JP2009037011A - Display photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the image quality of an image photographed by a photographing device in a display photographing device where a polarizing-object scattering plate is used as a projection screen. <P>SOLUTION: The display photographing device comprises: a screen 12 having a polarizing scattering function; a projection device 11 for projecting an image on the screen; a photographing device 14 that is installed on the opposite side to a subject 13 of the screen and photographs the subject over the screen; and a light source 1 for irradiating the subject. The polarization direction of the light used for photographing in the photographing device matches with the polarization direction of the light radiated from the light source. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display photographing apparatus, and more particularly, to a display photographing apparatus for photographing a conversation person at the same time as displaying a conversation partner of a conversation person used in a remote conversation apparatus or the like.

In the remote interaction device, a display photographing device for photographing a conversation person at the same time as displaying a conversation partner of the conversation person is used. In this display photographing apparatus, one using a polarization scattering plate as a projection screen is known. (See Patent Document 1 below)
FIG. 7 is a block diagram showing a schematic configuration of a conventional display photographing apparatus, which is the display photographing apparatus described in Patent Document 1 described above.
In FIG. 7, 11 is a liquid crystal projector, 12 is a polarization scattering plate, 13 is a subject, 14 is a camera, and 15 is a polarizing plate.
In the conventional display photographing apparatus shown in FIG. 7, since the light from the liquid crystal projector 11 is scattered by the polarization scattering plate 12 serving as a screen, an image is displayed on the screen in the same way as a normal projector display. The person (subject 13) can recognize the image.
At the same time, of the light from the person who is the subject 13, the polarized light with which the polarization scattering plate 12 becomes transparent passes through the polarization scattering plate 12 and reaches the camera 14 as it is, so that the subject 13 can be photographed by the camera 14. Here, the polarizing plate 15 installed in front of the camera 14 removes the light component scattered by the polarization scattering plate 12 which is a screen.

As prior art documents related to the invention of the present application, there are the following.
Japanese Patent No. 3496871

In the conventional display photographing apparatus described above, since the object 13 is photographed through the polarization scattering plate serving as a screen using the polarized light that makes the polarization scattering plate 12 transparent, the light from the object 13 is polarized. Compared to normal shooting that does not use 12, it is less than half.
For this reason, in the conventional display photographing device, it is necessary to increase the light amount of the light source, and there is a problem that not only the subject feels dazzling and hot, but also the image quality of the photographed image taken by the camera deteriorates. .
Further, the polarization scattering plate 12 serving as a screen also has some scattering with respect to polarized light on the transmission side, and this scattering causes the photographed image taken by the camera 14 to be blurred or the contrast to be lowered, thereby degrading the image quality. There was also the problem of doing.
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is a captured image photographed by a photographing apparatus in a display photographing apparatus that uses a polarization scattering plate as a projection screen. It is to provide a technique capable of improving the image quality.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) A screen having a polarization scattering function, a projection device that projects an image on the screen, a photographing device that is installed on the opposite side of the subject of the screen and photographs the subject through the screen, and the subject A display photographing device having a light source for irradiation, wherein a polarization direction of light used for photographing in the photographing device matches a polarization direction of light emitted from the light source.
(2) Display photographing including a screen having a polarization scattering function, a projection device that projects an image on the screen, and a photographing device that is installed on the opposite side of the subject of the screen and photographs the subject through the screen In the apparatus, a polarizing scattering plate having anisotropy in scattering is used for the screen, and the polarizing scattering plate is installed so that a large scattering direction is a vertical direction when viewed from an observer.
(3) Display photographing including a screen having a polarization scattering function, a projection device that projects an image on the screen, and a photographing device that is installed on the opposite side of the subject of the screen and photographs the subject through the screen An image processing unit that sharpens an image captured by the imaging device, and the image processing unit is anisotropic when the polarization scattering characteristics of the screen are anisotropic. A sharpening process is performed.
(4) Display photographing including a screen having a polarization scattering function, a projection device that projects an image on the screen, and a photographing device that is installed on the opposite side of the subject of the screen and photographs the subject through the screen A detecting means for detecting the luminance of an image displayed in an area through which light picked up by the photographing device of the screen is transmitted, and the photographing device is photographed based on the luminance detected by the detecting means. And an image processing unit for correcting the brightness of the image.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the display photographing apparatus using the polarization scattering plate of the present invention as the projection screen, it is possible to improve the image quality of the photographed image photographed by the photographing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
[Example 1]
FIG. 1 is a diagram illustrating the operation of the display photographing apparatus according to the first embodiment of the present invention.
As shown in FIG. 1, the display photographing apparatus of the present embodiment includes a polarization scattering plate 12 serving as a projection screen and a liquid crystal that projects an image onto the polarization scattering plate 12 from the opposite side of the subject 13 with the polarization scattering plate 12 interposed therebetween. A projector (projection device of the present invention) 11, a camera (imaging device of the present invention) 14 that is installed on the liquid crystal projector side of the polarization scattering plate 12 and photographs the subject 13 through the polarization scattering plate, and a light source that irradiates the subject 13 1 and the polarization direction of the light used for photographing in the camera 14 and the polarization direction of the light emitted from the light source 1 are the same. A polarizing plate 15 is installed on the front surface of the camera 14.
That is, the display photographing apparatus of the present embodiment uses the polarized light scattered by the polarization scattering plate 12 as the light for displaying an image on the polarization scattering plate 12 that is a projection screen, and the polarized light that passes through the polarization scattering plate 12. The person who is the subject 13 is photographed by the camera 14.

