get("#348") -- bright and rgb

w, h = img.width, img.height

min, max = 1, 0

for y = 0, h-1 do
  for x = 0, w-1 do
    b = bright(rgb(img.getInt(x, y)))
    min, max = math.min(min, b), math.max(max, b)
  end
end

minp = math.floor(min*100+0.5)
maxp = math.floor(max*100+0.5)

return "Brightness range: "..minp.."-"..maxp.."%"