I totally agree. For a simple user like me, directly retrieving unique values (like ArcGis does), and having direct access to raster tables, would be a major step to enhance raster work productivity.
All the best Pedro Monteiro 2017-01-11 3:55 GMT+00:00 Stéphane Henriod <[email protected]>: > Hi Richard > > this is a nice workaround, that I will also probably use in the future! > Thanks a lot! > > However, this becomes unhandy: > > - if the raster doesn't contain all values between 1 and 50 (let's > say, there are only classes 2, 23, 56 and 49) => need to manually remove > all the unnecessary values > - if the raster contains a discrete amount of decimal values (2.3, 4.5 > and 12.8) > - if I don't know in advance the number of classes (which happens > quite often: I receive a dataset that I don't know much about and want to > quickly display / style it to explore it) > > All the answers in this thread actually justify (IMO) the feature request: > it is at the moment possible to style discrete rasters in QGIS but only > using workarounds that are not necessarily adapted in all cases and that > are completely untransparent for beginners. > > All the best > > Stéphane > > > Le mardi 10 janvier 2017, Richard McDonnell <[email protected]> a > écrit : > >> Harrissou, >> >> Not sure if this is a solution, or if anyone has already given you this >> answer, but.... if you know a classified raster has *50* values, which >> you wish to style individually, you could try setting >> *: * >> >> - *Colour Interpolation* to *Linear* >> - *Mode *to* Equal Interval* >> - *Classes *to* 51 *(one more than the Max) >> >> I have only just tested this on a raster with 4 values and its worked for >> me! >> Hope this helps! >> Regards, >> >> Richard. >> >> On 10/01/2017 09:49, DelazJ wrote: >> >> Hi Stéphane, >> >> 2017-01-10 4:02 GMT+01:00 Stéphane Henriod <[email protected]>: >> >>> Hi Chris >>> >>> this is very nice! I indeed didn't know this trick and will certainly >>> use it again in the future! >>> >>> However... :-) >>> >>> I am currently teaching QGIS to beginners and this for sure is not an >>> appropriate method for them (especially in the case you have to generate >>> the symbology file through a script)! >>> >>> Since the user can style continuous rasters with some "button-clicking", >>> I believe the same option should be available for discrete rasters as well. >>> >>> I am thus wondering if anyone else than me sees it as a priority for >>> QGIS? If yes, how to motivate the developers to take it for the next >>> release and / or how much would such a development cost? (I unfortunately >>> don't have the competences to do it myself) >>> >>> There have been some work done in the raster properties dialog in the >> upcoming 3.0. I don't know if your concern was covered though. >> If you want, you can move the question to the developer's list >> <http://qgis.org/en/site/getinvolved/mailinglists.html#qgis-developers-list> >> and discuss whether/how this can be implemented (and its requirements). >> >> Regards, >> Harrissou >> >> Thanks again and cheers! >>> >>> Stéphane >>> >>> >>> Le mardi 10 janvier 2017, Chris House <[email protected]> a écrit : >>> >>>> Hi Stéphane, >>>> >>>> I don't know if this is what you are looking for or not but I have a >>>> method of classifying rasters by color based on a set (standard) colors. I >>>> created a spreadsheet that has several required columns, value, red, green, >>>> blue...and you can have an optional field for a display value. So say >>>> value 1 is water you can use that last column to name that value so that in >>>> the QGIS layer tree and in legend it says Water instead of value 1. >>>> >>>> save the spreadsheet as a csv and change the extension to .txt instead >>>> of .csv. >>>> >>>> I then go into the symbology section of the raster choose singleband >>>> pseudocolor. Use the folder to browse to your text file and click add. >>>> There is a format for this text file. It is below. If you need me to >>>> email it I will do that in direct email. >>>> >>>> # QGIS Generated Color Map Export File >>>> INTERPOLATION:EXACT >>>> -9999,0,0,0,255,NoData >>>> 0,176,176,176,255,Non-Forested >>>> 15,234,255,191,255,10 <= CC < 20 >>>> 25,187,230,149,255,20 <= CC < 30 >>>> 35,140,201,109,255,30 <= CC < 40 >>>> 45,98,176,74,255,40 <= CC < 50 >>>> 55,59,153,43,255,50 <= CC < 60 >>>> 65,0,128,0,255,60 <= CC < 70 >>>> 75,15,92,11,255,70 <= CC < 80 >>>> 85,17,61,12,255,80 <= CC < 90 >>>> 95,16,36,12,255,90 <= CC <= 100 >>>> >>>> In my example if I don't assign a value it gets ignored by QGIS. If >>>> you are wondering how to assign unique colors to say 200 unique >>>> values...just script it. I have done this and as long as you have the >>>> number of unique values you want and to make them unique in the script it >>>> works. >>>> >>>> I hope this helps. I know it isn't a "button" but to be honest I like >>>> this better. If you already knew this...well then maybe it will help >>>> someone out in the future. >>>> >>>> --Chris >>>> >>>> On Mon, Jan 9, 2017 at 3:00 PM, <[email protected]> >>>> wrote: >>>> >>>>> Send Qgis-user mailing list submissions to >>>>> [email protected] >>>>> >>>>> To subscribe or unsubscribe via the World Wide Web, visit >>>>> <http://lists.osgeo.org/mailman/listinfo/qgis-user> >>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user >>>>> or, via email, send a message with subject or body 'help' to >>>>> [email protected] >>>>> >>>>> You can reach the person managing the list at >>>>> [email protected] >>>>> >>>>> When replying, please edit your Subject line so it is more specific >>>>> than "Re: Contents of Qgis-user digest..." >>>>> >>>>> >>>>> Today's Topics: >>>>> >>>>> 1. Re: Symbolizing a discrete or a boolean raster (Stéphane Henriod) >>>>> >>>>> >>>>> ---------------------------------------------------------------------- >>>>> >>>>> Message: 1 >>>>> Date: Mon, 9 Jan 2017 23:07:36 +0600 >>>>> From: Stéphane Henriod <[email protected]> >>>>> To: Enrico Fiore <[email protected]> >>>>> Cc: qgis-user <[email protected]> >>>>> Subject: Re: [Qgis-user] Symbolizing a discrete or a boolean raster >>>>> Message-ID: >>>>> <[email protected] >>>>> ail.com> >>>>> Content-Type: text/plain; charset="utf-8" >>>>> >>>>> Hi >>>>> >>>>> thanks for following up! >>>>> >>>>> It actually does part of the job! >>>>> >>>>> Using *Color interpretation: Exact*, I can indeed input the exact >>>>> values I >>>>> want to display (1,5 and 10) and all other pixels are hidden. >>>>> >>>>> HOWEVER, >>>>> >>>>> this still feels like a workaround: >>>>> >>>>> - In the case of a discrete raster with many (> 50) unique values, >>>>> I do >>>>> not want to input all of them manually >>>>> - In some cases, I do not know in advance all the unique values of >>>>> my >>>>> raster >>>>> - If I click on *Classify*, QGIS will choose X values (based on the >>>>> number of classes and the classification method (continuous or equal >>>>> interval)), which no longer match the "exact" values of my raster. >>>>> It >>>>> doesn't really make sense to classify a discrete rendering >>>>> >>>>> So I would say, we still need a render type "discrete raster" which >>>>> offers >>>>> the function to "retrieve all unique values" (and automatically apply a >>>>> discrete color ramp) >>>>> >>>>> Attached a (fake) test dataset. >>>>> >>>>> Thanks and cheers >>>>> >>>>> Stéphane >>>>> >>>>> >>>>> Le lundi 9 janvier 2017, Enrico Fiore <[email protected]> a écrit >>>>> : >>>>> >>>>> > Hi, >>>>> > Sorry I can't do test, but if you use exact in color interpolation >>>>> > parameter? >>>>> > >>>>> > Cheers >>>>> > >>>>> > Enrico >>>>> >>>>> >>>>> Le lundi 9 janvier 2017, Stéphane Henriod <[email protected]> a écrit : >>>>> >>>>> > Hi >>>>> > >>>>> > unfortunately this is doing quite something different! >>>>> > >>>>> > If I have a raster with 10 Landcover classes (1,2,3,4,5,6,7,8,9,10) >>>>> and I >>>>> > want to display only 1,5 and 10, using *Discrete *(1: red, 5: >>>>> yellow, 10: >>>>> > blue) the following will happen: >>>>> > >>>>> > All pixels between 1 and 4 will be red >>>>> > All pixels between 5 and 9 will be yellow >>>>> > All pixels with 10 will be blue >>>>> > >>>>> > In this sense, the pixels are indeed not interpolated, but this >>>>> still is >>>>> > not the behavior I am expecting when styling discrete rasters. >>>>> > >>>>> > A "style discrete raster" function should offer the following: >>>>> > >>>>> > - Automatically recover all unique values from the raster >>>>> > - Only display the pixels to which the user has explicitly >>>>> assigned a >>>>> > color >>>>> > >>>>> > But thanks for your hint, this can be helpful in other cases! >>>>> > >>>>> > Cheers >>>>> > >>>>> > Stéphane >>>>> > >>>>> > >>>>> > Le lundi 9 janvier 2017, Enrico Fiore <[email protected] >>>>> > <javascript:_e(%7B%7D,'cvml','[email protected]');>> a écrit : >>>>> > >>>>> >> 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_r> >>>>> http://docs.qgis.org/2.14/en/docs/user_manual/working_with_r >>>>> >> aster/raster_properties.html#band-rendering >>>>> >> you have to use *Singleband pseudocolor *and set color >>>>> interpolation to >>>>> >> Discrete. >>>>> >> >>>>> >> Enrico >>>>> >> >>>>> >> >>>>> >> ----Messaggio originale---- >>>>> >> Da: "Stéphane Henriod" <[email protected]> >>>>> >> Data: 09/01/2017 6.30 >>>>> >> A: "qgis-user"<[email protected]> >>>>> >> 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> >>>>> http://resources.arcgis.com/en/help/main/10.1/index. >>>>> >> html#/representing_unique_categories_such_as_land_use/009t00 >>>>> 000074000000/ >>>>> >> 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-d> >>>>> http://gis.stackexchange.com/questions/194116/qgis-style-a-d >>>>> >> iscrete-raster >>>>> >> >>>>> >> and opened a ticket here: >>>>> >> <http://hub.qgis.org/issues/14845>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 >>>>> >>>>> Национальный статистический комитет Кыргызской Республики >>>>> Кыргыз Республикасынын Улуттук статистика комитети >>>>> National 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 <+49%20176%2028011050> (DE) >>>>> E [email protected] >>>>> W http://www.stat.kg >>>>> W3W: nightfall.into.bucket >>>>> <https://map.what3words.com/nightfall.into.bucket> // >>>>> запас.союз.дружный >>>>> <https://map.what3words.com/запас.союз.дружный> >>>>> -------------- next part -------------- >>>>> An HTML attachment was scrubbed... >>>>> URL: < >>>>> <http://lists.osgeo.org/pipermail/qgis-user/attachments/20170109/985fd14c/attachment-0001.html> >>>>> http://lists.osgeo.org/pipermail/qgis-user/attachments/2017 >>>>> 0109/985fd14c/attachment-0001.html> >>>>> -------------- next part -------------- >>>>> A non-text attachment was scrubbed... >>>>> Name: landcover.zip >>>>> Type: application/zip >>>>> Size: 2151 bytes >>>>> Desc: not available >>>>> URL: < >>>>> <http://lists.osgeo.org/pipermail/qgis-user/attachments/20170109/985fd14c/attachment-0001.zip> >>>>> http://lists.osgeo.org/pipermail/qgis-user/attachments/2017 >>>>> 0109/985fd14c/attachment-0001.zip> >>>>> >>>>> ------------------------------ >>>>> >>>>> Subject: Digest Footer >>>>> >>>>> _______________________________________________ >>>>> Qgis-user mailing list >>>>> [email protected] >>>>> List info: <http://lists.osgeo.org/mailman/listinfo/qgis-user> >>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user >>>>> Unsubscribe: <http://lists.osgeo.org/mailman/listinfo/qgis-user> >>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user >>>>> >>>>> ------------------------------ >>>>> >>>>> End of Qgis-user Digest, Vol 131, Issue 13 >>>>> ****************************************** >>>>> >>>> >>>> >>> >>> -- >>> Stéphane Henriod >>> CIM-Expert for GIS and Green Economy Statistics >>> >>> Национальный статистический комитет Кыргызской Республики >>> Кыргыз Республикасынын Улуттук статистика комитети >>> National 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 <+49%20176%2028011050> (DE) >>> E [email protected] >>> W http://www.stat.kg >>> W3W: nightfall.into.bucket >>> <https://map.what3words.com/nightfall.into.bucket> // >>> запас.союз.дружный >>> <https://map.what3words.com/%D0%B7%D0%B0%D0%BF%D0%B0%D1%81.%D1%81%D0%BE%D1%8E%D0%B7.%D0%B4%D1%80%D1%83%D0%B6%D0%BD%D1%8B%D0%B9> >>> >>> >>> _______________________________________________ >>> Qgis-user mailing list >>> [email protected] >>> List info: http://lists.osgeo.org/mailman/listinfo/qgis-user >>> Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user >>> >> >> >> >> _______________________________________________ >> Qgis-user mailing [email protected] >> List info: http://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user >> >> >> -- >> *Richard McDonnell* >> *GIS Specialist PgD GIS AssocSCSI* >> *OPW FRM Data Management* >> *52 Stephens Green, Dublin 2.* >> TEL: 01 6476543 >> >> <http://www.opw.ie/> >> > > > -- > Stéphane Henriod > CIM-Expert for GIS and Green Economy Statistics > > Национальный статистический комитет Кыргызской Республики > Кыргыз Республикасынын Улуттук статистика комитети > National 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 <+49%20176%2028011050> (DE) > E [email protected] > W http://www.stat.kg > W3W: nightfall.into.bucket > <https://map.what3words.com/nightfall.into.bucket> // запас.союз.дружный > <https://map.what3words.com/запас.союз.дружный> > > > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: http://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user >
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