Le mardi 20 mai 2014 02:22:12, Stephen Woodbridge a écrit : > Even, > > Thanks! > > I didn't set his up, I just inherited the maintenance of it and I'm just > trying to understand how it works and eventually make changes to it and > fix some of the processing that does not seem to be grounded in a good > process, which is looking like more and more of the code. :( > > I get the point about the color table values need to be values from 0-n > and you need 0-n entries in the color table. Or you need to use LUT > like you explained before. > > What I was trying to understand is more along the lines of > > input tif is Int16 > vrt is declared as Byte > > How does GDAL deal with this? There are no errors or warnings. gdalinfo > is reporting a Byte range of values for the vrt. I'm wondering how it is > interpreting an arbitrary Int16 value into a Byte? > > So some of the obvious guesses are: > > 1. it is scaling them (you say no on this) > 2. it is reading the Int16 and only using only the low or high order > byte as the value? > 3. something else?
It should clamp input values to the Byte range. So negative values in Int16 will transform to 0, and ones > 255 will be clamped to 255. -- Geospatial professional services http://even.rouault.free.fr/services.html _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
