-${bin}phm2rs sample-rs.rs 367 320 --nray 2
-${bin}rs2sdf sample-rs.rs sample-rs.sdf
-${bin}sdf2img sample-rs.sdf sample-rs.png --format png
+${bin}phm2rs sample-rs.rs 367 320 --nray 2 --phantom herman
+if [ -f sample-rs.rs ]; then
+ ${bin}rs2sdf sample-rs.rs sample-rs.sdf
+fi
+if [ -f sample-rs.sdf ]; then
+ ${bin}sdf2img sample-rs.sdf sample-rs.png --format png
+ ${bin}sdf2img sample-rs.sdf sample-rs16.png --format png16
+fi