A method for the watermarking of a sequence of video images implements a step for the insertion of at least one watermarking bit into at least one motion vector obtained by motion estimation between two images of said sequence, so as to obtain at least one watermarked motion vector. A scan converter scan converts slices in real-time of a two-dimensional ultrasonic image which form an arbitrary user-defined curve within the two-dimensional ultrasonic image. Two planetary gear sets have the two traction shafts being operatively connected with one of a two planet gear carriers, or two ring gears, respectively. The brush portion includes segregated tufts of bristles that correspond to the color channels. Cached information may be stored locally and may refer to the source for that information through the identifier.