I'm not sure if this is the best channel to ask this question as it might be beyond the scope, but I've asked it in a few others and have had no responses aside from others also being curious. <https://gis.stackexchange.com/posts/450396/timeline>
I am trying to understand the relationship between overviews and zoom levels so I know how to make more efficient Cloud Optimized GeoTIFFs. Using gdaladdo or gdal.BuildOverviews(), I can create overviews at [2,4,8,16] or at just [16]. From my understanding, this means the size is being divided by those values to provide downsample arrays of the original source. In the first example [2,4,8,16], I've created 4 separate overview arrays into the GeoTIFF that are 2x, 4x, 8x, and 16x downsampled. And in the second example using only [16], I've built one overview array into the GeoTIFF that is 16x downsampled. How can I understand how these overviews are applied when it comes to zoom levels? Does the 16x downsample appear sooner in the second example when zooming out than for the first example due to being first in order? Or do the 16x downsamples appear at the same zoom level for both cases but the second example has additional 2x, 4x, and 8x downsamples that also appear before getting there? Thanks for any insight into this anyone can provide. Despite using overviews all the time, I've struggled with this for a while and had largely consigned to not understanding it. Best, James
_______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
