Digital watermarking by geometric warping

A new method is presented for watermarking digital images and video streams. This technique embeds information in an image by changing the geometric features of the image. The method is essentially different from existing techniques in which a pseudo-noise pattern is added to the image. The new method has the advantage that the detection is computationally faster than existing methods. Furthermore, it is easier to detect the watermark in images that have been rotated, scaled, or distorted by a geometric transformation. The watermark is formed by a predefined dense pixel pattern, such as a collection of lines. Salient points in an image are warped into the vicinity of the line pattern in such a way that the changes to the image are imperceptible.