A reply to Dave Piston's comment about the masking command file.
 
The problem about SOM saving PMT1 on the "right" image buffer, and PMT2
on the "left" image buffer is even worse than Dave suggested. If you
start SOM from within COMOS (using the Program menu choice), then when
you quit SOM and reactivate COMOS, now COMOS will ALSO have PMT1 on the
right. The only way to realign the two channels is to restart COMOS and
let the framebuffer reinitialize.
 
The way I checked whether the scale 255 was working reproducibly was as
follows. I subtracted off the "mask value" (i.e. setting values below
this cutoff to zero), then performed scale 255 and base 254 to generate
a mask with (in theory) only 1's and zero's (affectionaly known as "The
Dave Piston algorithm"). I then performed scale 255 to visualize the mask
as 255 gray levels and saved it. I compared this mask with that which
appeared after a few more cycles of base 254, scale 255 commands (i.e.
take it back down to 1, then bang it back up to 255 to see it again).
this should give exactly the same mask every time. It did, so it seems
our system was being reproducible.
 
Ciao all,
 
Chip Montrose
Johns Hopkins University
410-955-9681