text: #!/usr/bin/python3
  #
  # Copyright (c) 2014-2022 The Voxie Authors
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in
  # all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  # THE SOFTWARE.
  #
  
  import voxie
  import numpy as np
  
  
  def get_operation_from_string(operation_string):
      if operation_string == 'de.uni_stuttgart.Voxie.Filter.UnaryOperation.Operation.Negate':
          return np.negative
      if operation_string == 'de.uni_stuttgart.Voxie.Filter.UnaryOperation.Operation.LogicalNot':
          return np.logical_not
      raise Exception('Unknown unary operation: ' + repr(operation_string))
  
  
  args = voxie.parser.parse_args()
  context = voxie.VoxieContext(args)
  instance = context.createInstance()
  
  if args.voxie_action != 'RunFilter':
      raise Exception('Invalid operation: ' + args.voxie_action)
  
  with context.makeObject(context.bus, context.busName, args.voxie_operation, ['de.uni_stuttgart.Voxie.ExternalOperationRunFilter']).ClaimOperationAndCatch() as op:
      inputData = op.GetInputData('de.uni_stuttgart.Voxie.Input').CastTo(
          'de.uni_stuttgart.Voxie.VolumeData')
      outputPath = op.Properties['de.uni_stuttgart.Voxie.Output'].getValue('o')
  
      inputDataVoxel = inputData.CastTo('de.uni_stuttgart.Voxie.VolumeDataVoxel')
  
      operation = get_operation_from_string(
          op.Properties['de.uni_stuttgart.Voxie.Filter.UnaryOperation.Operation'].getValue('s'))
  
      with inputDataVoxel.GetBufferReadonly() as inputArray:
          with op.GetOutputVolumeDataVoxelLike(outputPath, inputDataVoxel) as data:
              with data.CreateUpdate() as update, data.GetBufferWritable(update) as outputBuffer:
                  zCount = data[:].shape[2]
                  for z in range(0, zCount):
                      op.ThrowIfCancelled()
                      operation(inputArray[:, :, z], outputBuffer.array[:, :, z])
                      op.SetProgress((z + 1) / zCount)
                  version = update.Finish()
  
              result = {}
              result[outputPath] = {
                  'Data': voxie.Variant('o', data._objectPath),
                  'DataVersion': voxie.Variant('o', version._objectPath),
              }
              op.Finish(result)
              version._referenceCountingObject.destroy()
  