Abstract
A photograph on ID card or passport is essential for its owner to certify himself as correct. However, there are some attacks to substitute or tamper the ID-photograph for another one illegally and thus we try to apply a watermarking technique to this problem. The watermarking techniques are already developed to various areas on image media presented in digital format, but not successful for the photograph produced in hard copy. This paper presents experimental investigations on the problem for watermarking the ID photograph, and discusses the technical approaches to prevent it from substituting or tampering.
