JPH05316405A - Camera shake correction device in video camera - Google Patents

Abstract

PURPOSE:To obtain a stable image by preventing the occurrence of the shaking phenomenon of an image to be generated when the zooming operation of a zoom lens is a non-operation state. CONSTITUTION:The image information by an imager 14 is temporarily stored in an image memory 16. The camera shake detection information to be supplied from a camera shake sensor 10 and the zooming operation information from a zoom lens 11 are supplied to a sampling and filtering circuit 12 and a sampling is performed for the hand jiggle detection information by the sampling signal to be supplied from a timing generator 13. The hand jiggle detection information for which the sampling was performed is supplied to a memory controller 15, the reading location of the image signal stored in the image memory 16 is controlled by the memory controller 15 and the camera shake is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shake correction device for a video camera, which corrects a phenomenon in which a shooting screen is largely shaken due to a camera shake generated when a video camera shoots.

[0002]

2. Description of the Related Art It is well known that when a video camera is held by hand, a screen shakes due to camera shake. Especially, when the image is taken with the zoom lens set to the telephoto side, the phenomenon becomes remarkable. When such a hand shake phenomenon occurs, a stationary object shakes and moves, which makes it difficult to view a captured image and causes eyestrain. In addition, there is sometimes a problem that a part of the target subject is momentarily out of the screen, and further, there is a phenomenon that the subject blurs due to camera shake.

In order to solve such a problem, there has been proposed a means for correcting camera shake that occurs when a video camera shoots. For example, (1) speed detection by a sensor and direction detection (2) motion vector detection by image processing are generally used as a camera shake detection means for detecting the degree of the camera shake phenomenon.

Further, when the camera shake phenomenon is detected by the above-mentioned means, as correction means for correcting the photographed image, (1) means for changing the read-out position of the image data of the imager such as CCD (2) image data Means for changing the read-out position of image data from the image memory to be stored (3) Correction means by polarization in an optical prism is generally used.

[0005]

By the way, in the above-described camera shake phenomenon, even if camera shake having the same amplitude occurs, the amplitude of image shake is small when the zoom position of the zoom lens is on the wide side (wide) side. When the zoom position of the zoom lens is on the telephoto side, the amplitude of image shake becomes large. Therefore, when correcting the shake of the image, it is necessary to increase or decrease the correction amount of the shake detection information according to the zoom position of the zoom lens.

For example, a speed detection and direction detection means by a sensor is adopted as a camera shake detection means, and as a correction means for correcting a photographed image, a means for changing the read position of the image data of an imager such as a CCD or storing the image data. If a means for changing the read position of the image data from the image memory is adopted, it is necessary to add a correction amount to the camera shake detection information obtained by the camera shake sensor. Specifically, it is necessary to make the correction amount small when the zoom position of the zoom lens is on the wide side and increase the correction amount as the zoom position of the zoom lens becomes to the tele side.

According to the conventional camera shake correction device for a video camera, as shown in FIG. 8, for example, the camera shake detection information obtained by the camera shake sensor 1 as the camera shake detection means is converted into a digital signal by the A / D conversion circuit 2. , And taken into the microcomputer 3. On the other hand, information about the zoom position in the zoom lens 4 is extracted by the potentiometer 5, for example,
This output is converted into a digital signal by the A / D conversion circuit 6 and taken into the microcomputer 3.

In the microcomputer 3, the detection information obtained by the camera shake sensor 1, that is, the angular velocity is the integration circuit 3
It is converted into angle information a by -1, and this angle information a is supplied to the multiplication circuit 3-2. On the other hand, the digital information on the zoom position in the zoom lens 4 is converted into gain information in the gain table 3-3 and supplied to the multiplication circuit 3-2.

Therefore, the multiplication circuit 3-2, that is, the microcomputer 3 outputs the shake information obtained by the shake sensor 1 as a correction value corrected by the gain information according to the zoom position in the zoom lens 4.
This correction value acts to change the read-out position of the image signal obtained by the image sensor, for example, the read-out position of the image signal from the image memory for accumulating the image signal obtained by the image sensor. To be done.

