Changing color rendering of multiple raster layers at once

Question

I have many raster layers in my QGIS project and they're all currently rendered as: Multiband color Red band: Band 1 Green band: Band 2 Blue band: Band 3

I'd like to know if there's any way I can change the rendering of all raster layers to: Red band: Band 3 Green band: Band 2 Blue band: Band 1 without having to do it by hand, layer by layer.

Answer 1

You can use pyqgis. This will change symbology of all raster layers in layer tree to red band=band 3, green=band 2, blue=band 1:

for lyr in QgsProject.instance().mapLayers().values():
 if isinstance(lyr, qgis.core.QgsRasterLayer): #Check to make sure it is a raster layer
 r = lyr.renderer().clone()
 r.setRedBand(3)
 r.setGreenBand(2)
 r.setBlueBand(1)
 lyr.setRenderer(r)
 lyr.triggerRepaint()

enter image description here

• willsbit: I'm sorry to bother you, but I've ran into some trouble. The bands change accordingly, but the changes don't apply unless I go into each layer's symbology and hit the "Apply" button. I tried using triggerRepaint() and other similar methods like qgis.utils.iface.mapCanvas().refresh() but they don't seem to work. Any help?
• Bera: Try now, I've changed the code!
• willsbit: The same thing still happens. I think it has something to do with applying the "stretch to min-max" contrast settings. I tried working around it with something like this: layer = iface.activeLayer() contrastFilter = QgsBrightnessContrastFilter() contrastFilter.setContrast(50) layer.pipe().set(contrastFilter) layer.triggerRepaint() but it basically does nothing

Answer 2

Set it up for one layer.

Right click that layer, Styles -> Copy Style.

Select all the other layers you want to apply the same style to, right-click, Styles -> Paste Style.