Median vs. Average filter. The "bright spot" artefact (of Figure 2). Top row: raw image from the same are of three chips showing gene expression from the same sample under three experimental conditions. 3 chip filtering relies on information from the three presented chips measured at 6 hrs only, while 6 chip filtering also draws on the chips observed at 24 hrs.
Suárez-Fariñas et al. BMC Bioinformatics 2005 6:65 doi:10.1186/1471-2105-6-65