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I read and I read opinions and topics regarding this tool but I am still unclear if I should us this or not.

In my project I have thousands off tiff files which need to be put on a map. The problem is that while creating the tiles (map tiles) it runs really slow, especially when it needs to put a lot of tiffs on a tile..

I heard that gdaladdo can speed this up but I am unsure if this could affect the quality of the tiff files and/or any other side effects.

Unfortunately, I do not have a backup for the files and while I was testing this on a few bunch of files, the only thing I saw was the increase in size for each of the files.

If anyone had positive (and especially negative) experiences using this tool, I would appreciate an example, advice or anything you think can help.

Many thanks,

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up vote 1 down vote accepted

gdaladdo builds overviews internally by default. That is why you have seen the increased file size. You can build external overview by specifying:

gdaladdo -ro ...

This will build external overviews:

As far as benefits, it depends on the application. If the application uses gdal, then it is built in (for some drivers) to automatically use the overviews to speed up raster input/output. See the docs here:

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