JP2003008947A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera that moves a plurality of images photographed separately to positions at which the images joint most properly on the basis of the correlation of them so as to reconfigure the images. SOLUTION: This invention provides the electronic camera that displays in real time an overlapping part of an image picked up preceedingly to an image picked up this time on a finder as to the overlapping part of adjacent images in the finder in the case of sequentially photographing one object image in a way of splitting the one object image by an image pickup element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera suitable for wide range photography in which a subject image is divided into a plurality of images and the images are reconstructed.

[0002]

2. Description of the Related Art Generally, there is an electronic camera using a solid-state image pickup device such as a CCD in which photosensors are arranged in a matrix. In such an image sensor, the number of optical sensors to be arranged is limited due to problems in manufacturing technology for forming the optical sensor, reduction in yield, and the like. Therefore, in order to obtain a wide range of images, for example, as described in JP-A-63-191483, by controlling the optical system, the shooting range projected on the image pickup element surface is switched to divide the subject image. A technique has been proposed in which a wide range is captured with high resolution by capturing the image in a wide range with high resolution.

[0003]

However, in the reconstruction of the images obtained by dividing and photographing the subject image by the electronic camera described above, in order to photograph the divided images so that they are continuously connected at the adjacent portions, the optical Since it is necessary to control the system with extremely high accuracy, there have been problems that the control device of the optical system becomes complicated and the cost becomes high.

Further, when a camera for split shooting is handheld and the camera is moved, the shooting range of each image may shift and the images may not be accurately connected, and it is necessary to fix the camera on a tripod or the like for shooting. There was also a problem. It is therefore an object of the present invention to provide an electronic camera that reconstructs images by moving a plurality of divided images to a position where the images are most appropriately connected based on their correlation.

[0005]

To achieve the above object, the present invention is an electronic camera for reconstructing a plurality of images obtained by dividing a subject image and sequentially capturing the subject image. An image pickup means composed of an element, a viewfinder for displaying the image to be picked up this time in real time, together with a part of the image picked up last time to overlap the image picked up last time by the image pickup means and the image picked up this time, An electronic camera having the following is provided. With the electronic camera of the present invention having the above-described configuration, when performing split shooting, shooting is performed with a part of the shooting range overlapping between adjacent images.

[0006]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows the configuration of an electronic camera according to a first embodiment of the present invention, which will be described. This electronic camera is roughly divided into a photographing section A for photographing a subject and a recording section B for storing a photographed image in a predetermined memory, and an image signal is transmitted between the photographing section A and the recording section B. It is transmitted in the air by an optical signal.

In this electronic camera, a subject 1 is imaged on an image pickup device 4 such as a CCD through a taking lens system 2 and a mirror 3a. At one end of the mirror 3a, the rotary shaft 3
b is provided, and it rotates about this axis by a rotation drive device (not shown). Then, at the time of photographing, capturing of the subject image is intermittently performed a plurality of times. During this period, the mirror 3a is rotating, the photographing range moves on the subject, and a wide range is photographed as shown in FIGS.

In this photographing, the range of the images captured by two consecutive photographings is controlled by controlling the photographing time interval and the position of the mirror 3a so that a part of the current image overlaps a part of the previous image. To do.
It is also possible to eliminate the rotation mechanism section by manually adjusting the photographing range.

The image signal output from the CCD image pickup device 4 is digitized by an A / D converter 5. In this embodiment, since the image data is transmitted over the air, it is necessary to reduce the amount of information. The subsequent binarization circuit 6 binarizes the image signal, and the data compression circuit 7 compresses the data. For the binarization of this image signal, the well-known 2
The binarization method can be used, but especially if the new binarization method proposed in "The Institute of Electronics, Communication and Communication 90/8 Vo1.J 73-D-II No.8: Noboru Babaguchi No. 3" is used. Good image quality can be obtained.

By such binarization and data compression, the amount of data transmitted to the recording section B can be greatly reduced,
The time required for transmission can be shortened. However, since a transmission error may occur due to the influence of external light, the compressed image data is processed by the error correction code addition circuit 8 using a method such as the Reed-Solomon method.
A code for error correction is added and modulated by the modulation circuit 9 for transmission. Here, the modulated image signal is L
It is sent to the ED driver 10 and is sent as light by the LED 11.

The optical signal 12 transmitted by the photographing section A is converted again into an electric signal by the light receiving diode 13 of the recording section B, and demodulated by the demodulation circuit 14. The error correction circuit 15 corrects an error occurring during transmission with reference to the error correction code described above, and the compressed data decoding circuit 1
The data compressed by 6 is decoded. The image data decoded here is temporarily stored in the frame memory A17.

In the present embodiment, since a plurality of times of shooting are performed intermittently in order to perform a wide range of shooting, there is the effect of camera shake during that time, and even if the images taken by each shooting are simply connected, high quality is obtained. The image cannot be reconstructed. Therefore, the blur correction circuit 18 is used to correct the blur of the image,
It is stored again in the frame memory B19. Details of the blur correction circuit 18 will be described later.

However, only the image data of the first frame (first captured image) is not shake-corrected and is stored in the end of the frame memory B19. The image data after the second frame is moved to the position where the image of the first frame stored in the frame memory B19 is connected by the blur correction circuit 18 and is stored therein.

Here, the overlapping range of a plurality of shootings is
By recording the average value of the image signal of each photographing, it is possible to obtain a high-quality image with reduced noise.

The image recorded in the frame memory B19 may be used for analog conversion by the D / A conversion converter 20 for display on the CRT monitor 21 or for sending to the printer 22 to make a hard copy. To be It is also possible to construct a database of photographed images by transmitting information regarding the photographing situation from the photographing unit together with the image data and inputting them to the filing device 23.

Next, FIG. 2 shows a specific configuration of the above-described blur correction circuit, which will be described. Here, blurring correction of the image of the Nth frame is taken as an example. The blur correction circuit is roughly composed of two components. One is a movement amount calculation unit 1 that obtains the movement amount of an image from two adjacent images.
8a, and the other is an image moving unit 18b that transforms one of the adjacent images in parallel and rotationally to convert the other image into a position that is accurately connected.

As shown in FIG. 4, the photographing range moves on the subject with blurring, and the photographing is sequentially performed. When the captured images are viewed continuously, the images appear to move, and thus the shift between two adjacent images can be represented by a motion vector. In general, the motion vector has a different value at each position on the image because it includes a rotation component due to the blur.

