Patent ID: 8285998

Claim:
An electronic watermark detecting apparatus which detects an electronic watermark from video content which includes a plurality of segments configuring continuous predetermined N pieces of frame data, and which the same electronic watermark is embedded into each of the N pieces of frame data configuring the segment, the apparatus comprising: a unit divides the video content into a plurality of sub-segments, each sub-segment being composed of continuous N/2 pieces of frame data; a detecting unit which detects regularity information embedded preliminarily through the electronic watermark from the sub-segments; a unit which calculates a non-detection count in the case the electronic watermark is not detected from the sub-segment and which resets the non-detection count to zero when the electronic watermark is detected; a unit which calculates a difference value between the regularity information detected from a previous sub-segment and the regularity information detected from a current sub-segment; a unit which determines falsification of the sub-segment on the basis of the difference value and the non-detection count; and wherein the regularity information is embedded into a first predetermined number of pieces of continuous frame data through the electronic watermark, additional information is further embedded into a second predetermined number of pieces of continuous frame data through the electronic watermark, and the detecting unit detects the regularity information and the additional information.