When you use GeoExpress to create a world file, you may find that the resulting MrSID world file (.sdw) can not be read by GeoExpress (even with world file support enabled). This happens because some languages use a comma as a decimal separator while others use a point. GeoExpress only recognizes the point. Your file may contain commas instead of decimal points.
Given the original .tfw file…
1.000000
0.000000
0.000000
-1.000000
3390118.500000
5723245.500000
…GeoExpress produces the following *.sdw file:
1,000000000000000
0,000000000000000
0,000000000000000
-1,000000000000000
0,000000000000000
5871,000000000000000
Solution:
Change the settings for “Regional and Language Options” in the Control Panel of your computer. The decimal symbol should be a “.” (point) and the digit grouping symbol should be blank or “123,456,789″.