another proposed way of assessing lacunarity using box counting, the "prefactor" method, is based on the value obtained from box counting for the fractal dimension (formula_41). this statistic uses the variable formula_42 from the scaling rule formula_43, where formula_42 is calculated from the y-intercept (formula_45) of the ln-ln regression line for formula_4 and either the count (formula_47) of boxes that had any pixels at all in them or else formula_18 at formula_49. formula_42 is particularly affected by image size and the way data are gathered, especially by the lower limit of formula_4s used. the final measure is calculated as shown in equations through :