Blind watermarking algorithm using complex block selection method

Abstract

Digital watermarking is the technique, which embeds an invisible signal including owner identification and copy control information into multimedia data such as audio, video, images for copyright protection. A new watermark embedding algorithm is introduced in this paper. In this algorithm, complex 8× 8 DCT blocks are selected by calculating the AC coefficients of the DCT blocks, and watermark information is embedded into the selected complex blocks using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust to JPEG compression with 90% of compression ratio and has an excellent PSNR. With the fast watermark extraction property, this algorithm is suitable for real-time watermark extraction applications such as compressed video watermark.