JPH10200809A - Screen composing still picture camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain resolution almost as high as a silver salt photograph by a video camera. SOLUTION: When a still picture is taken, an optical axis is controlled in more than one direction by an optical hand shake correcting means 12A and pixel information of a subject at least two field angles are obtained from a photoelectric converting means 13A. Those pixel signals are stored in a storage means 15 and a screen correlation detecting means 16 operates the correlation between the pixel values of the field angles. The position where the largest correlation value is obtained is set as a connection border of each field angle and a screen composing means 17 while controlling a read address composes a screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen composite still image camera for photographing a wide-angle still image using a video movie.

[0002]

2. Description of the Related Art Conventionally, the function of a still image camera is realized by a still image shooting mode of a video movie or an electronic still camera. FIG. 8 is a block diagram showing a configuration of a camera unit of a conventional video movie. In this figure, incident light that has entered through an imaging lens 21 is incident on a photoelectric conversion unit 23 via, for example, an optical camera shake correction unit 22. The optical camera shake correction means 22 corrects the vibration of the angle of view due to camera shake by mechanically displacing the optical axis of the optical system. The photoelectric conversion unit 23 photoelectrically converts the incident light and supplies a signal obtained by scanning each pixel to the signal processing unit 24. Then, the signal processing unit 24 converts the input signal into a video signal of a predetermined standard, and supplies the video signal to a recording / reproducing device or an image memory (not shown).

In recent markets, there has been a demand for higher image quality at the time of camera shake correction, and an optical camera shake correction means for mechanically controlling the optical axis as in the above method has been used. It has been adopted in some video movies.
Strictly speaking, a camera-integrated V with a built-in recording / reproducing device
The TR is called a video movie, and the one without a built-in recording / reproducing device is called a video camera. In the following description, both are called a video camera.

[0004]

When a still image operation mode of a video camera having the above-described functions is called a still image camera, such a still image camera including a so-called electronic still camera includes: There is a demand for high resolution comparable to silver halide photography. However, in a conventional still image camera, a CCD is usually used as a photoelectric conversion unit, and the number of pixels is, for example, about 300,000 to 500,000 pixels. For example, in the case of 330,000 pixels, the vertical resolution at the time of field accumulation driving of the photoelectric conversion means is 250 TV lines, and the horizontal resolution is 500.
It is about TV. Further, as shown in FIG. 9, the vertical resolution of the photoelectric conversion means at the time of frame accumulation driving is 500 TV lines,
The horizontal resolution is about 500 TV lines.

On the other hand, the resolution of the silver halide photograph service size is 1.3 million pixels in terms of the number of pixels of the photoelectric conversion means, and the vertical resolution and the horizontal resolution are about 1000 TV lines. Therefore, in order to obtain a resolution comparable to that of a silver halide photograph, both the vertical resolution and the horizontal resolution of a still image camera are 100.
About 0TV is required.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has as its object to realize a video composite still image camera having a high resolution comparable to a silver halide photograph.

[0007]

In order to solve this problem, the invention according to claim 1 of the present application comprises an image pickup lens for forming an image of a subject on a predetermined image forming surface, and a photographing field of view having a plurality of angles of view. In this case, the optical axis of the imaging lens is displaced in a direction perpendicular to the optical axis so that a part of each angle of view is overlapped, and the light is incident via the imaging lens and the optical camera shake correction means. A photoelectric conversion unit that photoelectrically converts the image of each of the obtained angles of view and outputs a pixel signal; a signal processing unit that generates a video signal of each screen based on the pixel signal output from the photoelectric conversion unit; Storage means for storing the video signals of a plurality of screens output from the unit for each screen, and a correlation of pixel values between the respective screens stored in the storage means,
Screen correlation detection means for outputting an image correlation signal, and based on the image correlation signal output from the screen correlation detection means, read over a plurality of screens by switching the pixel value of the storage means in an overlapping area of the screen, Screen synthesizing means for generating a video signal of a synthesized screen.

