topic Re: The difference between the Minus and Compute Change raster function in ArcGIS Pro Questions

The difference between the Minus and Compute Change raster function

AvivitLevy — Wed, 23 Jun 2021 14:30:14 GMT

Hello,

I have a theoretical question: The difference between the Minus and Compute Change raster function?

Thanks in advance,

Avivit

Re: The difference between the Minus and Compute Change raster function

DanPatterson — Wed, 23 Jun 2021 19:37:53 GMT

Minus just subtracts

Compute Change can do one of three things....

Compute Change function—ArcGIS Pro | Documentation

Re: The difference between the Minus and Compute Change raster function

JayantaPoddar — Wed, 23 Jun 2021 19:43:05 GMT

The Minus tool has been there since a long time (even in ArcMap). It is available with extensions like 3D Analyst or Spatial Analyst (ArcMap/ArcGIS Pro) or Image Analyst (only ArcGIS Pro). It will give you an absolute difference between the pixel values of the two raster datasets.

Compute Change Raster is a newly added tool available with Image Analyst for ArcGIS Pro (ver. 2.7 and later). This tool can calculate not only the absolute difference (like Minus tool), but also relative difference and categorical difference between the two raster datasets.

Check the links for more details.

Re: The difference between the Minus and Compute Change raster function

AvivitLevy — Thu, 24 Jun 2021 16:42:21 GMT

Thank you very much, can I say that the Minus function generates a binary classifiaction?

Re: The difference between the Minus and Compute Change raster function

JayantaPoddar — Thu, 24 Jun 2021 17:04:12 GMT

In a sense, yes. You get the positive and negative values.

But It doesn't actually classify the data. But you can classify the output Raster's symbology as <0 and >0 (or whatever number of classes you desire).

If you want to change the actual output Raster values to binary (a number of classes), use Reclassify tool.

Re: The difference between the Minus and Compute Change raster function

DanPatterson — Thu, 24 Jun 2021 19:22:11 GMT

No... not in general, minus returns the numeric difference between data sets. The difference need not be positive or negative and it need not be binary!