1. A method for detecting defects on a wafer, comprising: generating output for a wafer by scanning the wafer with first and second inspection systems; generating first image data for the wafer using the output generated using the first inspection system and second image data for the wafer using the output generated using the second inspection system; combining the first image data and the second image data corresponding to substantially the same locations on the wafer thereby creating additional image data for the wafer; and detecting defects on the wafer using the additional image data.