[Gdal-dev] Problems with warping

[Joaquim Luis]

Hugo Martins wrote:
> Well i have been experiencing some problems with gdalwarp. I 
> downloaded some imagery in jpg format. After i converted it to tif and 
> no problem happened. These images are in Lisboa Hayford Gauss IgeoE 
> projection and i need to reproject them to WGS84. Here are the 
> gdalinfo from both files:

Hugo,
You didn't say how the reprojection to WGS84 was done but you need to 
take into account the datum change.

Here is a proj4 string that permits to recover exactly the same results 
as provided by the IgeoE coordinate conversions page.

+proj=tmerc +lat_0=39.66666666666666 +lon_0=-8.131906111111111 +k=1.0 
+x_0=200000 +y_0=300000 +ellps=intl 
+towgs84=-302.581,-61.360,103.047,0,0,0,0


Joaquim Luis