[gdal-dev] Trouble reprojecting feature that crosses antimeridian

[Alan Snow]

>From what I could tell, you are attempting to re-project a bounding box
across the antimeridian.

Here is one way to handle that (
https://pyproj4.github.io/pyproj/stable/api/transformer.html#pyproj.transformer.Transformer.transform_bounds
):
>>> import shapely.geometry
>>> from pyproj import Transformer
>>> transformer = Transformer.from_crs(32601, 4326, always_xy=True)
>>> def bounding_polygon(left, bottom, right, top):
...     if right < left:
...         return shapely.geometry.MultiPolygon(
...             [
...                 shapely.geometry.box(left, bottom, 180, top),
...                 shapely.geometry.box(-180, bottom, right, top),
...             ]
...         )
...     return shapely.geometry.box(left, bottom, right, top)
...
>>>
shapely.geometry.mapping(bounding_polygon(*transformer.transform_bounds(377120,
7577600, 418080, 7618560)))
{'type': 'MultiPolygon', 'coordinates': [(((180.0, 68.28494231541386),
(180.0, 68.66685731991039), (179.97430985556775, 68.66685731991039),
(179.97430985556775, 68.28494231541386), (180.0, 68.28494231541386)),),
(((-178.98557986959838, 68.28494231541386), (-178.98557986959838,
68.66685731991039), (-180.0, 68.66685731991039), (-180.0,
68.28494231541386), (-178.98557986959838, 68.28494231541386)),)]}

Alternatively, you could use rasterio.warp.transform_bounds (rasterio 1.3+
and GDAL 3.4+).
https://github.com/rasterio/rasterio/issues/2313


On Tue, Mar 29, 2022 at 3:30 PM Robin Wilson <robin at rtwilson.com> wrote:

> Hi,
>
> I’ve been running into problems creating STAC items for images that cross
> the antimeridian. The geometries for the images are coming out as spanning
> the width of the whole world (from -180 to +180 degrees). With the help of
> the author of the tool I was using to create the STAC items (rio-stac),
> I’ve narrowed it down to a simple test case of reprojecting geometries
> (which is what the tool is doing internally).
>
> If you put the following GeoJSON for an antimeridian-crossing polygon
> in WGS 84 / UTM zone 1N in a file called test_32601.geojson:
>
> ```
>
> {"type":"Polygon","coordinates":[[[377120,7577600],[418080,7577600],[418080,7618560],[377120,7618560],[377120,7577600]]]}
> ```
>
> and then run the following:
>
> ```
> ogr2ogr -f GeoJSON -s_srs epsg:32601 -t_srs epsg:4326 out_4326.geojson
> test_32601.geojson
> ```
>
> The contents of the output file will be:
>
> ```
> { "type": "Polygon", "coordinates": [ [ [ -179.018099960087909,
> 68.666857319910392 ], [ -178.985579869598382, 68.299719485120988 ], [
> -179.976982644969041, 68.284942315413858 ], [ 179.974309855567753,
> 68.651801088224246 ], [ 180.0, 68.652259945574556 ], [ 180.0,
> 68.652259945541758 ], [ 180.0, 68.652259944541754 ], [ -180.0,
> 68.652259944541754 ], [ -180.0, 68.652259945541758 ], [ -180.0,
> 68.652259945610126 ], [ -179.018099960087909, 68.666857319910392 ] ] ] }
> ```
>
> In that output geometry there are longitudes of 180 and -180, so when
> plotted on a map it spans the whole width of the world.
>
> The author of the rio-stac library did a PR to try and fix this problem (
> https://github.com/developmentseed/rio-stac/pull/30), but it doesn’t seem
> to have fixed it for this example, as the underlying GDAL code used by his
> library (through rasterio, I believe) is giving this result.
>
> I find this result unexpected, but I have no knowledge of how GDAL deals
> with the antimeridian. Is this to be expected, or is this potentially a
> bug? If it isn’t a bug, is there any way around this?
>
> Best regards,
>
> Robin
>
> Dr Robin Wilson
> www.rtwilson.com
>
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>


-- 
Alan Snow
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