khoo
Posts:
63
Registered:
8/9/08


Re: How to calculate the angle between two images?
Posted:
Apr 6, 2009 4:25 AM


> Why on earth are you trying to convert an image into a 1 dimensional vector? you are correlating 2 histograms  histograms are essentially graphs  in your case angle along the x axis, number of pixels of that angle in y direction. If you have say 256 angles, then each bin represents (2*pi)/256 radians. Thus the histogram will be a vector of 256 numbers, each number representing the number of pixels of that angle. > > I suggest you carefully read help hist(), doesn't that default to 10 bins  you will need to have much better resolution than that. > > I have had a look at your images, and would have thought they were ideally suited to this methodology. > > Regards > > Dave Robinson
Bro Dave, this is my code currently...and i ady change the hist not to default 10 binsand set to 256..
clear all;clc
im1=imread('image1.jpg'); im11=rgb2gray(im1); im111=im2double(im11); [dx,dy]=gradient(im111); p1=atan2(dy,dx); im1111=edge(p1,'canny'); bw1 = bwmorph(im1111,'dilate'); im11111=p1.*bw1; im6=hist(im11111(:),256); im66=fft(im6);
im2=imread('image2.jpg'); im22=rgb2gray(im2); im222=im2double(im22); im333=zeros(size(im111)); im333(1:size(im2,1),1:size(im2,2))=im222; [dx,dy]=gradient(im333); p2=atan2(dy,dx); im2222=edge(p2,'canny'); bw2 = bwmorph(im2222,'dilate'); im22222=p2.*bw2; im7=hist(im22222(:),256); im77=conj(fft(im7)); im99=im66.*im77; im8=real(ifft(im66.*im77)); XXX=hist(im8(:),256); stem(1:256,XXX, 'Marker', 'none');
and this is my new image2.. http://i278.photobucket.com/albums/kk119/khoo011/image21.jpg
just now i check all the histogram for the im11111 and im22222..all is correct..but once i fft the both histograms..when i inverse the FFT..the histogram cannot inverse and still stay in FFt mode...can you help me check my code got any problem ? and teach me how to fix the problem..so far i find the peak is at left side which is after FFT..

