[Gdal-dev] Creating an empty ColorTable in C++

[Roger Bivand]

I'm trying to replicate some of the inner logic of rgb2cpt.py in a C++ 
function from R. I'm stuck on how to declare/initialize a GDALColorTable 
*ct for GDALComputeMedianCutPCT() and GDALDitherRGB2PCT() - I'm using:

  GDALColorTable *ct = pRasterBand->GetColorTable();

where pRasterBand is the red band of the input data set. This obviously 
upsets GDALComputeMedianCutPCT() which seems to want a naked ColorTable, 
and seg.faults:

#0  0xb798bf3a in GDALColorTable::SetColorEntry ()
   from /usr/local/lib/libgdal.so.1
#1  0xb798bfe5 in GDALSetColorEntry () from /usr/local/lib/libgdal.so.1
#2  0xb79b742e in GDALComputeMedianCutPCT () from /usr/local/lib/libgdal.so.1

How should I declare ct?

Grateful for any hints,

Roger

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no