Support other projection types using proj4js

[annefou]

With QGIS, I can easily add a raster layer with https://pangeo-eosc-minioapi.vm.fedcloud.eu/afouilloux-work/srtm_41_19.tif and it works out of the box. However, it does not seem to work with JupyterGIS.

If I open a QGIS project with such COG, I don't see it on the map and I have the same issue if I try to add such COG as a raster layer in JupyterGIS.

Below is what I see in QGIS:

[martinRenou]

Thanks for the issue! Do you have an error in the console with that specific file?

[annefou]

I don't have any error in the console. By the way, I checked the content of this file more carefully and it is not a COG but a simple geotiff stored online (which is common with small raster files). I generated the COG for the same image and I also got the same issue e.g. I don't see anything but a black screen. The validated COG is https://pangeo-eosc-minioapi.vm.fedcloud.eu/afouilloux-work/srtm_41_19_cog.tif

[gjmooney]

It looks like the tif is loading, just around Strasbourg instead of Cape Town. The huge black square is probably because of how OpenLayers handles nodata values. We should look into making those transparent by default.

[martinRenou]

So the project is probably using a projection we're not supporting yet?

[gjmooney]

Yea it looks like the tif is using EPSG:32733, and OpenLayers only supports EPSG:4326 and EPSG:3857 out of the box

Reference

[martinRenou]

We may want to start looking into using https://github.com/proj4js/proj4js to support other projection types

There is an example here https://openlayers.org/en/latest/examples/wms-image-custom-proj.html using proj4js with OpenLayers

[martinRenou]

Actually let's close this issue in favor of #191, let's continue discussing there