IceMan

Bilinear Interpolation: Extract Values to Points

Discussion created by IceMan on Apr 17, 2014
Latest reply on Apr 24, 2014 by IceMan
I am attempting to use the Spatial Analyst Tool in the Extraction Toolset called 'Extract Values to Points'.

One option is to assign the Cell Values to the Input Points using "Bilinear Interpolation".

I have read about this in the Resampling Help Doc, though this seems like it would be the reverse situation. Either way, it is not clear to me which Cells will be used and how. The Tool itself Help Doc is not clear to me either.

Is it going to use only the 4 "nearest" Cell center Values? If so, I assume that includes the one it falls within..?

Or is it going to use the 4 "adjacent" Cell center Values? If so, I assume those are the Cells that share a side with the Cell containing the Point..? if so, I assume that this is really going to be using 5 Cell Values to include the one it falls within..?

Or, is this Tool not restricted to 4 or 5 Cell Values, and will use all the "neighboring"cells which will amount to 8 or 9 Cell Values? ...In other words, the diagonal Cells will also be included since they share a vertex with the Cell containing the Point.

In either case, are these Cell Values "distance-weighted"? If so, is this technique explained how it weights..?

Thanks!

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