% The procedure is as follows (note this does not compute scale)
% (1) Read in I1 - the image to register against
% (2) Read in I2 - the image to register
% (3) Take the FFT of I1, shifting it to center on zero frequency
% (4) Take the FFT of I2, shifting it to center on zero frequency
% (5) Convolve the magnitude of (3) with a high pass filter
% (6) Convolve the magnitude of (4) with a high pass filter
% (7) Transform (5) into log polar space
% (8) Transform (6) into log polar space
% (9) Take the FFT of (7)
% (10) Take the FFT of (8)
% (11) Compute phase correlation of (9) and (10)
% (12) Find the location (x,y) in (11) of the peak of the phase correlation
% (13) Compute angle (360 / Image Y Size) * y from (12)
% (14) Rotate the image from (2) by - angle from (13)
% (15) Rotate the image from (2) by - angle + 180 from (13)
% (16) Take the FFT of (14)
% (17) Take the FFT of (15)
% (18) Compute phase correlation of (3) and (16)
% (19) Compute phase correlation of (3) and (17)
% (20) Find the location (x,y) in (18) of the peak of the phase correlation
% (21) Find the location (x,y) in (19) of the peak of the phase correlation
% (22) If phase peak in (20) > phase peak in (21), (y,x) from (20) is the translation
% (23a) Else (y,x) from (21) is the translation and also:
% (23b) If the angle from (13) < 180, add 180 to it, else subtract 180 from it.
% (24) Tada!
% Requires (ouch):
% 6 x FFT
% 4 x FFT Shift
% 3 x IFFT
% 2 x Log Polar
% 3 x Phase Correlations
% 2 x High Pass Filter
% 2 x Image Rotation
% ---------------------------------------------------------------------
% Load first image (I1)
I1 = imread('lena.bmp');
% Load second image (I2)
I2 = imread('lena_cropped_rotated_shifted.bmp');
% ---------------------------------------------------------------------
% Convert both to FFT, centering on zero frequency component
% The procedure is as follows (note this does not compute scale)
% (1) Read in I1 - the image to register against
% (2) Read in I2 - the image to register
% (3) Take the FFT of I1, shifting it to center on zero frequency
% (4) Take the FFT of I2, shifting it to center on zero frequency
% (5) Convolve the magnitude of (3) with a high pass filter
% (6) Convolve the magnitude of (4) with a high pass filter
% (7) Transform (5) into log polar space
% (8) Transform (6) into log polar space
% (9) Take the FFT of (7)
% (10) Take the FFT of (8)
% (11) Compute phase correlation of (9) and (10)
% (12) Find the location (x,y) in (11) of the peak of the phase correlation
% (13) Compute angle (360 / Image Y Size) * y from (12)
% (14) Rotate the image from (2) by - angle from (13)
% (15) Rotate the image from (2) by - angle + 180 from (13)
% (16) Take the FFT of (14)
% (17) Take the FFT of (15)
% (18) Compute phase correlation of (3) and (16)
% (19) Compute phase correlation of (3) and (17)
% (20) Find the location (x,y) in (18) of the peak of the phase correlation
% (21) Find the location (x,y) in (19) of the peak of the phase correlation
% (22) If phase peak in (20) > phase peak in (21), (y,x) from (20) is the translation
% (23a) Else (y,x) from (21) is the translation and also:
% (23b) If the angle from (13) < 180, add 180 to it, else subtract 180 from it.
