The proposed function EmbedWatermark can be used to embed a watermark bit into a 16x16 pixel block using geometric warping. The function ExtractWatermark can be used to read out the embeded bit. The functions bases on the NCG (Normed Centre of Gravity (see my other fiels on MathWorks)).
Note 1: Only blocks with high NCG strength are robust.
Note 2: The resulting warping strength of the embedding process depends strongly on the used algorithm and parameters.
Note 3: This functions change the content of blocks without considering neighboring blocks. To prevent artifacts between neighboring blocks additional steps have to be applied (see works below).
Related works are:
Pröfrock, D.; Schlauweg, M.; Müller, E.
Video Watermarking by Using Geometric Warping Without Visible Artifacts
Information Hiding (8th IH 2006), 10 -12 July 2006, Alexandria, USA
Pröfrock, D.; Schlauweg, M.; Müller, E.:
A New Uncompressed-domain Video Watermarking Approach robust to H.264/AVC
Compression. Signal Processing, Pattern Recognition and Applications
(SPPRA 2006), 15 - 17 February 2006, Innsbruck, Austria |
