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I have a simple model that calculates the NDVI from bands 3 and 4 of a raster dataset. The input bands are 8-bit unsigned, whereas the default output NDVI is signed 32 bit.

How can I specify the pixel depth for the output NDVI as 8 bit unsigned?

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Can this be controlled with an environment setting? – L_Holcombe Feb 12 at 15:43
I haven't found a way to specify the pixel depth in the environment settings. – Aaron Feb 12 at 16:03

1 Answer

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The result from NDVI will be continuous (i.e. decimal) values between -1 to +1, therefore the raster must be able to store these values, and will use signed pixel depth. If you truly want 8-bit unsigned, you will need to adjust the expression in the raster calculator by linearly scaling to values between 0-255 and then applying the int() function on the entire calculation. However, this still does not guarantee that the output will be 8-bit unsigned. Perhaps try Copy Raster on the scaled raster with the optional pixel_type parameter in your model to help with this.

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