Morphological Operation 1) Opening 2)Closing 3) Erosion 4) Dilation 5) Boundary Extraction

% morphdemo.m

% demonstration of morphological operators

clc;

clear all; 

close all;

load p64int.txt; % 64 x 64 gray scale image

V=[80:168];

x=ones(size(p64int))-ismember(p64int,V);

figure(1),clf,

subplot(231),imagesc(x),colormap('gray')

% dialation and erosion

disp('***********************************')

disp('0 - square (default)');

disp('1 - circle');

disp('2 - lower triangle');

choice=input('Enter your structure element choice: ');

if isempty(choice), choice=0; end

switch choice

case 0                    % rectangle structure element

   dimen=input('enter dimension of the rectangle structure element (default 3): ');

   if isempty(dimen), dimen=3; end

   S=ones(dimen);

case 1                    % circle element

   r=input('enter radius of the circle structure element (default = 2): ');

   if isempty(r), r=2; end

   S=zeros(2*r+1); % a square of 2r+1

   for i=1:2*r+1,

      for j=1:2*r+1,

         if (i-r-1)^2+(j-r-1)^2 <=r^2; S(i,j)=1;

         end

      end

   end

case 2% triangular shape

   S=[1 0 0; 1 0 0; 1 1 1];

end

% figure(2),clf,imagesc(S);,colormap('gray')

disp('Dilation and Erosion')

% using command dilate and erode

y1=dilate(x,S);

figure(1),subplot(232),imagesc(y1),title('dilation')

y2=erode(x,S);

figure(1),subplot(233),imagesc(y2),title('erosion')

%pause

disp('Opening and Closing')

% opening and closing

y3=dilate(y2,S);  % opening

figure(1),subplot(234),imagesc(y3),title('opening')

y4=erode(y1,S); % closing

figure(1),subplot(235),imagesc(y4),title('closing')

%pause

% boundary extraction

beta=x-double(erode(x,S));

figure(1),subplot(236),imagesc(beta),title('boundary extraction')

Morphological Operations