JPH06133211A - Optical device with picture fluctuation correction function - Google Patents

Abstract

PURPOSE:To prevent the fluctuation correction effect from being largely changed depending on the position of a zoom optical system even at the same fluctuation of a picture by setting a fluctuation correction range of the picture to be narrow when the zoom optical system is set to the wide angle side and the fluctuation correction range of the picture to be wide when the zoom optical system is set to the telescopic side. CONSTITUTION:Upon the receipt of information representing a zoom optical system set to the wide position (high magnification position) from a zoom optical system control circuit 2, a read control circuit 12 controls a picture fluctuation correction range to be made narrow and upon the receipt the information representing a zoom optical system set to the telescopic position (low magnification position), the zoom optical system control circuit 2 controls the picture fluctuation correction range to be made wide. When a fluctuation takes place in a picture by hand blur during image pickup by a camcorder, the magnitude of the fluctuation of the picture on a screen is smaller with the zoom optical system set to the wide position than that with the zoom optical system set to the telescopic position while an angle of camera-shake is the same. Thus, the angle to correct the camera-shake is made the same regardless of the operation as above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an optical device having an image shake correcting function such as a video camera or a camera-integrated VTR.

[0002]

2. Description of the Related Art As is well known, recent camera-integrated VTs
In R, the mounting of a zoom lens is generalized, and the zoom ratio is about 8 to 12 times. In this case, when hand-held shooting is performed on the telephoto side, the screen shakes greatly even with slight camera shake, and the playback screen becomes very unsightly.

As one of the measures against this, by using a field memory, the fluctuation of an image is detected as a motion vector, and when the image signal stored in the field memory is read, the read position is controlled based on the detected vector. A method of correcting image shake is known. ("About Screen Shake Correction Device" Kai et al., 1987, TV Society) In this system, the shake of an image is corrected by controlling the position where the image signal stored in the frame memory is read. Since the size of the corrected image is smaller than that of the input image signal, it is enlarged by the electronic zoom and output.

A conventional example relating to this will be described with reference to FIG.

In FIG. 3, 101 is a zoom optical system and 1 is a zoom optical system.
Reference numeral 02 is an optical zoom control circuit for controlling the zoom optical system, 103 is an image pickup device such as a CCD, 104 is a camera signal processing circuit for generating a video signal from the output of the image pickup device 103, and 105 is an input video signal into a digital signal. A / D converter for conversion, 106 is a sync separation circuit for separating a horizontal sync signal and a vertical sync signal from an input video signal, and 107 is a clock generator for generating a system clock based on the separated sync signal. A circuit, 108 is a memory for storing the input video digital signal.

Reference numeral 109 denotes an image signal of one field before,
A motion vector detection circuit for detecting a motion vector by comparing the image signals of the current field, 110 is a correction for generating a correction vector for eliminating the image shake from the motion vector signal output from the motion vector detection circuit 109. A vector generation circuit, 111 is a write control circuit that generates a write address signal for writing an input video signal in the memory 108 from the synchronization signal and the system clock, and 112 is a video signal stored in the memory 108. A read control circuit which enlarges to a preset magnification and further controls a read position corresponding to the value of the correction vector output from the correction vector generation circuit 110,
Reference numeral 113 denotes an interpolation processing circuit for interpolating the enlarged video signal read from the memory 108, and 114 denotes a D / A for converting an output video signal of the interpolation processing circuit 113 into an analog signal.
It is a converter.

Next, the operation will be described.

The video signal output from the camera signal processing circuit 104 is converted into a digital signal by the A / D converter 105 and then stored in the memory 108 in accordance with the write control signal from the write control circuit 111.

On the other hand, in the motion vector detection circuit 109,
By comparing the image signal of the current field of the input video signal with the image signal of the preceding field, the motion vector of the subject of interest in the video signal is detected and output to the correction vector generation circuit 110. The correction vector generation circuit 110 outputs, as a correction vector, a vector value that is the opposite of the motion vector value output from the motion vector detection circuit 109 to the vector that moved so as to stop the shaking of the image. The read control circuit 112 that receives the correction vector value outputs a read control signal determined from the correction vector value and the image enlargement ratio to the memory 108.

By controlling in this way, the shake component can be removed from the shaken video signal.

The image enlargement ratio is determined by the size of the image shake correction range. The larger the correction range, the larger the enlargement ratio must be. However, the larger the enlargement ratio, the more severe the deterioration of the image. Therefore, it is necessary to balance the size of the correction range and the deterioration of the image quality.

[0012]

However, in the conventional apparatus, there is an image shake correction range regardless of whether the zoom optical system is on the wide-angle side (high magnification) or the telephoto side (low magnification). It was set to a constant value, which also kept the electronic zoom magnification constant. Therefore, there is a problem that the swing angle for correcting the swing changes depending on whether the zoom optical system is on the wide-angle side or on the telephoto side.

