d a grayscale image in its bit plane and put these 3 bit planes from Bit 5-7 into the Bit 0 of the RGB. To extract the hidden image the process is vice versa.</p>

<p>The Bits extracted from the coloured image are in Bit position 0, means they need to be shifted to their original position. That is Bit 7/6/5. For this we can use the &quot;Shift&quot; <code>&lt;&lt;</code> operator. Than the 3 Bytes with their proper position must be binary ORed with the OR <code>|</code> operator. Both operator exist in PDL 