8 February 2012 Last updated at 00:36

Deconstructing The Muppets film's special effects shots

Kermit's fellow Muppets appear to be staring him in the eyes...

...but the original shot was filmed against a blue screen

The two parts show that Kermit's image was blurred before being superimposed...

...a blue, rather than green, backdrop was used to make it easier to key Kermit afterwards

Sam the Eagle is seen presenting the news in a busy studio...

... his feathers made him a complicated character to remove from the background

Dr Teeth and The Electric Mayhem perform in a subway station...

...using a blue screen made it easier to control the elements

Having Gonzo balance a bowling ball on his hand would have posed a challenge...

...but creating a computer generated prop solved the problem

New character Walter admires himself in the mirror in one sequence...

...but only after the off-centre reflection created by the original shot was replaced

Filling Hollywood Boulevard with extras would have proved expensive...

...far cheaper to employ a limited number of actors and create the rest with graphics

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