[Gdal-dev] Georeferencing an image using gdalwarp: format of GCPs?

[wqual]

Hi list,
I have several scanned maps that I would like to give real coordinates using 
gdalwarp: after creating a GCS-file (a text file with four columns x_image 
y_image, east_coordinates, north_coordinates), I tried the following command:

wqual at standalone:~$ gdalwarp -t_srs /home/wqual/karte_GCP.txt Input_1.jpg 
output.tif

But the only thing I get is:
ERROR 1: Translating source or target SRS failed:
/home/wqual/karte_GCP.txt

Question therefore: what is the correct format of a GCS-file which can be read 
by gdalwarp? I would be glad to receive any comments on this.

Best regards,
Wolfgang