Question

Performance ECW reader

  • 23 March 2021
  • 6 replies
  • 24 views

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I'm trying to read a (big?) ecw file (EPSG 28992, 173 Mb) using FME 2020.1.0.1.

This is very slow (> 10 minutes), QGIS displays the same file in a matter of seconds. I'm wondering if I'm missing some reader parameters that might speed up the process. I do need best resolution though...


6 replies

Userlevel 4
Badge +26

Are you viewing the file in the data inspector? Check that you don't have a background map turned on. If a background map is on the image will be reprojected to match the background map. But I also find the inspector to be a bit slow when rendering rasters.

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Hi,

Thanks for this suggestion. I also applied this to the background map option in the visual preview, and that does make a difference. I also have the experience that the Data Inspector is slow with rasters, btw.

 

Userlevel 4
Badge +26

Hi,

Thanks for this suggestion. I also applied this to the background map option in the visual preview, and that does make a difference. I also have the experience that the Data Inspector is slow with rasters, btw.

 

I have also found the 3D view to be a little faster with rasters because there is no background map loaded. Perhaps it's worth submitting this file to Safe Software via a support case. Ask the support team why it's faster in QGIS and not the DataInspector. It would be great to know why here

Userlevel 1
Badge +10

Hi @r_huesken​. Can you confirm if you are experiencing slow performance with only viewing the ECW in the Data Inspector or Visual Preview, or is it taking >10mins to actually read the data into a workspace using the ER Mapper ECW Reader? If so, would you be able to share your log file and possibly your ECW dataset? This should help our team investigate this further. The log should hopefully tell us:

  • Is it ECW v2 or v3?
  • is there reprojection occurring?
  • are there warnings in the logfile?

Experimenting with the cache size might also be an option:

2021-03-29_12-55-04 

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Hi @r_huesken​. Can you confirm if you are experiencing slow performance with only viewing the ECW in the Data Inspector or Visual Preview, or is it taking >10mins to actually read the data into a workspace using the ER Mapper ECW Reader? If so, would you be able to share your log file and possibly your ECW dataset? This should help our team investigate this further. The log should hopefully tell us:

  • Is it ECW v2 or v3?
  • is there reprojection occurring?
  • are there warnings in the logfile?

Experimenting with the cache size might also be an option:

2021-03-29_12-55-04 

Hi,

Sorry for the late reply, I don't log in here everyday... The performance issues arise when having an inspector attached to the workflow. Writing to the FFS file taking a large amount of time...

Recently, I have learned to disable feature caching when rasters are involved, that also helps a lot.

Please find attached my logfile.

 

Kind regards,

 

Richard.

 

Badge +3

Turn off Feature Caching.  I’ve faced the same frustration, it’s unbelievable the difference between the two.  

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