Directional adaptive image filtering: application to DNA sequence analysis

DNA sequencing consists of retrieving the arrangement of nitrogenous bases which contain the genetic information of living systems. Most of sequencing devices are based on the analysis of electrophoretograms. Thus the 3D structure of DNA molecules is represented by a 2D grey level image. Because of the physical and chemical processes involved, resulting images are noisy and blurred. The objects to be localized in the image are thin and stretched structures. In this paper, we introduce a directional adaptive filter aiming at preserving the shape of the structures and at reducing noise and artifacts. This filter selects an appropriate sub-window and operates an order filtering in it. Some statistical properties of this filter are studied. Experimental results are then presented