between the images, a first correcting means for having a feedback loop and for correcting the image shake, and a field memory Second correction means for correcting the image shake by using the delayed image in the field memory, and the first correction means based on the motion vector information between the images detected by the motion vector detection means.
The present invention is characterized by including a ratio changing unit that changes a ratio of the correction unit and the second correction unit in the total image shake correction.

[0015]

According to the image blur prevention apparatus of the first invention, the ratio of the first correction means and the second correction means in the total image blur correction is changed based on the image blur frequency calculated by the blur frequency calculation means. Change by means.

The image blur prevention device of the second invention is based on the focal length information read by the focal length reading means.
The ratio changing unit changes the ratio of the correction unit and the second correction unit in the total image blur correction.

The image shake preventing apparatus of the third invention is such that all image shake corrections of the first correcting means and the second correcting means are based on the absolute deviation value from the reference point of the current image calculated by the absolute deviation calculating means. The rate of change in the ratio is changed by the ratio changing means.

According to the image blur prevention apparatus of the fourth aspect of the present invention, based on the motion vector information between the images detected by the motion vector detection means, the ratio of the first correction means and the second correction means in the total image blur correction is calculated as follows: It is changed by the ratio changing means.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of a video camera which is an image pickup means provided with an image blur prevention device according to the first embodiment of the present invention. In the figure, 1 is a rotatable variable angle prism (VAP),
It has a feedback loop and constitutes first correction means for correcting image shake, and is driven and controlled by the VAP drive means 2. The VAP drive means 2 has a VAP drive circuit (driver) 2a, a VAP drive coil 2b, and a VAP braking coil 2c, and is controlled by a control signal from a logical operation circuit 20 described later. 3 is V for detecting the apex angle of VAP1
The detection signal of the AP apex angle sensor is input to a logical operation circuit 20 described later.

Reference numeral 4 is a focus lens group for normal focusing, 5 is a zoom lens group for changing the focal length, 6 is a lens group for a correction system, 7 is a diaphragm for adjusting the amount of light, and 8 is, for example, two-dimensional. An image pickup device composed of a CCD converts an optical signal input via each of the lens groups 4 to 6 and the diaphragm 7 into an electric signal and outputs the electric signal. A sample hold (S / H) circuit 9 holds an electric signal output from the image sensor 8. An automatic gain control (AGC) circuit 10 automatically controls the gain of the signal output from the S / H circuit 9.

11 is an analog / digital (A / D)
The converter converts the analog signal output from the AGC circuit 10 into a digital signal. 12 is a delay circuit (2H
The output signal of the A / D converter 11 is input to the DLY) circuit, and the color difference line sequential signal from the image sensor 8 is delayed by two horizontal scanning periods. A color signal generation (C process) circuit 13 receives the output signal of the 2HDLY circuit 12 and generates a color (C) signal. 14 is a low-pass filter (L
PF), the output signal of the 2HDLY circuit 12 is input,
The color signal mixed in the luminance signal is removed. An enhancer 15 receives the output signal of the LPF 14 and emphasizes high frequency components.

A gamma (γ) correction circuit 16 receives the output signal of the enhancer 15 and performs gamma correction processing.
Reference numeral 17 denotes a two-dimensional bandpass filter (BPF) which is a spatial frequency filter and receives the output signal of the gamma correction circuit 16 and removes a signal in a predetermined band. A motion vector detection circuit 18 receives an output signal from the BPF 17 and a first field memory 19 described later, and detects a motion vector of an image. The motion vector detection circuit 18 is a circuit based on a matching calculation, and in this embodiment, it needs to be a detection method capable of real-time processing. Reference numeral 19 is a first field memory to which the output signal from the BPF 17 is input. The first field memory 19 is a delay circuit that delays the luminance signal by a predetermined time (one field time in this embodiment), stores the luminance signal of one field before, and enables matching calculation with the current field. To do.

