I have read some papers about steganography using perfect linear codes. The aim is sending more hidden message bits with changing less cover message bits. For example using the parity check matrix of [7,4,3] Hamming code, we can embed 3 bits of message in 7 bits by changing at most one of them.
It looks great. However, we are not free for choosing positions to be changed. Our message forces us when choosing positions that we will change. But what if the position we will change belongs to the most significant bit (MSB) or any other bits that the colour of the pixel changes perceptibly when we change that position? Is not it a handicap?