JPH0483480A - Polarizing key type image synthesizer - Google Patents

Abstract

PURPOSE:To easily synthesize an image of high quality by arranging a polarizing filter between' the foreground material and background material of a subject and optionally switching an image darkened by interrupting the background material to a video signal for another independently prepared background material. CONSTITUTION:The polarizing filter 2 is arranged between the foreground material 7 and background material 8 of the subject, an image capable of almost normally observing the material 'J through the filter 2 is picked up by the 1st image pickup part 9 and an image darkened by interrupting the material 8 through the filter 2 and another polarizing filter 11 rectangular to the polarizing face of the filter 2 is picked up by the 2nd image pickup part 10. Video signals outputted from the 1st and 2nd image pickup parts 9, 10 are respectively corrected as signals (a), (b), their level difference is extracted and optionally switched to an external video signal (d) for another independently prepared background. Consequently, an image of high quality can easily be synthesized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a polarization key type image synthesis device for synthesizing images by replacing the background of a person or the like as a subject of a camera with another image.

(Summary of the Invention) In the field of video production, a chromakey method has conventionally been often employed in order to insert a separate image different from the output of the imaging unit into the background portion of the person or object that is the subject of the imaging unit. However, the chromakey method had many drawbacks. Therefore, the present invention is not simply an improvement of the chromakey method, but is achieved by adopting a method completely different from the conventional method.

In order to separate the foreground and background of the subject of the imaging unit, which is the object of image synthesis, the optical brightness difference caused by the orthogonality of the polarization planes of the polarizing filters is used. For this purpose, a polarizing filter is placed between the foreground material and the background material of the subject, and one system of the imaging section consisting of two systems is equipped with an optical system that receives the other polarized light whose plane of polarization is orthogonal to the polarizing filter. An image with a filter that makes the background material look almost normal,
Due to the orthogonality of the polarizing filter, a background material is closed and a darkened image is obtained, and the difference between the video signals output from these two systems is electrically detected and used as a key signal for image synthesis.

Therefore, the feature of this method is that the subject in the photographing section is identified using an optical filter, and a key signal that is the basis for image composition is created.

(Prior Art) Conventionally, this type of image compositing method in which the background of a subject such as a person in an imaging unit is replaced with another image has been widely adopted in the field of video production such as movies and broadcasting.

There are several methods to achieve this method, but the chromakey method was used as the raw method.

This chromakey method uses key signals for image synthesis.
This is done by detecting a specific color of the subject on the imaging unit.

(Problems to be Solved by the Invention) However, this chromakey method has the following problems.

(1) If the make-up, clothing, etc. of a person who is a subject serving as a foreground material of a composite image contains a color in the same family as the key signal detection color, the image in that part will be lost or altered. The foreground material includes materials other than people, but in this case, the colors can be replaced, which is a fatal operational limitation.

(2) The background part actually requires a panel etc. that is uniformly filled with the key signal color, but it is difficult to view if such footage is taken with a normal camera that does not combine due to mis-switching etc. during live broadcasting etc. It gives people a feeling of Kairai.

(3) Conventional chromakey methods have complicated circuits in principle, and require many adjustments such as the image quality at the boundary between the foreground and background of a composite image, making operation complicated and potentially leading to mistakes.

(4) In live broadcasting, subjects often change suddenly, and in such cases it is difficult to take appropriate measures.

etc.

In view of the above-mentioned points, the present invention effectively solves the problems of the prior art, eliminates the limitations of relying on colors in the chromakey method, simplifies its configuration, facilitates its handling and operation, and provides high image quality. An object of the present invention is to provide a polarization key type image composition device that can achieve a unique image.

(Means for Solving the Problem) In order to achieve such an object, the present invention includes a polarizing filter provided between a foreground material and a background material of a subject, and a polarizing filter that allows the background material to pass through the polarizing filter. a first imaging unit that captures an almost normal-looking image; and a second imaging unit that captures an image in which the background material is blocked and darkened through the polarizing filter and another polarizing filter perpendicular to the polarization plane of the polarizing filter. a video signal correction unit that corrects each of the video signals output from the first and second imaging units; a comparator unit that extracts a level difference between the corrected video signals and uses it as a key signal for synthesis; The present invention is characterized in that it includes a video switching section that allows switching between the video signal of the first imaging section and another separately prepared background external video signal using the synthesis key signal.