Reference numeral 20 denotes a logical operation circuit for performing various kinds of signal processing to control the entire image pickup means. The VAP apex angle sensor 3,
The output signals of the motion vector detection circuit 18 and the image shake correction mode selection means described later are input. In the present embodiment, the logical operation circuit 20 determines whether the image shake correction mode selected based on the selection signal input from the image shake correction mode selecting means described later is the first correction (image shake correction only by VAP control) mode or the second correction. It has an image blur correction mode detecting means for detecting a correction (image blur correction only by field memory control) mode or a third correction (image blur correction using VAP control and field memory control in combination) mode.

Reference numeral 21 is a memory read control circuit, which controls the read position of a second field memory 22, which will be described later, based on a control signal from the logical operation circuit 20. The memory read control circuit 21 uses the first field memory 1
Second correction means for correcting the image shake is provided by using the image having the number 9 and delayed by the first field memory 19. A second field memory 22 receives the output signals of the C process circuit 13, the gamma correction circuit 16, and the memory read control circuit 21.

An electronic zoom circuit 23 receives the output signals of the second field memory 22 and the logical operation circuit 20 and converts the image into a desired size. A digital / analog (D / A) converter 24 converts a digital signal output from the electronic zoom circuit 23 into an analog signal. 25 is a signal output terminal for the electronic zoom circuit 2
The corrected image signal output from 3 is output.

Next, the operation of the image pickup means having the above structure will be described.

The subject 26 is VAP1, each lens group 4 to
6 and the diaphragm 7 are sequentially passed, and an image is formed on the image pickup surface of the image pickup element 8 and photoelectrically converted. The S / H circuit 9 holds the output signal of the image sensor 8, and the AGC circuit 10 following this holds the gain control processing automatically. The A / D converter 11 is an AG
The output signal of the C circuit 10 is A / D converted. The 2HDLY circuit 12 separates the color-difference line-sequential signal from the image sensor 8 into a 1H delay signal and a “0H + 2H” delay signal, and the luminance signal processing unit side (LPF 14 side) and the color signal processing unit side (C
It is sent to the process circuit 13 side). The signal sent to the color signal processing unit side is input to the C process circuit 13, the C process circuit 13 generates a color signal C, and the generated color signal C is sent to the second field memory 22. Written.

On the other hand, the signal sent to the luminance signal processing unit side is input to the LPF 14, which removes the carrier component from the color difference line sequential signal and performs luminance signal separation. The enhancer 15 performs a process of emphasizing a high frequency component such as an edge of the subject 26 for improving image quality. Normally,
The second derivative of the video signal is added to the original signal. Subsequently, the gamma correction circuit 16 prevents saturation in the highlight portion and widens the dynamic range. The BPF 17 extracts a spatial frequency component effective for detecting a motion vector.

Generally, the low-frequency component and high-frequency component of the image signal are not suitable for detecting the motion vector, and therefore BP
Preliminarily removed by F17. In this embodiment,
Only the sign bit of the BPF 17 is output. This means that the luminance signal is binarized using the DC level as a threshold. Therefore, the luminance signal after BPF17 is
It is 1 bit.

The motion vector detection circuit 18 includes a BPF 17
Also, the motion vector of the image is detected based on the signal input from the first field memory 19, and the detected motion vector signal is input to the logical operation circuit 20. Also,
The apex angle signal of VAP1 detected by the VAP sensor 3 is input to the logical operation circuit 20. Logical operation circuit 2
0 indicates the deviation from the reference position of the image at that moment based on the motion vector signal (each component in the horizontal and vertical directions of the motion vector at the predetermined screen position) and the apex angle signal according to the flowchart shown in FIG. calculate. Then, a feedback loop is applied to VAP1 based on this deviation, and VAP1 is driven and controlled by VAP driving means 2 to bend the optical axis to correct the image shake.

