Can you share the output of gdalinfo of your original file?
karsten <kars...@terragis.net> escreveu no dia sábado, 13/06/2020 à(s) 00:13: > Hi Pedro, > > using your suggestion I came up with this command : > > gdal_translate -co COMPRESS=DEFLATE -co PREDICTOR=2 -co ZLEVEL=9 -ot Byte > -of GTiff -tr 1.0 -1.0 -a_nodata 0 input.tif output.tif > > and got the 5GB file cut result raster from before down to 43 MB ! > > Thanks > Karsten > ------------------------------ > *From:* Pedro Venâncio [mailto:pedrongvenan...@gmail.com] > *Sent:* Friday, June 12, 2020 13:19 > *To:* karsten > *Cc:* QGIS User > *Subject:* Re: [Qgis-user] clip raster by mask layer (gdalwarp with > -cutline option) enormously bloats file size > > Hi Karsten, > > First you have to ensure that the output data type is also Byte: > -ot Byte > > Second, your original raster must be some kind of compression. You can see > it with gdalinfo. So, you need to apply compression to the output file, for > instance with: > > -co COMPRESS=DEFLATE -co PREDICTOR=2 -co ZLEVEL=9 > > > Best regards, > > Pedro Venâncio > > > > karsten <kars...@terragis.net> escreveu no dia sexta, 12/06/2020 à(s) > 21:09: > >> Hi All, >> >> I have a large *.tif raster data set ( 92000 * 69000 cells of one meter, >> projection EPSG:25832 - ETRS89 / UTM zone 32N ) >> It contains integer values 1 to 20 and has a file size of about 100 MB >> in "Byte - Eight bit unsigned integer" format. >> Now the result is a rectangle and I wanted to cut it down to the area of >> interest (via cutline gdal option) using a shape polygon file (with one >> continuous polygon inside) to and set all values outside the area of >> interest of that rectangle to NULL values (for example setting 0 as NULL >> data values). I used the QGIS ( QGIS v 3.12 on windows) Menu RASTER > >> Extraction > Clip Raster by mask Layer which is based on gdalwarp. >> That is when I am running into the problem that the 'cut' file size >> increases enormously and I ended up wit 50 times bigger file ( 5 GB size >> ! ) when I was actually expecting a smaller file size than before. >> I have not really an idea why the file becomes so enormously bloated. The >> same is the cass when I try gdalwarp directly on the command line or when >> using the QGIS Raster calculator or any other method I tried so far. >> >> How can I manage to get a smaller file size ( aka the 100 MB file size I >> started of with ) and which tools or formats are recommended to achieve >> this ? >> Cheers >> Karsten >> >> Karsten Vennemann >> www.terragis.net >> >> _______________________________________________ >> 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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