Figure 4 Cutting and pasting — a section of B pasted into A

  Image A     Image B    Cut and Paste Result

 1  2  3  4  0  0  0  1       1  2  3  4
 5  6  7  8  0  1  0  1       5  1  0  1
 9 10 11 12  0  1  0  1       9  1  0  1
13 14 15 16  0  1  0  1      13  1  0  1