Making a 3D image

This is the image I started off with.

Firstly, I had to duplicate the layer by selecting layer > duplicate layer...

Then, I had to select image > adjustments > levels...

When I clicked that, I had to change the channel to red

And then I changed the output level to 0, and pressed ok.

This made the picture look blue.

I then selected the other layer (Background)

Then, I selected image > adjustments > levels.. once again

And then changed the channel this time to green, and the output level to 0 again.

I did the same again by selecting image > adjustments > levels..

and changed the channel to blue, and the output level to 0 again.

I then selected the other layer (background copy), and clicked layers, and changed it to screen.

Then used the move tool on the left hand side on the toolbar.

Finally I moved the image down and right slightly, so that it can then be viewed through 3D glasses, to make it look 3D.