measurepxdist.m

function [ d ] = measurepxdist( imloc )
%MEASUREPXDIST Measure distance between pixels in an image
%   Returns distance in pixels.  
%   Shows line between left-click and right-click.
imshow(imloc)
  im = gcf();
hold on
title('Click the two points, left click and right click, q to quit','FontSize',16)

q = 113;
button = 0;
p1 = [0 0];
p2 = [0 0];
while (button ~= q)
    [x, y, button] = ginput(1);
    if button==1
        p1 = [x y];
    elseif button==3
        p2 = [x y];
    end
    d =  sqrt(sum((p1-p2).^2));
    try
        delete(g1)
    end
        
    g1 = plot([p1(1) p2(1)],[p1(2) p2(2)],'rx-');
    xlabel(['Distance is ' num2str(d)])
end
    close(im)
end