Clip raster with pyqgis and nodata value

Question

I'm writing a script to clip many raster by a shape. When a try the tool in pyqgis just for one raster, value around image are nadata, it's good !

Here is the code :

##test=group
##clip=name
##raster=raster
##shape=vector
##sortie=output raster

clip=processing.runalg('gdalogr:cliprasterbymasklayer', raster,shape,None,False,False,False,5,4,75.0,6.0,1.0,False,0,False,None,sortie)

After that I create a script with a loop on a folder. It's works but I have a little issue. Nodata value become 0 and I really don't know why.

Here is the new code :

##Fruition=group
##Clip_raster=name
##dossier_entree=folder
##dossier_sortie=folder
##parcellaire=vector

from qgis.utils import iface
import sys, processing, os, glob, numpy
from qgis.core import *
from PyQt4.QtCore import *
from PyQt4.QtGui import *


fichiers = os.listdir(dossier_entree)
ndvibruts = glob.glob(dossier_entree+'/*.tif')
for ndvibrut in ndvibruts:

    Clip = processing.runalg('gdalogr:cliprasterbymasklayer', ndvibrut,parcellaire,None,False,False,False,5,4,75.0,6.0,1.0,False,0,False,None,None)

    sortie = QgsRasterLayer(Clip['OUTPUT'])

    extent = sortie.extent()

    width, height = sortie.width(), sortie.height()

    renderer = sortie.renderer()

    provider = sortie.dataProvider()

    crs = sortie.crs().toWkt()

    pipe = QgsRasterPipe()

    pipe.set(provider.clone())

    pipe.set(renderer.clone())

    nomndvibrut = ndvibrut[(ndvibrut.find('ndvi_')):(len(ndvibrut))]

    file_writer = QgsRasterFileWriter("{0}/{1}".format(dossier_sortie,nomndvibrut))

    file_writer.writeRaster(pipe,
                   width,
                   height,
                   extent,
                   sortie.crs())

Somebody can help me ?

Answer 1

I finally found myself. I had to delete those 2 lines :

renderer = sortie.renderer()

pipe.set(renderer.clone())

Renderer allows to export raster current extent : QgsMapRenderer to export current extent using PyQGIS