The research and design of invisible digital watermarking based on DCT and Matlab

Digital watermarking can be used to protect the intellectual property for multimedia data. Digital watermarking has two main advantages: firstly, the authority on a particular file can be traced; secondly, there is no need to use additional space to maintain this information. A digital watermark is an invisible secret message that is embedded directly in a multimedia file. According to applications, watermarking systems can be classified in fragile and robust. The watermark is designed to be robust against attacks in order to protect ownership of the image. In addition, watermarking systems may be classified in non-blind detection or blind detection which decide whether the detector uses the original image to extract the watermark or not. In our paper, we introduce a blind image watermarking system, since only the embedded image and the secret key are required in the detection phase, and the original image is not required.