Alberto, I found that by clicking on “Style > Save as Default” in the “Symbology” tab it will store the symbology in the geopackage.
On Wed, Dec 2, 2020 at 10:11 AM Alberto Vavassori < alberto.vavass...@polimi.it> wrote: > Hi Kirk, > > I tried with another raster file that represents a temperature > distribution (continuous values). In this case, when I import it into the > Geopackage, I see the same issue that you have just described: minimum and > maximum values in the legend change, but it seems that the actual values > remain unchanged, thus correct. Unfortunately this is not the case of the > land cover raster (discrete set of values) that I have shared with you: in > this case, the raster characteristics change, as we have all noticed. > > Just another question, hoping that you might have an answer: is it > possible to store the symbology of a raster file inside the Geopackage? I > know that it is possible for vector data, by clicking on “Style > Save > style” in the “Symbology” tab. But I cannot find a way to save the > symbology in case of raster files. > > Thanks a lot. > > Alberto > > > > *Da:* Qgis-user <qgis-user-boun...@lists.osgeo.org> * Per conto di *Kirk > Schmidt > *Inviato:* mercoledì 2 dicembre 2020 16:00 > *A:* Nicolas Cadieux <njacadieux.git...@gmail.com>; > qgis-user@lists.osgeo.org > *Oggetto:* Re: [Qgis-user] R: Importing a raster into a Geopackage > > > > Hi all: > > I ran the r.stats to get a list of each pixel value on my test data (A > small DEM) before and after conversion to a geopackage (see second image > below). The values and summary stats are identical for the two rasters but > the default legend entry has a different min and maximum value. So, I can > conclude that the data is being written correctly but the default display > parameters for the geopackage are different than a geotiff. > > Kirk > > > > On 12/1/2020 3:24 PM, Nicolas Cadieux wrote: > > Hi, > > I changed the link so you have access to more files. > > > https://drive.google.com/drive/folders/1fMl9odowUFFRQFK61rTxgHeom_D8ymN6?usp=sharing > > Nicolas > > On 2020-12-01 1:58 p.m., Kirk Schmidt wrote: > > Hi Nicolas > > I did the same and the legend indicates a change magnitude but if I > subtract the geopackage raster from the original, all pixels equal zero. > > Kirk > > On 12/1/2020 2:36 PM, Nicolas Cadieux wrote: > > Hi, > > Tried this: > > gdal_translate -of GPKG -b 1 > C:/Users/Nicolas/Desktop/Land_cover_Corine2018.tif > C:/Users/Nicolas/Desktop/test.gpkg > > I read 4 band and still get data modifications. > > Nicolas > > On 2020-12-01 1:28 p.m., Kirk Schmidt wrote: > > Hi Nicolas: > > try the -b 1 parameter. I just tried this and wrote a single band raster > from a 3 channel tiff. > > Kirk > > On 12/1/2020 2:03 PM, Nicolas Cadieux wrote: > > I tried > > gdal_translate -of GPKG -co "BAND_COUNT=1" > C:/Users/Nicolas/Desktop/Land_cover_Corine2018.tif > C:/Users/Nicolas/Desktop/TEST.gpkg for the creation and > > C:\>gdal_translate -of GPKG -co "TILE_FORMAT = TIFF" > C:/Users/Nicolas/Desktop/Land_cover_Corine2018.tif > C:/Users/Nicolas/Desktop/TEST.gpkg > > Same problem. I wonder if we need to change the reading options... > https://gdal.org/drivers/raster/gpkg.html > "Opening options > > By default, the driver will expose a GeoPackage dataset as a four band > (Red,Green, Blue,Alpha) dataset, which gives the maximum compatibility with > the various encodings of tiles that can be stored. It is possible to > specify an explicit number of bands with the BAND_COUNT opening option." > > The problem could be when QGIS Reads the file, not when it writes the > file. I explains why we see 4 bands but not why values are changing. I > would make a bug report or ask the question on the gdal dev group to get > Even Rouault's attention. > > Nicolas > > > > On 2020-12-01 12:17 p.m., Sebastian Gutwein wrote: > > This looks like the same issue you are having. > github.com/qgis/QGIS/issues/38227 > > According to the documentation linked in the issue you need to set the > band count to 1 otherwise it defaults to 4. > > gdal.org/drivers/raster/gpkg.html > > I have not tried this to see if it works. > > > > On Tue, Dec 1, 2020 at 11:52 AM Nicolas Cadieux < > njacadieux.git...