Further, drive control of VAP1 (VAP control)
In order to correct high-frequency image shake with high amplitude that cannot be completely corrected, the following control is performed. That is, the logical operation circuit 2
Memory read control circuit 2 based on the control signal from 0
At 1, the image shake is corrected by controlling the read position of the second field memory 22 (field memory control), and the image is converted to a desired size in the electronic zoom circuit 23. In this way, an image with the image shake corrected is finally obtained. This corrected image signal is
After being D / A converted by the D / A converter 24, it is output from the signal output terminal 25.

Next, the operation of the logical operation circuit 20 in the image blur prevention apparatus according to this embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing the operation of the logical operation circuit 20. First, step S201 in FIG.
Then, the output signal from the motion vector detecting circuit 18 (each component in the horizontal direction and the vertical direction of the motion vector at the predetermined screen position) is read for each field. Then, step S2
In step 02, the motion vector at the read plural screen positions is subjected to predetermined processing to calculate one representative motion vector. The predetermined processing includes reliability evaluation processing of individual motion vectors, control target area determination processing, and the like.

Next, in step S203, the representative motion vector is integrated to obtain a deviation (image displacement amount) from the reference position on the screen, and an image shake correction signal is obtained. Next, in step S204, the shake frequency is obtained from the deviation value of the image obtained in step S203, and the control gain of each correction means is set to the optimum state based on the shake frequency. Next, in step S205, the image shake correction or VAP1 control (VAP control) is performed based on the image shake correction amount, which is the image deviation value obtained in step S203, and the control gain set in step S204. Executes the image shake correction by the field memory control, and then ends this processing operation.

Since the processing in step S204 forms the subject of the present invention, it will be described in detail with reference to FIG. FIG. 3 is a flowchart showing details of the processing routine of step S204 of FIG. In step S301 of the figure, the image displacement amount obtained in step S203 of FIG. 2 is subjected to frequency analysis according to the capability of the control device, for example, by counting the frequency of cross points with respect to a predetermined reference value, Obtain the shake frequency of the image. In the next step S302, according to the shake frequency of the image obtained in step S301, from the conversion table of the shake frequency and the control gain allocation shown in FIG.
Determine the control gains for VAP control and field memory control. In FIG. 4, the vertical axis represents the correction (control) gain, and the horizontal axis represents the shake frequency. As is clear in the figure,
This conversion table has a large proportion in the field memory control, that is, the whole image blur correction of the second correction means in the high frequency area, and a VAP control, that is, the proportion in the whole image blur correction of the first correction means in the low frequency area. It is set to do more.

Generally, low-frequency image shake tends to have a large amplitude, and high-frequency image shake tends to have a small amplitude. Therefore, it is desirable to perform small-amplitude image blur correction in the high frequency region and large-amplitude image blur correction in the low frequency region.

According to the image blur prevention device of this embodiment, V
In an image shake prevention apparatus that combines a first correction means by AP control and a second correction means by field memory control, the shake frequency of an image is calculated by a method that can be performed by this control device, and a large amplitude is obtained in a low frequency region. The ratio of the VAP control capable of correcting the image blur of the whole image blur correction is increased, and the ratio of the field memory control of the field memory control capable of correcting the image blur of the small amplitude in the high frequency region is increased in the total image blur correction. As described above, by appropriately changing the control gain, it is possible to perform image blur correction making the best use of the respective advantages of the first and second correcting means.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing the configuration of a video camera which is an image pickup means having an image blur prevention device according to the second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 of the first embodiment described above are designated by the same reference numerals. 5 is different from FIG. 1 in that FIG.
The VAP 1, the VAP control means 2, the VAP apex angle sensor 3 and the image pickup device 8 are respectively deleted from the configuration of FIG. That is. The large area image pickup device 8'and the image pickup device reading circuit 27 constitute a first correction means having a feedback loop and correcting image shake. Then, the image sensor read circuit 2
By changing the read address at 7, an arbitrary portion of the large area image pickup device 8'is cut out to perform image shake correction.

The rest of the configuration, operation, and effect of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a conversion table of the shake frequency and the control gain allocation in the image shake preventing apparatus according to the third embodiment of the present invention. In the present embodiment, the relationship between the shake frequency and the control gain allocation is not changed linearly as in the first embodiment, but is changed exponentially.

