"""vtkImageExportToArray - a NumPy front-end to vtkImageExportThis class converts a VTK image to a Numeric Python array.To use this class, you must have the LLNL Numeric Python distribution(http://numpy.sf.net)Methods  SetInput(input) -- connect to VTK image pipeline  GetArray()      -- execute pipeline and return a Numeric arrayConvert VTK_UNSIGNED_SHORT to python Int(this might be necessary because Python doesn't support unsigned short,the default is to cast unsigned short to signed short).  SetConvertUnsignedShortToInt(yesno)  ConvertUnsignedShortToIntOn()  ConvertUnsignedShortToIntOff()From vtkImageExport  GetDataExtent()  GetDataSpacing()  GetDataOrigin()"""import Numericimport umathfrom vtk import vtkImageExportfrom vtkConstants import *_NEW_NUMERIC = 0try:    val = float(Numeric.__version__)except ValueError:    _NEW_NUMERIC = 0else:    if val > 20.0:        _NEW_NUMERIC = 1    else:        _NEW_NUMERIC = 0class vtkImageExportToArray:    def __init__(self):        self.__export = vtkImageExport()        self.__ConvertUnsignedShortToInt = 0    # type dictionary: note that python doesn't support    # unsigned integers!    __typeDict = { VTK_CHAR:Numeric.Int8,                   VTK_UNSIGNED_CHAR:Numeric.UnsignedInt8,                   VTK_SHORT:Numeric.Int16,                   VTK_UNSIGNED_SHORT:Numeric.Int16,                   VTK_INT:Numeric.Int32,                   VTK_FLOAT:Numeric.Float32,                   VTK_DOUBLE:Numeric.Float64 }    __sizeDict = { VTK_CHAR:1,                   VTK_UNSIGNED_CHAR:1,                   VTK_SHORT:2,                   VTK_UNSIGNED_SHORT:2,                   VTK_INT:4,                   VTK_FLOAT:4,                   VTK_DOUBLE:8 }    # convert unsigned shorts to ints, to avoid sign problems    def SetConvertUnsignedShortToInt(self,yesno):        self.__ConvertUnsignedShortToInt = yesno    def GetConvertUnsignedShortToInt(self):        return self.__ConvertUnsignedShortToInt        def ConvertUnsignedShortToIntOn(self):        self.__ConvertUnsignedShortToInt = 1    def ConvertUnsignedShortToIntOff(self):        self.__ConvertUnsignedShortToInt = 0    # set the input    def SetInput(self,input):        return self.__export.SetInput(input)    def GetInput(self):        return self.__export.GetInput()    def GetArray(self):        input = self.__export.GetInput()        input.UpdateInformation()        type = input.GetScalarType()        extent = input.GetWholeExtent()        numComponents = input.GetNumberOfScalarComponents()        dim = (extent[5]-extent[4]+1,               extent[3]-extent[2]+1,               extent[1]-extent[0]+1)        if (numComponents > 1):            dim = dim + (numComponents,)        size = dim[0]*dim[1]*dim[2]*numComponents*self.__sizeDict[type]        if _NEW_NUMERIC:            imArray = Numeric.zeros((size,),Numeric.UnsignedInt8)            self.__export.Export(imArray)        else:            imString = Numeric.zeros((size,),                                     Numeric.UnsignedInt8).tostring()            self.__export.Export(imString)            imArray = Numeric.fromstring(imString,self.__typeDict[type])            # just to remind myself of the dangers of memory management            del imString        # reshape array appropriately.        imArray = Numeric.reshape(imArray, dim)        # convert unsigned short to int to avoid sign issues        if (type == VTK_UNSIGNED_SHORT and self.__ConvertUnsignedShortToInt):            imArray = umath.bitwise_and(imArray.astype(Numeric.Int32),0xffff)        return imArray            def GetDataExtent(self):        return self.__export.GetDataExtent()        def GetDataSpacing(self):        return self.__export.GetDataSpacing()        def GetDataOrigin(self):        return self.__export.GetDataOrigin()