COG Image disappears when zoomed out to world extent

[raster-blaster]

When viewing a COG in Titiler using the /cog/viewer, I noticed that the image is visible at a lower zoom level but disappears as I zoom out further. The same behaviour occurs in our front-end application. However, in QGIS, the COG image remains visible even when zoomed out to the world extent. I would appreciate any guidance on how to ensure the COG image stays visible when zoomed out. Thank you for your assistance.

When zoomed in, Image displays

When zoomed out, Image disappears

[vincentsarago]

when using titiler, we assume a dataset has a minzoom and a maxzoom (for a given TileMatrixSet). The minzoom is calculated in rio-tiler (https://github.com/cogeotiff/rio-tiler/blob/main/rio_tiler/io/rasterio.py#L168-L188) as the resolution of the smallest overview (theoretical). Beyond this minzoom, reading a COG might be pretty inefficient (ref: cogeotiff/rio-tiler#348) but you can force this in your application by ignoring the minzoom returned by the tilejson endpoint or by overwriting the dataset minzoom (using query parameters https://developmentseed.org/titiler/endpoints/cog/#tilesjson)