I would like to create smooth/distinct polygon zones from raster data that was interpolated from sparse point data. Is the only way to do this is to have a very small output cell size during the interpolation process? I don't like the look of the raster data when I zoom in and see the grids from the raster data. Is there a way I can eliminate these raster grids and have truly distinct polygon zones? In addition, it would be nice if I can change the number of classes that make up the zones easily by simply changing the symbology and changing the number of classes used or even the classification method used.
The standard way to do this in ArcGis using Spatial Analyst, is to:
If you want to be able to dynamically change the classification, you probably should leave the data as a raster and change the classification in the symbology tab of the layer properties.
As for reclassification, doesn't that depend on how you create the interpolated raster in the first place? I was under the impression that the interpolation function gives you several distinct classes.
This requirement for easy reclassification does seem to conflict somewhat with your need for eliminating the raster grid. Normally I'd recommend you vectorize your raster data (to get distinct areas) and generalize the resulting vector (to get rid of the raster grid artifacts), but you obviously can't reclass a vector.
The only way I can think of to harmonize these requirements is to build an analysis model with some adjustable parameters, and run that every time you want a new classification. In that case, depending on how accurate you want it to be, you might be able to get away with a relatively low-resolution interpolation raster, since you're going to vectorize/generalize the result anyway.
I'm assuming that processing time matters - if it's not critical, then maybe just try a higher resolution raster from the get-go.