ImageMagick - Add white transparent overlay to image

Question

I need to take a normal image:

and add a white, transparent overlay so it looks something like this:

Don't pay attention to the text on the converted image or the fact that it's a cropped version of the original. I need to simply convert the top to the exact same image, just with this white, transparent overlay. I also need it to be a cli command.

Answer 1

Updated Answer

This is even easier

convert house.jpg -fill white -colorize 80%  result.png

Original Answer

Something like this maybe...

convert house.jpg \( +clone -fill white -colorize 80% \) -composite result.png