# IMAGE PROCESSING

" Two roads diverged in a wood, and I,
I took the one less traveled by,
And that has made all the difference "-Robert Frost

### Swirl effect in MATLAB

After reading a couple of image processing books, I tried to implement some Photoshop effects in MATLAB.  First, I tried to implement the twirl effect in MATLAB.

The mid point of the image is stored in the variables ‘midx’ and ‘midy’.
The angle and the radius for each point in the image are found by converting the co-ordinates from Cartesian to polar co-ordinates.

The effect can be obtained by using the following formula:
new[rho , theta] = old[rho , theta + rho /K] .

By changing the value of K, the swirl can be increased or decreased.

For more fun, try this effect with your own photography image.

Additional Information: Learn to make your own Photoshop effects so that you can code your own effects.

For beginners in photoshop: Read photoshop for dummies .

MATLAB CODE:

B=uint8(zeros(size(A)));
figure,imshow(A);

%Mid point of the image
midx=ceil((size(A,1)+1)/2);
midy=ceil((size(A,2)+1)/2);
 K=150
K=100;
x2=zeros([size(A,1) size(A,2)]);
y2=zeros([size(A,1) size(A,2)]);
for i=1:size(A,1)
x=i-midx-K;
for j=1:size(A,2)
%Cartesian to Polar co-ordinates
[theta1,rho1]=cart2pol(x,j-midy+K);

phi=theta1+(rho1/K);

%Polar to Cartesian co-ordinates
[l,m]=pol2cart(phi,rho1);
x2(i,j)=ceil(l)+midx;
y2(i,j)=ceil(m)+midy;

end
end

%The result may produce value lesser than 1 or greater than the image size.

x2=max(x2,1);
x2=min(x2,size(A,1));

y2=max(y2,1);
y2=min(y2,size(A,2));

for i=1:size(A,1)
for j=1:size(A,2)
B(i,j,:)=A(x2(i,j),y2(i,j),:);
end
end

figure,   imshow(B);
 K=100

Reference:

FOR FUN:
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Chintan Patel said...

How to implement different color tint on image using matlab?

Chintan Patel said...

how can we implement different color tint on iimage using matlab?

abc said...

its really good but pretty confusing so can u plz explain a bit more about the code ans how u have implemented it.