Instructions for setting it up:

1. Go here: http://pdiff.sourceforge.net and download the Windows Binaries zip file to some folder (like c:\temp1)
2. Go here: http://freeimage.sourceforge.net/download.html and download the FreeImage DLL
3. Copy the FreeImage.Dll to C:\windows on the Windows system you are going to run this on
4. Open a command prompt and navigate to the folder you extracted Pdiff to (like c:\temp1)
5. type: perceptualdiff S:\scripts\test\screenshot\1a.png S:\scripts\test\screenshot\1b.png -verbose -threshold 10 -output foo.ppm

To create a batchfile to launch this, do something like:

start c:\temp5\perceptualdiff S:\scripts\test\screenshot\1a.png S:\scripts\test\screenshot\1b.png -verbose -threshold 10 -output foo.ppm