Abstract: The invention relates to embedding in, as well as to extracting a payload from a motion image signal. Furthermore, the invention relates to a motion image signal. A payload is embedded in the motion image signal by the following steps. A first and an at least second watermark are represented by at least a first sequence of watermark samples, and a first and at least a second global property of an image of the signal are determined. Subsequently, the first and the at least second watermark are embedded in the signal, so that a shift of the at least second watermark with respect to the first watermark represents the payload. The first and the at least second watermarks are embedded by modifying the first and the at least second global property in the image in accordance with the corresponding watermark samples. The first and second global properties may be the mean luminance and the mean color saturation of the pixels constituting the image.

Abstract: This invention relates to a watermarking scheme that is robust to general distortions such as scaling and rotation of multimedia content (audio, video, images). This is achieved by embedding a watermark in a first component of the host signal and a transformed version of the same watermark in a second component. For example, a watermark is embedded in the luminance component (Y) and a cyclically shifted version thereof in the chrominance component (UV) of a video signal. The detector correlates (46) the luminance watermark with all cyclicly shifted versions of the chrominance watermark. The highest correlation peak indicates the shift that was applied at the embedder end. By comparing the shift thus found with the original value, the scaling and rotation factors are retrieved (47). The invention allows the scaling and rotation operations to be undone, after which the embedded watermark can reliably be detected in a conventional manner.

Abstract: Watermarking schemes are known that embed the watermark directly in the MPEG domain. A requirement for these algorithms is that the watermarked MPEG stream does not increase in size. Therefore, a bit rate controller allows a modification of a DCT coefficient only if such modification does not increase the stream size. It happens frequently that DCT coefficients are skipped because of this requirement. As a direct consequence, the watermark energy is smaller than desired and therefore the watermark is less robust. This invention exploits the fact that stuffing bits have often already been added to the stream by the MPEG encoder. The embedder is arranged to analyse the stream so as to find out how many stuffing bits there are at the end of the slice. The embedder can then embed the watermark immediately at the beginning of a slice. As a direct result, the watermark energy will increase and therefore the watermark will be more robust.

Abstract: The present invention relates to a method for embedding a watermark (w) in an image motion signal (55). The invention describes a method for embedding a watermark (w) in a motion image signal (55) in the optical domain in several steps. Initially, the watermark, i.e. the information for embedding, is represented by a sequence of watermark samples. During embedding sharpness changing means (10) are applied to change the sharpness in response to the watermark samples, and thereby embedding the watermark in the motion image signal (55) in a simple and efficient manner in the optical domain. The sharpness changing can be implemented by various ways, e.g. by displacing a lens (10) slightly. A particular embodiment exploits a variable focus lens having a liquid lens operated by electro-wetting. Further, the present invention relates to a corresponding apparatus for embedding the watermark.

Abstract: A method of embedding data such as a watermark in a two dimensional information signal such as an image. The method comprises filtering a portion of the information signal using a two dimensional filter. In order to reduce the visibility of the watermark in sharp and elongated edges, the filter is configured to apply a net weighting of approximately zero to the portion of the information signal in at least two non parallel directions. Preferably, the two directions are mutually orthogonal, e.g. horizontal and vertical. The thus filtered signal is used to locally control the watermark embedding depth (energy).