The movement amount calculator 18a will be described. The movement amount calculation unit 18a obtains the parallel movement amount and the rotation movement amount of the images by obtaining the motion vectors at a plurality of different portions within the range in which the same subject appears in two adjacent images. The image conversion unit 18 is used by using these pieces of information.
It is possible to correct the relative positions of two images in which b is adjacent to each other and accurately connect the two images.

First, a part of the image data of the (N-1) th frame stored in the frame memory A17 is stored in the reference image memory 32 as a reference image. The size of this image is arbitrary, but here it is 16 pixels × 16 pixels. To examine the positional relationship between the (N-1) th frame image and the Nth frame image, the correlation between both images is used. That is, the correlation between the reference image (held in the reference image memory) that is a part of the (N-1) th frame image and the comparison image extracted from a part of the Nth frame image is checked.
Here, the comparison image is taken out from a position in the Nth frame image corresponding to the position where the reference image is taken out from the (N-1) th frame, and its size is larger than that of the reference image.

As shown in FIG. 5, while changing the position of the reference image with respect to the comparative image, the correlation between both images at each position is obtained. The correlation is obtained by summing the absolute values of the differences between the pixel signals of the corresponding pixels of the two superimposed images for all the pixels of the reference image. Then, the reference image is moved within the comparison image, the correlation at each position is obtained, and the relative position of both images for which the calculated value of the correlation is the smallest is found. What regarded this relative position as a vector becomes a motion vector between both images.

The relative position between the reference image and the comparative image is changed by the superposition position control circuit 40, and total control of calculation of the sum of absolute values of differences corresponding to all pixels of the reference image is performed. The circuit 41 is performing. The signal output from the overlay position control circuit 40 and the signal output from the total control circuit 41 are the pixel position calculation circuit 33.
1 pixel of the Nth frame that is input to the frame memory A17 and is input to one input end of the difference calculation circuit 34.

A signal output from the total control circuit 41 designates one pixel of the image of the (N-1) th frame stored in the reference image memory 32, and the other input of the difference calculation circuit 34. Entered on the edge. The absolute value of the output of the difference calculation circuit 34 is calculated by the absolute value calculation circuit 35. Further, under the control of the summing control circuit 41, the absolute values of 256 times for the 16 × 16 pixels of the reference image memory 32 are summed up in the summing memory 37. This total value is the (N
-1) A signal representing the correlation between the frame and the Nth frame.

The position at which the reference image and the comparative image are superposed is sequentially moved under the control of the superposition position control circuit 40, the correlation at each position is calculated, and the minimum value detection circuit 38 calculates the correlation signal. The position that is the smallest is required. As for this position, as described in Japanese Patent Application No. 4-96405 filed by the present applicant, it is possible to more accurately obtain the accuracy by performing the interpolation calculation of the correlation value. The position difference from the (N-1) th frame is transmitted to the ΔxΔyΔθ calculation circuit 39 as a motion vector.

As shown in FIG. 5, when the reference image is at the relative position (-x, -y) and the correlation is highest (the calculated value of the correlation is small), the motion vector v is (x, y). ). The motion vector is accumulated in a memory (not shown), and the motion vector (relative position) of the Nth frame with respect to the first frame is obtained. This motion vector is the Nth
Determined at any two points in the frame,
Each is input to the ΔxΔyΔθ calculation circuit 39. Here, the motion vector is determined at two points a and b, and the motion vector at each point is v1 (x1, y
1) and v2 (x2, y2).

The .DELTA.x.DELTA.y.DELTA..theta. Calculation circuit 39 uses the vectors v1 and v2 to write the position of the Nth frame image stored in the frame memory A17 in the frame memory B19 in parallel with the translation amount (.DELTA.x, .DELTA.y) and the counterclockwise direction. It is calculated as the rotational movement amount Δθ in the direction. Figure 6 shows this calculation method.
A description will be given based on (a) and (b). As shown in FIG. 6A, the motion vector can be considered as a combined vector of the vector S related to the parallel movement and the vector r related to the rotational movement.

That is, the vector v1 = S + r vector v2 = S-r Therefore, the vectors S and r can be obtained by the vector S = (v1 + v2) / 2 vector r = (v1-v2) / 2. The components of the vector S are Δx and Δy. Further, as can be seen from the relationship shown in FIG. 6B, Δθ can be calculated (approximately) by Δθ = arctan (| v1-v2 | / d).

The accuracy of the calculation can be improved by calculating the movement amount by using motion vectors at not only the two points a and b but also many points. Next, the parallel movement amounts Δx and Δy and the rotational movement amount Δθ are input to the image moving circuit 18b. The image moving circuit 18b
Rotates and translates the Nth frame image in the frame memory A17 and writes it in the frame memory B19 as shown in FIG. Here, the center position of the rotational movement may be the midpoint between the two points a and b. When the motion vectors are calculated and calculated for three or more points, the center of rotation may be appropriately determined according to the positions of those points.

Since the position of each pixel is discrete,
Generally, the pixel position of the image of the Nth frame that has been rotated and moved in parallel does not match the pixel position of the frame memory B19. Therefore, as the image signal to be written in the frame memory B19, the signal of the pixel of the Nth frame image moved to the closest position is used, or the signal value corresponding to the pixel position to be written is estimated by interpolation of several neighboring pixels. You may use. (Better image quality can be expected by performing interpolation.) Further, when writing an image in the frame memory B19, for a pixel in which a captured image has already been written, a signal value already written and a signal to be newly written. By writing a value obtained by combining the value with a predetermined ratio, noise components included in the image can be reduced and the image quality can be improved. The optimum value of the composition ratio differs depending on the number of times writing is performed on one pixel, and so on.

From the above, in the first embodiment of the present invention, the shooting range of the split shooting can be roughly set, so that the control of the optical system for switching the shooting range is performed by a polygon mirror or the like. Simple ones are enough. In addition, since the effect of camera shake can be corrected, handheld shooting can be performed.

FIG. 8 is a diagram for explaining a usage state of the electronic camera according to the first embodiment. According to the first embodiment, the influence of camera shake and the like can be corrected, so that hand-held photography can be performed as shown in FIG.
Further, as shown in FIG. 8, the photographing unit A and the recording unit B are separated, and signals are transmitted and received cordlessly by infrared rays, radio waves, etc., thereby reducing the size and weight of the photographing unit A. It is possible to improve the operability during shooting.

