finding rotation of angle

i have 2 images,one is say" dock.jpg"image and the second is same image ,but rotated 45 or some other angle.is it possible to say that the second image is how much rotated in angle from first,

please help

the image is grayscale

its size is 128x128

Answer 1

[Elad]

you can use imrotate() running over angles and subtract the result with the original image until you get a zero matrix.

Answer 2

[Sean de Wolski]

showdemo ipexaerial

Might help get you started.