I have a large number of geotiffs (a few thousand), that are in a few different projections. IE EPSG:32628, EPSG:32629, EPSG:32630. I would like to reproject the tiffs to 3857 so they are all in the same projection. I am also serving them out as 3857 so I would save some time not reprojecting on the fly.
If I reproject each file on its own gdal is very fast. However the tiffs do not mosaic together as the reproject leaves lines at the edges.
From the image above you can clearly see where the original tiffs were stitched together.
I have thought about using gdalwarp to create one giant image, but the processing might take days and I will likely end up with a tiff too big to handle.
Is there a way to reproject the individual tiffs but take into account surrounding tiffs when doing the reprojection so I don't end up with blank lines at the edges?