[gdal-dev] using gcp's without giving coordinates

[erik]

Hello,

I'm trying to convert a map from OziExplorer Map file fromat to Geotiff.
FOr this i'm using the calibration points in the Map file as Ground Control
Points.

I do the following:

gdal_translate \
-gcp 203 52 529000 4191000 \
-gcp 5174 3096 544000 4182000 \
-gcp 5201 99 544000 4191000 \
-gcp 176 3051 529000 4182000 \
-gcp 1861 1067 534000 4188000 \
-gcp 3517 2081 539000 4185000 \
-gcp 3526 1083 539000 4188000 \
-gcp 1851 2066 534000 4185000 \
-gcp 2844 2742 537000 4183000 \
-a_srs "+proj=utm  +ellps=intl  +k=0.999600  +x_0=500000.0  +y_0=0.0
+zone=30  +units=m
+towgs84=-125.098545,-76.000054,-156.198703,0.0,0.0,-1.129,8.30463103
+no_defs" \
map.bmp \
map.tif

However doing this still gives the maps upper left corner start at 0-0.
I was wondering if there was a way to make gdal infer the correct corners of
the map from the gcp's without specifying them directly.
Or is there another way to achieve this without specifying the coord
corners? (The calibration points are not corner-based)
One solution would be to calculate the corners myself programmatically (from
the pixels), but this would be the least good solution.

Many thanks,
Erik
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