Watermarking of motion pictures

Abstract

The problem of watermarking a sequence of images from a motion picture can be divided into two parts. The first part is embedding watermarks in the sequence of images. The second part is detecting embedded watermarks in a target sequence of images where the target sequence may have resulted from one or more attacks on an original sequence of images in which the watermarks were embedded. Motion pictures are watermarked by embedding information in different ways in different images. In general, the information to be embedded is used to define a plurality of watermark images. Each watermark image is an apparent pattern of noise in both signal and frequency domains, and is different from the other watermark images. Preferably, each watermark image is temporally uncorrelated with the other watermark images. Each watermark image is used to modify a corresponding image from the motion picture. To detect the presence of the information in a target sequence of images from a motion picture, the target images are processed to determine an alignment with a watermark sequence. When an alignment with the watermark sequence is determined, a sliding window detector is applied to detect the watermark and read the information embedded by the watermark. By embedding the same information in different ways in different images, and then detecting this information by combining data from the different images, the sensitivity of the detector is increased.