JPH1127703A - Display device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically correct the horizontal difference and also to easily perform correction that is suitable to user's taste by extracting the horizontal difference of a set of images that mutually have parallax and providing a means which corrects the extracted horizontal difference. SOLUTION: Automatic correction is performed by a program that is loaded to a storage device 13 under the control of a CPU 10. Two images undergo color processing by an image-processing part 12 and after that, they are respectively and separately shown on a display 19. A correspondence point area is designated is a left image by using a GUI 14 for left and right difference correction, while in a right image, a correspondence point is searched about each point in the area by using template matching, and parallax is calculated with acquired correspondence points with each other. Horizontal difference (vertical difference (d), rotation (θ) and a magnification rate (m)) based on two sets of correspondence points is calculated from a correspondence group that shows the parallax of a maximum frequency, while the right image is corrected so that the followings are established: (d)=0, (θ)=0 and (m)=1. Then they are shown as a stereoscopic image on the display 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device for stereoscopically displaying a set of images having parallax captured by at least one image pickup device and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, a stereoscopic image display method using a real image has been known. In this method, at least one or more imaging devices capture images from two viewpoints on the right and left at intervals given by the base line length. When a subject of interest is imaged from two viewpoints on the left and right in this way, the position of the object in the image captured by each imaging device is different from each other in the horizontal direction of the image. That is, this is parallax, and by viewing a set of images including this parallax in stereo, the user sees an image with a three-dimensional effect.

Next, a configuration of a conventional display device for realizing a stereoscopic display of a photographed image will be described with reference to FIG. FIG. 6 is a block diagram showing a configuration of a conventional display device for realizing stereoscopic display of a real image. In FIG. 6, the imaging device 1 is connected to a personal computer (hereinafter, referred to as a PC) 7 via an interface cable 6.
In order to capture and display a stereoscopic image, at least two
Imaging from a location is required. Here, it is assumed that imaging is performed from a plurality of locations by using only one imaging device 1 a plurality of times, but imaging can be performed simultaneously using a plurality of imaging devices.

[0004] An imaging device 1 comprises a lens 2, a CCD 3, an A /
A D converter 4 and a memory 5 are provided. And CC
The image captured by D3 is A / D converted by the A / D converter 4, and the image data obtained as a result of the conversion is temporarily stored in the memory 5. After that, it is input to the PC 7 via the parallel interface 9. Note that the image data obtained by imaging here is a set of left and right image data having parallax mutually obtained by performing imaging twice with a certain base line length changed.

[0005] In the PC 7, a parallel interface 9, a CPU 10, a memory 11, an image processing unit 12, a stereoscopic image display control unit 16, a recording device 13, and a display controller 17 are connected to a CPU bus 8. The output of the image to the display 19 is performed via the display controller 17. The pair of left and right image data input to the PC 7 is temporarily stored in the memory 11 and
Image processing such as color processing of each image is performed by the image processing unit 12 under the control of the PU 10. After the image processing is completed, the stereoscopic image display control unit 16 generates a control signal for displaying the image data on the display 19. Based on the generated control signal, the display controller 17 converts a set of left and right image data into a VRA.
Transfer to M18. Then, an image based on the image data transferred to the VRAM 18 is displayed on the display 19. As for the display of the image based on the image data, the captured right and left images are temporarily recorded in the recording device 13, reproduced from the recording device 13 again, and displayed on the display 19.
Is displayed in the same procedure.

There are various methods for stereoscopically viewing a set of left and right image data having parallax with each other. As one method, left and right image data are alternately output on the display 19. Then, the user can obtain a stereoscopic image by viewing the liquid crystal shutter glasses 20 that switch the left and right shutters in synchronization with the display switching of the image data that is output alternately to the left and right. In this method, the stereoscopic image display control unit 16
Then, the display controller 17 is controlled so that a set of left and right image data obtained by the imaging apparatus 1 is switched and displayed on the display 19 according to a vertical scanning frequency of about 120 Hz. On the other hand, switching of the left and right shutters is controlled by transmitting a signal synchronized with the switching of the pair of image data to the liquid crystal shutter glasses 20.

