JP3511096B2 - Background subtraction imaging method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup method for preventing a background of a subject from being optically reflected when an image of a person or the like is picked up by an image pickup means such as a videophone, and an apparatus for carrying out the method.

[0002]

2. Description of the Related Art When a person or the like is imaged by an image pickup means such as a videophone, it is inevitable that the background of the subject is reflected.
For example, it is not preferable to show yourself in a house with a videophone, because details such as the inside of the room are transmitted as the background. It is possible to make the background relatively dark by shining a spotlight on only the face, but this causes problems such as unclear images, increased equipment costs, and effects on others living together.

On the other hand, if computer processing is used,
It is possible to pick up an image of only the background in advance and discard the image of the background based on the difference from the case where the subject is added. Further, it is possible to eliminate the background image based on the difference between the background that is a static image and the subject that is a dynamic image. However, these require enormous data processing. Therefore, with the processing, the immediate responsiveness in communication is alienated, resulting in the loss of the realism in the face-to-face dialogue. In addition to the processing accuracy and processing speed, there is a cost problem of equipment. Further, according to the method in which only the background image is captured in advance and the difference from the case where the subject is added is used, it is difficult to correct when the camera moves due to vibration or the like, and the background is a static image. According to the method based on the difference between the subject and a dynamic image, it is difficult to determine the motion of the subject.

[0004]

Therefore, the present invention does not rely on computer processing, but only by optical means, while suppressing the influence on the subject and other cohabitants as much as possible,
An object of the present invention is to provide a method for capturing an image of a background of a subject so that the background is not reflected, and an apparatus for performing the method.

[0005]

In order to solve the above problems, the background image pickup method and apparatus of the present invention have the following configurations. That is, the background polarized light irradiating means for irradiating the background of the subject with polarized light, and the polarized light with a different polarization azimuth from the polarized azimuth of the polarized light radiated by the background polarized light irradiating means are received to shield the reflected light from the background of the subject. At the same time, the polarized image pickup means for picking up the image of the subject picks up the image of the subject and simultaneously removes the background of the subject.

Here, a subject polarized light irradiating means for irradiating a desired portion of the object with polarized light is provided, and the background polarized light irradiating means emits polarized light having a polarization direction different from that of the polarized light radiated by the object polarized light irradiating means. The polarized image capturing means illuminates the background of the subject, receives the polarized light having the same polarization azimuth as the polarized azimuth of the polarized light radiated by the polarized light illuminating means for the subject, and images the reflection of the polarized light radiated to the desired portion of the subject. ,
It may be possible to contribute to the supplement of the insufficient light amount for imaging without adversely affecting the subject or the like.

The polarized light irradiating means for background may be a light emitting member to which a polarizing filter is attached so as to contribute to the versatility of the polarized light irradiating means for background when the image is not picked up.

The polarization image pickup means may be provided with a polarization filter attached to the image pickup means to contribute to simplification of the configuration.

The polarized light irradiating means for a subject may be a light emitting member having a polarizing filter attached thereto, which may contribute to simplification of the structure.

The polarized light irradiating means for the subject may be used as a partner display monitor for displaying the image of the communication partner to contribute to the convenience of communication and simplification of the configuration.

The partner display monitor may be provided with a polarizing filter attached to the light emitting member to contribute to simplification of the configuration.

The other party display monitor may be a liquid crystal monitor or the like made of a member that emits polarized light to contribute to a simple structure.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a main part of a background subtraction imaging device according to the present invention. A person's face (10) as a desired part of the subject is illuminated with polarized light polarized in a predetermined direction by a subject light (20) as subject polarized light irradiating means from slightly above the front side thereof. The subject light (20) is provided at the output end of a conventionally known light emitting member (21).
It can be easily constructed by attaching the polarization filter (22).

