Question

Read part of Cloud Optimised Geotiff (COG)

  • 14 February 2023
  • 5 replies
  • 17 views

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Hi

 

Is it possible to read a portion of a Cloud Optimised GeoTiff using a bounding box?

 

I'm trying to use the GeoTiff reader with the search envelope set but just get an "Error occured during translation" message after the Geotiff is opened.

 

image 

Thanks

 

Tom


5 replies

Userlevel 2
Badge +13

Hello @tomcolley​, yes, FME should be capable of consuming COG datasets. If you specify the extents, it should only return the data you ask for. I have a few questions for you, if you don't mind:

 

  1. What version of FME are you using?
  2. Are you reading from a file or URL?
  3. Are you using a custom coordinate system in the Seach Envelope?

 

Fairly curious, if you were to reproject data to a common projection, does the error persist (LL84, for example)? I wasn't able to reproduce the error, but I used a standard CS. If you're unable to share data here, consider submitting a support case so we can take a closer look. Happy to help, Kailin

 

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Hello @tomcolley​, yes, FME should be capable of consuming COG datasets. If you specify the extents, it should only return the data you ask for. I have a few questions for you, if you don't mind:

 

  1. What version of FME are you using?
  2. Are you reading from a file or URL?
  3. Are you using a custom coordinate system in the Seach Envelope?

 

Fairly curious, if you were to reproject data to a common projection, does the error persist (LL84, for example)? I wasn't able to reproduce the error, but I used a standard CS. If you're unable to share data here, consider submitting a support case so we can take a closer look. Happy to help, Kailin

 

Hi @kailinatsafe​ , thanks for your reply.

 

  1. It's FME 2022.1
  2. I read from a URL (https://dmwproductionblob.blob.core.windows.net/cogs/LiDAR_1m_2020_22_DSM_16bit_COG.tif) originally but have just downloaded and tried it as a local file with the same result.
  3. The coordinate system is OSGB-GPS-2015-OSTN15. Originally I had it set to EPSG:27700 which gave this warning: "NOT changing coordinate system of reader identified by keyword `GEOTIFF_1' from `EPSG:27700' to `OSGB-GPS-2015-OSTN15' -- mapping file setting of `EPSG:27700' overrides coordinate system `OSGB-GPS-2015-OSTN15' read from file".

 

I don't have access to data in a more common projection but it would be really good to see if you get the same issue with my file.

 

Thanks again for your help

Tom

Userlevel 2
Badge +13

Hi @kailinatsafe​ , thanks for your reply.

 

  1. It's FME 2022.1
  2. I read from a URL (https://dmwproductionblob.blob.core.windows.net/cogs/LiDAR_1m_2020_22_DSM_16bit_COG.tif) originally but have just downloaded and tried it as a local file with the same result.
  3. The coordinate system is OSGB-GPS-2015-OSTN15. Originally I had it set to EPSG:27700 which gave this warning: "NOT changing coordinate system of reader identified by keyword `GEOTIFF_1' from `EPSG:27700' to `OSGB-GPS-2015-OSTN15' -- mapping file setting of `EPSG:27700' overrides coordinate system `OSGB-GPS-2015-OSTN15' read from file".

 

I don't have access to data in a more common projection but it would be really good to see if you get the same issue with my file.

 

Thanks again for your help

Tom

Hello @tomcolley​, thanks for your patience. By the way, you're using a standard CS, sorry if I confused you there! I've filed an issue with our development team as FMEENGINE-76657. I've made a note to update this thread when a fix is available. Hope this helps! Kailin.

Userlevel 2
Badge +13

Hello @tomcolley​, I am pleased to announce FMEENGINE-76657 has been resolved in FME 2023.0 b23288+, you can find this version on the Downloads Page. Happy to help, Kailin.

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Hello @tomcolley​, I am pleased to announce FMEENGINE-76657 has been resolved in FME 2023.0 b23288+, you can find this version on the Downloads Page. Happy to help, Kailin.

That's great, thanks for letting me know I'll give it a go and let you know how I get on.​

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