The Classified filter reclassifies the small isolated areas of cells (regions) in a classified raster. It allows you to specify a minimum region size, all region smaller than the specified size will be merged with the largest neighboring region class in the output file. This has the effect of smoothing the raster. This filter supports only classified raster. The output raster will also be a classified raster and the classification table is derived from the input raster.
You can use this tool to reclassify the smaller regions to their largest neighboring region, as shown below:
Before  |
After  |
In another example below, notice how the smaller regions have been reclassified to their largest neighboring region.
| Input - Classified raster of Alaska (zoomed-in) |
| Output - After re-classifying regions with less than 1000 cells |
- The minimum region value must be between 2 to 1000 cells.
- For better result, it is recommended that you use incremental filtering starting with the smaller region to larger region.
Filter Options
Select Category - Select the filter type, for example, Classified or Focal.
Minimum Region Area - Specifies minimum area threshold to be reclassified.