RectilinearWipe with different LevelWindows possible?

Hi

I made a (2D) image comparison application where two (geotiff) images can get compared using vtk’s rectiliear wipe widget. i used a vtk->itk->vtk pipeline to resample the images first so that both have same datatype, origin and spacing and piped those resampled images into the rectiliear wipe widget. it works good but the visialization sucks if images have a big difference in data range, e.g. if image 1 is in grayvaluerange [0,1] and image 2 is in range [0 255]. In that case you can only set the LevelWindow that you eighter see image 1 or image 2.

For sure you can add a kind of silder to multiply/add a value/factor on one of those imades but in sum i am not very statisfied about changing the image content (as i already did with the resampling). I would love to work with a second LevelWindow/Transferfunction (which grayvaluescale can also be displayed with a Legend)

is there a better possibility? e.g render 2 images overlayed and making the top image transparent in a wipe/chessboard manner? this way i could use 2 levelwindow functions which can be adjusted with mouse like on normal vtkImageViewe2? Perhaps i have no idea how to do that, any ideas or links to similar solutions? or other ideas to adjust the gray value more user friendly? A slider with multiplication seems very stupid for me

many thanks