(Function) According to such an image synthesizing device, a polarizing filter is provided between the foreground material and the background material of the subject, and the first imaging unit captures an image in which the foreground material appears almost normal with the polarizing filter in red. and capturing an image in which the background material is blocked and darkened by passing through the polarizing filter and another polarizing filter perpendicular to the polarization plane of the polarizing filter, using a second imaging unit;
After the video signals output from the first and second imaging units are respectively corrected, the level difference is taken out and can be switched to another external background video signal prepared separately, thereby simplifying the configuration. , its handling and operation are easy, and high-quality images can be achieved.

(Example) Next, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows a schematic configuration diagram of an embodiment of a polarization key type image synthesis apparatus of the present invention. In the figure, a polarization key type image synthesis device 1 mainly includes a polarization filter 2, an imaging section 3,
Video signal correction section (process section) 4, comparator section 5,
It is composed of a video switching section 6. Of these, the polarizing filter 2 is installed between a person 7, which is a foreground material, and a suitable studio set 8, which is a background material.

The imaging unit 3 consists of two systems, a first imaging unit (camera) 9 and a second imaging unit (camera) 10. On the front side, which is the optical system of the camera 10, a polarizing filter 11 is connected to the polarizing filter 2 and the polarization plane. The camera 9 captures an almost normal-looking image of the studio set 8, and the camera 1
In 0, the studio set 8 has two polarizing filters 2 and 11.
The light is blocked by the light, and a dark image is captured.

The processing unit 4 includes processes 12 and 13, corrects each of the video signals output from the cameras 9 and 10, and outputs corrected video signals a and b.

The comparator unit 5 takes out the level difference between the corrected video signals a and b in process 12.13 and uses it as a video signal switching control signal (key signal for synthesis) C.

The video switching section 6 switches between the background external video signal d prepared separately and the corrected video signal (foreground signal) a of the process 12 using the synthesis key signal C, thereby producing a completed composite video output e. Output.

Many operational problems caused by the dependence of the conventional FFI chroma key method on color can be solved centrally based on the brightness difference that occurs in the optical system using the polarization key method of the present invention.
All of that has been resolved.

This unified processing using an optical system means that, in principle, higher image quality can be obtained compared to a processing method using an electric system such as the chromakey method.

Overcoming the shortcomings of conventional techniques has been a long-standing challenge in daily broadcast production sites, so there are extremely high expectations for the possibility of high-quality video production using the image synthesis apparatus of the present invention.

(Effects of the Invention) As explained above, in the polarization key type image synthesis device of the present invention, a polarization filter is provided between the foreground material and the background material of the subject, and the background material is almost normal after passing through the polarization filter. A first imaging unit captures an image that appears as if the background material is blocked by passing through the polarizing filter and another polarizing filter perpendicular to the polarization plane of the polarizing filter, and a second imaging unit captures an image in which the background material is blocked and becomes dark, After the video signals output from the first and second imaging units are respectively corrected, the level difference is taken out and can be freely switched with the video signal of another background material prepared separately, thereby solving the problems of the prior art. This effectively solves the problem, simplifies the configuration, facilitates handling and operation, and achieves high-quality images.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the polarization key type image synthesis apparatus of the present invention. 1... Polarization key type image synthesis device

Claims (1)

[Claims] 1) A polarizing filter provided between a foreground material and a background material of a subject, a first imaging unit that captures an image in which the background material appears almost normal through the polarizing filter, and the polarizing filter and the polarizing filter. a second imaging unit that captures an image in which the background material is closed and darkened through another polarizing filter that is perpendicular to the polarization plane of the second imaging unit, and corrects the video signals output from the first and second imaging units, respectively. a video signal correction section, a comparator section that extracts the level difference of the corrected video signal and uses it as a key signal for synthesis, and another background external video signal prepared separately from the video signal of the first imaging section. A polarization key type image synthesizing device comprising: a video switching unit that can be switched freely by the synthesis key signal.