[Gdal-dev] Negative values returned by GetRasterYSize()

[Roger James]

Is there a convention for raster orientation in GDAL and if so is it
stated somewhere.

 

I am having some trouble with images that return negative values for
RasterYSize., and could do with some guidance on how to interpret this.

 

I assume that a negative value means that the raster should be
accessed/affined with a bottom up cell (pixel, display etc.) co-ordinate
system? If so I think this should be documented.

 

If it already is then please accept my apologies and tell me where to
look.

 

Is this handled consistently. I am getting images that display the right
way up but when I use the affine co-efficients the y geo co-ordinate is
flipped.

 

I realise that this is a problem in my code but I just cannot seem to
get the correct mapping between the window co-ord system and the image
co-ord system.

 

Thanks.

 

Roger

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