Next, FIG. 9 shows the structure of the photographing section of the electronic camera according to the second embodiment of the present invention, which will be described. Here, FIG. 9 shows only the characteristic portion of the embodiment of the present invention, and the configuration other than this characteristic portion is the same as that of the first embodiment.
In the second embodiment, in order to detect image blur,
An optical system dedicated to blur correction is provided.

First, the subject 65 is imaged on a recording image capturing image pickup device 69 via a lens system 66, a mirror 67a as a displacement generating section, and a half mirror 68. The image sensor 69 is composed of a line sensor. This image is used for CRT display and printout. Also,
The subject image passes through the half mirror 68, is magnified by the magnifying optical system 70, and is also imaged on the blur detection image sensor 71. This image is used for image blur detection.

In the second embodiment, since the image on the blur detecting image pickup device 71 is magnified by the magnifying optical system 70, the motion vector can be detected with high resolution. Therefore, the movement amounts Δx, Δy, and Δθ can be calculated at the time of reconstructing an image with higher accuracy than in the first embodiment, and the image quality of the reconstructed image is further improved. If a line sensor is used as the image pickup device 69 for photographing, high-speed reading can be performed, and image pickup with a higher number of pixels can be performed. In the first and second embodiments described above, the amount of shift between images is detected based on the correlation between images that are continuously captured. However, in an image with low contrast, the error of the correlation calculation becomes large.

Therefore, as a third embodiment, an example of improving the accuracy of the correlation calculation will be described. As shown in FIG. 10A, a highly correlated subject is provided above and below a subject (for example, a blackboard) to be imaged. Here, a highly correlated subject is a subject having a wide band, and is, for example, a two-dimensional chirp wave, a random dot pattern generated by random numbers, a pattern in which white noise is amplified, a point image, or the like. is there. However, all of them have a band smaller than the Nyquist frequency. Alternatively, FIG. 10 (b)
As shown in, write letters and lines on the subject. Then, by selecting the reference image for the correlation calculation from the vicinity of this dot pattern, the correlation accuracy can be greatly improved.

Next, as a fourth embodiment, the above-mentioned third embodiment
An example will be described in which the accuracy of the correlation calculation is improved when a pattern having a high correlation cannot be provided on the subject as in the above embodiment. The fourth embodiment is almost the same as the configuration of FIG. 1 and can add a correlation area selection circuit to the blur correction circuit 18 shown in FIG. 2 to select a highly correlated area. FIG. 11 shows and describes only the characteristic part of the blur correction circuit.

First, the image data from the frame memory A17 is input to the movement amount calculation circuit 18a, the image movement circuit 18b and the correlation area selection circuit 18c, respectively. The correlation area selection circuit 18c selects an area having a high correlation from the input image data and outputs a reference image described later to the movement amount calculation circuit 18a.

The movement amount calculation circuit 18a obtains the movement amount of the image from the two images corresponding to the reference image. Then, the calculated moving amount is calculated by the image moving circuit 18b.
By moving one of the images in parallel or rotationally, the other is converted into a position where the images are accurately connected.

FIG. 12 shows a specific structure of the correlation area selection circuit 18c. The image data is input to the candidate image selection circuit 42. In this candidate image selection circuit 42, for example, _{n from} (a ₁ , b ₁ ) to (an, b _n ) shown in FIG.
A candidate image is selected from the candidate images of the candidates based on the image data, and the variance detection circuits 43 and 44 detect the variance values σa _i and σb _i of the candidate images a _i and b _i .

[0039] Then, the sum sigma _i of these variance values sent to the maximum value detection circuit 45, the largest to i the sum sigma _i as i _max, are output. Next, the correlation area read circuit 46 reads the reference images a _{i max} and b _{i max} corresponding to i _max from the maximum value detection circuit 45 and outputs them to the movement amount calculation unit 18a. Therefore, a high correlation value can be obtained by a high variance value, that is, a high image contrast.

Various other modifications can be considered for the dispersion detection circuits 43 and 44. For example, a high-pass filter or a band-pass filter may be used, and a convolution filter set with coefficients as shown in FIG. Can also be used. Further, it is possible to use the sum of absolute values of the differences between adjacent pixels by the configuration shown in FIG.

By the way, a plurality of image pickup elements may be used for picking up a high-definition image or an image of a wide range. In this case, in a member constituting the apparatus, a mechanism based on a relative position between the members is used. It is necessary to prevent the members from expanding and contracting and changing the relative position between the members due to heat from the outside or heat generated by themselves. Therefore, it is generally practiced to use a material having a small coefficient of thermal expansion for a member that holds such a relative position so that the mutual positional relationship between the plurality of members does not change due to temperature. However, it is not preferable to use such a special material having a small coefficient of thermal expansion because it causes an increase in cost and difficulty in processing. Therefore, an example in which a general material is used without using a special material having a small coefficient of thermal expansion to prevent the relative position between members from changing due to expansion and contraction by heat will be described below. . FIG. 16 is a diagram showing an example of a configuration in which the relative position is prevented from changing in the image pickup unit.

That is, a beam splitter 82 for splitting a captured image into two is provided at one end on the mount 81.
Are fixed by the holding member 83. On the mount 81, an L-shaped holding member 85 to which an image pickup device 84a such as a CCD is attached and a holding member 86 to which an image pickup device 84b is attached so as to photoelectrically convert the image sent from the beam splitter 82. Fixed to. The image pickup device is arranged so as to maintain a conjugate relationship with a semi-transparent mirror of a beam splitter for dividing the captured image into two.

At the other end of the mount 81,
An optical system 87 is provided, and a rotary filter 88 is provided between the beam splitter 82.

In such an arrangement, the distances m and n from the semi-transparent mirror of the beam splitter 82 to the respective image pickup devices are equal. That is, considering the mounting base 81 as a reference, the respective image pickup elements are mounted by respective holding members, the distance q from the fixed end of the holding member 85 to the image pickup surface, and the play of the fixing screw of the holding member 86. The width is p (p <q).

When determining the material of each member,
Generally, a material having a thermal expansion coefficient as small as possible is selected in consideration of thermal expansion. This prevents displacement of the relative positions of the plurality of imaging planes due to temperature changes. But,
Since such materials have the drawbacks of being expensive and having very poor workability, they should be avoided. The coefficient of thermal expansion of general materials ranges from large to small. In this embodiment, a material having a large coefficient of thermal expansion is positively adopted, and as a result, it is attempted to realize it at low cost.

