Both utility widgets QmitkSurfaceToImageWidget and QmitkImageMaskingWidget provide additional options to define the resulting output image.
Inside QmitkImageMaskingWidget::MaskImage the options are supposed to be used but the code is commented.
Inside QmitkSurfaceToImageWidget the options are used but here the idea is unclear. It might be worth writing down the original intention and see if the UI can be improved to make it easy for the end-user to understand the different options.
Also: The QmitkImageMaskingWidget does not enable / disable the options as QmitkSurfaceToImageWidget does and the "Mask"-button should be at the bottom below the options, as in QmitkSurfaceToImageWidget.