function[samps] = getRoi(img)

imagesc (img);
rp = double(roipoly);

im_R = double(img(:,:,1));
im_G = double(img(:,:,2));
im_B = double(img(:,:,3));

rpi = find( rp > 0 );

samps = [im_R(rpi),im_G(rpi),im_B(rpi)];