From the relationship between the dimensions p and q in FIG. 16, the coefficient of thermal expansion of each member is selected (the coefficient of thermal expansion of each member is α and β), and the following equation: p × α = q × It is made of a material that satisfies β. With this configuration, even if the temperature changes, the dimensions m and n in FIG. 16 are always the same, the relative positions between the plurality of image pickup elements simultaneously change, and the conjugate relationship with the semi-transparent mirror can always be maintained.

The example in which the temperature is corrected in the direction of the optical axis has been described above with reference to FIG. 16. An example in which the correction in the direction perpendicular to the optical axis is also performed next is shown in FIG. explain. As shown in the figure, in this example, the fixed end of the L-shaped arm of the holding member 89 for holding the image pickup element arranged on the optical axis reflected by the semi-transparent mirror is the opposite of that shown in FIG. Fixed in the direction.

Consider a case where one of the holding members 86 extends in the direction of arrow a due to a change in temperature due to this structure. Similarly, the image pickup device is also displaced in the direction of arrow a due to thermal expansion and contraction, but the material of the holding member 86 is selected to have a large coefficient of thermal expansion. Further, due to the extension of the other holding member 89, the other element shifts in the arrow b direction, but if the shift amount in the a direction and the shift amount in the b direction are equal, the relative positional relationship between the two image pickup elements does not change. From the relationship of the first embodiment, α> β.

According to FIG. 16, in order to keep the relative relationship between the elements unchanged, r × α = S × β must be satisfied. As is clear from FIG. 17, r <
Since S, naturally α> β.

Therefore, if the relationship between r and S is selected according to the coefficients α and β determined by p × α = q × β, then both p × α = q × β and r × α = S × β are achieved. It is possible. Therefore, with the configuration as shown in FIG. 16, it is possible to prevent the displacement of the relative position both in the optical axis direction and in the direction orthogonal to the optical axis due to the temperature change between the elements.

As described above, it is possible to cancel the displacement of the relative positions of the plurality of image pickup devices at the conjugate position with respect to the reflecting mirror due to the temperature change by selecting different thermal expansion coefficients. Therefore, expansion and contraction due to heat can be prevented without using an expensive material having a small coefficient of thermal expansion and poor workability. On the other hand, when there are a plurality of materials having existing coefficient of thermal expansion, the same effect can be obtained by setting the arm length of the element holding member corresponding to the coefficient of thermal expansion.

As described above, according to the embodiment of the present invention,
Since a plurality of divided images are moved to the position where the images are most appropriately connected based on their correlation to reconstruct the images, the divided images can be taken by rough optical system control, and the configuration can be simplified. Further, there is an effect that the processing accuracy of the constituent members can be lowered. In addition, even if the camera shakes during split shooting, the shake of the image is corrected, so that you can shoot with your hand.

Further, the present invention is not limited to the above-mentioned embodiment, and for example, as shown in the above-mentioned examination example, a special material having a particularly small thermal expansion coefficient is used in the constituent member of the electronic camera. However, by appropriately arranging a plurality of common materials in combination, it is possible to prevent the relative position between the members from changing due to expansion and contraction due to heat.

Next, FIG. 18 shows the structure of a photographing section of an electronic camera according to a fifth embodiment of the present invention, which will be described. In the above-described first embodiment shown in FIG. 1, the mirror is arranged between the taking lens system 2 and the image pickup device 4. However, in this configuration, as the angle of view becomes wider, the aberration of the image off the optical axis and the peripheral dimming may increase. Therefore, a configuration example in which a mirror is arranged between the taking lens system 2 and the subject as shown in FIG. 18 will be described.

In the fifth embodiment, as an image pickup device, for example, a 2048 × 256 pixel CMD (Charge Modul) is used.
ation Device, charge modulation device) 4. This CMD
4, image receiving elements are arranged in a matrix as shown in FIG. 19, and a clock generating circuit 4-1, a horizontal scanning circuit 4-2, and a vertical scanning circuit 4-3 are provided. However, C
MD4 has 2048 pixels in the direction perpendicular to the paper surface.

The CMD4 is of an XY address type read system, and when a pulse for signal read is sent to the clock generation circuit 4-1, the horizontal scanning circuit 4-2, and the vertical scanning circuit 4-3, the pixel is read out. Signal is output from the SIG terminal.

The electronic camera shown in FIG. 18 has a strobe 91 for illuminating a subject, and a deflection filter 92 having deflection planes offset from each other by 90 ° in order to remove specularly reflected light that is reflected back to the subject. 93, a voice coil 90 for rotating the mirror 3a, the taking lens system 2, the above-mentioned CMD4, a processing unit 94 for processing an image signal detected by the CMD4, a shutter 99, and a memory card as a storage medium. It is composed of 97 and.

Next, FIG. 20 shows the configuration of the processing unit 94 and will be described. In this processing unit 94, the CMD 4 that detects an image signal from an optical image, the A / D conversion unit 5, and the A
A binarization circuit 6 for binarizing the image signal digitized by the / D converter 5, an image composition circuit 95 for image composition,
The compression circuit 7 for performing a predetermined compression process, and the memory card 97.
A writing circuit 96 for writing a signal to
These circuits, voice coil 90 and strobe 91
Are controlled by the controller 98. A signal indicating the pressed state of the shutter button 99 is input to the controller 98.

The image composition circuit 95 is composed of both the frame memory A17 and the blur correction circuit 18 described above. Then, the photographing by this camera is performed by causing the strobe 91 to emit light while rotating the mirror 3a. FIG. 21 shows the timing of strobe light emission. This chart shows the voltage applied to the vertical scanning circuit in each line (the total number of lines is N). FIG. 21B shows the waveform of the m portion of FIG. 21A, and the voltage level thereof differs depending on the exposure, reading, and reset. Further, as shown in FIG. 21A, in the CMD, since the exposure and readout timings are different for each line, strobe light emission is performed during the vertical blanking period in which all pixels correspond to the exposure period. The operation of the camera configured as described above will be described.

First, when the shutter button 99 is pressed, the voice coil 90 works to start the rotation of the mirror 3a, and the strobe emits light at the timing shown in FIG. 21 (a). As for the strobe light, subject light from which specular reflection is removed by the functions of the polarization filters 92 and 93 enters the CMD4.

