Mapfile Extent

[Frank Warmerdam]

On 9/26/05, Oliver Ishmael <oliver_ishmael at hotmail.com> wrote:
> Dear all,
>
> I'm still a bit of a noob to all this, but have the following problem:
>
> I am trying modify the Gmap demo to form a template i can work with.
> Currently it views a .tif (USA) and i would like it to view a .tif (UK) with
> additional associated layers.
>
> How do i work out the extents of my new layer (UK .tif)?

Oliver,

If you have a TIFF file there are various external-to-mapserver
utilities you can use to get the extents.  I would suggest gdalinfo
if you already have that or can easily get it (ie. s part of FWTools
at http://fwtools.maptools.org/)

> ..and ensure that i do not just see a dot at the centre of the screen which
> requires me to multi-zoom before it is visible and informative?
> (min manx-scale - how do i know??)

If you set the default extents to the extents for your image you
should be fine.  I usually start by setting MINSCALE to 0 and
MAXSCALE to 10000000.  You can always assign more reasonable
limits later once you have the basics working.

Good luck,
--
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