Recently, I tried to make a PDF lighter that I had run through K2PDFOpt for my Pocketbook, because the result was much darker than the original. So, I came across the command line options file on
https://www.willus.com/k2pdfopt/help/options.shtml . Under the heading of “-mode <mode>” it says: “If you want a perfect copy, do this: -mode copy -gamma 1 -s- -cmax 1”. So I tried that; didn't work. I did get “-gamma 1” in the file list of K2PDFOpt's GUI, though. Huh? I looked further and found out that you have to give K2PDFOpt “-g” instead of “-gamma”. Then, the option worked, and with “-g 1.5” I got just the right amount of lightening up of the result file.
I don't know how long this documentation error has been there, but I guess it's years. I've been using K2PDFOpt years ago, and it was already present then. So, I tought I'd mention it. As I couldn't find an appropriate forum, I chose the “PDF” forum to post in.
Regards, Jaap.