An Improvement Technique based on Structural Similarity Thresholding for Digital Watermarking

TL;DR

This paper introduces a thresholding-based technique for digital watermarking that enhances imperceptibility and robustness by embedding watermarks in image blocks until a structural similarity threshold is met, applicable across various algorithms.

Contribution

It proposes a novel thresholding scheme for watermark embedding that improves imperceptibility and robustness, adaptable to multiple watermarking methods.

Findings

Enhanced watermark imperceptibility at fixed capacity.

Maintained robustness against various attacks.

Applicable across DCT, wavelet, and spatial domain schemes.

Abstract

Digital watermarking is extensively used in ownership authentication and copyright protection. In this paper, we propose an efficient thresholding scheme to improve the watermark embedding procedure in an image. For the proposed algorithm, watermark casting is performed separately in each block of an image, and embedding in each block continues until a certain structural similarity threshold is reached. Numerical evaluations demonstrate that our scheme improves the imperceptibility of the watermark when the capacity remains fix, and at the same time, robustness against attacks is assured. The proposed method is applicable to most image watermarking algorithms. We verify this issue on watermarking schemes in Discrete Cosine Transform (DCT), wavelet, and spatial domain.