As another method, a set of left and right image data is alternately arranged every other line in the vertical scanning direction.
A single striped stereoscopic image is created. This stereoscopic image is, for example, disclosed in Japanese Patent Application No. 8-14861 by
Through a display having a lenticular lens disclosed in Japanese Patent Application No. 1 and Japanese Patent Application No. 8-148612, or through a polarizing plate or polarizing glasses, the right eye sees only the right image and the left eye sees only the left image. Thereby, a stereoscopic image can be obtained.

In this case, the stereoscopic image display control unit 16
A set of left and right image data is arranged one line at a time in the vertical scanning direction to create a stereoscopic image, and a control signal for displaying the stereoscopic image on the display 19 is generated. In this case, the display 19 includes a lenticular lens and a polarizing plate on the display surface. As described above, stereoscopic display is
This is realized by using the parallax of images captured from different viewpoints.

[0009] As described above, the stereoscopic display has at least one display.
A set of images having parallax captured by one or more imaging devices is simply superimposed and displayed. However, when these images are captured by the image capturing apparatus, there may be a left-right difference in the positional relationship between the viewpoints to be captured, which is a difference other than a shift in a horizontal position that causes parallax. The left-right difference includes a vertical difference, a rotation, a difference in enlargement ratio, a color, a white balance, an exposure amount, and the like, and is particularly likely to occur when a single imaging device is used to perform imaging multiple times. When there is such a left-right difference, the positional relationship between the subjects of the left and right images to be fused in stereoscopic view is shifted vertically, the other is inclined with respect to one, and the sizes of the two are different. Etc.,
It is difficult for the user to fuse.

Generally, as a process for correcting the left-right difference between a plurality of real images, there is a panoramic image synthesizing process for creating a high-definition image by connecting captured images in a horizontal direction or a vertical direction. The purpose of this panoramic image synthesizing process is to perform seamless synthesis by strictly matching overlapping areas of a plurality of images captured at the same viewpoint. Therefore, in order to correct the left-right difference between a plurality of captured images, at least two or more corresponding points of an overlapping area between images to be combined are determined,
What is necessary is just to correct so that the position, inclination, and length of the line connecting the two points may be adjusted. In the panoramic image synthesizing process, the position, inclination, and length of a line connecting two corresponding points satisfy a linear relationship with the translation, rotation, and enlargement ratio of the image to be synthesized.

[0011]

However, in the above-described stereoscopic image display in the conventional display device, since a pair of captured images are images having different parallaxes, a line connecting corresponding points by arbitrary two points is used. Min does not satisfy the above linear relationship. In addition, since the set of images has occlusion regions, there is a case where there is no corresponding point. Therefore, in order to correct the left-right difference in the stereoscopic image, the parallax is equal in the set of images, and a linear corresponding point in the vertical difference, rotation, and magnification of the partial image having no occlusion area is determined. It was necessary.

[0012] In addition, the document "3D display" (Chizuru Masuda, Industrial Books) shows an allowable range for the left-right difference of a set of images. However, these are all results of a survey on the left-right difference between stereoscopic images, and do not refer to a mechanism for correcting the left-right difference. In addition, the target of the allowable range refers only to a television that displays an interlace display, and does not assume a system connected to a display of a PC that displays a non-interlace display.

Although a process for automatically correcting the left-right difference has been proposed, a corresponding point may be erroneously determined, and a satisfactory stereoscopic image cannot be obtained. Whether the user perceives the corrected image as a good stereoscopic image is a subjective judgment of the user himself, and even if the left-right difference is automatically corrected, the optimal stereoscopic image for the user is determined. It is not necessarily an image. Therefore, even after the left-right difference is applied, it is necessary for the user to manually adjust the left-right difference.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to automatically and properly correct a left-right difference between a pair of images having parallax captured by at least one image pickup device. It is an object of the present invention to provide a display device and a control method for the display device, which can easily correct the left-right difference according to the user's preference.

