1. A wafer inspection system for detecting a feature located on a surface, comprising: a label attached to said feature, wherein said feature comprises one or more material types; an electromagnetic radiation incident on said label, said feature, and said surface to generate a label radiation from said label, a feature radiation from said feature, and a surface radiation from said surface; an imaging module positioned to collect said label radiation, said feature radiation, and said surface radiation; a filter positioned to receive radiation from said imaging module, wherein said filter separates said label radiation from said feature radiation and said surface radiation; a detector having one or more pixels disposed to capture the separated label radiation for generating an image of label; and a processor configured to locate label pixels corresponding to said label radiation by searching for pixels, in said image of label, that possess substantially different pixel values when compared to other pixels in local neighborhood, whereby said feature is located by detecting said label.