I have a 15-meter, integer DEM I converted into a float raster. However, the original DEM contains large lowland areas that are nearly completely flat. Due to the original resolution and integer format, these flat areas have a step-like appearance with only one meter of difference in elevation despite the large area covered.
How can I correct these large plateaus by smoothing them with a very gentle slope but without touching too much the other features in the landscape?
I am using ArcGIS Desktop but any other free software would be fine.