Patent ID: 6360000
Filing Date: 2002-03-19
Classification: G06T

Abstract:
A method of detecting a watermark embedded in a video stream formed of successive images, wherein the video stream with embedded watermark is scaled by an unknown scale among a predetermined finite number of scales, comprising, for each of the predetermined finite number of scales, the steps of:dividing the watermarked video stream into a plurality of equally sized read blocks; accumulating each of the plurality of read blocks having a same offset relative to the start of the respective watermarks into a respective read block bin of a predetermined number of read block bins determined by the specific scale, so as to reinforce the strength of the watermark while de-emphasizing the video stream signal; re-scaling each of the accumulated read blocks having the same offset to recover the original image size; combining the re-scaled accumulated read block bins by shifting them and combining them into a video accumulated block; and evaluating a predetermined quantity within the video accumulated block for each of the predetermined finite number of scales, to detect the watermark.