Hello,
This issue refers to a fix proposed by Ville Karppinen at Finnish Meterological Institute (FMI) regarding a patch to Geotools. The fix would enable Geoserver to serve raw raster data with 16 bit data trough WMS without it being rescaled to 8 bit. This would allow the user to fully utilize the benefits of 16 bit data trough WMS.
The original thread can be found here:
http://osgeo-org.1560.x6.nabble.com/RasterSymbolizerHelper-16-bit-raster-content-change-proposal-td5230022.html
It seems that this feature got some approbation back then.
The matter is now current again. The patch indeed works in the sense that it allows 16 bit data to be downloaded trough WMS. However, building Geoserver against the patched Geotools causes some of the unit tests in Geoserver to fail in a null pointer exception. The failing tests are in org.geoserver.wms.map.RenderedImageOutputFormatTest.java, namely testInterpolations and testInterpolationFromLayerConfig.
We are doing our best to localize the issue, but now we wanted to ask if anyone with greater knowledge on Geoserver's internals could shed some light on why these errors occur. The code is visible here:
https://github.com/asterycs/geotools/commit/307d4e2a3d0089b9c27d98ba18435599494f8c10
As can be seen, the fix is rather simple.
Any help on what might be causing this issue or where to search would be greatly appreciated.
Best regards
Jimmy Envall