Adaptive watermark mechanism for rightful ownership protection

Watermarking is used to protect the integrity and copyright of images. Conventional copyright protection mechanisms; however, are not robust enough or require complex computations to embed the watermark into the host image. In this article, we propose an adaptive copyright protection scheme without the use of discrete cosine transformation (DCT) and discrete wavelet transformation (DWT). This novel approach allows image owners to adjust the strength of watermarks through a threshold, so that the robustness of the watermark can be enhanced. Moreover, our scheme can resist various signal processing operations (such as blurring, JPEG compression, and noising) and geometric transformations (such as cropping, rotation, and scaling). The experimental results show that our scheme outperforms related works in most cases. Specifically, our scheme preserves the data lossless requirement, so it is suitable for medical and artistic images. (c) 2007 Elsevier Inc. All rights reserved.