The rest of the configuration, operation, and effect of this embodiment are the same as those of the first embodiment described above, so a description thereof will be omitted.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a block diagram showing the configuration of a video camera which is an image pickup means provided with an image blur prevention device according to the third embodiment of the present invention. In the figure, the same parts as those in FIG. 1 of the first embodiment described above are designated by the same reference numerals. 7 is different from FIG. 1 in that a position encoder 28 for detecting the position of the zoom lens group 5 is added to the configuration of FIG. And
Zoom lens group 5 detected by the position encoder 28
The position signal of is input to the logical operation circuit 20. Incidentally, FIG.
Other configurations and operations in are the same as those in the first embodiment described above.

Next, the operation of the logical operation circuit 20 in the image blur prevention apparatus according to this embodiment will be described with reference to FIGS. 7 and 8. FIG. 8 is a flowchart showing the operation of the logical operation circuit 20. First, step S801 in FIG.
Then, the output signal from the motion vector detecting circuit 18 (each component in the horizontal direction and the vertical direction of the motion vector at the predetermined screen position) is read for each field. Then, step S8
In step 02, the motion vector at the read plural screen positions is subjected to predetermined processing to calculate one representative motion vector. The predetermined processing includes reliability evaluation processing of individual motion vectors, control target area determination processing, and the like.

Next, in step S803, the representative motion vector is integrated to obtain a deviation (image displacement amount) from the reference position on the screen, and an image shake correction signal is obtained. Next, in step S804, the control gain of each correction unit is set to the optimum state based on the position signal of the zoom lens group 5 output from the position encoder 28, that is, the focal length signal of the optical system. Next, in step S805, the VAP1 control (VAP control) or the field memory control is performed based on the image shake correction amount, which is the image deviation value obtained in step S803, and the control gain set in step S204. After executing the image blur correction by, the present processing operation is ended.

Since the processing in step S804 is the subject of the present invention, it will be described in detail with reference to FIG. FIG. 9 is a flowchart showing details of the processing routine of step S804 of FIG. In step S901 of the figure, the focal length signal output from the position encoder 28 is loaded into the logical operation circuit 20, and in the next step S902, the focal length signal captured in step S901 is used as the actual focal length of the optical system. Determine how much. Next, in step S903, the control gain for VAP control and field memory control is determined from the conversion table of shake frequency and control gain allocation shown in FIG. 10 according to the focal length determined in step S902. In FIG. 10, the vertical axis represents the correction (control) gain, and the horizontal axis represents the focal length. As is clear from the figure, this conversion table increases the ratio of the field memory control on the wide-angle side, that is, the whole image blur correction of the second correction means, and the VAP control on the telephoto side, that is, the first correction means. It is set so as to increase the ratio of the entire image blur correction.

Generally, the image blur tends to increase as the focal length approaches the telephoto position. Therefore, it is desirable to perform small-amplitude image blur correction on the wide-angle side and large-amplitude image blur correction on the telephoto side.

According to the image blur prevention device of this embodiment, V
In an image blur prevention device that combines a first correction means by AP control and a second correction means by field memory control, all of VAP control that can monitor the focal length of an optical system and correct a large amplitude image blur on the telephoto side. The control gain should be changed appropriately so that the ratio of the image shake correction to the total image shake correction of the field memory control can be increased to increase the ratio to the image shake correction and to correct the small amplitude image shake on the wide angle side. As a result, it is possible to perform image blur correction making the most of the respective advantages of the first and second correction means.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a block diagram showing the configuration of a video camera which is an image pickup means having an image blur prevention device according to the fifth embodiment of the present invention. In the figure, the same parts as those in FIG. 7 of the fourth embodiment described above are designated by the same reference numerals. 11 is different from FIG. 7 in that
From the configuration of FIG. 7, VAP1, VAP control means 2, VAP
The apex angle sensor 3 and the image sensor 8 are respectively removed, and instead, a large-area image sensor 8'having a larger area than usual, an image sensor read circuit 27, and a position encoder 28 for detecting the positions of the zoom lens group 5 are provided. It is a thing. The position signal of the zoom lens group 5 detected by the position encoder 28 is input to the logical operation circuit 20. With the large area image sensor 8'and the image sensor readout circuit 27,
It has a feedback loop and constitutes first correction means for correcting image shake. Then, by changing the read address in the image pickup device read circuit 27, an arbitrary place of the large area image pickup device 8'is cut out and the image shake correction is performed.

