qgis-ndvi-try

import processing
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.analysis import *

band4LayerName = "b04-crs-cut"
band4Layer = QgsRasterLayer("C:/temp/b04-crs-cut.tif", band4LayerName)

band4RasterEntry = QgsRasterCalculatorEntry()
band4RasterEntry.raster = band4Layer
#band4RasterEntry.ref = "b04-crs-cut@1"
band4RasterEntry.ref = str(band4Layer.name()+"@1")
#band4RasterEntry.ref = band4Layer.name()
band4RasterEntry.band = 1
band4Raster = QgsRasterLayer(band4Layer.source())

band8LayerName = "b08-crs-cut"
band8Layer = QgsRasterLayer("C:/temp/b08-crs-cut.tif", band8LayerName)

band8RasterEntry = QgsRasterCalculatorEntry()
band8RasterEntry.raster = band8Layer
#band8RasterEntry.ref = "b08-crs-cut@1"
band8RasterEntry.ref = str(band8Layer.name()+"@1")
#band8RasterEntry.ref = band8Layer.name()
band8RasterEntry.band = 2


rasterEntries = [band4RasterEntry, band8RasterEntry]
output_file = "C:/temp/calculationNDVI.tif"
calculation = "'(\""+band8RasterEntry.ref+"\"-\""+band4RasterEntry.ref+"\")/(\""+band8RasterEntry.ref+"\"+\""+band4RasterEntry.ref+"\")'"
calc = QgsRasterCalculator(str(calculation),
                           output_file,
                           "GTiff",
                           band4Layer.extent(),
                           band4Layer.width(),
                           band4Layer.height(),
                           rasterEntries)
calc.processCalculation()

print type(calculation)
print output_file