[gdal-dev] Can GDAL open binary buffer contents as input for MEM format?

[Frank Warmerdam]

Roger André wrote:
> Hi Frank,
> 
> Thanks for the example.  How can I specify alpha in that, for one of the 
> quantized 8-bit PNG's (with alpha) that MapServer produces? 

Roger,

In a way this is simplier.  It is just a one band GDT_Byte file, so more
like the first example I gave.  The palette can be handled separately,
and assigned to the MEM dataset a bit like:

     gdaltest.test_ct_data = [ (255,0,0), (0,255,0), (0,0,255), (255,255,255,0)]

     gdaltest.test_ct = gdal.ColorTable()
     for i in range(len(gdaltest.test_ct_data)):
         gdaltest.test_ct.SetColorEntry( i, gdaltest.test_ct_data[i] )
     mem_ds.GetRasterBand(1).SetColorTable( gdaltest.test_ct )

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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