The image signal read from the CMD4 is
It is converted into a digital signal by the A / D converter 5, binarized by the binarizing circuit 6, and input to the image synthesizing circuit 95. This process is repeated a predetermined number of times, and the signal combined by the image combining circuit 95 is written in the memory 19. The image signal written in the memory 19 is compressed by the compression circuit 7 and written in the memory card 97.

With the above-described operation, for example, if stroboscopic light emission is performed about 15 times, high-resolution imaging equivalent to 2000 × 3000 can be performed. Further, since the mirror 3a is arranged between the taking lens system 2 and the subject, it is possible to take an image even in the peripheral region without causing aberration or dimming. Further, by using two polarizing filters 92 and 93, specular reflection can be prevented even if a strobe is used. Further, since the strobe light emission time is very short, even if the mirror 3a continues to rotate, the divided image is a sharp image with less blurring during the exposure period.

Further, since the image is recorded in the memory card 97, the portability is excellent and the data can be easily transferred to a personal computer, a printer or the like. Further, in the present embodiment, even if the mirror 3a does not rotate accurately at a constant speed, the shake correction circuit detects and corrects this, so that the voice coil is not required to be so accurate.

Next, FIG. 22 shows the structure of an electronic camera according to a sixth embodiment of the present invention, which will be described. In the constituent members of this embodiment, the same members as those in FIG. 18 are designated by the same reference numerals, and the description thereof will be omitted. In the electronic camera of FIG. 18 described above, the strobe irradiates the entire subject, so that useless light is emitted even to the area not imaged by the CMD4.

Therefore, in this electronic camera, the reflecting mirror 100 is used.
By irradiating the subject to be imaged by the CMD 4 with strobe light through the diaphragm half mirror 102 and the mirror 3a using the lens system 101 or the lens system 101, it is possible to irradiate the light without waste. Then, by configuring the half mirror with a deflecting plate, specular reflection can be removed as in the previous embodiment.

Further, when it is desired to use this electronic camera in a situation where the strobe cannot be used, the strobe is not emitted and the mirror drive and the stationary control (intermittent drive) are performed at the timing shown in FIG. Good. At this time, if the mirror is driven in one frame cycle, different images are mixed, so the mirror is driven in two frame (or two or more) cycles and only the signal exposed during the period A is processed by the processing unit 94.
The signal sent to the image synthesizing circuit of No. 2 and exposed in the period B is not used.

Similarly, FIG. 2 shows a seventh embodiment.
As shown in FIG. 4A, the spring 103, the cam 104a, and the connecting rod 104b may be provided to drive the mirror 3a intermittently. Further, as shown in FIG. 24B, a screw 112b for driving the mirror intermittently and a FIT (Flame Int).
An erline transfer type CCD image sensor may be used.

The screw 112b is formed with a screw groove so as to have a flat portion and a driving portion. That is, when the screw rotates at a constant speed, the gear 112a is repeatedly driven and stopped periodically. In addition, the FIT type CC used here
The characteristic of the D image pickup device is that, at the same time,
Even-numbered fields and odd-numbered fields can be exposed, and the exposure time can be changed.

Further, FIG. 24C shows the exposure timing and the rotation amount of the mirror. When the flat portion of the screw 112b meshes with the gear 112a (for example, 10 ms), the mirror stands still, and at this time, exposure is performed for both even and odd fields. When the driving part of the screw 112b meshes with the gear 112a (for example, 20 ms), the mirror is moving, and at this time, only signal reading is performed.

By using such a screw 112b, the rotary motion can be easily converted into an intermittent motion. Vibration and noise are less than when using the cam shown in FIG. In addition, the images are not mixed and useless imaging is not performed. Further, in these embodiments, the FIT type CCD image pickup device is used, but as described above, it is also possible to use the CMD by intermittently driving the mirror at a period of 2 frames or more of image pickup.

Next, FIG. 25 shows the structure of an image pickup apparatus as an eighth embodiment according to the present invention. In the above-described seventh embodiment, the mirror is rotated to obtain images in different directions, but in the present embodiment, the continuous image signals obtained by rotating the TV camera are combined.

In the image pickup apparatus shown in FIG. 25, the CCD
A TV camera 105 such as a camera, a processing unit 94 ′ having the same function as the processing unit 94 shown in FIG. 18, a recording medium 106 such as a hard disk for storing a combined image signal, a printer 22, a CRT monitor 21. Composed of and. The processing unit 94 'includes an A / D conversion unit 5, an image synthesis circuit 95, a memory 19, and a D / A conversion unit 20. In this embodiment, since a grayscale image is processed, the image signal is binarized. do not do.

Furthermore, as the ninth embodiment, not only the TV camera as in the eighth embodiment is used but also the ultrasonic diagnostic apparatus 107 and the like can be applied as shown in FIG. is there. However, in the case of the convex type ultrasonic image, as shown in FIG. 28, the image object has a fan shape, and the image has a background as an invalid area unnecessary for image combination such as text data. Therefore, it is necessary to process this invalid area so that it is not used in the combining process. That is, a portion of the left image overlapping the invalid area of the right image as shown in FIG. 29A and a portion of the right image overlapping the invalid area of the left image as shown in FIG.
Not used for image composition.

Then, as shown in FIG. 30, Japanese Patent Application No. 5-0 filed by the applicant of the present invention is applied to an overlapping portion of an actual image object.
No. 42402, a joint process is performed.

FIG. 27 shows a concrete structure of the ninth embodiment. In this image pickup device, the movement amount calculation circuit 18a and the image movement circuit 18 are provided on the output side of the memory A17.
b is connected. The image moving circuit 18b is connected to a structure emphasizing circuit 108 that performs structure emphasizing for recovering a signal deteriorated by interpolation.
The left border line detector 109 for detecting the left border line of the right image is connected to the synthesis circuit 111. In this synthesizing circuit 111,
The memory B19 and the right boundary line detector 110 are connected. Here, the left image corresponds to the image signal already written in the memory B 19, and the right image is newly input to the memory A.
It corresponds to 17 image signals.

Further, the synthesizing circuit 111 includes a memory B1.
9 is a circuit for generating a signal to be written in 9, and writes the corresponding signal value of the left image in the area on the left side of the right image left boundary line and the corresponding signal value of the right image in the area on the right side of the left image right boundary line in memory B19. , The joint process using both the right image and the left image is performed on the part sandwiched between both boundary lines, and the result is written in the memory B19. By the above processing, it is possible to satisfactorily perform image synthesizing processing even for an image of the convex type ultrasonic diagnostic apparatus.

