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

[Stéphane Henriod]

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 Henriod
CIM-Expert for GIS and Green Economy Statistics

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