@gmail.com> wrote: > > Hi, > > Looking at it now. I see what you see. I will try a few things. > > Nicolas > > On 2020-12-01 11:42 a.m., Alberto Vavassori wrote: > > Hi Nicolas, > > thank you for the answer. I send the raster that I am interested in. > > Alberto > > > > *Da:* Nicolas Cadieux <njacadieux.git...@gmail.com> > <njacadieux.git...@gmail.com> > *Inviato:* martedì 1 dicembre 2020 17:40 > *A:* Alberto Vavassori <alberto.vavass...@polimi.it> > <alberto.vavass...@polimi.it> > *Cc:* qgis-user@lists.osgeo.org > *Oggetto:* Re: [Qgis-user] Importing a raster into a Geopackage > > > > Hi, > > Send a sample data set if you can't figure it out. > > Nicolas > > On 2020-12-01 10:35 a.m., Nicolas Cadieux wrote: > > Hi, > > Perhaps this can help: https://gdal.orgdrivers/raster/gpkg.html > > > > “Various kind of input datasets can be converted to GeoPackage raster : > > · Single band grey level > > · Single band with R,G,B or R,G,B,A color table > > · Two bands: first band with grey level, second band with alpha > channel > > · Three bands: Red, Green, Blue > > · Four band: Red, Green, Blue, Alpha > > GeoPackage rasters only support Byte data type.” > > My guess is that if the original raster does not correspond to one of the > categories above, it will be converted to the closest format. > > > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > > > Le 1 déc. 2020 à 09:58, Alberto Vavassori <alberto.vavass...@polimi.it> > <alberto.vavass...@polimi.it> a écrit : > > > > Hello everybody. I have an issue regarding the Geopackage format. I have > tried to import a singleband raster file (it represents the land cover, > thus every pixel has a single integer value corresponding to the land cover > class), but this operation seems to modify the raster characteristics: the > raster becomes a 4-bands raster and the pixels values change accordingly > (basically, the original raster is saved in the Geopackage as an RGB > image). It seems to be a bug of QGIS. I have also tried to use GDAL > translate through the processing toolbox of QGIS to convert the TIFF file > to a Geopackage file, but the result is the same. > > Has anybody faced this problem? May anybody suggest a way to work this > problem out? > > Thank you. > > Alberto > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > -- > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Kirk Schmidt, MScF, BScF, RPF > > General Manager > > Nortek Resource Solutions Inc. > > RR # 1 > > Thorburn, NS > > B0K 1W0 > > Tel (902) 922.3607 > > Email: k...@nortekresources.com > > Web: www.nortekresources.com > > > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Kirk Schmidt, MScF, BScF, RPF > > General Manager > > Nortek Resource Solutions Inc. > > RR # 1 > > Thorburn, NS > > B0K 1W0 > > Tel (902) 922.3607 > > Email: k...@nortekresources.com > > Web: www.nortekresources.com > > > > _______________________________________________ > > Qgis-user mailing list > > Qgis-user@lists.osgeo.org > > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > > Nicolas Cadieux > > https://gitlab.com/njacadieux > > -- > > Kirk Schmidt, MScF, BScF, RPF > > General Manager > > Nortek Resource Solutions Inc. > > RR # 1 > > Thorburn, NS > > B0K 1W0 > > Tel (902) 922.3607 > > Email: k...@nortekresources.com > > Web: www.nortekresources.com > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >
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