According to a second aspect of the present invention, when an image pickup lens for forming an image of a subject on a predetermined image forming surface and a field of view having a plurality of view angles are formed, images at each view angle are continuous. Optical image stabilization means for displacing the optical axis of the imaging lens in a direction perpendicular to the optical axis, and photoelectrically converts images at each angle of view incident through the imaging lens and the optical image stabilization means, A photoelectric conversion unit that outputs a pixel signal, a signal processing unit that generates a video signal of each screen based on the pixel signal output by the photoelectric conversion unit, and a video signal of a plurality of screens output from the signal processing unit. It is characterized by comprising storage means for storing for each screen, and screen synthesizing means for sequentially reading pixel values of the storage means over a plurality of screens and generating a video signal of a synthesized screen.

Further, in the invention according to claim 3 of the present application, the photoelectric conversion means is an interlaced scanning type photoelectric conversion means.

Further, in the invention described in claim 4 of the present application, the photoelectric conversion means is a progressive scanning type photoelectric conversion means.

Further, in the invention according to claim 5 of the present application, the optical camera shake correction means is provided between the imaging lens and the photoelectric conversion means.

Further, in the invention according to claim 6 of the present application, the optical camera shake correction means is provided in front of the imaging lens facing a subject.

[0013] In the invention according to claim 7 of the present application, the optical camera shake correction means controls the position of a part of the lenses constituting the imaging lens.

According to the above configuration, the number of pixels originally possessed by the photoelectric conversion means is h pixels in the horizontal direction and v pixels in the vertical direction.
In the case of pixels, if the optical axis of each angle of view is moved in the horizontal and vertical directions by approximately one angle of view, respectively, so that a part of the angle of view is overlapped by using the optical camera shake correction means, it becomes approximately horizontal. 2h pixels,
An image of about 2 v pixels is obtained in the vertical direction. In this way, a still image having a wide angle of view with four times the number of pixels can be obtained. Further, when shooting a moving image, an image in which original camera shake is prevented by using an optical camera shake correction unit can be obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Hereinafter, a screen composite still image camera according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a screen composite still image camera 10A according to the present embodiment. As shown in the figure, the screen composite still image camera 10A includes an imaging lens 11, an optical camera shake correction unit 12A, and a photoelectric conversion unit 13.
A, a signal processing unit 14, a storage unit 15, a screen correlation detection unit 16, and a screen synthesis unit 17. Note that the imaging lens 11, the optical camera shake correction unit 12A, the photoelectric conversion unit 13A, and the signal processing unit 14 are the same as those in the conventional example shown in FIG.

An optical low-pass filter, such as a quartz filter, is attached to the front of the photoelectric conversion means 13A in order to remove interference distortion of pixels generated by the photoelectric conversion means 13A. The optical image stabilizing means 12A of the present embodiment includes this optical low-pass filter, and is displaced by a micromotor or another actuator that performs electromechanical conversion to control the optical axis of the optical low-pass filter. Things. The control method here is to displace the optical axis of the imaging lens in a direction perpendicular to the optical axis so that a part of each angle of view overlaps in the still image mode, as well as the normal camera shake correction. Further, in the present embodiment, the photoelectric conversion means 13A is constituted by a CCD and is an interline type photoelectric conversion means.

The storage means 15 is a memory for storing video signals of a plurality of screens output from the signal processing section 14 for each screen. The screen correlation detecting means 16 detects an overlapping part of the images from the strength of the correlation among the plurality of video signals stored in the storage means 15. The screen synthesizing means 17 is constituted by a read address control means for reading out a pixel value from the storage means 15, and when an image correlation signal is given from the screen correlation detecting means 16, a plurality of screens are synthesized to form an image having a wider angle of view. To generate.

