Prev: inverse of a polynominal function
Next: Vector to one Double in simulink
From: Deepak Sankar on 13 Jul 2010 12:43
Hey all,,

I have a question with image alignment. I have two sets of height data of a surface at different temperatures from an experiment. The data set has both translation and rotation. The data is saved as matrix format. Now i need to align those data sets.. What I have done is, I converted the matrix to gray format using mat2gray and found the edges of feature on the surface using canny filter. I found the angle by selecting a set of points in edge plot (logical data set) and fitted a line to it and then found the angle for that line. I have removed the rotation from both the data set using imrotate. Now the angle is removed I need to correct for translation in x and y.
Since I am doing the experiement at different temperatures some noise factor add in to the data set. I know I can use cpselect for manually selecting the contol points and then find the translation. Wondering if there is any automatic way of doing it?

Thanks
Deepak
From: Deepak Sankar on 13 Jul 2010 12:53
Forgot to add in this... Normalized Cross-Correlation isn't working well because of noise factor...
From: Sean on 13 Jul 2010 14:05
"Deepak Sankar" <deepaksankar(a)yahoo.com> wrote in message <i1i5lg$1a2$1(a)fred.mathworks.com>...
> Forgot to add in this... Normalized Cross-Correlation isn't working well because of noise factor...

Do a search on here for "phase correlation." It can handle both rotations and translations as well as scaling. Also it's fairly resilient to noise and intensity differences.
From: Sean on 13 Jul 2010 14:06
"Deepak Sankar" <deepaksankar(a)yahoo.com> wrote in message <i1i5lg$1a2$1(a)fred.mathworks.com>...
> Forgot to add in this... Normalized Cross-Correlation isn't working well because of noise factor...

Also, see this submission:
http://www.mathworks.com/matlabcentral/fileexchange/18401-efficient-subpixel-image-registration-by-cross-correlation
 | 
Pages: 1
Prev: inverse of a polynominal function
Next: Vector to one Double in simulink