[gdal-dev] gdalwarp and gdaladdo in multi-threaded mode

Hi, I noticed that in GDAL >2.0 some utilities and operations support multi-threaded calculations, such as the gdalwarp utility. I tested it and it seems to work well. I can see that multiple CPU cores are busy. Question 1: in gdalwarp there are at least two ways to tell that it should use more

[gdal-dev] Reprojecting orthoimages and transparent borders

Hi, When reprojecting RGB orthoimages with gdalwarp from one projection system into another, there is often rotation involved and thus there will be black pixels around the borders. My target format is TIFF with JPEG compression. Is there a way to tell gdalwarp to set these nodata pixels transp

[gdal-dev] gdalwarp and the -wm switch

Hi, I wonder if there are any recommendations regarding the -wm _memory_in_mb setting._ Should I use this setting or just ignore it? My machines usually have plenty of RAM. Do I have to increase this value if I want to utilize the available RAM or is this done automatically and this settings

[gdal-dev] Save Vector Layer in QGIS through OGR with Value Relations

Hi, Our users frequently ask for Spreadsheet export (xlsx, ods). This works well with GDAL 2.x. However, we have the problem with value relations. For a traditional value relation, in the main table we use integer codes, while the textual values are in a linked table. In QGIS this is nicely rep

Re: [gdal-dev] [Qgis-developer] Save Vector Layer in QGIS through OGR with Value Relations

? Thanks, Andreas On 2016-04-06 14:19, Neumann, Andreas wrote: > Hi, > > Our users frequently ask for Spreadsheet export (xlsx, ods). This works well > with GDAL 2.x. > > However, we have the problem with value relations. For a traditional value > relation, in

[gdal-dev] Question on TIFF compression alternatives

Hi, I have a question on TIFF compression alternatives. My data of concern is 8bit gray value. Lots of white pixel (>95%), the rest is black pixels (content) and some gray pixels because of antialiasing. I would like to compress to save some storage, but I need a good performance. What is the

Re: [gdal-dev] Question on TIFF compression alternatives

ge - right? Thanks, Andreas On 2016-10-14 12:09, Even Rouault wrote: > Le vendredi 14 octobre 2016 09:45:38, Neumann, Andreas a écrit : > >> Hi, >> >> I have a question on TIFF compression alternatives. >> >> My data of concern is 8bit gray value. Lots of white

[gdal-dev] Antialiasing problem with gdaladdo at edges/nodata sections

Hi, I have Orthoimages where the boundaries aren't rectangular, but they have corners and sometimes even diagonal edges. I noticed, that after creating pyramids/overview with gdaladdo, that I get antialiasing/rendering artefacts that aren't present in the original image at full resolution. See

[gdal-dev] Nodata values in RGB orthoimages (GeoTiff)

Hi, Is there a way to store nodata values in GeoTiffs that don't match an RGB value? I used either white or black as nodata values, but in some rare cases these black or white pixel values do appear as valid data in the image. How can I properly store nodata values in RGB Orthoimages in GeoTiff

[gdal-dev] ogr2ogr - exclude table option?

Hi, I want to convert a whole Postgis schema to a geopackage. This works fine with ogr2ogr -f GPKG av_1700.gpkg PG:'dbname=dbname host=localhost schemas=schemaname' Now - my problem is that the schema contains 64 tables and I want to convert all tables except one table. Is there a trick wi

[gdal-dev] Remove projection information from GeoTiff

Hi, Is there a way to remove the projection information from a GeoTiff file without having to copy the whole file with gdal_translate and use the BASELINE Profile that doesn't write GeoTIFF header? Something along the lines of the gdal_edit -unsetgt option, e.g. an -unsetprj option? Thanks fo

[gdal-dev] Geopackage ogr2ogr append question

Hi, I am, for the first time trying to append additional tables with ogr2ogr to an existing Geopackage file and have questions: ogr2ogr -progress -lco SPATIAL_INDEX=YES -f GPKG av_1700_lv03.gpkg PG:'dbname=publikation host=localhost schemas=av_1700' -sql "SELECT t_id, t_ili_tid, geom_03, bfs_nr

Re: [gdal-dev] Geopackage ogr2ogr append question

Hi Even, Thanks for your reply. My gdal version is 2.0.2 - I can update to a newer version and see if this warning disappears. I meanwhile also figured out that I need to use -nln for proper table names. Thanks also for the information about append vs. update. I'll switch to update then.

Re: [gdal-dev] Geopackage ogr2ogr append question

Hi Even, I upgraded to gdal 2.1.3 and everything works fine regarding the upgrades of the geopackage. I also switched to "-update" as you suggested, as -append is not necessary, since I am creating new tables within an existing gepackage and don't append to existing tables. Thanks a lot, An