QGIS Rel. 2.18 had a way to quickly and easily reduce the resolution/size of an Orthomosaic. _ Raster-Conversion-Translate _, then _ Outsize _. However I just updated to QGIS Rel. 3.6 and I cannot find the command. Does anyone know where it went, or an alternate method?
In QGIS 3.6, I would suggest you use the tool Warp , which can be found in: Raster >Projections >Warp (Reproject). The output resolution has to be written in the Output file resolution in target georeferenced units. Of course, you can keep the same coordinate system. In order to check the result, overlap both images (before and after resampling) and check the Height and Width values, they should be changed.
Hope this helps.
Thanks Teodora. That method is definitely more complicated than “Outsize”. I have tried several times unsuccessfully. I am probably doing something incorrect, and I will continue trying. Or I may revert back to the old Release 2.18, as it was a very easy task. But thank you for your quick response. -Matt
There is an alternative in QGIS 3.6: on the left side, go to your raster layer and left click on it > Export > click Save As > you can adjust your resolution value in the Resolution tab.
Hopefully it worked this time.
All the best,
Thanks Teodora. I gave that a shot, but it is not very straight-forward either. I much preferred the “Outsize” at say 25% or 50%, etc. I realize that QGIS is not your responsibility, so thank you for your help.
I have also been working with QGIS for a long time and it can be indeed annoying when functions change. As an alternative, I would also recommend the open source GDAL command line tools, they are quite stable and fast: https://gdal.org/programs/index.html#
It takes some time to get used to the syntax, but it will be worth the effort :)
I second that!
I am getting the hang of it. Once I figured out that the “resolution” shown, is the image resolution in decimal feet. It also took some trial-and-error to realize that I needed to change the Output Mode at the top to “Rendered Image”. It defaults to “Raw Data”. Thanks again Teodora. I may also look at using the command line tools.