title: gdal python background not really transparent
body: <p>When I merge my geotiffs using buildVRT and translate from gdal the transparity is showed as transparity blocks instead of the content of layer behind it.</p>
  <p>see image:</p>
  <p><a href="https://i.stack.imgur.com/D2yyH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/D2yyH.png" alt="example" /></a></p>
  <p>used code for merging geotiff:</p>
  <pre><code>demList = glob.glob(os.path.dirname(os.path.abspath(__file__)) + &quot;//..//icons//*.tif&quot;)
  print(demList)
  
  VRToptions = gdal.BuildVRTOptions(srcNodata=&quot;255 255 255&quot;)
  vrt = gdal.BuildVRT(os.path.dirname(os.path.abspath(__file__)) + &quot;//merged.vrt&quot;, demList, options=VRToptions)
  translateOptions = gdal.TranslateOptions(creationOptions=[&quot;TILED=YES&quot;])
  gdal.Translate(os.path.dirname(os.path.abspath(__file__)) + &quot;//mergedDEM.tif&quot;, vrt, options=translateOptions)
  vrt = None
  </code></pre>
  <p>my question is how i can use the previous layer as background instead of the transparity blocks.</p>
  <p>Compleet code with problem:
  <a href="https://github.com/NickSmeding/MergeGeotiff" rel="nofollow noreferrer">https://github.com/NickSmeding/MergeGeotiff</a></p>