function getLeftmostPoint(y)

  local x1 = 0

  while x1 < img.width and img.getInt(x1, y) >= 0xF00000 do

    x1 = x1+1

  end

  return x1

end

function getRightmostPoint(y)

  local x2 = img.width

  while x2 > 0 and img.getInt(x2-1, y) >= 0xF00000 do

    x2 = x2-1

  end

  return x2

end

function getWidth(y)

  local x2 = getRightmostPoint(y)

  local x1 = getLeftmostPoint(y)

  return math.max(0, x2-x1)

end

function getAverageWidth(y1, y2)

  local sum = 0

  for y = y1, y2-1 do

    sum = sum+getWidth(y)

  end

  return sum/(y2-y1)

end

function upperWidthToLowerWidth()

  local upper = getAverageWidth(0, math.floor(img.height/3))

  local lower = getAverageWidth(math.floor(img.height*2/3), img.height)

  return upper/lower

end