You open this dialog box by selecting an
SRAM Object File (.sof) Definition for a supported
device(CycloneIII, Cyclone IV, or
StratixIII) family in the Input files to
convert list in the Convert Programming Files dialog box
on the File menu and clicking Properties.
Allows you to compress the selected SRAM Object File. You can
specify whether or not the selected SRAM Object File has bitstream
compression.