Dual-watermarking by QR-code applications in image processing

Digital watermarking has recently emerged as a solution to the problem of providing guarantees about copyright protection of digital images. However, several problems related to the robustness of invisible watermarking techniques from malicious or non-malicious attacks still remain unsolved. Visible watermarking is an effective technique for preventing unauthorized use of an image, based on the insertion of a translucent mark, which provides immediate claim of ownership. Digital watermarking technology primarily joins the rightful owner of totem to the protected media. Once the media are suspected to be illegally used, an open algorithm can be used to extract the digital watermark, for the purpose of showing the media's ownership. A reversible visible watermarking scheme is proposed to satisfy the applications, in which the visible watermark is expected to combat copyright piracy but can be removed to recover the original image without loss. In this paper, we propose a reversible visible watermark method, which embeds QR code into gray-scale images to create a visible watermark. Not using complex calculations, this paper tries to simply change the pixel value to achieve the digital watermark. Furthermore, a reversible steganographic method is used to embed the watermarking information, which can be used to recover the original images, into the watermarking images.