Visible watermarking technique in compressed domain based on JND

Abstract

A distortion on an image can be invisible by the Human Visual System (HVS), if the distortion is under a threshold called Just Noticeable Distortion (JND), which is determined by several sensibility factors of the HVS, such as luminance and frequency sensibility. Until now, the JND is widely used for invisible watermarking schemes; however, in visible watermarking schemes this concept is not explored sufficiently. In this paper, a novel compressed domain visible watermarking method based on the JND profile is presented. The JND is estimated by texture and intensity of each 8×8 block of the Discrete Cosine Transform (DCT). Considering that the JPEG is the most widely used digital image format and almost all photographs captured by digital camera are stored in this format; the visible watermarking scheme in compressed domain without inverse DCT operation to obtain spatial image provides important advantage from security and complexity points of view.