BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an illustrative diagram of the present invention;
FIG. 2 depicts an illustrative view of one embodiment of the detection apparatus of the present invention;
FIG. 3 is an illustrative block diagram of a signal processor and analyzer in the embodiment of FIG. 2;
FIG. 4 is a pearl layer image obtained from the embodiment of FIG. 2.