Look Closely: Those Lines are Straight

on 22 Oct 2021

% Checkerboard optical illusion

% Ratul Das - rd608@cam.ac.uk

n=50; % width of each b/w cell

g=750; % width of checkerboard

m=@mod;

% checkerboard creation (shortest possible method)

o=ones(1,g);

o(m(0:749,100)<n)=0;

q=repmat(2*o-1,[g,1]);

a=.5-q'*q/2;

% smaller checkerboard dots creation

for c=6:n

h=m(c,2);

[r,d]=ind2sub([7 7],c);

x=[r;d]-8;

e=n*r;

f=n*d;

if x*x'<n

if r<7

a=p(e+35:e+48,f+3:f+16,h,a);

end

if d<7

a=p(e+3:e+16,f+35:f+48,h,a);

end

imshow(a);

function a=p(u,v,w,a)

l=751;

a([u l-u],[v l-v])=w;

end