| 摘要 |
<p>A method ( 2 ), an apparatus, a computer readable medium and use of said method for authenticating an audio-visual signal ( 10 ), such as a digital image or video, are disclosed. A signature is derived from all image regions, including areas with flat or otherwise un-watermarkable content. By combining signature bits from all regions of the audio-visual signal and spreading the signature bits over the whole audio-visual signal or at least a large area of it, preferably by applying a spread spectrum watermarking technique ( 2.40 ), the authenticity of flat regions is verified.</p> |
