Ticket #778 (closed bug: fixed)

Opened 6 years ago

Last modified 4 years ago

Displaying raster images extremely slow

Reported by: cdavila Owned by: homann
Priority: critical: causes crash or data corruption Milestone:
Component: Rasters Version: Trunk
Keywords: Cc: cdavilam@…, msieczka, warmerdam
Platform Version: testing Platform: Debian
Must Fix for Release: Yes Awaiting user input: yes

Description

After updating from 0.8.1 to 0.9 ecw rester images that before were displayed at once now take very long time: 4 images of 9 MB each one take about 8 minutes and images of about 700 MB don't display after one hour. More information can be found here:  http://forum.qgis.org/viewtopic.php?t=461 Reproduced in two machines with debian-testing and reported by other user in windows XP

Attachments

diff_7951_vs_7952 Download (2.5 KB) - added by cdavilam 5 years ago.
Diff between revisions 7951 and 7952

Change History

Changed 6 years ago by cdavila

  • cc cdavilam@… added
  • platform_version changed from testting to testing

I have just replace 0.9.0 package with 0.9~svn20071023-1 from debian.gfoss.it and the problem has disappeared.

Changed 5 years ago by homann

  • owner changed from nobody to homann
  • status changed from new to assigned
  • status_info set

Let's check with 0.9.1 when it is released.

Changed 5 years ago by homann

0.9.1 is now released. I believe this error has disappeared. Can you check?

Changed 5 years ago by cdavila

I'm still not using definitive 0.9.1, but 0.9.1~pre20071219 from debian.gfoss.it, but problem has certainly disappeared, so I think bug can be closed if no one has same problem.

Changed 5 years ago by homann

  • status changed from assigned to closed
  • resolution set to fixed

I also noted slow performance on 0.9.0, but not anymore.

Changed 5 years ago by cdavila

  • status changed from closed to reopened
  • resolution fixed deleted

I'm having the same problem again. Tested with versions r7994, r8009 and r8022 and in two different machines. Not with 0.9.1 packages.

Changed 5 years ago by cdavilam

The problem persists in r8223. Now a bug squashing is being planned, I would really appreciate if this bug is resolved, as I need to use ecw rasters in my daily work and it's really annoying to wait so much time each time I move map canvas, having to use other programs too often.

Changed 5 years ago by msieczka

  • cc msieczka added

I'm not sure if this is relevant, but in general QGIS is very slow displaying tiled GeoTIFFs. Stripped GeoTIFFs display about 10 (ten) times faster.

Stripped GeoTIFF can be created with: 

gdal_translate -co "TILED=NO"

and a tiled one with: 

gdal_translate -co "TILED=YES"

Changed 5 years ago by cdavilam

Diff between revisions 7951 and 7952

Changed 5 years ago by cdavilam

After some investigation compiling various revisions, I have found this bug was introduced in r7952. I have attached diff between revisions 7951 and 7952. Log for r7952 is:

r7952 | ersts | 2008-01-14 04:48:11 +0100 (lun, 14 ene 2008) | 1 line

-Set default contrast enhancement to STRETCH_TO_MIN_MAX

Changed 5 years ago by warmerdam

  • cc warmerdam added

Changed 5 years ago by ersts

  • status changed from reopened to closed
  • resolution set to fixed

There is now an ability to set the default contrast enhancement that will remain persistent between sessions, which resolves this problem to some extent. If stretching is too slow and not needed, the user can elect not to stretch on initial load.

I think this closes this ticket for QGIS, if there are any upstream issues with GDAL that are also fixed in the future, all the more better.

If this is still not a satisfactory solution, feel free to reopen.

Changed 4 years ago by anonymous

  • milestone Version 0.9.2 deleted

Milestone Version 0.9.2 deleted

Note: See TracTickets for help on using tickets.