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satellogic / telluric

telluric is a Python library to manage vector and raster geospatial data in an interactive and easy way
MIT License
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Minimum handling of rasters without CRS and avoid meaningless RecursionError #291

Closed marcronq closed 3 years ago

marcronq commented 3 years ago

It is known that GeoRaster2 class is not designed to support non-geographic rasters.

Right now if you try to copy a raster without CRS it raises a RecursionError because it tries to read over and over a None attribute. This can be triggered with the next lines:

import telluric
raster = telluric.GeoRaster2.open(
    "/vsicurl/https://github.com/satellogic/telluric/blob/master/tests/data/raster/no_georef.png?raw=true")
raster_copy = raster.copy_with()
print(raster_copy.crs)

To avoid this exception which is not really informative, I propose to differentiate between a crs not yet read (None) and one already read from file but non-existing or void which can be a rasterio.crs.CRS() instance without init arguments. This empty crs allows upper lines to work.

In the future, if a proper exception wants to be raised with the message that some method is not supported for this kind of rasters, the rasterio.crs.CRS property is_valid can be checked, which for an empty instance returns False.

I can create the PR with the proposal if maintainers think the idea is worth it.