ABSTRACT
Digital watermarking is one of the technologies being developed as a suitable tool for identifying the source, creator, owner, distributor, or authorized consumer of a document or an image. It can also be used for tracing images that have been illegally distributed. There are two major steps in the digital watermarking process: watermark embedding, and watermark extraction. This chapter categorizes digital watermarking technologies into five classes according to the characteristics of embedded watermarks: blind versus nonblind, perceptible versus imperceptible, private versus public, robust versus fragile, and spatial domain-based versus frequency domain-based. It also categorizes digital watermarking technologies into five classes according to their applications: copyright protection watermarks, data authentication watermarks, fingerprinting watermarks, copy control watermarks, and device control watermarks. With the rapidly increasing number of electronic commerce web sites and applications, intellectual property protection is an extremely important concern for content owners who exhibit digital representations of photographs, books, manuscripts, and original artwork on the Internet.
