How to reclassify raster inside polygon mask, leaving values outside as they are?

Question

I am in the final stages of a landcover classification and need to reclassify thematic raster values that are inside different polygon masks, while leaving the values outside as they are.

Can I do this with raster calculator? And, if so, how?

Apologies. I meant to add that I need to do this is in ArcGIS. — Simon, Aug 21 '13 at 13:45
check this question: http://gis.stackexchange.com/questions/40474/how-do-i-use-polygons-to-apply-a-unique-value-to-all-raster-cells-within-those-p — Gago-Silva, Aug 21 '13 at 14:08
Thanks, but I need to reclassify specific classes inside the polygon mask, rather than make all the cells inside the mask one value. — Simon, Aug 21 '13 at 14:36
I'm voting to keep it open, as I feel it is sufficiently different from the candidate question. — Devdatta Tengshe, Aug 21 '13 at 15:22
Reclassify the entire raster, then replace the original values by the reclassified values using Con. For details, search our site for applications of Con. — whuber, Sep 27 '13 at 15:48

Aaron · Answer 1 · 2013-08-21T14:52:52.647

8

Because the Raster Calculator is a spatial analyst tool, you can utilize the Mask environment.

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From there, you can use a variety of commands to perform the reclassification: common ones include Con, Pick, Is Null and Set Null, based on your needs.

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To check if a specific spatial analyst tool honors the Mask environment, simply scroll down to the bottom of the help page and check the available environment settings.

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edited Aug 21 '13 at 14:52

answered Aug 21 '13 at 14:44

Aaron

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Love the first illustration. It very clearly explains what is changed, however the answer itself doesn't address "leaving the outside values as they are", exactly. It leaves the outside values behind. – matt wilkie Dec 07 '17 at 18:20

How to reclassify raster inside polygon mask, leaving values outside as they are?

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