Next explained is the tenth embodiment of the invention. In this embodiment, as shown in FIG. 31 (a), three images having mutually overlapping areas are photographed, and these images are subsequently connected to realize wide-range photographing (panoramic photographing).

In this embodiment, a part (edge) of the image captured last time is displayed in the viewfinder, and the image capture unit is moved to a position where the edge of the image captured this time overlaps with the partial image. It is to be photographed. As shown in FIG. 31B, this finder is a part of the image captured last time, and in order to connect the image captured last time and the image captured this time, the part where the images overlap (the same subject or one of them) Overlapping area image display section A for displaying an image of a copy) and a captured image display section B for displaying an image captured this time.
Composed of and. Taking the above-mentioned FIG. 31A as an example,
When the image 2 is captured this time after the image 1 is captured, a part of the previously captured image 1 (overlapping area 1) is displayed on the overlapping image display section A, and the image to be captured this time is the captured image. It is displayed in real time on the display.
Then, in the finder, the image pickup section is moved to a position where these two images 1 and 2 coincide and are connected to each other, and the image 2 is picked up.

FIG. 31 shows a configuration example of the image pickup section of this embodiment.
It shows in (c). The electronic camera shown in FIG. 31C is provided with a lens 121 that condenses incident subject light, a CCD 122 that photoelectrically converts a formed optical image, and a preamplifier 123 that amplifies a detected image signal. Further, a signal processing circuit 124 for performing γ correction or the like on the image signal output from the preamplifier, an A / D converter 125 for digitizing the image signal, a luminance signal (Y) and a color signal (Y) for the digitized image signal. A color separation circuit 126 for separating Cr, Cb) is connected.

The luminance signal Y is input to the output side of the color separation circuit 126, and the image addition unit 127 for superimposing images as described above and the luminance signal Y and the color signals Cr and Cb are input. A data compressor 128 for inputting and compressing data is connected.

The image adding unit 127 has an overlapping area memory 129 for recording the previously captured image, multipliers 130 and 131, and coefficients C1 and C2 for this multiplication.
The coefficient setting circuit 132 and the adder 133 for setting

The image adding unit 127 is provided in the color separation circuit 12
The luminance signal Y is input from 6, a part of the image captured last time is added, and the result is sent to the D / A conversion unit 134. Here, the coefficients C1 and C2 are C1 = 1 and C2 = 0 in each overlap area image display section as shown in FIG. 31B, and C1 = 0 and C2 = 1 in the captured image display section. . And D /
A finder 135 is provided on the output side of the A conversion unit 134, and the finder 135 includes a liquid crystal display 136 and an eyepiece lens 137.

The data compressor 128 has Y, C
The data of each signal of r and Cb is compressed. The compressed signal is written to the memory card 139 which is detachably attached to the electronic camera at the same time when the shutter button 138 is pressed. The shutter button 138 is a two-stage switch,
Distance measurement and photometry are performed at t, and image capturing is performed at 2nd. A controller 140 for controlling the image addition unit 127 and a write address to the memory card 139.
Are connected respectively.

The image pickup operation of the electronic camera configured as described above will be described. First, aim the image pickup section of the electronic camera toward the left end of a wide range of subjects, and press the shutter button 138 to 1
Press halfway as a step. After the focus and exposure are adjusted by the functions of the distance measuring system and photometric system (not shown), the CCD
The image signal photoelectrically converted by 122 is supplied to the preamplifier 12
The signal is amplified in 3 and subjected to signal processing such as γ correction in the signal processing circuit 124, and then converted into a digital signal by the A / D converter 125.

Then, in the color separation circuit 126, the luminance signal Y
And the color signals Cr and Cb are separated and input to the data compressor 128. When the shutter button 138 is completely pressed, the image signal (image 1) input to the data compressor 128 is data-compressed and the memory card 13
9 is written at a predetermined position.

On the other hand, the right end portion of the image 1 (FIG. 31 (a))
Image signal in the overlapping area 1) of the overlapping area memory 129
Memorized in. Then, the image stored in this memory is added to an image signal that is subsequently picked up, D / A converted, and then displayed on the LCD 136. In this display, as shown in FIG. 31B, the rightmost image of the image 1 stored in the overlapping area memory is displayed in the overlapping area image display portion A. In addition, in the captured image display section B, the current CCD
The image signal formed on 122 is displayed. However, the left end is for displaying the overlapping area image and cannot be seen from the viewfinder.

The image pickup section is panned to a position where the image of the overlapping area image display section A and the image of the picked-up image display section B are well connected. Then, when the photographer determines that the images are well connected, the shutter button 138 is completely pressed, the image (image 2) formed on the CCD 122 at that time is written in a predetermined position of the memory card, and at the right end. Image (overlap region 2) is stored in the overlap area memory 127.

Similarly, the image 3 can be picked up, and a plurality of images having a predetermined overlapping area can be picked up.
At this time, even if the overlapping area deviates from the planned position, good image composition can be realized by the image composition processing described later, and thus it is not necessary to strictly superimpose the plurality of images in a short time. It can be imaged.

Next, FIG. 32 shows the structure of an image reproducing apparatus for reproducing the image picked up by the electronic camera described above, and will be described. The memory card 139 which is mounted on the electronic camera and photographed is taken out and mounted on the image reproducing apparatus.

This image reproducing apparatus includes a data decompressor 141 for decompressing image signal data, an image synthesizing circuit 142 for synthesizing a plurality of decompressed images, a read address of a memory card 139 and an image. Synthesis circuit 142
And the like, a filing device 144 for storing or displaying the image-combined image signal, a monitor 145, and a printer 146. The image synthesizing circuit 142 is applicable to the above-described embodiment, and a configuration example as shown in FIG. 33 for synthesizing three images can be considered. In this image synthesizing circuit, frame memories 151, 152, 153 for storing the images 1, 2, 3 shown in FIG. 31 are provided, respectively.

On the output side of the frame memory, a shift detector 154 for detecting a shift from a predetermined superposition position from the image signals of the overlapping regions of the images 1 and 2 and the images 2 and 3, respectively. , 155 are connected.
These deviation detectors 154 and 155 show the deviation amount as
The parallel movement amounts S1 and S2 and the rotation amounts R1 and R2 are calculated and input to the interpolation calculators 156 and 157.