In the background (11) of the subject, from above, the background light (30) as the polarized light irradiation means for the background.
Then, polarized light having a polarization direction different from the polarization direction of the polarized light emitted from the subject light (20) is emitted. The background light (30) has a conventionally known light emitting member (31) such as an indoor fluorescent lamp, to which a polarizing filter (32) is attached at the output end thereof, because of its versatility during non-imaging and simplicity of configuration. It is preferable in terms.

3 and 4 are a front sectional view and a side sectional view of the background light (30). A support (34) extending outward from the lower part of the reflector (33) of the fluorescent lamp (31)
A polarizing film (32) made of resin is attached to the.
The polarizing film (32) is removable and is normally removed, exposing the fluorescent lamp (31). In the illustrated example, the polarization direction of the polarizing film (32) is in the major axis direction of the fluorescent lamp (31), while the subject light (2
The polarization azimuth according to 0) is a horizontal direction perpendicular to it, and the polarization azimuths of both are orthogonal.

A polarization imager (40) as a polarization imager is arranged in front of the face (10) of the person as the subject.
The polarization imager (40) has a polarization filter (42) attached to the lens of the camera (41). The polarization direction of the polarization filter (42) is designed to be the same as the polarization direction of the polarization filter (22) of the subject light (20). Therefore, the camera (41) receives the polarized light emitted from and reflected by the face (10) of the subject, but does not receive the polarized light emitted from the background light (30).
Therefore, the polarized imager (40) captures an image of the face (10) of the person of the subject, and at the same time, the background (11) of the subject is captured.
Is discarded.

The lens used in the camera (41) is preferably a lens having a small F value. When the F-number is small, it is bright and can be imaged with a small amount of light, and since the depth of field is shallow, the background (11) is also blurred.

The subject light (20) complements the insufficient light quantity for imaging and is not an essential component. If installed, it is preferable to irradiate polarized light as in this embodiment. If it is non-polarized, the polarization imager (4
This is because the polarization filter (42) of 0) reduces the light amount, and if the light amount of the subject light (20) is increased in order to compensate for it, the person of the subject or a joint living person becomes dazzled.

The polarization imager (40) and the partner display monitor (50) are connected to a data processing transmission device, a display monitor on the communication partner side, and a polarization imager via a communication line (60).

FIG. 2 is an explanatory view of the essential parts of a background image pickup device according to another embodiment. In this embodiment, the subject (10)
A partner display monitor (50) such as a videophone arranged in front of is provided with a light (52) around a light emitting surface (51) such as a cathode ray tube for displaying a partner image. A part of a cathode ray tube or the like may be applied to the light (52), or another light emitting member such as a fluorescent lamp may be attached. If the light (52) is a light source that cannot emit polarized light by itself, it may be equipped with a polarizing filter so that polarized light can be emitted. FIG. 6 shows a front view of the partner display monitor (50) according to this embodiment, and FIG. 5 shows the partner display monitor (50) according to the embodiment.
FIG. According to the present embodiment, the outer peripheral portion of the light emitting surface (51) of the partner display monitor (50) can be utilized to add a light irradiation means for a subject to the partner display monitor (50). Communication convenience can be achieved. In particular, with the annular light (52) as shown in the figure, the face (10) of the subject person is irradiated with light from four directions, so that there is an effect of alleviating the casting of dark shadows on the face (10).

A slide type filter or the like may be attached to the front surface of the light (52) so that the light quantity of the light (52) can be adjusted appropriately. Alternatively, the other party display monitor (50) may be composed of a liquid crystal monitor or the like, and the light emitted from the light emitting surface for displaying the other party's image may be polarized to serve as the subject light (20).

[0022]

The present invention has the following effects by having the above-mentioned configuration. According to the background subtraction imaging method according to claim 9 or the apparatus according to claim 1, the polarized light received by the polarization imaging means is different from the polarization azimuth of the polarized light irradiated on the background of the subject, and thus the optical means. Only with this, the background of the subject can be removed and only the desired portion of the subject can be imaged.

