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Thread Subject:
image registration

Subject: image registration

From: Snow White

Date: 24 Nov, 2011 12:57:07

Message: 1 of 4

Hello,

I have an image set, which i have to register. The problem is that the intensity varies from one image to the other and there is a translational difference amongst the images. So they have to be registered only considering translation.

i have tried the following method which apparently gives the translational distances and works on binary images but its not working.

[x,y]=max(ifft((fft(img)*conj(fft(ref_img)))/abs(fft(img)*fft(ref_img))))

Could anyone please help me out with this?

Subject: image registration

From: Matt J

Date: 24 Nov, 2011 14:52:08

Message: 2 of 4

"Snow White" wrote in message <jalev3$b$1@newscl01ah.mathworks.com>...
>
> i have tried the following method which apparently gives the translational distances and works on binary images but its not working.
>
> [x,y]=max(ifft((fft(img)*conj(fft(ref_img)))/abs(fft(img)*fft(ref_img))))
>
> Could anyone please help me out with this?
====================

I'm pretty sure you want to be using .* operations instead of *

You could also try calculating the weighted centroids of each image using REGIONPROPS and assessing the translation of the centroids.

Subject: image registration

From: Matt J

Date: 24 Nov, 2011 15:04:08

Message: 3 of 4

"Matt J" wrote in message <jallmo$ito$1@newscl01ah.mathworks.com>...
>
>
> I'm pretty sure you want to be using .* operations instead of *
--------------------------------

And ./ of course....

Subject: image registration

From: Snow White

Date: 24 Nov, 2011 15:07:08

Message: 4 of 4

"Matt J" wrote in message <jallmo$ito$1@newscl01ah.mathworks.com>...
> "Snow White" wrote in message <jalev3$b$1@newscl01ah.mathworks.com>...
> >
> > i have tried the following method which apparently gives the translational distances and works on binary images but its not working.
> >
> > [x,y]=max(ifft((fft(img)*conj(fft(ref_img)))/abs(fft(img)*fft(ref_img))))
> >
> > Could anyone please help me out with this?
> ====================
>
> I'm pretty sure you want to be using .* operations instead of *
>
> You could also try calculating the weighted centroids of each image using REGIONPROPS and assessing the translation of the centroids.

i have used .*
assessing the translation using the method i have used above?

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