Because this is not clear in documentation, especially in WMTS driver docs, my question is strictly about this issue to programmers who have already explored this topic.
Regards Michal W dniu śr., 29.05.2024 o 10:04 Rahkonen Jukka < jukka.rahko...@maanmittauslaitos.fi> napisał(a): > Hi, > > > > No, I am not sure because I do not program myself. Reading this document > https://gdal.org/user/multithreading.html makes me feel that it is > possible to do some things in parallel, but the programmer must know how to > do it right. > > > > -Jukka Rahkonen- > > > > *Lähettäjä:* Javier Jimenez Shaw <j...@jimenezshaw.com> > *Lähetetty:* keskiviikko 29. toukokuuta 2024 10.41 > *Vastaanottaja:* Rahkonen Jukka <jukka.rahko...@maanmittauslaitos.fi> > *Kopio:* Michał Kowalczuk <michkowalc...@gmail.com>; > gdal-dev@lists.osgeo.org > *Aihe:* Re: [gdal-dev] GDAL WMTS get tiles no documentation > > > > > > > > On Wed, 29 May 2024 at 08:59, Rahkonen Jukka via gdal-dev < > gdal-dev@lists.osgeo.org> wrote: > > Hi, > > > > When you have a RasterBand from the WMTS data source, it is abstracted > and you can read the raster data just like from any other data source and > raster band > https://gdal.org/tutorials/raster_api_tut.html#reading-raster-data “There > are a few ways to read raster data, but the most common is via the > GDALRasterBand::RasterIO() method. This method will automatically take care > of data type conversion, up/down sampling and windowing.” GDAL knows which > tiles to read. > > > > I do not know if the WMTS driver can do parallel tile downloads. If not, > it is possible to run many RasterIO() at the same time, each reading data > from a different window like in this rasterio document > https://rasterio.readthedocs.io/en/latest/topics/concurrency.html. > > > > Jukka, are you sure you can run several RasterIO in parallel (on the same > dataset)? in GDAL GeoTIFF you cannot: the cache may be corrupted. In that > case I open several datasets over the same file. I do not know about WMTS. > > > > > > -Jukka Rahkonen- > > > > *Lähettäjä:* gdal-dev <gdal-dev-boun...@lists.osgeo.org> *Puolesta *Michal > Kowalczuk via gdal-dev > *Lähetetty:* keskiviikko 29. toukokuuta 2024 9.08 > *Vastaanottaja:* gdal-dev@lists.osgeo.org > *Aihe:* [gdal-dev] GDAL WMTS get tiles no documentation > > > > Hi GDAL fellows > > This is my first post on this mailing list, so I'm asking for > understanding. > > > > As all we know the purpose of using WMTS over WMS, I'd like to implement > parallel downloading tiles from service using C API. > > In my opinion GDAL documentation ( > https://gdal.org/drivers/raster/wmts.html) says nothing on this topic. > > I can get capabilities from WMTS, I can open the selected subdataset but > how to get tiles for given extent? I could not find any information how to > do it, even in the GDAL tests on github. > > > > I am kindly asking for tips. It also can be in python. How using pure GDAL > API fetch tiles to dynamically complete the displayed map. This is my goal. > > > > Thank you! > > Michal > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev > >
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