As described above, in this embodiment, an image is projected from the liquid crystal projector 11 onto the polarization scattering plate 12 so that the image is displayed on the polarization scattering plate 12 while the subject 13 is photographed by the camera 14. is there.
Here, as shown in FIG. 1, the case where the light of the liquid crystal projector 11 is a component L1 parallel to the paper surface will be described.
In FIG. 1, the direction of the polarization scattering plate 12 is set in a direction in which the polarization component L1 parallel to the paper surface is scattered. The polarization scattering plate 12 transmits a specific linearly polarized light component (L2 and L3 in FIG. 1) as it is, and scatters light of a polarized light component (L1 in FIG. 1) orthogonal to this like a ground glass. It is a scattering plate.
Since the light from the projector 11 (component L1 parallel to the paper surface) is scattered by the polarization scattering plate 12, an image is displayed on the screen (that is, the polarization scattering plate 12) in the same way as a normal projector display, and the screen is viewed. The person (subject 13) can recognize the image.

On the other hand, in the case of shooting, the component L2 perpendicular to the paper surface of the light from the person who is the subject 13 is polarized light that makes the polarization scattering plate 12 transparent, so that it passes through the polarization scattering plate 12 and passes to the camera 14 as it is. Reach.
By installing the polarizing plate 15 installed on the front surface of the camera 14 so as to transmit the polarized light component L2 perpendicular to the paper surface, the light from the subject 14 is photographed as it is and is scattered by the polarization scattering plate 12 which is a screen. The light component can be removed.
In the present embodiment, the polarized light L3 perpendicular to the paper surface is used as the irradiation light from the light source 1. In order to change the light irradiating the subject 13 to polarized light L3 perpendicular to the paper surface, for example, only light having a specific polarization direction (here, polarized light L3 perpendicular to the paper surface) is transmitted before a normal light source. A polarizing filter may be arranged.
Therefore, since the polarization direction of the light emitted from the light source 1 and the light photographed by the camera 14 coincide with each other, the polarization L2 perpendicular to the paper surface in the light reflected by the subject 13 and reaching the camera 14 with respect to the entire illumination light. The rate increases.
That is, in this embodiment, since the polarized light is used for the irradiation light that irradiates the subject 13, the ratio of the light that contributes to photographing among the light from the subject 13 is increased, and the amount of irradiation light that irradiates the subject 13 is increased. It becomes possible to reduce.

As described above, in this embodiment, it is possible to capture a bright image even with irradiation light with a small amount of light, and improve the image quality of a captured image captured with the camera 14 as compared with the case where irradiation light with the same light amount and no polarization is used. It becomes possible to do.
In the present embodiment, the rear projection projected from the opposite side of the subject 13 with respect to the screen (polarized light scattering plate 12) is used, but the front projection projected from the same side as the subject 13 may be used. In particular, in the case of front projection, stray light prevention means such as providing a hood on the lens of the camera 14, providing a louver on the front surface, or providing an aperture in the lens to prevent the projection light from directly entering the lens of the camera 14. Needless to say, it is effective.
Furthermore, in the present embodiment, the entire screen is the polarization scattering plate 12, but it goes without saying that only the area used by the camera 14 for photographing may be the polarization scattering plate. The camera 14 can be prevented from taking an image on the screen by being close to the screen (polarized light scattering plate 12) within a range not disturbing the projection light. Needless to say, the same effect can be obtained by using a lens having a shallow depth of field.

