After importing a USGS SDTS DEM, the resulting .img file displays very dark. How to fix?
This happens very often due to a null data value of -32767 within the image. This value dramatically skews the histogram causing your image to appear either very dark or very light.
The simplest solution is to recode this value to zero. This can also be done in Spatial Modeler by creating a simple model to automate this process.