M. J. Aqel, A. Umar, and M. Agoyi, “A performance Evaluation of Transform Domain Algorithm in Watermarking Based on Different Levels of Sub-Bands of Discrete Wavelet Transform”, Period. Eng. Nat. Sci., vol. 7, no. 2, Aug. 2019, doi: 10.21533/pen.v7.i2.1563.