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Topic: How to calculate the angle between two images?
Replies: 41   Last Post: Dec 8, 2012 11:02 PM

 Messages: [ Previous | Next ]
 khoo Posts: 63 Registered: 8/9/08
Re: How to calculate the angle between two images?
Posted: Apr 3, 2009 12:29 PM

> > > Now you need to make 2 histograms (one from each of your angle images) of your trusted angles. What you find is that these histograms are virtually identical, with the exception that they are shifted relative to each other. This shift is equal to the relative rotation of the original images.
> > >

> >
> > i ady done the in front part but stuck at the modified edge image over corresponding angle..i dunno wat function need to be used..i using time but got error..
> >
> > this is the code i currently obtained so far
> >
> > im11=rgb2gray(im1);
> > im111=im2double(im11);
> > p1=atan2(dy,dx);
> > im1111=edge(p1,'canny');
> > bw1 = bwmorph(im1111,'dilate');
> > im=p1*bw1;
> > imshow(im)
> >
> > this is the error messange i got
> > ??? Error using ==> mtimes
> > Inner matrix dimensions must agree.
> >
> > so wat the function i need to used??

>
> I am a bit busy to study your code closely right at the moment, but what seem to be a problem is
> im=p1*bw1;
> I would have thought that it should read
> im=p1.*bw1;
>
> The dot before the * is kind of crucial check the help files.
>
> By the way I am impressed with the speed at which you converted my description into code, it might not have worked first time, but this is the only way to really get to grips with a very powerful problem solving tool
>
> Well done
>
> Dave Robinson

now i ady done until get the histogram, but how to get the angle between two image?? i no understand this statement

What you find is that these histograms are virtually identical, with the exception that they are shifted relative to each other. This shift is equal to the relative rotation of the original images.

this is my code currently..i dunno how to find the angle out between two image....

clear all;clc

im11=rgb2gray(im1);
im111=im2double(im11);
p1=atan2(dy,dx);
im1111=edge(p1,'canny');
bw1 = bwmorph(im1111,'dilate');
im11111=p1.*bw1;
[max_angle1]=find(max(max(im11111)));
subplot(2,1,1);hist(im11111)

im22=rgb2gray(im2);
im222=im2double(im22);
p2=atan2(dy,dx);
im2222=edge(p2,'canny');
bw2 = bwmorph(im2222,'dilate');
im22222=p2.*bw2;
[max_angle2]=find(max(max(im22222)));
subplot(2,1,2);hist(im22222)

the max angle i try find for each image..but all is same...is 1..what i need to do next??

Date Subject Author
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 khoo
4/4/09 khoo
4/4/09 Dave Robinson
4/4/09 khoo
4/4/09 khoo
4/5/09 khoo
4/5/09 Dave Robinson
4/5/09 khoo
4/5/09 khoo
4/5/09 Dave Robinson
4/5/09 khoo
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 khoo
4/6/09 khoo
4/7/09 khoo
4/7/09 khoo
4/7/09 Dave Robinson
12/8/12 Jeff
4/3/09 Skeptic
4/3/09 Dave Robinson
4/3/09 Roger Stafford
4/3/09 khoo
4/3/09 Roger Stafford
4/3/09 ImageAnalyst
4/3/09 khoo
4/4/09 khoo
4/6/09 Matt
4/6/09 khoo
4/6/09 Matt