The rest of the configuration, operation, and effect of this embodiment are the same as those of the above-mentioned fourth embodiment, so a description thereof will be omitted.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 12 is a diagram showing a conversion table of shake frequency and control gain allocation in the image shake preventing apparatus according to the sixth embodiment of the present invention. In the present embodiment, the relationship between the shake frequency and the control gain allocation is first described.
The exponential function is used instead of the linear one as in the embodiment.

The rest of the configuration, operation and operational effects of this embodiment are the same as those of the above-mentioned fourth embodiment, so a description thereof will be omitted.

(Seventh Embodiment) Next, a seventh embodiment of the present invention will be described with reference to FIGS. Since the structure of the video camera, which is the image pickup means having the image blur prevention device according to this embodiment, is the same as that of FIG. 1 in the above-described first embodiment, the description will be made by diverting the drawing. FIG. 13 is a flowchart showing the operation of the logical operation circuit 20 in the image blur prevention apparatus according to this embodiment. First, FIG.
In step S1301, the output signal (the horizontal and vertical components of the motion vector at the predetermined screen position) from the motion vector detection circuit 18 is read for each field. Next, in step S1302, a predetermined representative motion vector is calculated by performing a predetermined process on the read motion vector at the plurality of screen positions. The predetermined processing includes reliability evaluation processing of individual motion vectors, control target area determination processing, and the like.

Next, in step S1303, the representative motion vector is integrated to obtain a deviation (image displacement amount) from the reference position on the screen, and an image shake correction signal is obtained. Next, in step S1304, the absolute value (absolute deviation value) of the deviation value of the image obtained in step S1303.
Based on the above, the control gain of each correction means is set to the optimum state. Next, in step S1305, image shake correction by VAP control and field memory control is performed from the image shake correction amount that is the image deviation value obtained in step S1303 and the control gain set in step S1304. After the execution, this processing operation ends.

The processing in step S1304 is as follows.
Since it forms the subject of the present invention, it will be described in detail with reference to FIG. FIG. 14 is a diagram showing a conversion table for allocating the image deviation value and the control gain of each correction means. In the figure, the vertical axis represents the correction gain and the horizontal axis represents the image deviation value. As is clear from the figure, as the image deviation value increases, the VAP control, that is, the ratio of the first correction means to the entire image blur correction increases, and the field memory control decreases as the image deviation value decreases. That is, the ratio of the second correction means to the entire image shake correction is increased. Therefore,
In step S1304 of FIG. 13, V corresponding to the absolute value of the image deviation value is calculated according to the conversion table of FIG.
The control gain of the AP control and the field memory control is set.

(Eighth Embodiment) Next, an eighth embodiment of the present invention will be described with reference to FIG. FIG. 15 is a diagram showing a conversion table of the shake frequency and the control gain allocation in the image shake preventing apparatus according to the eighth embodiment of the present invention. In the present embodiment, the relationship between the shake frequency and the control gain allocation is
Instead of changing linearly as in the embodiment, it is changed exponentially.

The rest of the configuration, operation and operational effects of this embodiment are the same as those of the above-mentioned seventh embodiment, so a description thereof will be omitted.

