[Gdal-dev] Maximum number of GCP at gdal_translate

[Frank Warmerdam]

Hannes Isaak Reuter wrote:
> Dear Gdal people,
> 
> anyone experience with the maximum number of GCPS one can specify at the 
> commandline ?

Hannes,

In theory there is no practical limit.  In practice you are limited by
whatever the maximum commandline length is on your system (or you can
use the --optfile switch to get some options from a file) and by the
limits on the number of gcps that will fit in a GeoTIFF tag if you are
copying to geotiff.  I think geotiff will allow only something like
1000 gcps (64K / 48 bytes per gcp).

So, if you really want to have a lot of gcps, use --optfile to read them
from a file, and use an output format with no limit, like VRT.

Best regards,
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