[Example 2]
FIG. 2 is an explanatory diagram regarding a method for minimizing blurring of an image to be captured in the display photographing apparatus according to the second embodiment of the present invention, and the position of an image photographed by the display photographing apparatus according to the second embodiment of the present invention. It is a graph which shows the relationship of a brightness | luminance.
2A is an original image captured by the camera 14 of the above-described display photographing apparatus, FIG. 2B is an image photographed by the camera 14 of the display photographing apparatus, and FIG. The relationship between the position of an image subjected to image processing and luminance is shown.
FIG. 3 is a block diagram illustrating a configuration for minimizing blurring of an image to be captured in the display photographing apparatus according to the second embodiment of the present invention.
When the original image shown in FIG. 2A is photographed by the camera 14 of the display photographing device, as shown in FIG. 2B, the photographed image has an offset in brightness due to the wraparound of the projection light, and is whitish and has a contrast. At the same time, the image is blurred by the polarization scattering plate 12.
Therefore, as shown in FIG. 2C, the image processing unit 20 shown in FIG. 3 can display a good image when the brightness level is lowered and sharpening processing is performed at the same time.
An example of image processing of the image processing unit 20 is an unsharp mask. In this unsharp mask process, an image obtained by performing a process corresponding to {A−k (B−A)} on the original image A and an image B obtained by blurring A is displayed. By subtracting the difference between the blurred image and the original image from the original image, the image becomes almost the same as the original image when blurred.

In this embodiment, the case of unsharp mask processing has been described, but it goes without saying that other image processing methods such as Wiener filter and deconvolution may be used.
In addition, when there is anisotropy in the scattering property of polarized light on the transmission side of the polarization diffusing plate 12, the anisotropy may be given to the filter characteristics. In particular, when the scattering in one direction is sufficiently smaller than the other, the configuration can be simplified by mounting the filter only in the direction in which the scattering is large. That is, when there is anisotropy in the polarization scattering characteristics of the polarizing diffuser plate 12 serving as a screen, the image processing unit 20 sharpens only in the direction of large scattering, or sharpens mainly in the direction of large scattering. Processing (that is, sharpening processing having anisotropy) may be performed.
In addition, the direction in which the scattering of the polarized light scattering plate 12 is large is set up and down when viewed from the observer, so that the horizontal direction where the resolution of the human eye is high can be made high resolution and the blurring experienced can be reduced. . That is, the apparent blur can be reduced by making the direction in which the scattering of the polarized light scattering plate 12 is large as seen from the observer, so that the image processing can be simplified.
Further, in the correction of the black level of the image processing unit 20, the image information displayed on the liquid crystal projector 11 is used as shown in FIG. 4, or the screen brightness sensor 21 is used as shown in FIG. Needless to say, it can be corrected with high accuracy by actually measuring the brightness of the area captured by the camera 14 on the screen. Needless to say, when the screen of a personal computer is displayed, the luminance of the area may be detected by calculation based on the digital data of the image.
As described above, in this embodiment, since the image processing that is performed by the polarization scattering plate 12 is previously performed on the captured image captured by the camera 14, the image is captured by the camera 14. The image quality of the captured image can be improved.

