Spatial Join Polygon the Raster

Discussion created by dunhama on Feb 16, 2011

I am working on a model that takes the a sidewalk polygon layer and gives an approximation of the material using the RGB values of an aerial photo. In the end I want to have a polygon with attributes for: average red value in its area, average green value in its area and average blue value in its area.

The only method I have used is to clip the aerial to the polygon, convert each of bands to points (using raster to point), and spatial join the point layers to the polygon. The trouble is, each layer has about 18 million points.

Is there something in spatial analyst that can help me get the average RGB value of an area and put it in a polygon?

Thanks in advanced.