locationtech / locationtech/geotrellis
GeoTrellisRasterSource possible reprojection bug
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bug
- Dominant language
- Scala
- Stars
- 1.4k
- Forks
- 360
- Avg merge
- 6h 57m
- Merged PRs (30d)
- 12
Description
During the geotrellis-server work I notcied that WMS produces an incorrect metadata for some certain layers:
val rs = RasterSource("gt+s3://geotrellis-demo/catalog/napl?layer=markham&zoom=18&band_count=1")
val rr = rs.reproject(LatLng)
val expected = ReprojectRasterExtent(rs.gridExtent, rs.crs, LatLng, Options.DEFAULT)
rr.extent shouldBe expected.extent
// actual: Extent(-79.40248489379884, 43.81618476019972, -79.15603855282134, 43.943257696006555) was not equal to
// expected: Extent(-79.42689299583435, 43.78121880534035, -79.13940902524496, 43.95686961703119)
The difference is pretty signifcant for WMS visualisation. The temporary workaround for WMS services would be applied.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the RasterSource.reproject(LatLng) path and compare its extent with ReprojectRasterExtent(rs.gridExtent, rs.crs, LatLng, Options.DEFAULT) using the supplied S3 catalog example. Run or add a focused regression test around the shown extent mismatch; done means the reprojection metadata matches the expected extent and WMS visualization no longer needs the workaround.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- scala
- Domain
- data, web-dev
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100