Patent ID: 6342924
Filing Date: 2002-01-29
Classification: H04N

Abstract:
An additional information superposition method for superposing additional information spectrum spread with spread codes synchronized with a vertical synchronizing signal on a second video signal for forming an image of an aspect ratio of N:n which is to be converted into and outputted as a first video signal for forming an image of another aspect ratio of M:m, comprising the steps of:setting a size of a unit block before conversion in the second video signal based on a size of a unit block after conversion to which one chip of spread codes for despreading determined in advance is allocated and co contents of a conversion process into the first video signal; and superposing the additional information spectrum spread with the spread codes of one chip allocated for each unit block before conversion having the set size in such a manner as to allow the additional information to be extracted from the first video signal.