From: "khoo" <>
Newsgroups: comp.soft-sys.matlab
Subject: Re: How to calculate the angle between two images?
Date: Mon, 6 Apr 2009 15:16:02 +0000 (UTC)
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References: <gr4ten$oks$> <grd4l5$m4s$>
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"Matt " <> wrote in message <grd4l5$m4s$>...
> "khoo" <> wrote in message <gr4ten$oks$>...
> > Hi all, currently i face the problem to find the rotation angle...i got one image is rotate in unknown angle compare with the original image, but i not have idea how to calculate the angle cause the angle is a variable angle..can anyone senior teach me here,...need it urgently...and i quite noob in image processing..
> Another approach is to use the radon() function (assuming you have the image proc toolbox) of both images. The rotations of the 2 images will manifest as a shift in their radon projections. You can then use correlation techniques to compute the shift. Because this employs integration operations instead of differentiation, it might be more robust to noise than the gradient-angle technique.

the radon() function no need theta to to work on??