The interpolation computing unit 156 interpolates the image signal of the image 2 stored in the frame memory 152, and the interpolation computing unit 157 interpolates the image signal of the image 3 stored in the frame memory 153 so as to be connected to the image 1. The image signal is converted and output to the synthesis processing unit 158.

The synthesizing processing unit 158 includes a multiplier 159,
160, 161, a coefficient setter 162 for setting the multiplication coefficients a, b, c, and an adder 163. In the coefficient setter 162, as shown in FIG.
The coefficient changes linearly in the overlapping area of each image.
The image signal of the output image area shown in FIG. 34 is sequentially calculated by the synthesis processing unit 158, and the frame memory 16 is calculated.
4 is stored.

The image signal of the frame memory 164 is the filing device 144 or monitor 1 shown in FIG.
45, the printer 146 and the like.

As described above, the plurality of images picked up by the above-mentioned image pickup unit can be combined by this image reproducing apparatus and converted into the corresponding images of the subject in a wide range. Needless to say, the reproduction may be performed by a camera integrally provided therein.

In the present embodiment, the image captured last time and the image captured this time are displayed in different areas on the finder, but both images are displayed together in the overlapping area image display section. May be. In this case,
In the image adding section 7, the coefficients C1 and C2 may be set to C1 = C2 = 0.5 in the overlap area image display section, and C1 = 1 and C2 = 0 in the captured image display section. The photographer
The image capturing unit may be moved so that the two images displayed on the overlapping region image display unit overlap each other, and the image having the desired overlapping region can be captured at higher speed and with higher accuracy.

In this embodiment, the LC of the finder is used.
In D, various displays were made only with the luminance signal, but color LC
Color display may be performed using D, or the previously captured image displayed on the overlapping area image display unit may be displayed in a different color from the image captured this time. Further, as shown in FIG. 35, the image signal read from the overlap area memory 129 is added to the HPF (High Pa) such as Laplacian calculation.
If ss Filtering) 165 is applied, it becomes easier to superimpose two images.

Further, in the present embodiment, an example has been described in which three images are picked up in the lateral direction and combined, but the present invention is not limited to this, and more images may be combined.

Next, FIG. 36 shows the structure of an electronic camera according to an eleventh embodiment of the present invention, which will be described. Here, the members of the sixth embodiment which are equivalent to the members shown in FIG. 33 are designated by the same reference numerals, and a description thereof will be omitted.

As a characteristic of this electronic camera, a correlation calculator 171 is additionally provided, and a correlation calculation between an image signal from the overlapping area memory 129 and a current image signal which is sequentially picked up is performed to calculate a displacement amount thereof. To do. Then, according to the amount of displacement, the arrow display portion 17 provided inside the finder.
The arrow 2 is displayed and the moving direction of the imaging unit is notified by sound or voice from the audio output device 173. The arrow display portion 172 in the viewfinder is configured as shown in FIG. 37, and is provided with arrows showing up, down, left and right and a light source 174 showing "red" or "blue" at the center.

When the correlation signal calculated by the correlation calculator 171 is extremely weak (when the same portion does not exist in the two images), the light source 174 is turned on in "red", and the correlation signal is correctly detected. When the displacement is detected, the arrow in that direction is turned on.

Next, when the two images are almost overlapped with each other and the displacement amount is almost "0", the light source 174 is turned on "blue". The photographer can easily take a plurality of images having overlapping regions according to the information indicated by the arrow display portion. Further, the voice output device 173 generates voices such as "right" instead of the right arrow and "left" instead of the left arrow. In addition, expressions such as “swing more to the right” and “slightly swing to the left” may be used depending on the magnitude of the displacement amount. May be blinked.

Next, referring to FIG. 38, the first embodiment of the present invention will be described.
The second embodiment will be described. In this embodiment, FIG.
As shown in (a), nine images are picked up so as to have overlapping regions, and a wider range is picked up. In FIG. 38 (a), the numbers attached to the respective images indicate the order in which images are taken. When capturing the image 5, the viewfinder is displayed as shown in FIG. That is, the image at the lower end of the image 2 is displayed on the upper side of the LCD, and the image at the left end of the image 4 is displayed on the right side of the LCD. Then, the photographer moves the image pickup unit to a position where the currently picked up image properly overlaps these images 2 and 4, and picks up the image 5.

As described above, in the present embodiment, not only the left and right sides of the LCD but also the upper and lower sides are displayed first, so that a large number of images can be easily picked up and down. be able to. Further, in the present embodiment, although the image pickup unit is not particularly described, the overlapping area memory 129 of the image addition unit requires a larger capacity as compared with the tenth embodiment described above.

Next, FIG. 39 shows, as a thirteenth embodiment of the present invention, a configuration example in which the image pickup section of the electronic camera is applied to a reading apparatus for a flat original, and description will be given. In this reading device, as shown in FIG. 39 (a), the support 1 is placed so that the image pickup section 175 is positioned above the document table 176 on which a flat document is placed.
The document table 176 is supported by 81, and a shutter button 177 for capturing an image of the document is provided on the document table 176.

The image pickup section 175 has a finder 178.
And a removable memory card 179 is attached. In this reading device, the photographer does not move the image pickup unit while looking into the finder as in the above-described embodiment, but moves the flat original to pick up a wide range of images.

If the operation of the XY stage 180 is controlled according to the amount of displacement using the XY stage 180 as shown in FIG. 39 (b) and the above-mentioned correlation calculator, a plurality of XY stages 180 are automatically arranged. Images can also be taken. Further, instead of controlling the operation of the XY stage, the imaging unit 175
Image synthesizing may be performed by controlling the operation of the support base 181 that supports the. In the display in each of the above-described embodiments, it is possible to taper-impose a number or the like indicating which image is picked up, or at a predetermined time point, another SW operation is performed to combine images that have been picked up to that point. All the images may be temporarily displayed so that the entire image can be confirmed, or a line sensor may be used for the image sensor of the image capturing unit 175. Further, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and applications can be made without departing from the scope of the invention.

[0108]

As described above in detail, according to the present invention, an electronic camera for reconstructing an image by moving a plurality of divided images to a position where the images are most appropriately connected based on their correlation is provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electronic camera according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a specific configuration of the blur correction circuit shown in FIG.

FIG. 3 is a diagram showing a state in which a shooting range moves on a subject without blurring.

FIG. 4 is a diagram showing a state in which an imaging range moves on a subject while being shaken.

FIG. 5 is a diagram for explaining obtaining the correlation between both images at each position while changing the position of the reference image with respect to the comparison image.

