Method for compressing and decompressing moving picture information and video signal processing system

Abstract

The present invention provides a method for compressing and decompressing moving picture information. At the time of coding a video signal, conversion is carried out for make large a distance between an ordinary digitized video signal and a key signal indicative of whether an image indicates background or foreground for data compression. At the time of decoding the coded video signal, the video signal and key signal of the decompressed image are separated based on a predetermined threshold and reverse conversion opposite to the coding mode is carried out. Since the coding is carried out with the ordinary video signal separated from the key signal, the video signal and the key signal can be separated by a suitable threshold from the compressed and then decompressed image and thus the video signal and key signal can be correctly reproduced.

Description

technical field [0001] The present invention relates to image processing techniques, and more particularly to a technique that can be particularly effectively applied to moving image compression and decompression methods. More specifically, the present invention pertains to a method of compression / decompression by which, when it is desired to combine a restored image with another image into a composite image or video signal, the A key signal is properly recorded or transmitted simultaneously with the composite video signal, and the present invention also relates to a video signal processing system capable of removing the key signal from a composite video signal including the key signal and outputting the composite video signal. Background technique [0002] When it is desired to superimpose a moving image on another image to form a composite image, there are methods known as "chroma key" diagrams, which are used to color the target subject in monochrome or behind it. A patt...

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Problems solved by technology

[0003] However, in the prior art image synthesis method as described above, when a moving image is subjected to high-efficiency encoding processing (i.e., data compression) followed by decompression, the compressed moving image cannot always be restored. is the original image, so the keying signal is sometimes not reproduced correctly

For this reason, sometimes there is such a problem that the position (hereinafter referred to as background) to be replaced with another image according to the key signal cannot be replaced correctly, but on the contrary, the position which should not be replaced with another image (hereinafter referred to as the foreground) may thus be erroneously replaced by

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