Open-EO / openeo-udf

The OpenEO UDF Python reference implementation and interface description
https://open-eo.github.io/openeo-udf/
Apache License 2.0
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Axis direction of data models #13

Open flahn opened 5 years ago

flahn commented 5 years ago

Normally the direction of the dimension values in combination with a reference system should not be a problem. But I stumbled on a potential issue regarding the y-axis (North-South axis) of the spatial dimensions of the incoming and outgoing data. In the Real-World the coordinates are intended to have a right-handed coordinate system meaning the axis are running South->North and West->East coordinate wise. The image coordinate systems inverts this order by accessing pixels from top -> bottom in the corresponding y-axis. I wonder which one do I have to assume here? It would make sense if it would be South->North to align with the assigned projection.

Anyway, it should be the same when a back-end prepares data to send to the UDF and we should expect the same behavior throughout different UDF implementations.