Default Raster Visualization

[Benjamin Jakimow]

The default rendering of raster layers should consider the following options:

#bands	byte	int	float
1	DN	2% GC	2% GC
2	DN	2% GC	2% GC
>= 3	DN	2% RGB	2% RGB

2% RGB = QgsMultiBandColorRenderer with default or, if possible, True Color band combination from 2% to 98 % (band-wise)

2% GC = QgsSingleBandGrayRenderer grey color gradient from 2% to 98%

DN = direct use of digital number as RGB color values

QgsPalettedRasterRenderer in case of ClassificationScheme

[Andreas Janz]

we do not need the table, use this logic:

#!

if bands=3 and type=byte: 
    strech=DN
elif bands=1:
    if type=byte: 
        strech=0% GC
    else:
        stretch=2% GC
else: 
    strech=2% RGB

[Benjamin Jakimow]

The table is needed to support documentation of EnMAP-Box behaviour for none-programmers. I updated it with your logic.

[Andreas Janz]

following the given if-elif-else logic, it is more like this

#bands	byte	int / float
1	0% GC	2% GC
3	DN	2% RGB
else	2% RGB	2% RGB

[Benjamin Jakimow]

added layerproperties.py defaultRasterRenderer() closes Issue #166

→ <<cset 7b7c8dccca0c>>