Theoretical Foundations -- Euler Well-Composedness -- On Connectedness of Discretized Sets -- Persistent Homology as Stopping-Criterion for Voronoi Interpolation -- Atomic Super-Resolution Tomography -- Characterizations of Simple Points on the Body-Centered Cubic Grid -- A 4D Counter-Example Showing that DWCness does not Imply CWCness in nD -- 3D-Array Token Petri Nets Generating Tetrahedral Picture Languages -- Simulating Parallel Internal Column Contextual Array Grammars Using Two-Dimensional Parallel Restarting Automata with Multiple Windows -- Grayscale Uncertainty of Projection Geometries and Projections Sets -- Finding the Maximum Empty Axis-Parallel Rectangular Annulus -- Parallel Contextual Array Insertion Deletion Grammar and (Context-free : Context-free) Matrix Grammar -- Digital Hyperplane Fitting -- Methods and Applications -- Repairing Binary Images through the 2D Diamond Grid -- Transmission Based Adaptive Automatic Tube Voltage Selection for Computed Tomography -- MicrAnt: Towards Regression Task Oriented Annotation Tool for Microscopic Images -- Graph Cuts Based Tomography Enhanced by Shape Orientation -- Dealing with Noise in Cluster Pattern Interface -- Local Q-Convexity Histograms for Shape Analysis -- k-Attempt Thinning -- Fuzzy Metaheuristic Algorithm for Copy-Move Forgery Detection in Images.

This book constitutes the refereed proceedings of the 20th International Workshop on Combinatorial Image Analysis, IWCIA 2020, held in Novi Sad, Serbia, in July 2020. The 20 full papers presented were carefully reviewed and selected from 23 submissions. The papers are grouped into two sections. The first one includes twelve papers devoted to theoretical foundations of combinatorial image analysis, including digital geometry and topology, array grammars, picture languages, digital tomography, and other technical tools for image analysis. The second part includes eight papers presenting application-driven research on topics such as image repairing, annotation of images, image reconstruction, forgery detection, and dealing with noise in images.