A frame of Crosson in full-motion video the art and science of digital compositing pdf shot in his own living room. A color range in the foreground fo
A frame of Crosson in full-motion video the art and science of digital compositing pdf shot in his own living room. A color range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. No part of the subject being filmed or photographed may duplicate the color used as the backing.
When using a blue screen, different weather maps are added on the parts of the image where the color is blue. If the news presenter wears blue clothes, his or her clothes will also be replaced with the background video. This was done using black draping where a green screen would be used today. In order to have figures in one exposure actually move in front of a substituted background in the other, a travelling matte was needed, to occlude the correct portion of the background in each frame. Academy Award for his refinement of these techniques in 1964.
His technique exploits the fact that most objects in real-world scenes have a color whose blue-color component is similar in intensity to their green-color component. In the early 1970s, American and British television networks began using green backdrops instead of blue for their newscasts. For decades, travelling matte shots had to be done “locked-down”, so that neither the matted subject nor the background could shift their camera perspective at all. Meteorologists on television often use a field monitor, to the side of the screen, to see where they are putting their hands against the background images.