We ended up only using the lower section. There was a great deal of Photoshop used to remove the taxi cab, the pedestrians, and the baby carriage. Color correction was used (as it often is in Hollywood)  to switch the scene from daytime to night. For a fun detail, I changed the corner shop to be the Claus of Gaga with images from the film remixed to look like window displays. My thinking was that Gaga was returning to her shop when encounters the homeless man.

If you have seen the film, the scene starts wide and zooms up close. The reason this works is because the photo is so large that the zoomed in section is still enough pixels wide to remain HD once zoomed. Otherwise, it would pixelate.