How do I get overviews to work with VRT datasets ?<br><br>What I do is<br> - creating a .vrt with additional alpha band + nodata using gdalbuildvrt (wrapping an existing TIFF)<br> - creating overviews using gdaladdo. I then get an external .ovr file.<br>
- creating a new TIFF from the VRT<br><br>First, it seems that the .vrt does not get updated, as there is no <Overview> tags. I then tried to manually add <Overview> for each band,<br>but the output TIFF does not have overviews in it.. just the original bitmap and a mask for it.<br>
<br>Example:<br><br>gdalbuildvrt _r-32-2-4776-64728.vrt -overwrite -addalpha -srcnodata 0 -vrtnodata 0 r-32-2-4776-64728.tif<br><br>gdaladdo _r-32-2-4776-64728.vrt 2 4 8 16 32 64<br><br>gdal_translate -of GTiff -co COMPRESS=JPEG -co JPEG_QUALITY=80 -co PHOTOMETRIC=YCBCR -b 1 -b 2 -b 3 -mask 4 -co COPY_SRC_OVERVIEWS=YES --config GDAL_TIFF_INTERNAL_MASK YES _r-32-2-4776-64728.vrt output\r-32-2-4776-64728.tif<br>
<br><br>Also, I tried to add overviews embedded inside the source tiff (wrapped in the same .vrt), but still no overviews in the output.<br><br>Note, that what I'm really trying to do, is to create TIFF with JPEG compression, and adding a mask that is not "contaminated" with jpeg artifacts.<br>
<br>What am I doing wrong ? :)<br><br><br>-- oyvind<br>