By the way, in the correction means composed of the microcomputer 3 shown in FIG. 8, even if the zoom lens 4 is stationary, noise or the like is mixed in the output of the A / D conversion circuit 6, and the lower bit of the digital data is mixed. Causes so-called "fluttering", which changes the gain information in the gain table 3-3, which may affect the multiplication result in the multiplication circuit 3-2. That is, when the above-mentioned “fluttering” occurs, the output in the gain table 3-3 changes in the range of k1 to k2, and the microcomputer 3
The output of the correction means composed of k1 × a to k2 ×
It will fluctuate within the range of a.

As a result, although the video camera is in a stationary state, for example, the read position of the image signal from the image memory is unnecessarily changed, and the recorded image fluctuates.

The present invention has been made by paying attention to such a point, and prevents the occurrence of the above-described image fluctuation phenomenon that occurs when the zooming operation of the zoom lens is in a non-operating state, and stabilizes the image. It is an object of the present invention to provide a camera shake correction device in a video camera capable of obtaining the following.

[0013]

A camera shake correction apparatus for a video camera according to claim 1 of the present invention, which has been made to achieve the above object, captures an image in accordance with camera shake detection information provided from a camera shake detection means. A camera shake correction device in a video camera for correcting a camera shake by changing a readout position of an image signal obtained by an element, and a correction value for camera shake detection information provided by a camera shake detection unit only during zooming operation of a zoom lens. It is characterized in that the read position of the image signal obtained by the image pickup device is changed based on the camera shake detection information obtained by the corrector.

According to a second aspect of the present invention, in the image stabilization apparatus for a video camera according to the first aspect, the image obtained by the image pickup device is further based on the image stabilization information obtained by the correction means. It is characterized in that the read position of the image signal from the image memory that stores the signal is changed.

According to a third aspect of the present invention, in the image stabilizing apparatus for a video camera according to the first aspect, the image signal from the image pickup device is further generated based on the handshake detection information obtained by the correcting means. It is characterized in that the read position of is changed.

[0016]

According to another aspect of the present invention, there is provided a camera shake correction apparatus for a video camera, comprising correction means for adding a correction value to camera shake detection information provided by the camera shake detection means only during a zooming operation of the zoom lens. Since the read position of the image signal obtained by the image pickup device is changed based on the camera shake detection information obtained by the means, the occurrence of the image shaking phenomenon that occurs when the zooming operation of the zoom lens is in a non-operating state is prevented. Therefore, it becomes possible to obtain a stable image.

According to a second aspect of the present invention, there is provided the image stabilization apparatus for a video camera according to claim 2, wherein an image signal obtained by the image pickup device is obtained based on the image stabilization information obtained by the correction means in the image stabilization apparatus for the video camera. The reading position of the image signal to be stored in the image memory is changed.

Further, in the image stabilization apparatus for a video camera according to a third aspect of the present invention, the readout position of the image signal from the image pickup device is changed based on the image stabilization information obtained by the correction means.

[0019]

The present invention will be described below with reference to the embodiments shown in the drawings. The camera shake correction apparatus in the video camera of the present invention is premised on detecting and correcting camera shake during recording (at the time of shooting). Therefore, the following embodiments show only the blocks of the recording system. First, FIG. 1 shows a camera shake correction information correcting means in a camera shake correcting apparatus in a video camera according to the present invention. It should be noted that this FIG.
In the above, the same parts as those shown in FIG. 8 have the same functions, and therefore detailed description thereof will be omitted. The newly added portion indicated by reference numeral 7 indicates a switch that interlocks with the electric zoom switch. When the zoom position of the zoom lens 4 is moved to the tele side, the contact 7-1 is selected, and When moving the zoom position of the zoom lens 4 to the wide side, the contact 7-3
Is selected and the zoom operation of the zoom lens 4 is stopped, the contact 7-2 is selected. The output of the switch 7 is the delay circuit 3 in the microcomputer 3.
-4 is supplied.

