I have a .tiff raster layer and I want to update raster color ramp with new min/max values using PyQGIS and export to .png image with new color ramp.
The update raster color ramp I can do with code from this post :
from PyQt4.QtCore import *
from PyQt4.QtGui import *
layer = iface.activeLayer()
renderer = layer.renderer()
provider = layer.dataProvider()
extent = layer.extent()
ver = provider.hasStatistics(1, QgsRasterBandStats.All)
stats = provider.bandStatistics(1, QgsRasterBandStats.All,extent, 0)
if ver is not False:
print "minimumValue = ", stats.minimumValue
print "maximumValue = ", stats.maximumValue
if (stats.minimumValue < 0):
min = 0
else:
min= stats.minimumValue
max = stats.maximumValue
range = max - min
add = range//2
interval = min + add
colDic = {'red':'#ff0000', 'yellow':'#ffff00','blue':'#0000ff'}
valueList =[min, interval, max]
lst = [ QgsColorRampShader.ColorRampItem(valueList[0], QColor(colDic['red'])),
QgsColorRampShader.ColorRampItem(valueList[1], QColor(colDic['yellow'])),
QgsColorRampShader.ColorRampItem(valueList[2], QColor(colDic['blue']))]
myRasterShader = QgsRasterShader()
myColorRamp = QgsColorRampShader()
myColorRamp.setColorRampItemList(lst)
myColorRamp.setColorRampType(QgsColorRampShader.INTERPOLATED)
myRasterShader.setRasterShaderFunction(myColorRamp)
myPseudoRenderer = QgsSingleBandPseudoColorRenderer(layer.dataProvider(),
layer.type(),
myRasterShader)
layer.setRenderer(myPseudoRenderer)
layer.triggerRepaint()
but how to export this raster to new .png image with new colors ?
