Reeb graph based examination of root development

This paper presents an approach to analyze plant root development by means of topological image analysis. For phenotyping of plants their root development, the architecture of their root systems and thereby root characteristics such as branches and branch endings are analyzed. In order to simplify the examination of root characteristics and enable an efficient comparison of roots, a representation of imaged root data by Reeb graphs is introduced. Reeb graphs capture the topology of the represented structure in this case the locations of branches and branch endings of the roots and form a skeletal representation of the underlying image data in this way. As the roots are pictured as 2D image data, the projection of a 3D structure to a 2D space might result in an overlap of branches in the image. One major advantage when analyzing roots based on Reeb graphs is posed by the ability to immediately distinguish between branching points and overlaps in the root structure. This is not as easily possible by an analysis solely based on contours.