That is, as shown in FIG. 4, when the zoom ratio by the electronic zoom is the same, the shake correction angle θ _T on the telephoto side and the shake correction angle θ _W on the wide angle side are the same when the zoom ratio of the optical system is 8 times. θ _W = 8 · θ _T , and the shake correction angle is 8 times larger on the wide angle side than on the telephoto side. Therefore, even in the case of a similar camera shake, the correction effect greatly changes depending on the zoom position of the optical system.
For example, when the camera shake is large, the shake is sufficiently corrected on the wide angle side, but the shake remains outside the correction range on the telephoto side.

Further, when the camera is moved to perform panning and tilting, the point at which the shake correction operation is stopped outside the correction area is different between the wide-angle side and the telephoto side, which causes a feeling of strangeness in operation.

(Object of the Invention) The object of the present invention is to prevent the correction effect from changing greatly depending on the position of the zoom optical system even when the same image is shaken, and to prevent widening of the zoom optical system. It is an object of the present invention to provide an optical device with an image shake correction function that can reduce image quality deterioration.

[0016]

According to the present invention, when the zoom optical system is on the wide-angle side (high-magnification side), the image shake correction range is narrowed, and the electronic enlargement ratio of the video signal is further reduced. However, when the zoom optical system is on the telephoto side (low magnification side), the image shake correction range is widened, the electronic magnification of the video signal is further increased, and the position of the zoom optical system (magnification ), The video signal is electronically enlarged so that the image shake correction angle is always constant.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. In this embodiment, a camera-integrated VTR is used.
Is taken as an example.

In FIG. 2, reference numeral 1 is a zoom optical system, 2 is a zoom optical system control circuit for controlling the zoom optical system, and for outputting information on the magnification of the zoom optical system, 3 is a CCD.
Such as an image sensor, 4 is a camera signal processing circuit for generating a video signal from the output of the image sensor 3, 5 is an A / D converter for converting an input video signal into a digital signal, and 6 is a horizontal direction from the input video signal. A sync separation circuit that separates a sync signal and a vertical sync signal, 7 is a clock generation circuit that generates a system clock based on the separated sync signal, and 8 is a memory that stores the input video digital signal.

Reference numeral 9 is a motion vector detecting circuit for detecting a motion vector by comparing the image signal of the previous field with the image signal of the current field, and 10 is an image from the motion vector signal output from the motion vector detecting circuit 9. A correction vector generation circuit for generating a correction vector for eliminating the fluctuation of the image, a write control circuit 11 for generating a write address signal for writing an input video signal in the memory 8 from the synchronization signal and the system lock. , 12 are electronic zoom magnifications corresponding to the zoom magnifications from the zoom optical system control circuit 2 for the video signals stored in the memory 8, and further correspond to correction vector values output from the correction vector generation circuit 10. And a read control circuit for controlling the read position, and 13 interpolates the enlarged video signal read from the memory 8. Interpolation processing circuit, 14 converts an output video signal of the interpolation circuit 13 into an analog signal D
/ A converter.

Next, the operation will be described.

In the present embodiment, the zoom optical system control circuit 2 reads out information on the magnification of the zoom optical system from the read control circuit 1.
2 is the same as the conventional one except that the shake correction range of the image is controlled according to the magnification of the zoom optical system. Therefore, regarding the description of motion vector detection, correction vector generation, etc.,
It is omitted here.

When information about the wide-angle side (high-magnification side) of the zoom optical system is input from the zoom optical system control circuit 2,
The readout control circuit 12 controls the image shake correction range to be narrow, and controls the image shake correction range to be wide when the zoom optical system is on the telephoto side (low magnification side).

In a camera-integrated VTR, when an image shakes due to camera shake during shooting, if the camera shake angle is the same, the size of the image shake on the screen is longer when the zoom optical system is on the wide-angle side. It is smaller than the one on the side. Therefore, when the zoom optical system is on the wide-angle side, the correction range of the image shake on the screen is narrowed, and when the zoom optical system is on the telephoto side, the correction range of the image shake on the screen is wide, The angles to correct camera shake can be the same (see Fig. 2). When the correction range of the image shake on the screen may be narrow, the enlargement ratio by the electronic zoom can be reduced and the deterioration of the image quality can be reduced.

(Second Embodiment) Next, a second embodiment of the present invention will be described. Since the circuit configuration is the same as that of FIG. 1, its explanation is omitted here.

Generally, when a video signal output from a camera-integrated VTR or the like is displayed on the screen of a television (monitor television), the video signal displayed on the television is about 90% of the entire video signal. This occurs in order to take into account adjustment variations in the deflection circuit of the television. By utilizing that only about 90% of the video signal is displayed on the TV, by moving the position of 90% of the video displayed on the TV (reading position of memory) according to the value of the correction vector, Shake can be corrected. This method has the drawback that the correction range of the image is narrow, but has the advantage that it does not need to be enlarged electronically and the image quality does not deteriorate.

