Using polygonize function on a raster doesn't keep the original raster coordinates

[BG-AIMS]

When I use GeometryOps.polygonize() on a raster the resulting polygons do not have the same coordinates as the input raster although the same CRS is attached to the resulting polygon. This is an example with lon/lat to show effect.

using GLMakie, ArchGDAL
using Rasters, GeometryOps, GeoFormatTypes, GeoInterface

lon, lat = X(120:1:150), Y(-40:-1:-60) # Example used for clear difference from polygonize() output
ras = Raster(rand(lon, lat); crs=GeoFormatTypes.EPSG(4326))
plot(ras)

plot(ras .< 0.3)
polygons = GeometryOps.polygonize(x-> x.<0.3, ras[:, end:-1:1]) # Flip reverseordered Y 
poly(polygons)
GeoInterface.coordinates(polygons)

plot(ras .< 0.3) output:

poly(polygons) output:

[asinghvi17]

I can confirm locally...guess our tests for DimensionalData and Rasters were a bit lacking. #200 should fix this but it might take a few days.

Thanks for the bug report!

[asinghvi17]

Specifically this is because (evil is a Raster here)

julia> axes(evil)[1]
DimensionalData.Dimensions.DimUnitRange(Base.OneTo(100), X{Projected{Int64, UnitRange{Int64}, DimensionalData.Dimensions.Lookups.ForwardOrdered, DimensionalData.Dimensions.Lookups.Regular{Int64}, DimensionalData.Dimensions.Lookups.Points, DimensionalData.Dimensions.Lookups.NoMetadata, EPSG{1}, Nothing, X{Colon}}}([-100, -99, -98, -97, -96, -95, -94, -93, -92, -91  …  -10, -9, -8, -7, -6, -5, -4, -3, -2, -1]))

julia> axes(evil)[1] |> collect
100-element Vector{Int64}:
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
   ⋮
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100

(cc @rafaqz - what's the best way to get the actual lookup values generically? Do we need an extension?)

[rafaqz]

I'll have to look at the code... But if you call similar on those axes you get a Raster.

(But there is no generic Base way to get axis lookup values)

[rafaqz]

Also note this is covered in #178 I just need to find time to finish it. (and to even remember that I'm half way through working on that 😅 )