title: How to build Internal Overviews with Python gdal BuildOverviews()?
body: <p>Trying to mimic the result of running <code>gdaladdo -r average "D:\image.tif"</code> using python gdal bindings. When I run the code below, I get an external .ovr file. How can I generate an internal overview? Am I using the correct function to mimic gdaladdo?</p>
  
  <pre><code>from osgeo import gdal
  InputImage = r"D:\image.tif"
  
  Image = gdal.Open(InputImage,1)
  Image.BuildOverviews("AVERAGE", [2,4,8,16,32,64])
  </code></pre>
  
  <p>I've also tried </p>
  
  <pre><code>Image = gdal.Open(InputImage, gdal.GA_Update)
  </code></pre>