From: Dow Hurst (
Date: Mon Jan 08 2018 - 17:22:03 CST

Creating a ppm file using tachyon optiX on the gpu renders beautifully on
my laptop with a Quadro K5100M gpu. Opening the ppm file in gimp and
converting to png after cropping and whatnot, works great. If the ppm file
is moved to a different workstation with a lesser gpu, such as Geforce 950,
then opening in GIMP shows dull colors. I've been reading about the ppm
image format to try and get a handle on what is going on at

But, I was wondering if other people have experience with this problem and
have solved it? We'd like to remote render with tachyonOptiX for
publication images but need to solve this problem first. Everyone wants to
use my laptop to render and convert ppm to png...

It is like the available color space is different and graphic card
dependent when using a ppm file as the source. A rasterized file format
doesn't produce this effect.

⚛Dow Hurst, Research Scientist
       340 Sullivan Science Bldg.
       Dept. of Chem. and Biochem.
       University of North Carolina at Greensboro
       PO Box 26170 Greensboro, NC 27402-6170