When the screen composite still image camera 10A is used as an original video camera, the incident light passing through the imaging lens 11 is imaged on the photoelectric conversion surface of the photoelectric conversion unit 13A via the optical camera shake correction unit 12A. The optical camera shake correction unit 12A corrects camera shake caused by the photographer holding the camera when shooting a normal moving image and stabilizes the optical axis with respect to the photoelectric conversion unit 13A, thereby preventing the subject image from shaking.

As described above, the screen composite still image camera 10A of the present invention positively utilizes the optical camera shake correction means 12A even when there is no camera shake when shooting a still image. FIG. 2 is a schematic diagram showing a change in the angle of view taken by the optical camera shake correction means 12A. As shown in the figure, images of at least two angles of view such as different angles of view A1 and A2 with respect to the subject A are formed on the photoelectric conversion unit 13A via the imaging lens 11 and the optical camera shake correction unit 12A. . For example, an image with an angle of view A1 is formed on the photoelectric conversion unit 13A with an optical path indicated by a solid line, and an image with an angle of view A2 is formed on the photoelectric conversion unit 13A with an optical path indicated by a dotted line.

That is, the optical image stabilizer 12A drives the built-in actuator to shift the optical axis so as to obtain incident light as shown by the solid line and the dotted line in FIG. An image of a corner is formed. The degree of the angle of view change by the optical camera shake correction means 12A is determined by the angle of view A1 and the angle of view A
2 are controlled so as to have a predetermined overlap.

FIG. 3 is a schematic view showing a case where the angle of view taken by the optical image stabilizer 12A is four. Although FIG. 2 shows an example of a change in two angles of view, an image with four angles of view is obtained by controlling the optical axes in the vertical and horizontal directions, respectively, as shown by the hatched portions in FIG. The change of each angle of view may be controlled, for example, in synchronization with the signal readout timing of the photoelectric conversion unit 13A. However, it is needless to say that in the effective period of the photoelectric conversion, the change in the angle of view must be stopped or in a fine movement state to avoid blurring of the image accompanying the change in the angle of view.

The incident light input to the photoelectric conversion means 13A of FIG. 1 is photoelectrically converted, and a pixel signal is input to the signal processing unit 14. In the case of interlaced scanning, the signal processing unit 14 performs an averaging process on the luminance and color signals of each pixel from the photoelectric conversion unit 13A for each scanning line, converts the signal into a video signal of a predetermined standard, and stores it in the storage unit 15. To enter. The storage unit 15 stores video signals of at least two screens in different memory areas. When combining n screens, the storage means 15 must have a storage capacity equal to or greater than n screens.

The screen correlation detecting means 16 checks the correlation between the video signals of at least two screens stored in the storage means 15 and detects the area (address) of the overlapping part of the image as shown by the hatched portion in FIG. Are output as image correlation signals. As a method of correlation detection, for example, video signal processing such as pattern matching or correlation calculation processing for calculating a two-dimensional correlation of a screen can be performed.

The screen synthesizing means 17 reads out pixel values between predetermined addresses of the storage means 15 from information on the position of the strongest image correlation calculated from two adjacent screens before synthesis, and synthesizes video signals of two or more screens. And outputs it as a video signal of one screen.

FIG. 4 shows the storage means 1 by the screen synthesizing means 17.
FIG. 9 is a schematic diagram illustrating a control method of a read address No. 5;
For example, when the screen correlation detection means 16 determines that the image correlation is the strongest at the position β in FIG. 4, the image value is read up to the address RA1 of the storage area of the image A1 stored in the storage means 15. Then, at the position of β, the image value is read from the address RA2 of the storage area of the image A2. FIG. 5 shows an example of four-screen synthesis. In this case as well, the image to be read is switched at the position having the strongest correlation. This way each screen B
The resolution of 1 to B4 is, for example, αTV in both the vertical and horizontal directions, but a high-resolution still image of approximately 2αTV in both the horizontal and vertical directions is obtained by the above-described screen composition.