According to the background image pickup device of the second aspect, the polarization direction of the polarized light for the subject that illuminates a desired portion of the subject is the same as the polarization direction of the polarized light that the image pickup means receives, and at the same time, the background of the subject is illuminated. Since it is different from the polarization direction of the background polarized light, it is possible to supplement the insufficient light amount for imaging without adversely affecting the subject or the like.

According to the background image pickup device of the third aspect, since the background polarized light irradiating means is constituted by attaching the polarization filter to the light emitting member, the background polarized light irradiating means is used as a normal room light when no image is picked up. Available.

According to the background image pickup device of the fourth aspect, since the polarization image pickup means is constructed by attaching the polarization filter to the image pickup means, it can be easily formed.

According to the background subtraction image pickup device of the fifth aspect, since the polarized light irradiation means for the subject is constituted by attaching the polarization filter to the light emitting member, it can be easily formed.

According to the background subtraction image pickup device of the sixth aspect, since the polarized light irradiation means for the subject is constituted by the display monitor for displaying the image of the communication partner, it can be easily formed together with the convenience of communication.

According to the background image pickup device of the seventh aspect, since the other party display monitor is constructed by attaching the polarization filter to the light emitting member, it can be easily formed.

According to the background subtraction image pickup device of the eighth aspect, since the other party display monitor is composed of a liquid crystal monitor or the like composed of a member that emits polarized light, it can be simply formed.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of a background image pickup device according to the present invention.

FIG. 2 is an explanatory view of a main part of a background subtraction imaging device according to another embodiment.

FIG. 3 is a front sectional view of a background light.

FIG. 4 is a side sectional view of the same.

[Figure 5] Front view of the partner display monitor

FIG. 6 is a front view of a partner display monitor in an embodiment in which a light is provided around a light emitting surface.

[Explanation of symbols]

10 Desired part of subject 10 'Subject reflected on the display monitor 11 background 11 'Background on the other party's display monitor 20 Light for subject 21, 31 Light emitting member 22, 32, 42 Polarizing filter 30 background lights 33 Reflector 34 Support 40 Polarization imager 41 camera 50 partner display monitor 51 Light emitting surface 52 lights 60 communication lines

Claims (9)

(57) [Claims] 1. A reflected light from a background of a subject, which receives polarized light for a background for illuminating a background of the subject, and receives polarized light having a polarization direction different from that of the polarized light emitted by the polarized light for the background. And a polarization image pickup means for picking up an image of a subject while shielding the object. 2. A polarized light irradiating means for an object for irradiating a desired portion of the object with polarized light, wherein the polarized light irradiating means for the background emits polarized light having a polarization direction different from that of the polarized light irradiated by the polarized light irradiating means for the object. 2. The polarized light imaging means receives the polarized light having the same polarization direction as the polarized light direction of the polarized light irradiated by the polarized light irradiation means for the subject, and images the reflection of the polarized light irradiated to the desired portion of the subject. The described background image pickup device. 3. The background image pickup device according to claim 1, wherein the polarized light irradiation means for background is a light emitting member to which a polarizing filter is attached. 4. The background image pickup device according to claim 1, wherein the polarization image pickup means is one in which a polarization filter is attached to the image pickup means. 5. The background image pickup device according to claim 1, wherein the polarized light irradiating means for an object is a light emitting member to which a polarizing filter is attached. 6. The background image pickup device according to claim 1, wherein the polarized light irradiation means for a subject is a partner display monitor for displaying an image of a communication partner. 7. The background image pickup device according to claim 6, wherein the partner display monitor is a light emitting member having a polarizing filter attached thereto. 8. The background image pickup device according to claim 6, wherein the partner display monitor is composed of a member that emits polarized light. 9. The polarized light for background illuminates the background of the subject with polarized light, and the polarized image pickup means receives a polarized light with a polarization direction different from the polarization direction of the polarized light irradiated by the polarized light for background illumination, and A background subtraction imaging method characterized by imaging a subject while blocking reflected light from the background.