Multifractal nature in the power-law of the gray image of leaf MX017. (a): The plots of the detrended fluctuation function F
(s) for different values of q. In order to make clearer contrast among the different curves, some constants are subtracted. The straight lines are the best fitted lines whose slopes are shown in the legend. (b): Dependence of τ(q) and h(q) on q.