An Image Watermarking Based on Rayleigh Distribution Detector

This work proposes an image watermarking procedure, covering both watermark embedding and detection. A Rayleigh distribution-based detector is proposed for watermark detection using the expression for the local optimal detector. The embedding procedure is applied in the DCT domain, on the selected <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$8\times 8$</tex> DCT blocks. A block selection procedure is based on the block variance and resistance to JPEG compression. The approach is tested against common attacks such as JPEG compression, impulse noise, median filtering, and brightness variation, demonstrating robustness.