[gdal-dev] ogr2ogr -tps with more than 1000 control points

[Jan Hartmann]

Thanks Even. GDAL was built with Armadillo, so I'm going to test the 
GCP's. Just wanted to be sure there was no possibility of a buffer 
overflow, or something like that. The program should be able to handle 
an unlimited number of control points, right?

On 8/9/2019 5:59 PM, Even Rouault wrote:
> On vendredi 9 août 2019 13:31:57 CEST Jan Hartmann wrote:
>> Hi all,
>>
>> I'm converting large historical vector maps with ogr2ogr, using -gcp and
>> -tps to rubbersheet the polygons with control points. Works fine up to
>> about a thousand control points, each in the form of "-gcp fromx fromy
>> tox toy". After that, the converted map becomes erratic. Is this a bug?
> Two hypothesis:
> - the extra GCP you're adding are wrong
> - there's numerical instability in the matrix computations with the extra GCP.
> If your GDAL build doesn't use libarmadillo, then consider rebuilding against
> it, as it might improve numeric stability.
>
> Even
>