(Embodiment 2) A screen composite still image camera according to a second embodiment of the present invention will be described. In this embodiment, a progressive scanning type photoelectric conversion unit 13A is used, and the overall configuration of the screen synthesis still image camera is the same as that shown in FIG. In the photoelectric conversion unit 13A of the present embodiment, the vertical resolution of the screen obtained from one angle of view is 500 TV lines. For example, when the vertical and horizontal 4 are each divided into two and four screens are combined, if the horizontal resolution of one screen is 500 TV lines and the vertical resolution is 500 TV lines, the resolution after combining into one screen is vertical And about 10
00TV books are obtained. In this way, a high-resolution still image comparable to a silver halide photo service size can be realized. An image of one frame can be obtained in one field period of a normal TV signal. In this case, the total time for capturing images of four screens is 1/15 second. If the drive time of the optical image stabilizer is sufficiently shorter than the shooting time of each screen, it can be said that the above shooting time is comparable to the slower shutter speed of the still camera.

The screen composite still image cameras of the first and second embodiments described above may have the configuration shown in FIGS. 6 and 7 in addition to FIG. FIG. 6 is a block diagram showing another configuration example of the screen synthesis still image camera 10B according to both embodiments.
The image synthesis still image camera 10B of FIG. 6 includes an imaging lens 11 and an optical camera shake
B, photoelectric conversion unit 13B, signal processing unit 14, storage unit 1
5. It includes a screen correlation detecting means 16 and a screen synthesizing means 17. Incidentally, the optical camera shake correction means 12B is mounted in front of the imaging lens 11. For example, a new objective lens is provided in front of the imaging lens 11, and this objective lens is driven by an actuator in a direction perpendicular to the optical axis. The photoelectric conversion means 13B may be either a progressive scanning type or an interlaced scanning type.

FIG. 7 is a block diagram showing the overall configuration of another screen composite still image camera 10C in both embodiments. In FIG. 6, the optical camera shake correction means 12B is provided in front of the imaging lens 11. However, the screen synthesis still image camera 10C shown in FIG. This is used as the optical camera shake correction means 12C. Further, the photoelectric conversion means 13C may be either a progressive scanning type or an interlaced scanning type. Such a configuration is desirable when the optical system including the image pickup lens and the optical image stabilizing means is to be small in size.

In the first embodiment, the photoelectric conversion means 13A is an interline type photoelectric conversion means.
Performing the X drive is not preferable because the vertical resolution per screen before composition is reduced to 250 TV lines. Note that P
DMIX driving means averaging the pixel values of the n-th and (n + 1) -th scanning lines to obtain the pixel signal of the n-th line, and
And the average of the pixel values of the (n + 2) th scanning line,
This is a driving method in which one line of pixel signal is used. Therefore, it is desirable to use a frame accumulation method as a driving method of the interline type photoelectric conversion means. Of course, the photoelectric conversion unit is driven by PDMIX, and one screen before screen combination is interlaced over two fields. Then, after images captured over 2n fields are stored in the storage means, they may be combined on one screen.

In the above description, the screen correlation detecting means 16 is used.
If the degree of change in the angle of view of 12C can be controlled with high precision, the image may be switched and read from adjacent pixel positions held in the storage unit 15 according to the change in the angle of view.

In the above description, the optical axis is controlled by the camera shake correcting means so that a part of the angle of view is overlapped. However, the control may be performed such that the angles of view are completely adjacent. In this case, the screen can be synthesized by successively reading out the adjacent images stored in the storage means.

[0032]

As described above, according to the present invention, in a video camera provided with an optical image stabilizer,
Without changing the resolution of the new optical system mechanism or the photoelectric conversion means such as CCD, storage means, screen correlation detection means,
A high-resolution still image with a wide angle of view can be captured simply by adding a screen combining unit.

