Hi,
I think that the solution is in the QGIS documentation, that you can read here: 
http://docs.qgis.org/2.14/en/docs/user_manual/working_with_raster/raster_properties.html#band-rendering
you have to use Singleband pseudocolor and set color interpolation to Discrete.

Enrico





----Messaggio originale----

Da: "Stéphane Henriod" <s...@henriod.info>

Data: 09/01/2017 6.30

A: "qgis-user"<qgis-user@lists.osgeo.org>

Ogg: [Qgis-user] Symbolizing a discrete or a boolean raster



Dear all
As much as I love QGIS and use it in my everyday life, there is one feature 
that I find particularly annoying: the styling of discrete rasters.
Basically, if I have a raster layer consisting of discrete landcover values (1: 
water, 2: forest, 3: built-up), it seems that there is no easy way to style it. 
QGIS will assume that the data is continuous and basically interpolate the 
color between each value, which leads to the following issues:
Let's say I want to display only water and built-up (values 1 and 3), water in 
blue and built-up in grey. QGIS will still display the forests, using a color 
somewhere "between" blue and grey. My only left option is to process the raster 
to actually replace all the 2 with NoData, which is highly unpractical...
Same if I have a boolean raster (only 0 and 1 values). QGIS will by default 
make a color ramp from 0 to 0.9999.
Also, the whole rather feels like a work-around for a missing feature.
I dream of a feature similar to this one from ArcGIS: 
http://resources.arcgis.com/en/help/main/10.1/index.html#/representing_unique_categories_such_as_land_use/009t00000074000000/
 where all unique values are styled independently and where I can easily skip 
the values I don't want to see on my map.
I asked a question 
here:http://gis.stackexchange.com/questions/194116/qgis-style-a-discrete-raster
and opened a ticket here:http://hub.qgis.org/issues/14845
But none has gotten lots of attention yet... Am I the only one to be annoyed by 
this? If no, please raise your hand and let's try to get some momentum and see 
how to push this feature forward!
Thanks a lot in advance!
Cheers
Stéphane

-- 
Stéphane HenriodCIM-Expert for GIS and Green Economy Statistics
Национальный статистический комитет Кыргызской РеспубликиКыргыз Республикасынын 
Улуттук статистика комитетиNational Statistical Committee of the Kyrgyz Republic
374 Фрунзе ул. / Frunze str.720033 Бишкек / Bishkek
T   +996 778 46 99 02 (KG)T   +49 176 280 11 050 (DE)E    s@henriod.infoW   
http://www.stat.kgW3W: nightfall.into.bucket  //  запас.союз.дружный





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