Smooth edge mask is possible?

I am tring to use masking. for example, I added photoshop example image.
I want to find a way to render in vvvv as Photoshop.
Just Blend or Group node with texture transform … is ok simply mask.
But it hasn’t edge smooth.
Blur filter? It seems not well.
How can I do?

This should help…

Mask.rar (3.8 kB)

@Urbankind thanks!
I solved this problem by obsolete-see-addonpack-transitionmegapack(ex9.texture-mixer)
your help also.