MATLAB: Finding pixel coordinates from pixel value

Question

I am using the code as shown below to accquire the pixel coodinates of an image whose pixel value is below 80.

clc

clear all

close all

X=imread('cameraman.tif');

Y=rgb2gray(X);

for i=1:3

for j=1:3

if Y(i,j) < 80

[y z]=find(Y(i,j));

end

disp([y z]);

end

end

But my code is not working, it is showing the result as

1 1

1 1

1 1

Please help me in fixing this

Answer 1

% there might some elegant solutions but as for now try to use this one

% prepare the desktop

close all; clc; clear;

% read the image

img = imread('cameraman.tif');

% obtain the size of the image

[row, col] = size(img);

ind = 0;

for ind1 = 1:row

for ind2 = 1:col

if img(ind1,ind2)<80

ind = ind + 1;

pix_cor(ind,1) = ind1;

pix_cor(ind,2) = ind2;

end

end

end