Image Processing Color Euclidean Distance Algorithm

clc; clear; close all;
I= imread('peace.jpg');

[R,C,D] = size(I);
imshow(I);

[y,x] = ginput(1);
x=round(x);
y=round(y);

pr=I(x,y,1);
pg=I(x,y,2);
pb=I(x,y,3);

for r=1:R
for c=1:C
qr=I(r,c,1);
qg=I(r,c,2);
qb=I(r,c,3);
distance =sqrt(double(power((pr - qr),2) + power((pg - qg),2) + power((pb - qb),2)));
if(distance <10)
I(r,c,:)=255;
end
end
end

figure;
imshow(I);