Question

What is the most convenient approach for reading XYZ raster tiles in FME Desktop?

  • 23 February 2023
  • 3 replies
  • 29 views

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If I am not mistaken there is no direct FME reader for XYZ tiles in FME Desktop. Do you see a convenient method for reading raster data being served via an api looking like http://<url>/{z}/{x}/{y}.png ?

I need to read such data on the fly. These are Terrain RGB files which I need to convert into some GeoTIFF DEM format for different resolutions.

What are possible workarounds or solutions? Could a HTTPCaller help in this case?

Thanks!


3 replies

Userlevel 2
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Hi @olivier​,

I think the ImageFetcher transformer would be the best to download images from URLs, since it can auto-detect the image type. It is quite a bit simpler than the HTTPCaller to use.

Most of FME's file based readers can read from URLs as well, so you could also use a FeatureReader transformer with the PNG format.

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Hi @daveatsafe​ ,

Thanks for your reply and suggestion. I have now also tried the ImageFetcher but I keep getting time-outs for all services. That being said I don't think the problem is a real time-out because setting the time-out parameters to 0. Furthermore all services work well from QGIS (without time-outs). Just to be clear I am trying to read from the following type of web map service: https://docs.qgis.org/3.22/en/docs/user_manual/managing_data_source/opening_data.html#using-xyz-tile-services

Indeed everything on our end is served via this protocol.

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Quick update: I noticed a bit late that the Windows virtual machine I was trying to do this from had network/firewall settings making it impossible to reach such web services. I tried this on my own personal machine and it worked like a charm. Thank you!

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