[0015]

A display device according to the present invention for achieving the above object has the following arrangement. That is, a display device for stereoscopically displaying a set of images having parallax captured by at least one or more imaging devices, and extracting means for extracting a left-right difference that is a difference other than the parallax of the set of images. And a correcting unit for correcting the left-right difference extracted by the extracting unit.

Preferably, the left-right difference includes at least a vertical difference, a rotation, a magnification ratio, a color, a gradation, a white balance, and an exposure amount in the set of images. Preferably, the correction means corrects the left and right difference extracted by the extraction means so as to be minimum. Preferably, the image processing apparatus further includes display means for displaying the set of images in which the left-right difference has been corrected by the correction means.

Preferably, the extraction means includes designation means for designating a partial image from which the left-right difference is to be extracted with respect to one image in the set of images, and One partial image in the set of images;
The left-right difference is extracted by comparing partial images of the other image in the set of images corresponding to the partial image.

Preferably, the correction means includes a user interface for receiving an input of a correction amount for the left-right difference extracted by the extraction means from a user, and based on the correction amount input from the user interface, Correct the left / right difference. Preferably, the image processing apparatus further includes display means for displaying the set of images in which the left-right difference has been corrected by the correction means.

A computer readable memory according to the present invention for achieving the above object has the following configuration. That is,
A method of controlling a display device for stereoscopically displaying a set of images having parallax captured by at least one or more imaging devices, the method comprising extracting left and right differences other than the parallax of the set of images. And a correcting step for correcting the left-right difference extracted in the extracting step.

A computer readable memory according to the present invention for achieving the above object has the following configuration. That is,
A computer-readable memory storing a program code for controlling a display device for stereoscopically displaying a pair of images having parallax captured by at least one or more imaging devices, the computer-readable memory storing a program code other than the parallax of the pair of images. There is provided a program code for an extraction step for extracting a left-right difference as a difference, and a program code for a correction step for correcting the left-right difference extracted in the extraction step.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. [Embodiment 1] FIG. 1 is a block diagram showing a configuration of a display device according to Embodiment 1 of the present invention. Note that, in the display device of FIG. 1, the same components as those of the display device shown in FIG. 6 are denoted by the same reference numerals, and the details thereof are omitted here.

FIG. 1 differs from the display device shown in FIG. 6 in that a graphical user interface 14 for correcting left and right differences (a GUI for correcting left and right differences) is connected to a CPU bus 8 in the PC 7. One set of left and right image data captured by the imaging device 1 and input to the PC 7 is once stored in the memory 11. Next, the image processing unit 1
At 2, color processing is performed on the left and right image data.
Conventionally, a stereoscopic image was displayed immediately from here. However, if a stereoscopic image is displayed by superimposing a set of left and right image data as it is, the vertical difference and rotation of the left and right image data generated when capturing an image. However, there is a problem that a good stereoscopic image cannot be displayed when there is a difference in the magnification ratio.

Therefore, in the present embodiment, the automatic correction of the difference between the left and right image data, the rotation, and the enlargement ratio is performed through the left / right difference correction GUI 14 here. This automatic correction is performed, for example, by using a program loaded from a storage medium (not shown) on the program memory of the recording device 13. This program operates under the control of the CPU 10.

Next, the processing executed in the first embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing the processing executed in the first embodiment of the present invention. Here, a description will be given in conjunction with a specific example as shown in FIG. Also, a set of left and right images 201a, 2a shown in FIG.
01b is an image stereoscopically captured using the imaging device 1 twice.

First, the right image 201b includes a difference between the top and bottom, rotation and enlargement ratio with respect to the left image 201a. After the two images are subjected to color processing by the image processing unit 12, they are separately displayed on the display 19 before being stereoscopically displayed (step S1). Next, an area for searching for a corresponding point in the left image 201a is designated using the mouse on the left / right difference correction GUI 14 (step S2).
Although the size of the area to be searched is arbitrary, it is preferable that the user selects a specific subject. This is because, in the processing after step S2, by selecting two points in the region where the parallax on the main subject of the stereoscopic image is the same, a line segment having a linear position, rotation, and length in the left-right difference between the left and right images In order to extract

Next, for each point in the corresponding point search area of the designated left image 201a, a corresponding point is searched by template matching in the right image 201b, and parallax is calculated between the obtained set of corresponding points. (Step S3). Next, a parallax histogram in the corresponding point search area is created, for example, as shown in FIG. 4 (step S4).
In FIG. 4, the horizontal axis indicates parallax, and the vertical axis indicates power.

