Patent ID: 7336799

Claim:
A digital watermark embedding device for embedding digital watermark information in a picture signal, said digital watermark embedding device comprising: digital-watermark-pattern generating means for generating a digital watermark pattern based on embedding information; motion detecting means for detecting motion associated with an entire frame of the picture signal by (i) calculating, for each respective pixel in the associated frame of the picture signal, an absolute value of a difference in brightness values between that pixel and a corresponding pixel of an earlier frame of the picture signal, the corresponding pixel being determined using a given motion vector in a motion vector search range, (ii) summing the absolute values of the differences over the entire frame to obtain an index of frame-to-frame correlation that is associated with the given motion vector, (iii) repeating (i) and (ii) for each motion vector in the motion vector search range, (iv) selecting the motion vector having the smallest associated index of frame-to-frame correlation; modulating means for modulating the digital watermark pattern over the entire associated frame of the picture signal using the selected motion vector; and embedding means for embedding the modulated digital watermark pattern in the picture signal.