Hello Hannes, Andreas and Ian,
Thank you for the links. They have been really useful for understanding the
overviews/pyramids concept. I'm still experimenting but was able to decrease
the file size.
Thanks,
Arturo
Johannes Kröger (WhereGroup) via QGIS-Developer wrote:
Sorry Arturo,
I totally miss
A good introduction to fast rasters is Paul Ramsey's GeoTiff compression
for dummies blog post -
https://blog.cleverelephant.ca/2015/02/geotiff-compression-for-dummies.html
it takes you through all the steps needed using gdal.
Ian
On Wed, 31 May 2023 at 08:47, Johannes Kröger (WhereGroup) via
QGI
Sorry Arturo,
I totally missed that Martin had already recommended it and that you
said you didn't know about it. I didn't mean to come across pushy or
anything :))
Andreas' links are great to see how to create them. Here is a nice post
that explains the concept:
https://developers.planet.c
Hi,
See
https://docs.qgis.org/3.28/en/docs/user_manual/working_with_raster/raster_properties.html#pyramids-properties
(for a QGIS based solution)
or https://gdal.org/programs/gdaladdo.html (for a command line or python
version).
Andreas
On Tue, 30 May 2023 at 16:00, afernandez via QGIS-Developer
Hello Hannes,
Sorry to say that I'm at a loss here. I had not previously heard of 'overviews'
and am having a hard time finding much information. I couldn't find anything in
the PyQGIS (v3.28) developer cookbook, which is my main reference in this QGIS
journey. The found information is at
https
Hi Arturo,
make sure you create overviews on your big rasters or QGIS will re-read
the whole file all the time to render an appropriate representation in
the map.
Cheers, Hannes
Am 30.05.23 um 04:35 schrieb afernandez via QGIS-Developer:
Hello Martin,
I'm trying to understand what you're sa
Hello Martin,
I'm trying to understand what you're saying but my background is in numerical
methods where tasks are split into threads for acceleration purposes. If a
single layer is rendered by a single core (as you write and I was observing),
how would a 1,000 x 1,000 (or a 5,000 x 5,000) laye
Hi
On Fri, May 26, 2023 at 11:30 PM afernandez via QGIS-Developer <
qgis-developer@lists.osgeo.org> wrote:
> Hello,
> One of my project would greatly benefit from a much faster rendering.
> After some testing, the bulk (>99%) of the time is spent at rendering the
> layer with QgsRasterLayer(...,.
Hello,
One of my project would greatly benefit from a much faster rendering. After
some testing, the bulk (>99%) of the time is spent at rendering the layer
with QgsRasterLayer(...,...). What I have also noticed is that rendering
time does not change with the number of cores, which suggests that t
