Speck Removal Show Difference preview

[davidh]

What does the Speck Removal Difference preview really show? Which specks will be removed or which will stay?
If you check both Light and Dark, both are displayed in the difference preview. This suggests that Light and Dark will be removed.

If you check only one of them, the unchecked specks are displayed. See the exaggerated example:
I would expect it to be the other way round - to display which light specks will be removed, not which dark specks will be preserved.
I am right or is the current way intended?

[jsachs]

The difference preview was showing preview - input which make white specks looks black and vice versa. For the next release, I switched it to input - preview so white specks show up white in the preview and black specks show up black. I think this is what was causing the confusion.