6 (a) and 6 (b) are diagrams for explaining how to obtain a parallel movement amount and a rotational movement amount.

FIG. 7 is a diagram showing a moving state of an image.

FIG. 8 is a diagram for explaining a usage state of the electronic camera according to the first embodiment.

FIG. 9 is a diagram showing a configuration of a photographing unit of an electronic camera according to a second embodiment of the present invention.

FIG. 10 is a diagram showing an example of improving the accuracy of correlation calculation as the third embodiment of the present invention.

FIG. 11 is a diagram showing an example of improving the accuracy of correlation calculation as a fourth embodiment of the present invention.

12 is a diagram showing a specific configuration of the correlation area selection circuit shown in FIG.

13 is a diagram showing an example of candidate images selected by a candidate image selection circuit shown in FIG.

FIG. 14 is a diagram illustrating an example of coefficients of a convolution filter.

FIG. 15 is a diagram illustrating an example of a circuit that obtains a sum of absolute values of differences between adjacent pixels.

FIG. 16 is a diagram showing a configuration of a photographing unit of an electronic camera according to a third embodiment of the present invention.

FIG. 17 is a diagram showing a configuration of a photographing unit of an electronic camera according to a fourth embodiment of the present invention.

FIG. 18 is a diagram showing a configuration of a photographing unit of an electronic camera according to a fifth embodiment of the present invention.

19 is a diagram showing a configuration of the CMD shown in FIG.

20 is a diagram showing a configuration of a processing unit shown in FIG.

FIG. 21 is a timing chart showing the timing of strobe light emission of the electronic camera of the fifth embodiment shown in FIG. 18.

FIG. 22 is a diagram showing a configuration of an image capturing section of an electronic camera according to a sixth embodiment of the present invention.

FIG. 24 is a timing chart showing operation timings of mirror driving and stationary control (intermittent driving).

FIG. 24 is a diagram showing a configuration of a photographing unit and an exposure timing of an electronic camera according to a seventh embodiment of the present invention.

FIG. 25 is a diagram showing a configuration of an image pickup section of an electronic camera according to an eighth embodiment of the present invention.

FIG. 26 is a diagram showing a configuration example when the eighth embodiment shown in FIG. 25 is applied to an ultrasonic diagnostic apparatus as a ninth embodiment of the present invention.

FIG. 27 is a diagram showing a specific configuration of an image capturing unit according to the ninth embodiment.

FIG. 28 is a diagram showing an example of a convex ultrasonic image.

FIG. 29 is a diagram showing a state of image combination according to the ninth embodiment.

FIG. 30 is a diagram showing a state of image combination.

FIG. 31 is a diagram showing a configuration example of a photographing unit of an electronic camera according to a tenth embodiment of the present invention.

FIG. 32 is a diagram showing an example of the configuration of an image reproducing apparatus for reproducing an image captured by the electronic camera according to the present invention.

FIG. 33 is a diagram showing a specific configuration example of an image synthesizing circuit.

FIG. 34 is a diagram showing changes in overlapping regions and their coefficients when a plurality of images are superimposed.

FIG. 35 is a diagram illustrating a configuration example of an image addition unit.

FIG. 36 is a diagram showing a configuration of an electronic camera as an eleventh embodiment of the present invention.

[Fig. 37] Fig. 37 is a diagram showing a configuration example in a finder of an eleventh embodiment.

[Fig. 38] Fig. 38 is a diagram showing an arrangement state of image synthesizing and a configuration in a finder for performing wide-range imaging by synthesizing a plurality of images as a twelfth embodiment according to the present invention.

[FIG. 39] FIG. 39 is a diagram showing a configuration example in which an imaging unit of an electronic camera is applied to a flat original reading device as a thirteenth embodiment of the present invention.

[Explanation of symbols]

1 ... Subject image 2 ... Shooting lens system 3a ... Mirror 3b ... Rotating axis 4 ... Image sensor 5 ... A / D converter (part) 6 ... Binarization circuit 7 ... Data compression circuit 8 ... Code addition circuit for error correction 9 ... Modulation circuit 10 ... LED driver 11 ... LED 12 ... Optical signal 13 ... Light receiving diode 14 ... Demodulation circuit 15 ... Error correction circuit 16 ... Compressed data decoding circuit 17 ... Frame memory A 18 ... Blurring correction circuit 19 ... Frame memory B 20 ... D / A conversion converter (part) 21 ... CRT monitor 22 ... Printer 23 ... Filing device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/335 H04N 5/335 A // H04N 101: 00 101: 00 (72) Inventor Wang Katsuda Tokyo 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Hideo Tomamechi Tokyo 2-43-2 Hatagaya, Shibuya-ku Olympus Optical Co., Ltd. (72) Inventor Yasuhiro Komiya Tokyo 2-43-2 Hatagaya, Shibuya-ku, Tokyo Within Olympus Optical Co., Ltd. (72) Inventor Toshiyuki Ebihara 2-43-2, Hatagaya, Shibuya-ku, Tokyo F-Term (Reference) within Olympus Optical Co., Ltd. 5C022 AA13 AB68 AC13 AC26 AC51 AC74 CA07 5C024 BX01 CY15 CY41 EX41 EX47 GY44

Claims (5)

[Claims] 1. An electronic camera that reconstructs a plurality of images obtained by dividing a subject image and sequentially capturing the subject image, the image capturing unit including an image sensor for photoelectrically converting the subject image; and an image previously captured by the image capturing unit. And a viewfinder that displays the image to be captured this time in real time, as well as a part of the image captured last time that is a portion to overlap the image to be captured this time. 2. Correlation calculation means for calculating a displacement amount by performing a correlation calculation between an image signal of an overlapping area which is a part of a previously captured image and a current image signal sequentially captured, and the correlation calculation. The electronic camera according to claim 1, further comprising output means for notifying a moving direction of the image pickup means according to a displacement amount calculated by the means. 3. A mirror rotatably arranged between a subject and the image pickup device, wherein when the image pickup means picks up an image of the subject, the image of the subject is intermittently captured a plurality of times. 2. The electronic camera according to claim 1, wherein the mirror rotates and a photographing range moves on a subject during the period. 4. The electronic camera according to claim 1, wherein the viewfinder displays a part of an image captured last time and an image captured this time in different colors. 5. The electronic camera according to claim 1, wherein a part of a previously photographed image displayed on the viewfinder is HPF (High Pass Filtering).