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Image Analysis or Raster Calculator

Question asked by nrwilson14 on Feb 24, 2016
Latest reply on Mar 2, 2016 by nrwilson14

I calculated NDVI using two different methods. One was the NDVI calculation through the Image Analysis window (using Scientific Output) as explained here: How to Create NDVI Maps in ArcGIS - GIS Geography

I also ran NDVI through raster calculator, converting to floating point.

 

The statistics for the two images were slightly different, though the images are similar to the eye.

Image Analysis: Min: -1, Max: 1, Mean: -0.029, Median: -0.03124, STD: 0.077

Raster Calculator: Min: -1, Max: 1, Mean: -0.034, Median: -0.039063, STD: 0.081

 

Any idea as to why there's a difference? It's a little unsettling. Has anyone else had the same experience.

It was my first time using the Image Analysis window.

FYI: I'm using 4 band aerial imagery flown by a contractor. R, G, B, NIR

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