An edge inspection method for detecting defects on a wafer edge normal surface
includes acquiring a set of digital images which captures a circumference of the
wafer. An edge of the wafer about the circumference is determined. Each digital
image is segmented into a plurality of horizontal bands. Adjacent edge clusters
about the circumference of the wafer are combined into edge pixel bins. The edge
pixel bins are analyzed via edge clusters analysis to identify defects. The edge
pixel bins are also analyzed via blob analysis to determine defects.