Multiple-chirp typed blind watermarking algorithm based on fractional Fourier transform

The novel blind digital image watermarking algorithm using fractional Fourier transform (FRFT) is proposed and the energy distribution of two-dimensional signal at different FRFT domain is discussed. In this technique, multiple chirps are used as watermark which is embedded in the spatial domain directly, and detected in the FRFT domain. Experimental results show that the watermarking algorithm using proposed techniques can have good image quality and are robust to some common image processing.