A blind Robust Image Watermarking Approach exploiting the DFT Magnitude

TL;DR

This paper introduces a blind, robust image watermarking method using DFT magnitude and DCT coefficients, demonstrating high robustness against various common image processing attacks while maintaining high image quality.

Contribution

It proposes a novel watermarking technique combining DFT and DCT for improved robustness and security in digital image copyright protection.

Findings

Achieves PSNR > 66 dB indicating high image quality.

Demonstrates robustness against JPEG compression, noise, filtering, and histogram equalization.

Ensures perfect watermark extraction under tested conditions.

Abstract

Due to the current progress in Internet, digital contents (video, audio and images) are widely used. Distribution of multimedia contents is now faster and it allows for easy unauthorized reproduction of information. Digital watermarking came up while trying to solve this problem. Its main idea is to embed a watermark into a host digital content without affecting its quality. Moreover, watermarking can be used in several applications such as authentication, copy control, indexation, Copyright protection, etc. In this paper, we propose a blind robust image watermarking approach as a solution to the problem of copyright protection of digital images. The underlying concept of our method is to apply a discrete cosine transform (DCT) to the magnitude resulting from a discrete Fourier transform (DFT) applied to the original image. Then, the watermark is embedded by modifying the coefficients of the DCT using a secret key to increase security. Experimental results show the robustness of the proposed technique to a wide range of common attacks, e.g., Low-Pass Gaussian Filtering, JPEG compression, Gaussian noise, salt & pepper noise, Gaussian Smoothing and Histogram equalization. The proposed method achieves a Peak signal-to-noise-ration (PSNR) value greater than 66 (dB) and ensures a perfect watermark extraction.