METHOD FOR DETECTING ACCOMPANIED INFORMATION AND ITS DEVICE AND DATA RECORDER AND DATA REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To correctly detect accompanied information, even if the fluctuation of a pixel value is large in an image to be detected. SOLUTION: Accompanied information is added to image information as a preliminarily decided pattern. At detecting of this accompanied information, the evaluation value of the accompanied information added to the image information is calculated by an evaluation value calculator 41 through the use of the preliminarily decided pattern. The detected output of the accompanied information is obtained by using the evaluation value calculated through the evaluation calculator 41 with an evaluation value comparator 43. The conversion processing of the pixel value is operated for changing engagement, related to the evaluation value for the image information by a pixel value converter 45 as one example of a pre-processing means prior to the calculation of the evaluation value.