ref: c91479e8172bc493694e9c1e1d15e7eb867af6f8
dir: /sys/src/cmd/gs/lib/ras3.upp/
-supModel="SUN rasterfile, 3 Bit, 7 Colors (RGB-Ghostscript)" -sDEVICE=uniprint -dNOPAUSE -dSAFER -dupColorModel=/DeviceRGB -dupRendering=/ErrorDiffusion -dupOutputFormat=/SunRaster -dupComponentBits="{1 1 1}"