ER Mapper .ECW File Description


MapViewer imports ERMapper .ECW files.


Enhanced Compression Wavelet .ECW is an open standard wavelet compression image format developed by Earth Resource Mapping. The file format is optimized for aerial and satellite imagery, and efficiently compresses very large images with fine, alternating contrast. This is a lossy compression format.


The .ECW file format has the following properties:

Import Options

See .ECW Image Import Options Dialog.


Import Automation Options

See ER Mapper .ECW Import Automation Options.


Export Options

MapViewer does not currently support .ECW export.



When loading a very large .ECW file, it may load with poor resolution. To save on loading and processing time, it was necessary to design MapViewer to automatically reduce the resolution of very large .ECW files, even when choosing a Pixel Reduction of 1/1 during import. If the .ECW file is larger than 8192 x 8192 pixels, then MapViewer will automatically scale it down by halving the number of pixels until the largest dimension is under 8192 pixels.


For example, your .ECW file is 28000 x 14000 pixels. Divide that in half to get 14000 x 7000 pixels. Since the largest dimension is still over 8192 pixels, divide it again to get the pixel dimensions of 7000 x 3500 pixels (with a Pixel Reduction of 1/1).


There is currently not a way to change this. If you would like to add your vote for more user control over the maximum pixel dimensions when importing .ECW files, please email



See Also

ECW Image Import Options Dialog

ER Mapper .ECW Import Automation Options

File Format Chart