I've tried to use the lupe script from Fred's ImageMagick scripts but it does not seem to work. It seems to be related to the multiply composition (see image below).
I can confirm the problem. IM has made quite a few changes to colorspaces (and changed gray to linear) and I am still catching up with adjusting my scripts. I will see if I can find where the problem is and fix it or report a bug. Please note that some of my script, even after fixing, may still not work correctly between IM 6.7.5.5 and IM 6.7.8.1 due to various changes that progressed during that time. So I cannot cover all bases. So I would suggest that if a script fails, try upgrading to the latest release. However, it may take me a while to get all the scripts adjusted for the changes, so if any one finds a problem such as this, bring it to my attention and I will try to fix it next if possible or report a bug if not.
I have fixed the lupe script. It had not been working for a long time due to some dumb errors on my part. I believe it should now work for most versions of IM.