Next, two sets of corresponding points are extracted from the corresponding histogram from the corresponding point group showing the parallax of the maximum frequency (step S5). In order to improve the accuracy of a line segment formed by connecting them, the corresponding points to be extracted are selected as long as possible. Since the corresponding point selected here can be determined to be a point on a specific subject having the same amount of parallax in the area designated by the user, the line connecting the corresponding points is linearly represented by the left and right difference between the left and right images. Can be considered to be.

As described above, the template matching of the designated area in the left image 201a is performed, and two corresponding points A, A, B, and B 'of the left and right images are determined. Now, with the origin at the upper left of each image, A (Xa, Ya), B (Xb, Y
b), A '(Xa', Ya ') and B' (Xb ', Yb'). At this time, the right image with respect to the left image 201a

The vertical difference d, the rotation θ, and the magnification ratio m of the image 201b are calculated by equations (1) to (3), respectively (step S6).

[0030]

(Equation 1)

[0031]

(Equation 2)

[0032]

(Equation 3) The vertical difference d, rotation θ, and magnification ratio m between these left and right images
Is a line segment AB connecting the corresponding points in each image,
The position, inclination, and length of A'B 'are linear. So AB
, The right image 201b is corrected so that A′B ′ becomes d = 0, θ = 0, and m = 1 (step S7).
Hereinafter, the correction for the right image 201b will be described with reference to FIG. First, the right image 20 is set so that the rotation θ = 0.
1b is rotated to create an image 202. Image rotation is
Rotate around the center of the image. Next, the magnification ratio m =
The image 203 is created by enlarging or reducing to become 1. In FIG. 3, the image 202 is enlarged because the ratio of the enlargement ratios is m <1. The enlargement and reduction of the image are performed radially from the center of the image. Next, the vertical difference d =
0 to the right image 20a with respect to the left image 201a.
Move 3 up and down to fit. Then, the image is displayed on the display 19 as the stereoscopic image 204 (step S8).

For stereoscopic display, a control signal to be displayed on a display 19 is generated by a stereoscopic image display control unit 16. Based on this control signal, the display controller 18 converts the corrected left image data and the original right image data into VR.
The data is transferred to the AM 18 and displayed on the display 19 in a stereoscopic manner. FIG. 3 shows a stereoscopic image display method using liquid crystal shutter glasses, but the same applies to other display methods using lenticular lenses.

The rotation θ of the right image 201b, the ratio m of the magnification, and the polarization of the vertical difference d are performed with the center of the image as an axis. However, the present invention is not limited to this. For example, the rotation or enlargement ratio may be changed using any portion in the image as an axis. At the same time, the interval between the positions of the main subjects in the left and right images can be changed. In addition, as shown in the image 204, although a region that can be stereoscopically viewed by the correction is slightly missing, the region is stereoscopically viewed in that range.

As described above, the display of the stereoscopic image according to the first embodiment is different from the case of simply superimposing and displaying, and there is no difference in the vertical difference, rotation, and the ratio of the enlargement ratio between the left and right images. An excellent stereoscopic image 204 can be displayed. However, the first embodiment is an example, and other left and right differences of the captured right and left images, for example, color, gradation, white balance, and exposure amount are also automatically compared by comparing corresponding points in the left and right images. Can also be corrected.

[Second Embodiment] Next, as a second embodiment, a method in which a user corrects a difference between a vertical direction, a rotation, and an enlargement ratio through the left / right difference correction GUI 14 in addition to automatically correcting the left / right difference will be described. I do. Also, in Embodiment 2, Embodiment 1
As in the case of the above, the method of correcting the vertical difference, rotation, and magnification ratio as the left / right difference between the left and right images will be described. However, the same applies to other differences in color, gradation, white balance, exposure amount, and the like.

