[mapserver-users] Raster image performance

[Ian Walberg]

Does anyone have any experience of how to get the best performance out
of raster formats.

We have an application which needs to be able to display a number of
zoom levels and once we get out to whole earth or continent level the
performance is poor. Our assumption is that it is the shrinking of the
images which where is the time if being used up.

The raster files are tifs with external world files, adding overviews
helps a little.

The zoom levels and output resolution can be fixed so if the overviews
match exactly the required image size that look like it would work but
we cannot see how to do this.

So any advice on what are the most efficient file formats to open and
the most efficient  output format.

The application is written in  php mapscript which runs as a service and
not via a browser.

Thanks

Ian