A watermarking scheme for digital cinema

In this paper a video watermarking scheme is presented, that is designed for the future digital cinema format, as it will be used on large projector screens in theatres. The watermark is designed such that it has minimal impact on the video quality, but still is detectable after capture with a handheld camera and conversion to, for instance, VHS, CD-Video or DVD format. In order to achieve the severe requirements, concerning visibility and robustness, the proposed watermarking system only exploits the temporal axis. A watermark is inserted by changing the mean of the luminance values of a frame according to the samples of the watermark. Watermark detection is performed by correlating the watermark sequence with extracted mean luminance values of a sequence of frames. A demonstrator, implementing the proposed algorithm, has been built which shows the aforementioned requirements can be met with the proposed scheme

Issues with digital watermarking and perceptual hashing

Robust identification of audio, still images and video is currently almost always associated with watermarking. Although being a powerful tool, there are some relevant issues with the use of watermarking. In this paper we review these issues, and at the same time propose to reconsider the older technique of robust feature recognition as a serious alternative. Moreover, we argue that not only in the context of content recognition, but also for other applications, a benefit is to be expected from the combination of robust feature recognition and digital watermarking

Copy control using digital speed bumps

A digital media recorder and a method of controlling such is shown. During attempts to copy media content such as audio or a video sequences, sub-sequences are extracted from an input media sequence. A digital fingerprint of the sub-sequence is calculated and compared with at least one first reference fingerprint from a database. The outcome of the comparison determines the action to take in the further processing. Recording of the input media sequence on the media carrier is either allowed or obstructed, e.g. disallowed. In the case recording of the sequence is allowed, the database is updated with information that the digital media sequence has been recorded. This has the effect of a speed bump, which limits the rate at which those copies of media content can be made, i.e. the effect is that of prohibiting more than a given number of copies within a given time frame

Watermark detection

A method and arrangement for detecting a watermark in an information signal. The method may include the steps of computing the correlation (dk) of the watermark (Wi) and the information signal (e.g. an image Q) for a plurality of positions (k) of the watermark with respect to the information signal, and detecting whether at least one of the respective correlation values exceeds a given threshold. The step of detecting may include determining the standard deviation (sigmad) of the respective correlation values (dk), and setting the threshold to a given multiple (T) of the standard deviation. The multiple (T) is derived form a desired false alarm rate (watermark detected when there is none, or no watermark detected when there is one)

Implementation of a real-time digital watermarking process for broadcast monitoring on a TriMedia VLIW processor

The implementation of a real-time digital watermark embedder and detector for television broadcast monitoring is addressed. A TriMedia processor with 4 BOPS (billion operations per second) is used for a software implementation. The performance of the system is tested in a laboratory environment under real-time conditions. The results prove the feasibility of a professional broadcast surveillance system, which is the aim of a European Esprit project named VIVA (visual identity verification auditor)