Multipurpose Digital Watermarking Algorithm Based on Dual-Tree CWT

A multipurpose digital watermarking algorithm based on dual-tree complex wavelet transform (CWT) is proposed for two purposes: to notify the copyright owner with a visible watermark, and to protect the copyright with an invisible watermark. These two watermarks are embedded in different blocks with different methods. Experimental results show that the dual-tree CWT has relatively high capacity to make the visible watermark hard to remove and the invisible watermark robust