supported by the National Natural Science Foundation of China(Nos.61601467,61379102,61502498,U1433105 and U1433120);the Fundamental Research Funds for the Central Universities(3122017044)
A robust digital watermarking algorithm is proposed based on quaternion wavelet transform(QWT) and discrete cosine transform(DCT) for copyright protection of color images. The luminance component Y of a host color ima...