What's behind the CCTV weatherman?

Many viewers don't know that the background of the weather forecast is just a blue wall. Because of the use of "keying" technology, the map seen on TV will appear. "Keying" simply means that the back of the host is blue. After keying, all the blue in the picture will become transparent, and then the image with the color removed will be superimposed on the map, so that the host will stand in front of the map. Therefore, the weather host is actually "pointing the country" in front of a blue wall. In front of an empty blue screen, the host should not only accurately express it, but also accurately point out the position of the information described in the manuscript on the map according to the change of graphics. Anyone who has visited the Weather Forecast studio will find it very difficult and even a little frustrating to point out the geographical position quickly and accurately in front of a blue wall.

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