Image-Based Virtual Studio

Toward a realistic electronic studio set

Yuko YAMANOUCHI, Research Engineer,
Multimedia Services

NHK Science & Technical Research Laboratories have been promoting research and development of efficient program production technology which makes the best use of computer technology. As part of the research, we have developed a new type of virtual studio system which is based on image components from real pictures instead of CG. A HDTV compliant virtual set can be shot from any desired camera angle and is equipped with zooming functions.

Features

  • An all-round ambient scene is digitized as an environmental image component. This allows scenes from varying directions to be outputted as real time HDTV images.
  • Pictures of a small object taken from four angles to be placed on the scene's image are also changed into electronic data as a three-dimensional image component. The component image can be placed in any desired location and freely zoomed or rotated as needed.
  • It outputs an HDTV image of a virtual studio scene, which is created by environmental image components, three-dimensional image components, and the real image produced by a studio camera, all of which can be freely arranged.
We will continue working on more realistic HDTV image production by adding the natural shadows of objects.

In a virtual studio, the image of a studio set is created by using computer graphics (CG) combined with the real images taken by a studio camera. These combined CG and real images are synthesized using a chroma-keying device for program production. The CG image in a studio set is linked to a studio camera and moved or zoomed according to camera operation. This function will provide a variety of image production possibilities.


Multi-Beam Receiving Flat Antenna for Satellite Broadcasting

Simultaneous reception of broadcasting from multiple satellites

Takao MURATA, Senior Research Engineer,
Digital Satellite Broadcasting Systems

Satellite broadcasting services are carried out using a Broadcasting Satellite (BS) at 110 degrees east longitude and three Communication Satellites (CSs) at 124, 128, and 144 degrees east longitude. Our Laboratories have been conducting research on a flat antenna which will be capable of receiving multiple satellite broadcasts from different orbital locations.
We succeeded in the trial manufacture of a flat antenna which can receive signals from any satellite located within a 40 degrees arc.
The experimental flat antenna has the following characteristics;

  • Compact size. (W 37cm, H 70cm, D 8cm)
  • Reception area covers a wide direction, East to West 20 degrees, allowing coverage of BS at 110 degrees east longitude, to CS at 144 degrees east longitude.
  • Beam direction is controlled by a beam forming circuit. A corresponding number of these beam forming circuits will enable simultaneous reception from satellites located in different directions.
BSs and CSs differ not only in orbital position, but also in the manner of transmission, including polarization.
We are pressing forward with the development of technology that will enable an antenna to adjust to these differences. Additionally, technological development towards miniaturization and product cost reduction will be advanced with the aim of its commercialization.

A flat antenna is formed by arranging many small antenna elements. By receiving radio waves with each antenna element and combining them appropriately, even weak satellite signals can be received efficiently. Moreover, the beam direction of the antenna can be changed electronically.