In certain cases, the Reclassify Tool (Spatial Analyst) generates wrong results: The number of classes generated for the output layer (specified by the Attribute Table) deviates from the custom n.o. classes. However, the preview table presented in the Tool Pane is always correct.
Obviously, the problem occurs mainly when Reclassify is applied on 64bit dataset, potentially when it's minimum value is below a certain value. therefore the following indicators:
- problem rarely occurs with Input data of 32 bit.
- problem occured first on a Raster (TIFF, 64 bit, double precision) with value range [0.4, 19]. With a custom n.o. classes > 19, Reclassify worked correct.
- After multiplying the same raster with 100, Reclassify worked correct. The value range was now [40, 1900], dataset format / type was the same.
- At a DEM dataset (TIFF, 64 bit, double precision) with value range [1080, 4000], Reclassify worked correct.
- After subtracting 1080 from this Raster (--> value range [0, 2920]), the problem ocurred again
- The original DEM Raster [1080, 4000] converted to 32 bit (Esri Grid format) was correctly reclassified for n.o. classes <= 25. With n.o. classes > 25, the problem ocurred again.
Supplement: after reporting the problem to Esri Support, the behavior was reproduced and is addressed to be solved (2015-04-24).
I was tearing my hair out and about to give up for the night when I finally found your comment. 64-bit grid, same problem on 10.2.2. Thanks for posting this.
Thanks very much for this post. I have the same problem: I am reclassifying a layer into four classes, but the output will only give me 2. I have reclassified a lot and this never occured before. However, my pixel depth is 32 bit. I was wondering if you have any other idea what might be the reason for this issue?
We have experienced bug on reclassify tool too. We use 32 bit TIFF data with 0, 1 and NoData(which value is -2147473648). We tried to reclassfy NoData to 1 and keep the rest. The result we got is a raster with 1 in all the cells in the image...
This is in ArcMap 10.3