“…Effectively, for pixel X i,j that belongs to C 1 or C 5 , the minimum, maximum, median and average values, B min i;j , B max i;j , B med i;j and B avg i;j , respectively, of the pixels X i+1,j , X i,j+1 and X i+1,j+1 in the current block are used as the prediction values. Afterwards, embedding of data bits proceeds as discussed in [22], where the polarity of the four prediction error values decides on how the data bits are inserted and how the pixels are modified.…”