Dicom to PNG setting window and level. Modified from: http://vtk.1045678.n5.nabble.com/Set-window-level-and-convert-image-DICOM-tp5736087p5736157.html

dicom-converter.py

#!/usr/bin/python

import sys, getopt
from vtk import *

def main(argv):
   inputfile = ''
   outputfile = ''
   window = 80
   level = 40
   try:
      opts, args = getopt.getopt(argv,"hi:o:",["ifile=","ofile="])
   except getopt.GetoptError:
      print '__main__.py -i <inputfile> -o <outputfile>'
      sys.exit(2)
   for opt, arg in opts:
      if opt == '-h':
         print('test.py -i <inputfile> -o <outputfile>')
         sys.exit()
      elif opt in ("-i", "--ifile"):
         inputfile = arg
      elif opt in ("-o", "--ofile"):
         outputfile = arg
 
   print 'Generating ', inputfile
   generateImg(inputfile, outputfile, window, level)


def generateImg(inputfile, outputfile, window, level):

    reader = vtkDICOMImageReader()
    reader.SetFileName(inputfile)
    reader.Update()
    image = reader.GetOutput()

    windowlevel = vtkImageMapToWindowLevelColors()
    windowlevel.SetInput(reader.GetOutput())

    windowlevel.SetWindow(window)
    windowlevel.SetLevel(level)
    windowlevel.Update()

    shiftScaleFilter = vtkImageShiftScale()
    shiftScaleFilter.SetOutputScalarTypeToUnsignedChar()
    shiftScaleFilter.SetInputConnection(windowlevel.GetOutputPort())

    shiftScaleFilter.SetShift(-1.0*windowlevel.GetOutput().GetScalarRange()[0])
    oldRange = windowlevel.GetOutput().GetScalarRange()[1] - windowlevel.GetOutput().GetScalarRange()[0]
    newRange = 255

    shiftScaleFilter.SetScale(newRange/oldRange)
    shiftScaleFilter.Update()

    writer = vtkPNGWriter()
    writer.SetFileName(outputfile)
    writer.SetInputConnection(windowlevel.GetOutputPort())
    writer.Write()


main(sys.argv[1:])