is non-persistence a known issue?

[xunxky]

I kinda don't know what anyone wants to achieve with this, but you are aware that it is not invariant to repeated execution, are you? (at least the thing I tested "dwtDctSvd" .. the others did not work )
this means the watermark can be "cleared"

[mexicantexan]

From what I understand each time you "rerun" this operation you degrade the image, but I do believe that this is a known issue with this approach for watermarking an image.