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I have a large (size of lower 48 U.S.) 100m resolution raster dataset that has a raster attribute table (RAT). The data were created by someone else. One of the attributes in the RAT has the data values I care about, while the actual raster cell values are meaningless. I've been trying to figure out how to reassign the value of the attribute I care about to the actual raster cell value but have not been able to figure out how to do this. The reason I want to do this is that I have a fairly involved custom Python tool that someone else developed that will do the calculations I need, but unfortunately it doesn't have the ability to use RAT attributes. It only uses the raster cell assigned value which as I said in this instance is meaningless.

I tried a roundabout way of running the raster to point tool to create a point feature class with the target field being the attribute I care about, thinking I could then create a new raster from the resulting point feature class. However, the raster to point tool failed stating I didn't have enough temporary memory (I'm running an Alienware machine with 16 GB of RAM and a 1 TB data drive).

Do I have any options? I'm using ArcGIS 10, but if I could do what I describe readily in another package I'd be willing to try another way (I'm not married to ArcGIS).

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up vote 2 down vote accepted

In ArcGIS 10 you can use the Lookup tool (requires a Spatial Analyst license though) which is used to create a new raster based on the value in the attribute table of another raster.

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cool, I new this functionality had to be in there. The tool name "Lookup" isn't exactly intuitively obvious though so I probably looked right at it and skipped over it. thanks. –  turkishgold Jan 14 '13 at 16:19
    
@turkishgold I am curious how long the Lookup tool took to assign the values in the field to the raster. I am doing a similar process on a nationwide raster at 30 m resolution and the Lookup tool has been incredibly slow. –  Naresh Pai Nov 11 '13 at 17:35
    
@Naresh Pai - I don't recall how long it took me at this point, but since it doesn't stand out in my mind it probably wasn't hateful. Just now saw this comment. There may be some more streamlined ways of just doing it in Python outside of ArcGIS, but I didn't need to explore that option. –  turkishgold Jan 22 at 0:27
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