User talk:AndyE

cracked it.

it works in 16 bit, not 8 so it needs to be something like

gm convert -type grayscale -colors 256 -operator ALL AND 32768 -threshold 32767 (infile) (outfile)_8
gm convert -type grayscale -colors 256 -operator ALL AND 16384 -threshold 16383 (infile) (outfile)_7
gm convert -type grayscale -colors 256 -operator ALL AND 8192 -threshold 8191 (infile) (outfile)_6
gm convert -type grayscale -colors 256 -operator ALL AND 4096 -threshold 4095 (infile) (outfile)_5
gm convert -type grayscale -colors 256 -operator ALL AND 2048 -threshold 2047 (infile) (outfile)_4
gm convert -type grayscale -colors 256 -operator ALL AND 1024 -threshold 1023 (infile) (outfile)_3
gm convert -type grayscale -colors 256 -operator ALL AND 512 -threshold  511 (infile) (outfile)_2
gm convert -type grayscale -colors 256 -operator ALL AND 256 -threshold 255 (infile) (outfile)_1

Then the 8 files layered on top of each other in the cutter software with halving engrave depths on each one