A Numeric Watermark Method Based on Valve-Value Surface

This paper proposes a digital watermarking method based on valve-value surface. First it builds the valve value of curve surface of the original image to get the outline information of the original image; then it embeds watermarks into the edge of the outline. Because the function used by the method to build valve-value surface has high gliding property and easy interpolation ability, the method has strong resistance to attacks like filtering and zooming. The experimental outcome shows that the method has the above advantages.