(Ninth Embodiment) Next, a ninth embodiment of the present invention will be described with reference to FIGS. Since the structure of the video camera, which is the image pickup means having the image blur prevention device according to this embodiment, is the same as that of FIG. 1 in the above-described first embodiment, the description will be made by diverting the drawing. FIG. 16 is a flowchart showing the operation of the logical operation circuit 20 in the image blur prevention device according to this embodiment. First, FIG.
In step S1601, the output signal from the motion vector detection circuit 18 (each component in the horizontal and vertical directions of the motion vector at a predetermined screen position) is read for each field. Next, proceeding to step S1602, a predetermined processing is performed on the read motion vector at the plurality of screen positions to calculate one representative motion vector. The predetermined processing includes reliability evaluation processing of individual motion vectors, control target area determination processing, and the like.

Next, in step S1603, the representative motion vector is integrated to obtain a deviation (image displacement amount) from the reference position on the screen, and an image shake correction signal is obtained. Next, in step S1604, the control gain of each correction means is set to the optimum state based on the absolute value of the representative motion vector obtained in step S1602. Then, the process proceeds to step S1605, and step S16 is performed.
After performing the image shake correction by the VAP control and the field memory control from the image shake correction amount which is the deviation value of the image obtained in 03 and the control gain set in step S1604, this processing operation is ended. .

The processing in step S1604 is as follows.
Since it forms the subject of the present invention, it will be described in detail with reference to FIG. FIG. 17 is a diagram showing a conversion table for allocating the representative motion vector and the control gain of each correction means. In the figure, the vertical axis represents the correction (control) gain, and the horizontal axis represents the representative motion vector. As is clear from the figure, as the representative motion vector, that is, the shake width at the present time increases, the VAP control, that is, the ratio of the first correction means to the entire image shake correction is increased, and the shake width at the present time is increased. As the value becomes smaller, the field memory control, that is, the ratio of the second correction means to the total image shake correction is increased. Therefore, in step S1604 of FIG. 16, the control gains of VAP control and field memory control according to the absolute value of the representative motion vector are set according to the conversion table of FIG.

(Tenth Embodiment) Next, a tenth embodiment of the present invention will be described with reference to FIG. FIG. 18 is a diagram showing a conversion table of the representative motion vector and the control gain allocation of each correction means in the image shake prevention apparatus according to the tenth embodiment of the present invention. In the present embodiment, the relationship between the shake frequency and the control gain allocation is not changed linearly as in the seventh embodiment, but is changed exponentially.

The rest of the configuration, operation, and effect of this embodiment are the same as those of the above-described ninth embodiment, so a description thereof will be omitted.

[0062]

According to the image shake preventing apparatus of the present invention, when the shake amount at that moment is large, the ratio of the first correcting means capable of correcting the image shake having a large amplitude to the whole image shake correction is increased, When the shake amount is small, the control gain can be appropriately changed so that the image shake having a small amplitude can be corrected and the ratio of the second correction unit having good correction characteristics to the entire image shake correction can be increased. Despite being a combination of a plurality of correction means, it is possible to easily and surely perform fine image shake correction according to the shooting condition without deteriorating the high frequency characteristics or exceeding the correction range. Produce an effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a video camera which is an image pickup unit including an image blur prevention device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control operation of a logical operation circuit in the image blur prevention device according to the embodiment.

FIG. 3 is a flowchart showing details of a main processing operation of a logical operation circuit in the image blur prevention device according to the embodiment.

FIG. 4 is a diagram showing a conversion table of a shake frequency used in the image shake preventing apparatus according to the embodiment and a control gain allocation of each correction unit.

FIG. 5 is a block diagram showing a configuration of a video camera which is an image pickup unit including an image blur prevention device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a conversion table of a shake frequency used in an image shake preventing apparatus according to a third embodiment of the present invention and a control gain allocation of each correction unit.

FIG. 7 is a block diagram showing a configuration of a video camera which is an image pickup means provided with an image blur prevention device according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing a control operation of a logical operation circuit in the image blur prevention device according to the embodiment.

FIG. 9 is a flowchart showing details of a main processing operation of a logical operation circuit in the image blur prevention device according to the embodiment.

FIG. 10 is a diagram showing a conversion table of focal lengths and control gain allocation of each correction means used in the image blur prevention apparatus according to the embodiment.

