[Mapserver-users] Converting from png to geotiff with gdal

[Pyro-X]

Hi all

     I want to include into mapserver a new layer based on a collection 
of raster files i have in PNG format, i know the extents values for each 
image ( they are named as this: mad_441600-4478928_442581-4479909.png ), 
it seems i need to convert them to tiff (or geotiff?) format so i can 
include them in my project and then make an index from them, but i can't 
just get along the first step.

    I've tried using gdal utilities to convert them from png to a tiff 
with the geometry information using this:

gdalwarp -s_srs EPSG:23030 -t_srs EPSG:23030 -te 444544 4481872 445525 
4482853 mad_444544-4481872_445525-4482853.png test.tiff

But instead of a brand new tiff image this is what i get :

ERROR 1: Unable to compute a transformation between pixel/line
and georeferenced coordinates for mad_444544-4481872_445525-4482853.png.
There is no affine transformation and no GCPs.


I've tried to find more info about this with no luck, i think it have to 
be easy but i can't get it....  Any help will be greatly appreciated. :)



Many Thanx in advance.

--
David Monterroso Cabello