A DCT-based ownership identification method with gray-level and colorful signatures

Abstract

In this paper, we propose an ownership identification method based on discrete cosine transformation (DCT). The copyright owner can select a gray-level or colorful image to be an ownership statement, which is used as a claim to the ownership of his/her work. Unlike traditional watermarking schemes, the ownership statement is not embedded into the image to be protected. Instead, our method will construct an ownership share for the author according to the feature of the original image and the ownership statement. The feature map of the original image is composed of DC coefficients of different DCT blocks. When piracy happens, the author can show his ownership share to reveal the ownership statement to prove his/her copyright. Note that the size of the ownership statement is not restricted to being smaller than that of the host image. In addition, multiple ownership statements can be registered for a single image without destroying each other. The experimental results will show the robustness of our scheme against several common attacks. Finally, we will give some discussions and comparisons with other researchers' study.