Showing papers on "Digital watermarking published in 1990"

A proposal on digital watermark in document image communication and its application to realizing a signature

Abstract: With the advance of telematic technology, increasing document image information utilized in the state of soft copy is expected. In these situations, copies of obtained document image information are made illegally with ease, and hence the validity authentication of the information itself and its provider becomes more necessary. Since document image information to be authenticated exists in a form which can be read at an unidentified number of receiver terminals, the realization of an authentication scheme where document image and signature are combined is necessary. This is characteristic of document image information including nature pictures and photographs. This paper proposes a new concept of signature, which is called “digital watermark” for document image communication. A digital watermark is the coding scheme in which secret information is embedded into a document image similar to a watermark. Image coding schemes already proposed are available to realize a digital watermark. We present a method of obtaining a digital watermark using a well-known predictive coding algorithm. Also, we define a criterion for security and show to what extent the digital signature is safe using simulation results, where two or three illegal actions are considered.