title: Atomic force microscope, molecular imaging, and analysis.
abstract: Image visibility is a central issue in analyzing all kinds of microscopic images. An increase of intensity contrast helps to raise the image visibility, thereby to reveal fine image features. Accordingly, a proper evaluation of results with current imaging parameters can be used for feedback on future imaging experiments. In this work, we have applied the Laplacian function of image intensity as either an additive component (Laplacian mask) or a multiplying factor (Laplacian weight) for enhancing image contrast of high-resolution AFM images of two molecular systems, an unknown protein imaged in air, provided by AFM COST Action TD1002 (http://www.afm4nanomedbio.eu/), and tobacco mosaic virus (TMV) particles imaged in liquid. Based on both visual inspection and quantitative representation of contrast measurements, we found that the Laplacian weight is more effective than the Laplacian mask for the unknown protein, whereas for the TMV system the strengthened Laplacian mask is superior to the Laplacian weight. The present results indicate that a mathematical function, as exemplified by the Laplacian function, may yield varied processing effects with different operations. To interpret the diversity of molecular structure and topology in images, an explicit expression for processing procedures should be included in scientific reports alongside instrumental setups.
authors.affiliation: 10A Rue Ampère, 38000, Grenoble, France.
authors.forename: Shu-wen W
authors.initials: SW
authors.lastname: Chen
authors.affiliation: CEA, iBEB, Service de Biochimie et Toxicologie Nucléaire, F-30207, Bagnols sur Cèze, France.|CEA, IBS, Univ. Grenoble Alpes/CNRS/CEA, 71 avenue des Martyrs CS 10090, F-38044, Grenoble cedex 9, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Teulon
authors.affiliation: CEA, iBEB, Service de Biochimie et Toxicologie Nucléaire, F-30207, Bagnols sur Cèze, France.|CEA, iBEB, Service de Biologie Végétale et Microbiologie Environnementale/LBDP, F-13108, Saint-Paul-Lez-Durance, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Godon
authors.affiliation: CEA, iBEB, Service de Biochimie et Toxicologie Nucléaire, F-30207, Bagnols sur Cèze, France.|CEA, IBS, Univ. Grenoble Alpes/CNRS/CEA, 71 avenue des Martyrs CS 10090, F-38044, Grenoble cedex 9, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Pellequer
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D014027:Tobacco Mosaic Virus / Q000737:chemistry
chemical_list: D011506:Proteins
keywords: AFM; COST Action; TMV; image processing; imaging