Step 3. Still using PSP, I selected area outside wetland pool and filled with red at 80% opacity.
Step 4. I applied the command color > split channel > split to RGB. Note how the upland area appears white in the grey scale image because the red values were near the maximum of 255. The water appears dark because the red values are near zero. The cattail canopy was somewhere in between.
Step 5. I saved it as a bitmap file and imported it into Idrisi32 using Import > desktop > BMPIDRISI .