Quote Originally Posted by TheRonin
I have qjpeg1.dll and qjpegd1.dll in my Qt/plugins/imageformats/ folder though. Aren't those the right ones?
Yes, but for linking you need libqjpeg.a or libqjpegd.a. Do you have these files somewhere?

Anyway, if you want to use QJPEG plugin on a system where Qt isn't installed, just create a imageformats subdirectory in the directory where your executable is and place qjpeg1.dll there.