getting texscreen before the scene is shown on the screen

Question

I'm still trying to make some cool transitions when changing the scene so here's another related question.
My thinking is to grab the image of the next scene (not only a sprite, but the whole picture, background image, buttons, whatever the next scene will show on the screen) using a texscreen or backbuffercopy ( or something else ?) and apply some image effects to have the cool transitions ...
I may completely be on the wrong track here, but is there a way to do this ?
thanks !

Comments

Don't know if is possible to get something is not on screen...

Another approach, get both scenes on screen, pause the game except the transition process and work over both scenes.

Then I don't know what could be better, working with 2 cameras, 2 canvaslayers, 2 viewports or a bit of everything to capture the scenes image data and work with them.