[Example 3]
FIG. 6 is a block diagram illustrating a schematic configuration of a remote interaction apparatus according to the third embodiment of the present invention, and is a block diagram illustrating a schematic configuration of a remote interaction apparatus using a plurality of display photographing apparatuses according to the above-described embodiments.
In FIG. 6, 10A and 10B are display photographing devices at two distant points, 11A and 11B are liquid crystal projectors, 12A and 12B are polarization scattering plates, 13A and 13B are subjects, 14A and 14B are cameras, and 15A and 15B are polarizations. It is a board.
In the example shown in FIG. 6, the liquid crystal projector 11A of the display photographing apparatus 10A and the camera 14B of the display photographing apparatus 10B are connected by a cord 16, and the liquid crystal projector 11B of the display photographing apparatus 10B and the camera 14A of the display photographing apparatus 10A are connected. Connect with cord 16. Needless to say, the code 16 can be replaced not only by actual wiring but also by information transmission means such as the Internet or wireless communication.
Although not shown in FIG. 6, the light source 1 and the image processing unit 20 described above are also used for the display photographing devices (10A, 10B). The position of the image processing unit 20 may be close to or opposite to the camera (14A, 14B).
In the remote interaction apparatus shown in FIG. 6, it is felt that the image of the other party at another point is directly in front at each point, so that a natural conversation is possible.

As described above, in this embodiment, in the display photographing apparatus using the polarization scattering plate 12 as the projection screen, the image quality of the photographed image photographed by the camera 14 can be improved.
Specifically, by using irradiation light with polarization, the amount of light of an image to be photographed is approximately twice that of using irradiation light with the same illuminance and without polarization. It is possible to improve the image quality of the captured image taken with.
Further, by setting the large direction of polarization scattering of the polarization scattering plate 12 used as a projection screen to the vertical direction when viewed from the observer, the apparent blur can be reduced, and the image taken by the camera 14 is taken. The visual quality of the image can be improved.
Further, by providing the image processing unit 20 that performs the sharpening process, the influence of blurring of the image due to the use of the polarization scattering plate 12 as a projection screen is reduced, and the image quality of the captured image captured by the camera 14 is improved. Can do.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

It is a figure which shows the effect | action of the display imaging device of Example 1 of this invention. It is explanatory drawing regarding the method of minimizing the blur of the image | photographed image in the display imaging device of Example 2 of this invention. It is a block diagram which shows the structure for minimizing the blur of the image | photographed image in the display imaging device of Example 2 of this invention. It is a figure for demonstrating an example of black level correction | amendment in the display imaging device of Example 2 of this invention. It is a figure for demonstrating the other example of black level correction | amendment in the display imaging device of Example 2 of this invention. It is a block diagram which shows schematic structure of the remote interaction apparatus of Example 3 of this invention. It is a block diagram which shows schematic structure of the conventional display imaging device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 10A, 10B Display imaging device 11, 11A, 11B Liquid crystal projector 12, 12A, 12B Polarization scattering plate 13, 13A, 13B Subject 14, 14A, 14B Camera 15, 15A, 15B Polarizing plate 20 Image processing part 21 Screen brightness sensor L1 Polarization component parallel to the paper surface L2, L3 Polarization component perpendicular to the paper surface

Claims (4)

A screen having a polarization scattering function;
A projection device for projecting an image on the screen;
A photographing device installed on the opposite side of the subject of the screen and photographing the subject through the screen;
A display photographing device having a light source for illuminating the subject,
A display photographing apparatus, wherein a polarization direction of light used for photographing in the photographing apparatus coincides with a polarization direction of light emitted from the light source. A screen having a polarization scattering function;
A projection device for projecting an image on the screen;
A display photographing device having a photographing device installed on the opposite side of the subject of the screen and photographing the subject through the screen,
A polarizing scattering plate having anisotropy in scattering is used for the screen,
The display photographing apparatus, wherein the polarization scattering plate is installed such that a large scattering direction is a vertical direction when viewed from an observer. A screen having a polarization scattering function;
A projection device for projecting an image on the screen;
A display photographing device having a photographing device installed on the opposite side of the subject of the screen and photographing the subject through the screen,
An image processing unit that sharpens an image captured by the imaging device;
The display photographing apparatus, wherein the image processing unit performs an anisotropic sharpening process when the polarization scattering characteristic of the screen is anisotropic. A screen having a polarization scattering function;
A projection device for projecting an image on the screen;
A display photographing device having a photographing device installed on the opposite side of the subject of the screen and photographing the subject through the screen,
Detecting means for detecting luminance of an image displayed in an area through which light captured by the imaging device of the screen is transmitted;
A display photographing apparatus comprising: an image processing unit that corrects the luminance of an image photographed by the photographing apparatus based on the luminance detected by the detecting unit.

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