A Novel Zero Watermarking Based on DT-CWT and Quaternion for HDR Image

This paper presents a high dynamic range (HDR) image zero watermarking method based on dual tree complex wavelet transform (DT-CWT) and quaternion. In order to be against tone mapping (TM), DT-CWT is used the three RGB color channels of HDR for obtaining low-pass sub-bands, respectively, since can extract contour change small after TM. The provides wide range, thus, three-color channel correlations are higher than inner-relationships quaternion consider as whole transformed. Quaternion fast Fourier (QFFT) singular value decomposition (QSVD) utilized decompose robust features, which fused with binary watermark generate copyright protection. Furthermore, scrambled security by using Arnold transform. Experimental results denote that proposed zero-watermarking TM other processing attacks, protect efficiently.