FIG. 11 is a block diagram showing a configuration of a video camera which is an image pickup means including an image blur prevention device according to a fifth embodiment of the present invention.

FIG. 12 is a diagram showing a conversion table of focal lengths and control gain allocation of each correction means used in the image shake preventing apparatus according to the sixth embodiment of the present invention.

FIG. 13 is a flowchart showing the control operation of the logical operation circuit in the image blur prevention device according to the seventh embodiment of the present invention.

FIG. 14 is a diagram showing a conversion table of an image deviation value and a control gain allocation of each correction means used in the image blur prevention device according to the embodiment.

FIG. 15 is a diagram showing a conversion table of image deviation values and control gain allocation of each correction means used in the image shake prevention apparatus according to the eighth embodiment of the present invention.

FIG. 16 is a flowchart showing a control operation of a logical operation circuit in an image blur prevention device according to a ninth embodiment of the present invention.

FIG. 17 is a diagram showing a conversion table of a representative motion vector used in the image blur prevention apparatus according to the embodiment and a control gain allocation of each correction unit.

FIG. 18 is a diagram showing a conversion table of a representative motion vector used in the image blur prevention apparatus according to the tenth embodiment of the present invention and a control gain allocation of each correction unit.

[Explanation of symbols]

Reference Signs List 1 variable apex angle prism (first correction means) 18 motion vector detection circuit (motion vector detection means) 19 first field memory (field memory) 20 logical operation circuit (runout frequency operation means, absolute deviation operation means, ratio changing means) ) 21 memory reading circuit (second correcting means) 28 position encoder (focal length reading means)

Claims (4)

[Claims] 1. An image blur prevention apparatus that detects a motion vector from an image signal and corrects the image blur in real time, and detects a motion vector between the images by performing a correlation calculation between images that are consecutive in time series. A motion vector detecting means, a shake frequency calculating means for calculating a shake frequency of an image based on the motion vector detected by the motion vector detecting means, and a first correcting means having a feedback loop for correcting the image shake. Second correction means for correcting the image shake by using an image having a field memory and delayed by the field memory, and the first correction means based on the shake frequency of the image calculated by the shake frequency calculation means.
An image blur preventing device comprising: a correction unit and a ratio changing unit that changes a ratio of the second correction unit to the total image blur correction. 2. An image blur preventing device for detecting a motion vector from an image signal and correcting the image blur in real time, comprising a feedback loop and correcting the image blur.
Correction means, second correction means for correcting the image blur by using an image having a field memory and delayed by the field memory, focal length reading means for reading the focal length of an optical system, and the focal length reading An image blur preventing device comprising: a ratio changing unit that changes a ratio of the first correction unit and the second correction unit in the total image blur correction based on focal length information read by the unit. 3. An image blur prevention apparatus for detecting a motion vector from an image signal and correcting the image blur in real time, for detecting a motion vector between the images by performing a correlation calculation between images consecutive in time series. A motion vector detecting means, an absolute deviation calculating means for adding the motion vectors detected by the motion vector detecting means to calculate an absolute deviation from the reference point of the current image, a feedback loop, and correcting the image shake. First correction means, a second correction means for correcting the image blur by using an image having a field memory and delayed by the field memory, and a reference of the current image calculated by the absolute deviation calculation means. Ratio changing means for changing the ratio of the first correcting means and the second correcting means in the total image blur correction based on the absolute deviation value from the point. An image blur prevention device characterized by being provided. 4. An image blur prevention device for detecting a motion vector from an image signal and correcting the image blur in real time, for detecting a motion vector between the images by performing a correlation calculation between images continuous in time series. A motion vector detecting means, a first correcting means having a feedback loop for correcting the image shake, and a second correcting means having a field memory and correcting the image shake by using an image delayed by the field memory. And ratio changing means for changing the ratio of the first correction means and the second correction means in the total image shake correction based on the motion vector information between the images detected by the motion vector detection means. An image blur prevention device characterized by the above.