Fig. 6

DSR (see text for details) with respect to the number of pictures composited. Blue and red curves show the examples from Mt. Tokachidake (Fig. 3) and those from Mt. Meakandake (Fig. 4), respectively. The thicker lines with symbols are processed in the order of time, while the thinner lines are the cases in which pictures are randomly resorted and composited, and averaged over 10 times