Fig. 3
From: Unsupervised image segmentation for microarray spots with irregular contours and inner holes
a The schematic diagram shows rectangles, R small (1) and R big (2). R small embeds only the spot in the middle of the field, whereas R big encloses additionally the local background area. b A blow up of the two rectangles, R small and R big , lead to the definition of the three inscribed ellipses E F , E B , and E E . The defined ellipses show the areas of foreground (1), background (2), and exclusion zone (3) pixels