Fig. 8. Three-dimensional comparison of the electric images of different objects, with the modulation caused by the object colour coded. (A) The electric image of a metal cube. (B) The electric image of a plastic cube. (C) The electric image of a metal sphere. (D) The electric image of a plastic sphere. Note that high modulation values are shown in red and low modulation values are shown in blue. Therefore, the baseline for conductive objects (metal) is shown in blue and the baseline for non-conductive objects (plastic) in red.