x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');

SquareMask = [1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1]; 
CircleMask = [0 0 1 0 0; 0 1 1 1 0; 1 1 1 1 1; 0 1 1 1 0; 0 0 1 0 0]; 


w=imerode(x,SquareMask);
w1=imerode(x,CircleMask);

figure 
imshow(w);
figure
imshow(w1);
figure
imshow(x)



x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');

SquareMask = [1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1]; 
CircleMask = [0 0 1 0 0; 0 1 1 1 0; 1 1 1 1 1; 0 1 1 1 0; 0 0 1 0 0]; 


w=imdilate(x,SquareMask);
w1=imdilate(x,CircleMask);

figure 
imshow(w);
figure
imshow(w1);
figure
imshow(x)



x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');

CircleMask = [0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;0 1 0 1 0 1 0 1 0 1 0;]; 


w1=imdilate(x,CircleMask);

figure
imshow(w1);
figure
imshow(x)


x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');

SquareMask = [1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1]; 
CircleMask = [0 0 1 0 0; 0 1 1 1 0; 1 1 1 1 1; 0 1 1 1 0; 0 0 1 0 0]; 


w=imopen(x,SquareMask);
w1=imopen(x,CircleMask);

figure 
imshow(w);
figure
imshow(w1);
figure
imshow(x)

x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');

SquareMask = [1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1; 1 1 1 1 1]; 
CircleMask = [0 0 1 0 0; 0 1 1 1 0; 1 1 1 1 1; 0 1 1 1 0; 0 0 1 0 0]; 


w=imclose(x,SquareMask);
w1=imclose(x,CircleMask);

figure 
imshow(w);
figure
imshow(w1);
figure
imshow(a)


x=imread('boats.pgm');
y=imread('lena.pgm');
z=imread('noised2.pgm');
c=imread('noised3.pgm');
a=imread('noised4.pgm');




w=medfilt2(z,[5 5]);


figure 
imshow(w);
figure
imshow(z)