how to add edges to nodes and how use minimum spanning tree

i want to apply minimum spanning to my code but it is asking graph as input

    clc;
    clear all;
    close all;
    X=imread('i2.jpg');
    imfinfo('i2.jpg')
    figure,imshow(X)
  b = imresize(X,[100,100]);
  si = size(b,1);
  sj = size(b,2);
  figure;imshow(b);
  % Binarization
  th = graythresh(b);
  I = im2bw(b,th);
  w = 5;
  h = 5;
  c=si/w;
  r=sj/h;
  kl=bwmorph(~I,'thin',inf);
  figure,imshow(kl)
  R(:,:)=kl(:,:);
  I=1;
  U1=w;
  J=1;
  U2=h;
  E=1;
  for i=1:r
    for j=1:c
  B(I:U1,J:U2)=R(I:U1,J:U2);
  [x,y]=find(B==1);
  CX=mean(x);
  CY=mean(y);
  CXX(E)=CX;
  CYY(E)=CY;
  T(I:U1,J:U2)=B(I:U1,J:U2);
  J=J+w;
  U2=U2+h;
  E=E+1;
  clear B x y
   %CYY(isnan(CYY)) = [];
   %CXX(isnan(CXX)) = [];
    end
  I=I+w;
  U1=U1+h;
  J=1;
  U2=h;
  end
  %kl(isnan(kl(:,1)),:) = [];
  imshow(R)
  hold on
  hold on
  plot(CYY,CXX,'.c','Markersize',8)
  hold off
  r = imread('empty.jpg');
  re = imresize(r,[100,100]);
  figure,imshow(re)
  hold on
  hold on
  p = plot(CYY,CXX,'k*','Markersize',8);
  hold off
  CXX(isnan(CXX)) = [0]
  CYY(isnan(CYY)) = [0]

from this i am getting only nodes i want to connect all the nodes after connecting each nodes i want to apply MINIMUM spanning tree please give me some code for add edges to nodes and how to use minimum spanning tree,

thanks in advance

[Walter Roberson]

There is no spanning tree for that graph. Spanning trees only apply to connected graphs, and that graph is very disconnected.

[Raghu Rao]

i do not know how to connect the nodes please give me some code for connecting nodes.

[Walter Roberson]

Please post your i2.jpg image

[Raghu Rao]

[Raghu Rao]

Sir, this is my input image.

[Christine Tobler]

Hi Raghu,

There is a package on the File Exchange for converting images to graphs, maybe this would be helpful to you?

Image Graphs File Exchange package

Here are also some blog posts on the topic:

• Image-based graphs » Steve on Image Processing
• A cheating maze solver with image graphs » Steve on Image Processing

[Raghu Rao]

Sir, first I want to add the edges using node neighbours analysis after adding the edges I want to apply minimum spanning algorithm. Please give me some code for add the edges to nodes

[Christine Tobler]

I'm afraid I don't understand your goal: Node neighbors analysis is typically done to understand a graph with nodes and edges, it isn't a method for adding edges to a graph.

Also, looking at the picture, it seems that the graph would already be nearly a tree, since there is only one loop. So what is your next step once you have the minimum spanning tree of this graph?

[Raghu Rao]

Am doing my project on extraction of graph from handwritten word image, In my code I am only getting nodes but I want to add edges nodes I do not know how to add the edges to nodes I need some code for adding edges to nodes, after adding nodes I want to apply minimum spanning tree.algorith to represent the image in graph

[Raghu Rao]

i want represent the hand written word in this form