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Classify a large DEM

November 25 2008 | 0 comments
Categories: Data Modeling

I am trying to classify a large DEM in the symbology tab so I can use it for hypsometric tinting on a shaded relief. When I click on the classified selection it asks if I would like to compute the Histogram and I say ok, but then it reverts immediately back to the streched selection. I have the 9.3 service pack installed, and had previously installed the patch to address the histogram issue, but no luck with this larger DEM. It works fine with smaller DEMs. Any ideas?

Thanks, and Happy Thanksgiving,


Mapping Center Answer:

Here is a suggestion from our Raster team:

Since you already have the larger DEM, you can resample the DEM to a large cell size to make the size of the raster smaller, but the value range of the raster should not change too much. Here is how you would do that:

Add the DEM to ArcMap, then on layer context menu, click Data -> Export Data. Here you can set the cell size. Make this bigger and observe the file size. Then when you are satisfied, export the data.

Set a classified renderer for this resampled dataset.

Apply this renderer to each individual raster.

We will further investigate your original problem - 6GB data is not that large, and we should have some in house that we can test with.

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