Hi Andreas: It is solved: you have to reproject your TEMP layer. I've tried with UTM-32N zone and raster calculator works fine.
Why raster calculator (and SAGA) doesn't work with your original CRS? Well, I don't know, perhaps devs group have the answer. It was a good challenge. Carlos 2014-11-18 4:37 GMT-05:00 Andreas Neumann <[email protected]>: > Hi Carlos, > > Thank you for your help! > > I tried with > > (TEMP@1=249)*255 + (TEMP@1<249)*TEMP@1 + (TEMP@1>249)*TEMP@1 > > My layer is called "temp". However, the resulting file contains all 0. > > I tried in both QGIS 2.4 and 2.6. > > Is there something wrong with the input file? It was generated from a PDF > with ghostscript. Here is the metadata: > > ----- > > GDAL provider > GTiff > GeoTIFF > Datensatzbeschreibung > //gis/gis/mapserverdata/uep/release_2014_11/temp.tif > TIFFTAG_DATETIME=2014:11:17 09:50:08 > TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch) > TIFFTAG_SOFTWARE=GPL Ghostscript 9.10 > TIFFTAG_XRESOLUTION=600 > TIFFTAG_YRESOLUTION=600 > Kanal 1 > STATISTICS_MAXIMUM=255 > STATISTICS_MEAN=247.18714741724 > STATISTICS_MINIMUM=0 > STATISTICS_STDDEV=37.198102288306 > Dimensionen > X: 71575 Y: 70867 Kanäle: 1 > Leerwert > *Leerwert nicht gesetzt* > Datentyp > Byte - Acht Bit vorzeichenlose Ganzzahl > Pyramidenübersichten > Räumliches Bezugssystem des Layers > +proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 > +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 > +units=m +no_defs > Layerausdehnung (in urspünglicher Projektion des Layers) > 0.0000000000000000,-70867.0000000000000000 : 71575.0000000000000000,0. > 0000000000000000 > Kanal > Kanal 1 > Kanal Nr > 1 > Keine Statistik > Noch keine Statistik gesammelt > > ------------ > > Thanks again if you have any idea what may be wrong with my file or the > above listed raster calc statement. > > Andreas > > > > Am 2014-11-17 18:38, schrieb Carlos Cerdán: > >> Hi Andreas: >> >> I think QGIS raster calculator can make this job. Conditional syntax >> is a little bit... different. The sentence that can do it is: >> >> (TIFF=249)*255 + (TIFF<249)*TIFF + (TIFF>249)*TIFF >> >> Where TIFF is your raster layer. The trick is: if the sentence in >> parentheses is true, it gets value 1, else zero; so we have to >> multiply by 255 to replace the 249 values. Next we have to add the >> other values. >> >> Good luck, >> >> Carlos Cerdán >> >> PD. Please let me know if i'm wrong with this suggestion >> >> 2014-11-17 12:02 GMT-05:00 Andreas Neumann <[email protected]>: >> >> Hi, >>> >>> I have a very simple task (at least I thought it is simple), but am >>> not able to do it properly. >>> >>> I have a grayscale tiff value where I would like to replace the >>> value of 249 with 255 - all other values should stay as they are. >>> >>> I tried with gdal "nearblack", but nothing changed - I started a >>> separate email-thread about that at the gdal list. >>> >>> Then I tried with the QGIS raster calculator - but it does not >>> support conditional syntax. >>> >>> I tried with Processing and GRASS - but it would stop at 8% - the >>> file is quite big. >>> >>> Finally I came across SAGA "Reclassify with grid value". The >>> dialogue is very complicated and hard to understand. After a while >>> it would stop with an error message telling me that Saga may not be >>> properly configured - but it says that it is properly installed. >>> Quite confusing ... >>> >>> I am trying on Win7 64bit. >>> >>> If the file wouldn't be so big I would try this task in The Gimp - >>> where it is very simple to replace one pixel values with another - >>> using "Select by color" and "fill with a specific color". >>> >>> Any idea how I could achieve my task with GDAL, QGIS, GRASS or >>> Saga? >>> >>> Thanks, >>> Andreas >>> >>> _______________________________________________ >>> Qgis-user mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/qgis-user [1] >>> >> >> >> >> Links: >> ------ >> [1] http://lists.osgeo.org/mailman/listinfo/qgis-user >> >> _______________________________________________ >> Qgis-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-user >> > _______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user >
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