An image-adaptive watermark based on a redundant wavelet transform

In this paper, an image-adaptive watermarking technique based upon a redundant wavelet transform is proposed. The redundant transform provides an overcomplete representation of the image which facilitates the identification of significant image features via a simple correlation operation across scales. Although the watermarking algorithm is image adaptive, it is not necessary for the original image to be available for successful detection of the watermark. The performance and robustness of the proposed technique is tested by applying common image-processing operations such as filtering, requantization, and JPEG compression. A quantitative measure is proposed to objectify performance; under this measure, the proposed technique outperforms a wavelet scheme based on the usual critically sampled DWT.