The display device of the second embodiment can be described using the display device of FIG. 1 as in the first embodiment. However, the difference from the first embodiment is that the user sets the left-right difference correction G
The point is that the UI 14 has a function of manually correcting the left-right difference. This is because the corresponding points of the left and right images determined when correcting the left and right difference between a pair of left and right images in the correction described in the first embodiment may cause a search matching error, and are not necessarily correct. Not necessarily a point. Therefore, when an accurate corresponding point is not determined, a stereoscopic image favorable for the user is not provided from the left and right images corrected by the corresponding point. In addition, as for the visibility of the left and right images to be stereoscopically viewed, the automatically corrected left and right images are not necessarily good for the user because the subjective judgment of the user is involved.

In order to solve such a problem, the user can directly use the left / right difference correction GUI 14 to directly
It is possible to correct a vertical difference, a rotation, and a difference in magnification between left and right images. GU for correcting left and right differences realized in the second embodiment
I14 will be described with reference to FIG. FIG. 5 is a view showing a left-right difference correction GUI according to the second embodiment of the present invention.

In FIG. 5, the user interface 40
3 is displayed on the display 401 together with the stereoscopic image 402. The user interface 404 obtained by enlarging the user interface 403 includes a vertical adjustment button 405, a rotation adjustment button 406, an enlargement ratio adjustment button 407, and a horizontal direction adjustment button 408. By clicking the + direction and the-direction of each of these buttons with the mouse, each parameter of the right image with respect to the left image can be changed.

The horizontal direction adjustment button 408 controls the amount of overlap between the left and right images in a stereoscopic image. When the button in the + direction is pressed as shown at 409, the right image indicated by the dotted line moves rightward with respect to the left image, and when the button in the-direction is pressed, it moves rightward. The up / down difference adjustment button 405 controls the up / down difference in the stereoscopic image of the left and right images. When the button in the + direction is pressed as shown at 410, the right image indicated by a dotted line moves vertically upward with respect to the left image, and moves downward in the vertical direction when the button in the-direction is pressed.

The rotation adjustment button 406 controls the vertical difference between the left and right images in the stereoscopic image. When the button in the + direction is pressed as shown at 411, the right image indicated by the dotted line with respect to the left image rotates counterclockwise around the center of the image, and when the button is pressed in the-direction, it rotates clockwise. . The enlargement ratio adjustment button 407 controls the ratio of the enlargement ratio between the left and right images in the stereoscopic image. When the button in the + direction is pressed as shown at 412, the right image indicated by the dotted line is enlarged, and when the button is pressed in the-direction, it is reduced.

As described above, according to the second embodiment, the user can freely adjust the difference between the left and right images through the user interface 404.
Even if there is an error in the automatic left / right difference correction,
The user can directly re-correct the correction. Further, correction and adjustment according to the user's own preference can be performed.

However, Embodiment 2 is an example, and other left and right differences of the captured right and left images, for example, color, gradation, white balance, and exposure amount can be similarly determined by the user using the user interface 404. It can be corrected manually. Further, it is also possible to assign the user interface 404 to a specific function key on the PC and to give a similar operation.

As described above, according to the first and second embodiments, in a set of images having parallax captured by at least one image capturing apparatus, a vertical difference between left and right images generated when capturing images, By automatically correcting the difference between the rotation and the enlargement ratio and performing stereoscopic display, it is possible to display a stereoscopic image that is easily fused to the user. In addition, since the user can freely correct the left and right difference between a pair of left and right images using the user interface, a stereoscopic image suitable for the user's preference can be displayed.

Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copier, a facsimile) comprising one device Device). Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer (or CPU or MPU) of the system or apparatus to store the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in the program.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk,
A CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowcharts. Each module shown will be stored in a storage medium. That is, at least the program code of each of the “extraction module” and the “correction module” may be stored in the storage medium.

The "extraction module" extracts a left-right difference, which is a difference other than the parallax of a set of images. The “correction module” corrects the extracted left-right difference.

