A GUI isn't really needed. When you install the ImageMagick windows binary it installs a great set of command line tools. Simply run 'cmd' and enter the command line provided in the IIPImage documentation:
convert input1.jpg -define tiff:tile-geometry=256x256 -compress jpeg ptif:output.tif
It's probably easier than you think. I know you were interested in a GUI, but honestly it's not needed in this case. Much easier and faster using the command line.