function y=imfftplot(imagename)
%
% imfftplot plots spectrum of image and of regions selected by user
%
% WRITTEN BY   William Martin, will@rapidnet.com
%
% Purpose      Plots spectrum of image, of selected region (rectangular or polygon),
%              plots histogram of area, and edge detects image and overlays
%              that edge detected (and thresholded part) with original image. 
%
% USAGE        imfftplot('filename.ext');  
%              Where filename is the name of the file you want to use, extension is 
%              an extension that Matlab handles.  For a list of supported file types, 
%              type "help imread" in the matlab command window
%
% OUTPUT       These are the steps that will occur when you call this script.
%              Figure(1): Original Image and Spectrum of image
%             
%              Menu: Select either Rectangle or Polygon for selection method.
%               
%              The rectangle method assumes you are selecting while
%              holding down the left mouse button.  When you let up, that 
%              will select the region. 
%
%              The polygon method works by selecting points using the left
%              mouse button to select your points.  Once you are finished,
%              right click to select the region of interest(ROI).
%
%              Figure(2): Selected region is displayed along with its spectrum.
%
%              Figure(3): Histogram of selected region (ROI).
%
%              Figure(4): Edge detected regions overlayed on original image. 
%       
%
% NOTE   To clear all windows after you have run this several times, use
% 'close all', in the command window.
%
% SEE ALSO: imread, imagesc, imshow, imhist, fft2, fftshift, edge

% read in image and its color map
[A,map]= imread(imagename);
if(ndims(A)>2)
    A = rgb2gray(A); % convert to grayscale
end
    figure
% plot image and its fourier spectrum.
F = fftshift(fft2(A));
subplot(1,2,1),imshow(A), title(strcat('Filename:', imagename));

% display menu
answer = menu('Select method to use for spectrum analysis','Rectangle','Polygon');
% do Rectangle selection
if(answer==1)
    % get ROI.
    copied = imcrop;
    %colormap('jet');   % uncomment for "pretty colors"
    subplot(1,2,2),imagesc(log(1+abs(F)))
    figure
    subplot(1,2,1),imshow(copied),title('selected area');
    copiedfft=fftshift(fft2(copied));
    %colormap('jet');       %  uncomment for "pretty colors"
    subplot(1,2,2),imagesc(log(1+ abs(copiedfft))),title('spectrum of selected');
    
    figure, imhist(copied);
    title('Histogram of selected area');
end 
% do Polygon selection
if(answer==2) 
      
    [selected,xi,yi]=roipoly;
    % plot the spectrum of the first image (done after selecting region).
    subplot(1,2,2),imagesc(log(1+abs(F)))
   
    [r,c]=find(selected);
    ind=sub2ind(size(A),r,c);
    J=zeros(size(A));
    J(ind)=A(ind);
    figure
    subplot(1,2,1),imshow(J,map),title('Selected Area');
    subplot(1,2,2),imagesc(log(abs(fftshift(fft2(J))))), title('Plot of spectrum of a polygon');
    selected=im2uint8(J);
    figure, imhist(selected);
    title('Histogram of selected area');
end

% perform edge detection on image
r=edge(A,'canny');
% convert binary image to pseudo grayscale
r=im2uint8(r);
% do a linear combination of images
A=imlincomb(1,r,1,A,'uint8');

figure
imshow(A);
title('Edges overlayed original image');


y=F;
end