Therefore, when the magnification of the zoom optical system is smaller than a preset value, the read control circuit 12 stops the enlargement by the electronic zoom and controls the read position from the memory 8 to correct the image shake. When the magnification of the zoom optical system becomes larger than a preset value, electronically enlarging processing is performed to widen the shake correction range.

That is, when the zoom optical system is on the wide-angle side, the correction range of the image shake may be narrow, so the read position of the memory 8 is controlled without performing the electronic enlargement as described above. Shake correction. However, when the zoom optical system moves to the telephoto side, the shake on the screen becomes large even with the same shake angle, and the correction range cannot be corrected by the read control of the memory 8 alone. Spread.

(Third Embodiment) Next, a third embodiment of the present invention will be described. Since the circuit configuration of this embodiment is similar to that of FIG. 1, the description thereof is omitted here.

In accordance with the value of the magnification of the zoom optical system, the readout control circuit 12 controls the enlargement ratio of the electronic zoom that electronically enlarges so that the camera shake correction angle is always constant. By doing so, more optimal control becomes possible.

According to the first to third embodiments, the image shake correction range is narrowed when the zoom optical system is on the wide angle side, and the shake correction range is set when the zoom optical system is on the telephoto side. Since the control is performed to widen the image, the shake correction angle of the image is always the same regardless of the magnification of the zoom optical system. Therefore, the shake correction operation is out of the correction area when panning and tilting. There is no sense of incongruity that the point to stop is different between the wide-angle side and the telephoto side.

Further, when the zoom optical system is on the wide-angle side, by narrowing the correction range, it is possible to reduce the enlargement ratio by the electronic zoom and reduce the image quality deterioration. Due to the characteristics of the lens, when the zoom optical system is on the wide-angle side, the spatial frequency extends to a higher range than when the zoom optical system is on the telephoto side. Is effective for.

[0033]

As described above, according to the present invention,
If the zoom optical system is on the wide-angle side, the image shake correction range is narrowed, and the electronic magnification of the video signal is further reduced.If the zoom optical system is on the telephoto side, the image shake correction is performed. Depending on the position of the zoom optical system (magnification rate), widening the range and increasing the electronic magnification rate of the video signal
The video signal is electronically enlarged so that the image shake correction angle is always constant.

Therefore, even when the same image is shaken, the correction effect can be prevented from being greatly changed depending on the position of the zoom optical system, and the image quality deterioration on the wide angle side of the zoom optical system can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram for assisting the operation in the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional example.

FIG. 4 is a diagram for explaining an operation in a conventional example.

[Explanation of symbols]

 1 Zoom Optical System 2 Zoom Optical System Control Circuit 3 Image Sensor 4 Camera Signal Processing Circuit 8 Memory 9 Motion Vector Detection Circuit 10 Correction Vector Generation Circuit 12 Readout Control Circuit

Claims (3)

[Claims] 1. A zoom optical system, a video signal generating means for converting a signal obtained by an imaging means into a predetermined video signal, a motion vector detecting means for detecting a motion vector of an image from the video signal, and the motion. A correction vector generation means for generating a correction vector for correcting the shake of an image from a vector value, a memory means for recording an input video signal, and an input video signal recorded in the memory means according to the correction vector value. And an image shake correction function-equipped optical device equipped with a reading control means for electronically enlarging the video signal, in the reading control means.
When the zoom optical system is on the wide-angle side, a shake correction range control means is provided to narrow the shake correction range of the image, and to widen the shake correction range of the image when the zoom optical system is on the telephoto side. An optical device with an image shake correction function, which is characterized in that 2. A zoom optical system, a video signal generation means for converting a signal obtained by the image pickup means into a predetermined video signal, a motion vector detection means for detecting a motion vector of an image from the video signal, and A correction vector generation means for generating a correction vector for correcting the shake of an image from a motion vector value, a memory means for recording an input video signal, and an input video image recorded in the memory means according to the correction vector value. In an optical device with an image shake correction function, which is provided with a read control means for reading a signal and electronically magnifying the video signal, in the read control means,
When the zoom optical system is on the wide-angle side, the image shake correction range is narrowed, and the electronic magnification of the video signal within this correction range is reduced, and when the zoom optical system is on the telephoto side, An optical device with an image shake correction function, comprising: a video signal control means for widening a shake correction range of an image and for increasing an electronic enlargement ratio of a video signal within the correction range. 3. A zoom optical system, a video signal generation means for converting a signal obtained by the image pickup means into a predetermined video signal, a motion vector detection means for detecting an image motion vector from the video signal, A correction vector generation means for generating a correction vector for correcting the shake of an image from a motion vector value, a memory means for recording an input video signal, and an input video image recorded in the memory means according to the correction vector value. In an optical device with an image shake correction function, which is provided with a read control means for reading a signal and electronically magnifying the video signal, in the read control means,
An optical device with an image shake correction function, which is provided with a video signal expanding means for electronically expanding a video signal so that an image shake correction angle is always constant according to a zoom position of a zoom optical system.