| 摘要 |
Methods and devices are provided to thwart analysis of a watermarking system by preventing analysis of watermarks in a host content. Upon receiving a content at a watermark embedding device, the content is analyzed to ascertain whether one or more test features are present in at least a first portion of the received content. When the analysis reveals that one or more test features are present, embedding of watermarks in at least the first portion of the received content is disabled. The test features of interest include a temporal, a spatial and/or a frequency characteristic such that, if a region of the content that includes test feature is embedded with a watermark, at least one characteristic of the embedded watermark is detectable upon analysis of that region. The test feature can, for example, approximate an impulse signal, a step function signal or a pure sinusoidal signal.
|
