Study of Gray level transformations on an image using MATLAB

Contrast stretching-Study of Gray level transformations on an image using MATLAB

a= input (Enter the path of the image:); % accept image path from user

b= imread (a); % read the image

[x,y]=size (b); % store the image in matrix form

d=max (max (b)); % find he max value in the matrix
for i=1:x

for j=1:y

if(b(i,j))<=50

f(i,j)= 0.2*(b(i,j));

elseif (50<=(b(i,j))<=150)

f(i,j)=2*(b(i,j)); %formula for contrast stretching;

elseif 150<=b(i,j)<=d

f(i,j)= 0.3*(b(i,j));

end

end

end

figure

subplot(1,2,1)

imshow(b) % show original image

title(Original image)

subplot(1,2,2)

imshow(f) % show transformed image

title(Contrast Stretching)

Negative transform-Study of Gray level transformations on an image using MATLAB

% Log Transformation
clc; clear all; close all;
a= input (Enter the path of the image:); % accept image path from user
[x,y]=size (b);

b= imread (a); % read the image


e=im2double(b);

for i=1:x

for j=1:y

S(i,j)= 1*(1+log10(e(i,j))); % formula for log transformation

end

end

figure

subplot(1,2,1)

imshow(b) % show original image

title(Original image;)

subplot(1,2,2)

imshow(S) %Show log transformed image

title(Log transformed Image&)

Power law transformation-Study of Gray level transformations on an image using MATLAB

% Power law transformation
clc; clear all; close all;
a= input (Enter the path of the image:); % accept image path from user

b= imread (a); % read the image

[x,y]=size (b); % store the image in matrix form

d=max (max (b)); % find he max value in the matrix

r=input(Enter value of r:)

for i= 1:x

for j= 1:y
a= input (Enter the path of the image:); % accept image path from user

b= imread (a); % read the image

[x,y]=size (b); % store the image in matrix form

d=max (max (b)); % find he max value in the matrix

Study of Gray level transformations on an image using MATLAB

1] Negative Transform

clc; clear all; close all;

% Negative transformation

a= input (Enter the path of the image:); % accept image path from user

b= imread (a); % read the image

[x,y]=size (b); % store the image in matrix form

d=max (max (b)); % find he max value in the matrix

for i=1:x

for j=1:y

fn(i,j)=d-b(i,j); %formula for negative transform of image

end

end

figure

subplot(1,2,1)

imshow(b) ; % show original image

title(Original image)

subplot(1,2,2)

imshow(fn) % show –ve transform of image

title(Negative image)