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I have a set of polygons which I would like to display in different colours.

The only information I can give on the colours is the percent reflectance of sunlight in different channels, e.g.:

B: 0.45 - 0.51µm, 5.1%

G: 0.53 - 0.59µm, 7.2%

R: 0.64 - 0.67µm, 6.1%

NIR:0.85 - 0.88µm, 38.7%

(Landsat 8 OLI channels)

Is there any chance that I can get an RBG or CIR composite, when the values are stored like this in the attribute table of a shapefile?

Hornbydd
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countryman
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  • You have lots of GIS software tags but what are you using? "You should only ask practical, answerable questions based on actual problems that you face." – PolyGeo Oct 08 '15 at 08:10
  • I use all four softwares and I was searching for a solution in all of them. I would be glad if any of them worked. – countryman Oct 08 '15 at 08:14
  • To me this means that you are asking four questions (rather than the one question per question of the [Tour]): "How do I do ... in QGIS?", "How do I do ... in ArcGIS for Desktop?", "How do I do ... in GRASS?" and "How do I do ... in ERDAS IMAGINE?" What have you tried to do in ArcGIS for Desktop so far? – PolyGeo Oct 08 '15 at 08:19
  • Okay, I will ask a separate question for ArcGIS and delete this one. I was looking for a method how to display polygon values based on rgb values in the attribute table. – countryman Oct 08 '15 at 08:28
  • Please don't delete this one - just [edit] it to narrow its focus. Deleting questions feeds into the algorithms that can lead to question bans. – PolyGeo Oct 08 '15 at 08:29
  • I think that I have mistaken this as being a duplicate of http://gis.stackexchange.com/questions/123606/symbolizing-using-rgb-values-from-excel-in-arcgis-for-desktop so I am re-opening. – PolyGeo Oct 08 '15 at 08:48
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    Just thinking aloud, if there is a way to colour your polygons based on RGB values stored in the attribute table then assuming you rounded to nearest % then potentially you could generate a layer symbology of 1,000,000 symbols. That's 100R * 100G * 100B. No GIS would support that but it's unlikely you would reach that. You would need to group your reflectance values to reduce the combination down to something a GIS could actually display. – Hornbydd Oct 08 '15 at 11:43
  • @Polygeo I think that it IS a duplicate of http://gis.stackexchange.com/questions/123606/symbolizing-using-rgb-values-from-excel-in-arcgis-for-desktop/123612#123612 and I am afraid for countryman that there is no solution to his problem – radouxju Oct 08 '15 at 11:47
  • I just followed the links to an old forum page here there is some VBA code supplied that appears to solve this problem. It builds the renderer manually. Looks like it attempts to construct every combination which I think could blow up in your face if the data has a huge range of RGB values. – Hornbydd Oct 08 '15 at 11:53
  • @radouxju I'll trust your judgement on that more than my own. – PolyGeo Oct 08 '15 at 12:13
  • Thanks @Hornbydd and for all the other comments. I will definitely try the VBA code. However, sad to here that this quite simple issue is obviously not solvable with the present means. – countryman Oct 09 '15 at 05:17

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