Bug report #15679
Raster resampling happens before map canvas rotation
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | Unknown | ||
| Affected QGIS version: | 2.16.3 | 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 #: | 23602 |
Description
If you use QGIS' canvas rotation feature and have raster images in your map, they will look much worse than intended.
It seems like the resampling is done before the rotation. The rotation of course leads to different neighborhood relationships between pixels so the quality degrades. Would it be possible to resample after rotating?
Attached is an example of the same area with Nearest Neighbor resampling as well as Average with 0° and 10° rotation applied. As you can see, the image quality in the 10° Average image looks not very good.
History
#1
Updated by Giovanni Manghi over 7 years ago
- Easy fix? set to No
- Regression? set to No
#2
Updated by Jürgen Fischer over 7 years ago
- Category set to Unknown
#3
Updated by Johannes Kroeger almost 7 years ago
- File no resampling on reprojection.png added
This also affects OTF reprojection as shown in this image. I would update the title if I could.
#4
Updated by Giovanni Manghi almost 6 years 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.