pasting an image ontop of another image in matlab : [posterimage][1]


Hello. I have this poster image that i have to blend with another image. I have to put this image on a picture of a building. 
[Buildingimage][2]
The rotated posterimage has white pixels that i dont know how to get rid of. Can someone please help me with code to paste this image on the building image. The front of the building.


  [1]: https://i.stack.imgur.com/MeW9a.jpg
  [2]: https://i.stack.imgur.com/TG9jI.jpg