“…Classic methods can include methods, such as those based on the least significant bit [ 23 , 24 , 25 ] or methods based on frequency domain manipulation (discrete wavelet transform, discrete Fourier transform, discrete sine, and cosine transform) [ 10 , 26 , 27 , 28 , 29 , 30 , 31 ]. There are many modifications of these methods, such as a combination of the least significant bit method and those based on manipulation of the frequency domain, which includes publications concerning hybrid domains [ 23 , 32 , 33 , 34 ].…”