MATLAB PROGRAM FOR HISTOGRAM EQUALIZATION

/*MATLAB PROGRAM FOR HISTOGRAM EQUALIZATION*/

clear all

clc

a=imread('cameraman.tif');

a=double(a);

big=max(max(a));

[row col]=size(a);

c=row*col;

h=zeros(1,300);

z=zeros(1,300);

for n=1:1:row

for m=1:1:col

if a(n,m)==0

a(n,m)=1;

end

end

end

for n=1:1:row

for m=1:1:col

        t=a(n,m);

h(t)=h(t)+1;

end

end

pdf=h/c;

cdf(1)=pdf(1);

for x=2:1:big

cdf(x)=pdf(x)+cdf(x-1);

end

new=round(cdf*big);

new=new+1;

for p=1:1:row

for q=1:1:col

temp=a(p,q);

b(p,q)=new(temp);

        t=b(p,q);

z(t)=z(t)+1;

end

end

b=b-1;

subplot(3,3,1)

imshow(uint8(a));

title('original image')

subplot(3,3,2)

bar(h)

title('original histogram')

subplot(3,3,3)

imshow(uint8(b));

title('image after histogram equalization')

subplot(3,3,4)

bar(z)

title('Histogram Equalized')

OUTPUT