[0051]

As described above, according to the present invention,
It is possible to automatically and satisfactorily correct the left-right difference between a pair of images having parallax captured by at least one or more imaging devices, and easily correct the left-right difference according to the user's preference. And a control method thereof.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a display device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating processing executed in the first embodiment of the present invention.

FIG. 3 is a diagram for explaining correction of a left-right difference according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a histogram of parallax according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a left-right difference correction GUI according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional display device that realizes stereoscopic display of a real photographed image.

FIG. 7 is a diagram showing a structure of a memory map of a storage medium storing a program code for realizing an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging device 2 lens 3 CCD 4 A / D converter 5 memory 6 interface cable 7 personal computer 8 CPU bus 9 parallel interface 10 CPU 11 memory 12 image processing unit 13 recording device 14 GUI for correcting left-right difference 15 user interface 16 stereoscopic image Display controller 17 display controller 18 VRAM 19 display 20 liquid crystal shutter glasses

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nao Kurahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kotaro Yano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the corporation

Claims (15)

[Claims] 1. A display device for stereoscopically displaying a pair of images having parallax captured by at least one or more imaging devices, wherein a left-right difference that is a difference other than the parallax of the pair of images is extracted. A display device, comprising: an extraction unit that performs the extraction and a correction unit that corrects the left-right difference extracted by the extraction unit. 2. The apparatus according to claim 1, wherein the left-right difference includes at least a vertical difference, a rotation, a magnification ratio, a color, a gradation, a white balance, and an exposure amount in the set of images.
The display device according to claim 1. 3. The display device according to claim 1, wherein the correction unit corrects the left-right difference extracted by the extraction unit to be minimum. 4. The display device according to claim 3, further comprising display means for displaying the set of images in which the left-right difference has been corrected by the correction means. 5. The image processing apparatus according to claim 1, wherein the extracting unit includes a specifying unit that specifies a partial image from which the left-right difference is to be extracted with respect to one image in the set of images, and the one set specified by the specifying unit. The left-right difference is extracted by comparing a partial image of one of the images and a partial image of the other image in the set of images corresponding to the partial image. The display device according to the above. 6. The correction means includes a user interface for receiving, from a user, an input of a correction amount for the left-right difference extracted by the extraction means, and calculates the left-right difference based on the correction amount input from the user interface. The display device according to claim 1, wherein the correction is performed. 7. The display device according to claim 6, further comprising display means for displaying the set of images in which the left-right difference has been corrected by the correction means. 8. A control method for a display device for stereoscopically displaying a set of images having parallax mutually captured by at least one or more imaging devices, wherein the left and right images are differences other than the parallax of the set of images. A control method for a display device, comprising: an extraction step of extracting a difference; and a correction step of correcting a left-right difference extracted in the extraction step. 9. The method according to claim 8, wherein the left-right difference includes at least a vertical difference, a rotation, a magnification ratio, a color, a gradation, a white balance, and an exposure amount in the set of images.
A control method for a display device according to claim 1. 10. The control method for a display device according to claim 8, wherein the correcting step corrects the left and right difference extracted in the extracting step to be a minimum. 11. The control method for a display device according to claim 10, further comprising a display step of displaying the set of images in which the left-right difference has been corrected in the correction step. 12. The extracting step includes, for one image in the set of images, a designated partial image from which the left-right difference is to be extracted and an image in the set of images corresponding to the partial image. The method according to claim 8, wherein the left / right difference is extracted by comparing partial images of the other image. 13. The method according to claim 8, wherein the correcting step corrects the left-right difference based on a correction amount for the left-right difference input from a user interface. 14. The method according to claim 13, further comprising a display step of displaying the set of images in which the left-right difference has been corrected in the correction step. 15. A computer-readable memory storing a program code for controlling a display device for stereoscopically displaying a set of images having parallax captured by at least one or more imaging devices, the computer-readable memory comprising: A computer-readable memory comprising: a program code for an extraction step for extracting a left-right difference that is a difference other than parallax of an image; and a program code for a correction step for correcting the left-right difference extracted in the extraction step.