convert bb1_0001.png bb1_0001.pnm
convert bb1_0009.png bb1_0009.pnm
convert bb1_0049.png bb1_0049.pnm
pnmcat -lr bb1_0001.pnm bb1_0009.pnm bb1_0049.pnm > H1152k2c_sig01_bb1.pnm