The delay circuit 3-4 includes the switch 7
Is delayed to generate an output, and only while the switch 7 is in contact with the contact 7-1 or the contact 7-3, that is, only while the zooming operation of the zoom lens 4 is performed. , Is located in the microcomputer 3 and is A / D
A control signal for closing (turning on) the switch 3-5 interposed between the conversion circuit 6 and the gain table 3-3 is generated. The delay circuit 3-4 arranged in the microcomputer 3 outputs the output corresponding to the final zoom position to the gain table even if the position of the zoom lens slightly moves due to inertia after the zoom switch is operated. 3-
It is for supplying to No. 3. Therefore, the delay circuit 3-4 has a delay characteristic corresponding to several to several tens of fields.

FIG. 2 shows the gain characteristics of the gain table 3-3 arranged in the microcomputer 3. That is, in FIG. 2, the horizontal axis represents the zoom position of the lens, and the left end is the wide end and the right end is the tele end. The vertical axis represents the zoom gain, which has a non-linear correlation in which the zoom gain k increases as the zoom position approaches the telephoto end. The gain table 3-3 has a function of holding the zoom gain k corresponding to the zoom position immediately before the zoom lens 4 and outputting it to the multiplication circuit 3-2.

Further, FIG. 3 is a block diagram showing details of the processing in the microcomputer 3. In FIG. 3, first, a so-called angular velocity sensor is used as the camera shake sensor 1. This angular velocity sensor is generally composed of two sensors that independently detect a vertical sensor that detects a vertical (vertical) pitching component angular velocity and a horizontal sensor that detects a horizontal (horizontal) yawing component angular velocity. .. However, in the figure, for convenience of explanation, only one sensor is shown.

Information on the angular velocity obtained by the sensor 1 is converted into a digital signal by the A / D conversion circuit 2, and the digital data is taken into the microcomputer 3 by means of serial communication, and software processing is performed in the microcomputer 3. To obtain a correction value based on the zoom position.

The digital data is supplied to the subtraction circuit 301 and also feedforward to the subtraction circuit 301 via the delay circuit 302. Further, the output of the subtraction circuit 301 is supplied to the addition circuit 303, and the output thereof is also added through the delay circuit 304.
Be fed back to. These subtraction circuit 301, delay circuit 302, addition circuit 303, delay circuit 304
Thus, a high-pass filter (HPF) for DC removal having a cutoff frequency of 0.1 to 0.01 Hz is configured.

The output of the HPF is supplied to the multiplication circuit 305, where it is multiplied by the sensor gain for adjusting the variation of the sensor 1, and supplied to the multiplication circuit 306. This multiplication circuit 306 is the multiplication circuit 3 shown in FIG.
-2, and the zoom gain k obtained from the gain table 307, that is, the gain table 3-3 shown in FIG. 1 is supplied to the other side of the multiplication circuit 306. In this way, the angular velocity information multiplied by the zoom gain k is supplied to the minute noise removing circuit 308.
The minute noise removing circuit 308 performs so-called coring processing of subtracting the threshold value from the input and setting it to zero when the sign is reversed. Then, the output is supplied to the limiter circuit 309. This limiter circuit 309
When the input level is higher than the threshold value, it is considered that the shooting state is pan or tilt, and the process of replacing with the limiter value is performed.

Next, in order to convert the angular velocity information into the angular information, an integration (low-pass) filter including an adder circuit 310, a delay circuit 311, a multiplication circuit 312, and a conversion table 313 is passed. The conversion table 313 multiplies the conversion signal by the conversion signal by using the input signal as an address. Therefore, the integration coefficient becomes non-linear. Finally, the output of the integration (low-pass) filter is subjected to overall gain adjustment in the buffer amplifier 314, a correction value based on the zoom position is obtained, and serially transferred to the output end 315.

