I intend to convert a raster to several polygons, but I want to ignore too small polygons, and just keep larger polygon. How can I do that? Thanks in advance!
There are several approaches you may take. The first involves the Raster to Polygon tool itself. Make sure to check the "Simplify polygons" checkbox--this will greatly reduce the number of small polygons. If there are still too many sliver polygons, use the Eliminate (Data Management) tool. Eliminate works by merging smaller polygons with larger polygons. You can specify an expression in the SQL window to further reduce the sliver polygons (e.g. "Area_Sq_Miles" < 0.15).
If you are having difficulty dialing in the Eliminate SQL expression, try selecting the polygons you would like to remove directly in the attribute table: