Watermarking Scheme based on Chinese Remainder Theorem and Integer Wavelet Filters for Copyright Protection

Abstract

The development of image watermarking schemes has grown rapidly especially in non-block watermarking. However, non-block watermarking produced less robustness against compression and filtering attacks. This study proposed a new model to improve the robustness using a Euclidean distance on the wavelet sub-bands of Integer Wavelet Transform (IWT) with the Chinese Remainder Theorem (CRT). The watermark is then embedded on a low-frequency coefficient according to a predetermined location. CRT is used on the embedding scheme by utilizing integer wavelet filters for decomposing the host images. Both methods are work on signed integer values to avoid the truncation process that usually occurs in the embedding process. The experimental results show that the proposed method produced a better robustness level compared to the CRT method under Gaussian filter, rescaling, cropping, JPEG, and JPEG2000 compression. The proposed scheme achieved high imperceptibility with an average SSIM value of 0.998. The results show that our method can improve the robustness and maintain the visual quality of the watermarked image.