When the optical axis from the subject to the photoelectric conversion means via the imaging lens and the photoelectric conversion means is changed in the horizontal direction by the optical camera shake correction means, a horizontally long still image can be obtained. A vertically long still image can be obtained in the same manner. Furthermore, if the focal length of the imaging lens is set to the telephoto side, and the optical axis is changed in the horizontal and vertical directions to synthesize an image with four angles of view, the resolution (number of pixels) is greatly improved. An image is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a screen synthesis still image camera according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an operation principle (two-screen synthesis) of an optical image stabilization unit according to the present embodiment.

FIG. 3 is a schematic diagram illustrating the operation principle (four-screen synthesis) of the optical camera shake correction unit according to the present embodiment.

FIG. 4 is a schematic diagram showing operations of a screen synthesizing unit and a storage unit according to the embodiment.

FIG. 5 is a schematic diagram showing a combined image of four screens in the present embodiment.

FIG. 6 is a block diagram showing another configuration example (part 1) of the screen synthesis still image camera according to the first and second embodiments of the present invention.

FIG. 7 is a block diagram illustrating another configuration example (part 2) of the screen synthesis still image camera according to the first and second embodiments of the present invention.

FIG. 8 is a block diagram illustrating a configuration example of a conventional still image camera.

FIG. 9 is a schematic diagram showing an example of an image captured by a conventional still image camera.

[Explanation of symbols]

 10A, 10B Screen synthesis still camera 11 Imaging lens 12A, 12B, 12C Optical camera shake correction means 13A, 13B, 13C Photoelectric conversion means 14 Signal processing unit 15 Storage means 16 Screen correlation detection means 17 Screen synthesis means

Claims (7)

[Claims] 1. An imaging lens for forming an image of a subject on a predetermined imaging plane, and when an imaging field of view is constituted by a plurality of angles of view, the optical axis of the imaging lens is set so that a part of each angle of view overlaps with the light. Optical camera shake correction means for displacing in the direction perpendicular to the axis, photoelectric conversion means for photoelectrically converting an image at each angle of view incident via the imaging lens and the optical camera shake correction means, and outputting a pixel signal; A signal processing unit that generates a video signal of each screen based on a pixel signal output by the photoelectric conversion unit; and a storage unit that stores video signals of a plurality of screens output from the signal processing unit for each screen. A screen correlation detecting unit that calculates a correlation between pixel values between respective screens stored in the storage unit and outputs an image correlation signal; and the storage unit based on the image correlation signal output from the screen correlation detecting unit. Pixel value of the screen overlap A screen combining means for switching over an area to be read and reading over a plurality of screens to generate a video signal of a combined screen. 2. An image pickup lens for forming an image of a subject on a predetermined image forming plane, and, when a field of view is constituted by a plurality of angles of view, the optical axis of the image pickup lens is set so that images at each angle of view are continuous. Optical camera shake correction means for displacing in the direction perpendicular to the axis, photoelectric conversion means for photoelectrically converting an image at each angle of view incident via the imaging lens and the optical camera shake correction means, and outputting a pixel signal; A signal processing unit that generates a video signal of each screen based on a pixel signal output by the photoelectric conversion unit; and a storage unit that stores video signals of a plurality of screens output from the signal processing unit for each screen. A screen synthesis still image camera comprising: a screen synthesis unit that sequentially reads pixel values of the storage unit over a plurality of screens and generates a video signal of a synthesis screen. 3. The screen composite still image camera according to claim 1, wherein the photoelectric conversion unit is an interlaced scanning type photoelectric conversion unit. 4. The screen composite still image camera according to claim 1, wherein the photoelectric conversion unit is a progressive scanning type photoelectric conversion unit. 5. The screen composite still image camera according to claim 1, wherein said optical camera shake correction means is provided between said imaging lens and said photoelectric conversion means. . 6. The image synthesis still image camera according to claim 1, wherein said optical camera shake correction means is provided in front of said imaging lens facing a subject. 7. The optical image stabilizer according to claim 1, wherein a position of a part of the imaging lens is controlled.
Screen synthesis still image camera described in the item.