Digital Watermarking distingusihed form other techniques

Digital Watermarking is distingusihed form other techniques in three important ways.

First,Watermarks are Imperceptible.Unlike bar codes,they do not  detract form the aesthetices of an image.

Second,Watermarks are inseparable from the Works in which they are embedded.Unlike header fields.the do not get removed when the Works are Displayed or converted to other file formats.

Finally,Watermarks Undergo the same trandofrmations as the Workss ,This means theat it is sometimes possible to learn somthing about those transformations by looking at the resulting watermarks.It si these three attributes that make watemarking invaluable for certain Applicatons.