Fig. 2From: Joint pre-processing framework for two-dimensional gel electrophoresis images based on nonlinear filtering, background correction and normalization techniquesTwo-dimensional gel electrophoresis – 2-DGE – image from a human urine sample (samp_05). a Original image. b 2-DGE image normalized using histogram equalization. c 2-DGE image normalized using adaptive piecewise histogram equalization. d 2-DGE image normalized using modification of background pixel intensityBack to article page