Removing Alpha Channel?

[Ofnuts]

Tried with an image of mine and results with and without an alpha channels are identical.

Now, there is an alpha channel, and there are partially opaque pixels, you can have the first without the second.
So if you problem is that partially opaque pixels in the copies (layer_copy and layer_copy1) are skewing the result of the contrast/color layers overlay, you can just make these two layers totally opaque by using :

Code:

if layer.has_alpha:
    pdb.plug_in_threshold_alpha(image,layer,0)