[gdal-dev] bug in gdaldem color-relief?

[Idan Miara]

Hi

I think I found a bug in gdaldem color-relief (tested on gdal 2.4.4 and
3.1.0).
I'm trying to make a color-relief with the attached dtm file (see attached
a micro sample d.tif).
The dtm has no "nodata" value set.
The following commands produce a very different output, although the
difference between the input palettes is just an added nv line which
shouldn't make a difference as the input has no ndv value.
It seems that gdal is treating the "nv" value as 0 and colors the value 0
as black accordingly.

gdaldem color-relief d.tif c.txt c.tif -CO COMPRESS=DEFLATE
gdaldem color-relief d.tif c_nv.txt c_nv.tif -CO COMPRESS=DEFLATE

c_nv.txt:
200 red
-200 green
nv black

Should I open a bug report or am I missing something here?

Kind regards,
Idan
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200 red
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