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