FIG. 4 is a camera shake correction apparatus for a video camera of the present invention including the camera shake detection means shown in FIGS. 1 to 3 and a correction means for adding a correction value to the camera shake detection information provided by the camera shake detection means. 2 is a block diagram showing a configuration of an embodiment. The camera shake detection means and the correction means shown in FIGS.
In the figure, the camera shake sensor 10, the zoom lens 11, and the sampling and filtering circuit 12 are shown in FIG.

A sampling pulse from a timing generator 13 is supplied to the sampling and filtering circuit 12. This sampling pulse is synchronized with a vertical drive pulse, that is, a V reset pulse supplied to an imager 14 composed of an image pickup device such as a CCD, and the sampling and filtering circuit from the timing generator 13 at an interval of 1 degree per field. 12 are supplied. The sampling and filtering circuit 12 receives the sampling pulse from the timing generator 13 and samples the camera shake detection information obtained by the correction means.

The camera shake detection information sampled in this way is filtered and supplied from the sampling and filtering circuit 12 to the memory controller 15. The memory controller 15 supplies a read control signal to the image memory 16 and the electronic enlarging circuit 17 based on the sampled camera shake detection information. That is, the image signal obtained by the imager 14 is stored in the image memory 16, and the read position of the image signal stored in the image memory 16 is changed based on the sampled camera shake detection information. It

FIG. 5 illustrates the operation,
FIG. 5A shows the case where there is no camera shake phenomenon and the camera shake correction amount is zero, and FIG. 5B shows the case where the camera shake phenomenon occurs and camera shake correction is performed. First, when there is no camera shake phenomenon and the camera shake correction amount is zero, the central portion B of the effective memory area A supplied from the imager 14 is read from the image memory 16 as shown in FIG. 5A. Then, the portion corresponding to the central portion B read from the image memory 16 is enlarged by the electronic enlargement circuit 17 and an image shown as C is obtained.

In addition, when the hand shake phenomenon occurs, the condition shown in FIG.
As shown in (b), the read control signal supplied from the memory controller 15 adds, for example, a correction amount + v corresponding to the amount of camera shake in the vertical direction to the central portion B of the effective memory area A, and also horizontally. A position B ′ formed by adding, for example, a correction amount −h corresponding to the amount of camera shake in the direction
Is read out, and this is read by the electronic expansion circuit 17
To obtain an image shown as C '.

As a result, the image signal obtained from the electronic enlarging circuit 17 is subjected to correction corresponding to the shaking of the image caused by camera shake, which is almost unchanged from that of FIG. 5A. A still screen as shown is obtained.

The image signal thus subjected to the camera shake correction is supplied to the recording system signal processing circuit 18, is subjected to signal processing by it, and is recorded by the recording head 19 on the magnetic tape 20 which is a recording medium.

In the above-mentioned configuration, the read position of the image signal from the image memory 16 for accumulating the image signal obtained by the imager 14 is changed based on the camera shake detection information sampled by the sampling and filtering circuit 12. Although an example is shown, a configuration as shown in FIG. 6 can also be adopted.

The configuration shown in FIG. 6 shows a case in which the read position of the image signal from the imager 14 is changed based on the camera shake detection information sampled by the sampling means. In FIG. 6, the same reference numerals as those in FIG. 1 achieve the same functions, and therefore detailed description thereof will be omitted. In the example shown in FIG. 6, the camera shake detection information supplied from the camera shake sensor 10 is sampled by the sampling and filtering circuit 12 and supplied to the imager 14 as a read control signal.

Here, the control signal supplied from the sampling and filtering circuit 12 to the imager 14 acts as a V reset signal in the imager 14. That is, the read signal at the timing corrected for each field based on the shake information in the vertical and horizontal directions is supplied, and the read start position of the image signal in the vertical direction and the horizontal direction in the imager 14 is corrected by the shake information. As a result, the image signal output from the imager 14 has the vertical and horizontal camera shake corrected.

