Mismatch in Diff Statistics Between TiTiler cog statistics and QGIS Raster Statistics

[ap-rottengrapes]

I’m seeing different Diff Statistics values when running cog statistics in TiTiler compared to Raster Layer Statistics in QGIS.
Why are the results different, and which one should be considered correct?

[vincentsarago]

Because it's not from the same data! if you're COG has overviews, titiler will use one of them to get the statistics while if loaded in QGIS, it will use the full resolution data.

you can try with the max_size=0 option in the statistics endpoint force using the full resolution data, but if the COG is huge you might blow up your service

cogeotiff/rio-tiler#788