Patent ID: 6553127
Filing Date: 2003-04-22
Classification: G06T,H04N

Abstract:
A device (150) for detecting the watermark in a watermarked source data stream which includes a plurality of data elements, each data element having at least one characteristic associated therewith, wherein the watermark embedded in selected blocks of the source data stream meet a texture criterion measuring a variation of a selected characteristic associated with each data element of the source data stream, wherein the texture criterion is unrelated to any relationship between corresponding blocks of two different frames, the device comprising:a buffer circuit (160) receiving as input the watermarked data stream, the buffer circuit buffering and dividing the watermarked data stream into the selected blocks, wherein the blocks are of the same size as chosen arbitrarily in the embedding process reflected in the watermarked source data stream (145); a block selector circuit (120, 170) coupled to an output of the buffer circuit, the block selector circuit selecting blocks of the watermarked data stream based on a substantially similar texture criterion as that used in selecting the blocks for embedding the watermark, wherein the data input to the criterion function comes only from the block being tried for selection; and a detector circuit (180) coupled to an output of the block selector circuit, the detector circuit detecting the watermark only in the blocks selected by the block selector circuit, to decrease the time and number of operations necessary to process a given number of blocks.