FIG. 7 illustrates the operation,
In the effective screen D of the image sensor, that is, the imager 14, an image stabilizing area E is held as blanking in the vertical and horizontal directions, and by utilizing this blanking portion, the vertical direction of the imager 14 and The reading position of the image signal in the horizontal direction is changed for each frame.

In the structure shown in FIG. 4, for example,
The vertical shake can be corrected by changing the read position of the image signal from the imager 14, and the horizontal shake can be corrected by changing the read position of the image signal from the image memory 16.

Further, as can be easily recalled from the above description, vertical camera shake is corrected by changing the read position of the image signal from the image memory 16,
It is also possible to correct the camera shake in the horizontal direction by changing the signal read position of the image from the imager 14.

[0040]

As is apparent from the above description, claim 1
According to the image stabilization apparatus for a video camera described in (1), the image stabilization device includes a correction unit that adds a correction value to the image stabilization information provided by the image stabilization unit only during the zooming operation of the zoom lens. Since the reading position of the image signal obtained by the image pickup device is changed based on the detection information, the occurrence of the image shaking phenomenon that occurs when the zoom lens zooming operation is in a non-operating state is prevented, and a stable image is displayed. It becomes possible to obtain.

Further, according to the image stabilizing apparatus in the video camera of the second aspect, the read position of the image signal from the image memory for accumulating the image signal obtained by the imager is changed based on the sampled camera shake detection information. To be done. For this reason, in addition to the above-mentioned unique effect, most of the pixels possessed by the imager composed of CCD or the like can be effectively used, and the image stabilization apparatus does not sacrifice the resolution. Can be provided.

Further, according to the camera shake correction apparatus in the video camera of the third aspect, the read position of the image signal of the imager is changed based on the sampled camera shake detection information. Therefore, it is not necessary to separately provide an image memory, and it is possible to provide an economical image stabilization apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a camera shake detection information correction means used in a camera shake correction apparatus in a video camera of the present invention.

FIG. 2 is a characteristic diagram showing a gain characteristic of a gain table used in the image stabilizing apparatus of the present invention.

FIG. 3 is a block diagram illustrating details of a camera shake detection information correction unit.

FIG. 4 is a block diagram showing an overall configuration of a camera shake correction device in the video camera of the present invention.

FIG. 5 is a schematic diagram illustrating how an image signal is read out from an image memory.

FIG. 6 is a block diagram showing the overall configuration of another embodiment of the image stabilizer in the video camera of the present invention.

FIG. 7 is a schematic diagram for explaining the operation of the embodiment shown in FIG.

FIG. 8 is a block diagram showing a configuration of a conventional camera shake detection information correction unit.

[Explanation of symbols]

1,10 Camera shake sensor (camera shake detection means) 2,6 A / D conversion circuit 3 Microcomputer (camera shake detection information correction means) 4,11 Zoom lens 5 Potentiometer 7 Electric zoom interlock switch 12 Sampling and filtering circuit 13 Timing Generator 14 Imager (imaging device) 15 Memory controller 16 Image memory 17 Electronic enlargement circuit 18 Recording system signal processing circuit 19 Recording head 20 Magnetic tape

Claims (3)

[Claims] 1. A camera shake correction device in a video camera for correcting a camera shake by changing a read-out position of an image signal obtained by an image sensor according to camera shake detection information provided by a camera shake detection means, wherein zooming of a zoom lens is performed. The image pickup device includes a correction unit that adds a correction value to the shake detection information provided by the shake detection unit only during operation, and reads out an image signal obtained by the image sensor based on the shake detection information obtained by the correction unit. An image stabilizer for a video camera, characterized in that the position is changed. 2. The read position of the image signal from the image memory for accumulating the image signal obtained by the image pickup device is changed based on the shake detection information obtained by the correction means. An image stabilizer for a video camera according to Item 1. 3. The image stabilization in the video camera according to claim 1, wherein the readout position of the image signal from the image sensor is changed based on the image stabilization information obtained by the correction unit. apparatus.