[Gdal-dev] NITF ICHIPB Extension?

[William Lyons]

Frank,

>However, I notice the GDALRPCInfo structure (and corresponding
>metadata) have fields named dfLINE_OFF, dfSAMP_OFF, dfLINE_SCALE
>and dfSAMP_SCALE.  I think it would be much easier to just adjust these
>if the change is just a non-rotated windowing. 

I agree.  But, the chips I'm working with are rotated.  Which leads me
to another question about the geo-transform.  I'm assuming that the
values at indices 2 and 4 are how I would define a rotation.  My
assumption is that the value at index 2 is a ratio of change in x as
line increases and the value at index 4 is a ratio of change in y as
pixel increases.  Please tell me I'm wrong and there's an easier way so
I don't have to calculate these for a rotated chip.

Thanks,

William Lyons