Bug report #16324

RGB palettes are dropped on export

Added by Mira Ressel over 3 years ago. Updated over 1 year ago.

Status:Closed
Priority:Low
Assignee:-
Category:Rasters
Affected QGIS version:2.18.4 Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:end of life
Crashes QGIS or corrupts data:No Copied to github as #:24234

Description

When GeoTiff rasters using an RGB palette encoding are exported using "Layer -> Save as", the palette metadata is omitted from the exported file.

Steps to reproduce:
  • Load the attached palette_example.tif raster
  • Export is using "Layer -> Save as" (output mode "raw data", format GeoTiff)
  • The exported TIFF will have identical pixel values, but no palette information, so it'll be displayed in "singleband grey" mode.

palette_example.tif (14 KB) Mira Ressel, 2017-03-08 08:50 AM

History

#1 Updated by Giovanni Manghi over 3 years ago

  • Status changed from Open to Feedback

save it using the "rendered image" option, you'll get a RGB raster that then you cna converted to palleted with the "rgb to pct" tool. Sounds fair enough?

#2 Updated by Mira Ressel over 3 years ago

Thanks for the tip. I'll admit this is a low-priority bug with many possible workarounds, but it is nevertheless a bug which should be fixed in the long run.

The gdal command-line utilities handle paletted TIFFs just fine, so it's apparently possible to implement this.

#3 Updated by Giovanni Manghi over 3 years ago

  • Priority changed from Normal to Low
  • Status changed from Feedback to Open

Luis Ressel wrote:

Thanks for the tip. I'll admit this is a low-priority bug with many possible workarounds, but it is nevertheless a bug which should be fixed in the long run.

The gdal command-line utilities handle paletted TIFFs just fine, so it's apparently possible to implement this.

not sure raster "save as" uses gdal at all.

#4 Updated by Mira Ressel over 3 years ago

Giovanni Manghi wrote:

not sure raster "save as" uses gdal at all.

I think so, since the "Save as" dialog offers some GDAL-specific compression settings in the "Create Options" tab.

#5 Updated by Giovanni Manghi over 3 years ago

  • Regression? set to No
  • Easy fix? set to No

#6 Updated by Giovanni Manghi over 1 year ago

  • Resolution set to end of life
  • Status changed from Open to Closed

End of life notice: QGIS 2.18 LTR

Source:
http://blog.qgis.org/2019/03/09/end-of-life-notice-qgis-2-18-ltr/

QGIS 3.4 has recently become our new Long Term Release (LTR) version. This is a major step in our history – a long term release version based on the massive updates, library upgrades and improvements that we carried out in the course of the 2.x to 3x upgrade cycle.

We strongly encourage all users who are currently using QGIS 2.18 LTR as their preferred QGIS release to migrate to QGIS 3.4. This new LTR version will receive regular bugfixes for at least one year. It also includes hundreds of new functions, usability improvements, bugfixes, and other goodies. See the relevant changelogs for a good sampling of all the new features that have gone into version 3.4

Most plugins have been either migrated or incorporated into the core QGIS code base.

We strongly discourage the continued use of QGIS 2.18 LTR as it is now officially unsupported, which means we’ll not provide any bug fix releases for it.

You should also note that we intend to close all bug tickets referring to the now obsolete LTR version. Original reporters will receive a notification of the ticket closure and are encouraged to check whether the issue persists in the new LTR, in which case they should reopen the ticket.

If you would like to better understand the QGIS release roadmap, check out our roadmap page! It outlines the schedule for upcoming releases and will help you plan your deployment of QGIS into an operational environment.

The development of QGIS 3.4 LTR has been made possible by the work of hundreds of volunteers, by the investments of companies, professionals, and administrations, and by continuous donations and financial support from many of you. We sincerely thank you all and encourage you to collaborate and support the project even more, for the long term improvement and sustainability of the QGIS project.

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