IMAGE PROCESSING METHODS FOR DETERMINING
MANUSCRIPT AND CHARACTER FEATURES
Project WSP3 in the DFG Collaborative Research Center "Manuscript Cultures"
Visual features of manuscripts - layout, text and image appearance, shapes of individual characters - may provide clues about the origin of the manuscript and eventually about its historical and cultural context. To date, methods for determining and analysing such features were primarily based on manual selection and subjective evaluation by human experts.
Goals of this project:
Recovering individual strokes in historical manuscripts can provide a valuable basis for various goals of manuscript analysis, e.g. retrieving similar allographs, comparing the handwriting of scribes, or recognising characters. We have developed a method for stroke analysis using the Constrained Delaunay Triangulation (CDT), previously proposed for shape decomposition in image analysis. Applied to handwritten graphemes, this method marks possible start points, end points and intersections of strokes based on local contour properties, thus providing stroke segments from which complete strokes can be formed by concatenation.
A possible common origin of manuscripts may be determined by comparing character features such as angles between strokes. Using subpixel watershed segmentation, the contour of a character can be determined even in degraded low-resolution images. Stroke directions are determined by fitting straight lines to individual strokes.
|Herzog, R.; Neumann, B.;
Solth, A.: Computer-based Stroke Extraction in Historical Manuscripts.
Manuscript Cultures, Newsletter No. 3, 2011, 14-24 PDF
|Solth, A., Neumann, B.,
Stelldinger, P.: Strichextraktion und -analyse handschriftlicher
chinesischer Zeichen. Report FBI-HH-B-291/09, Department
of Informatics, University of Hamburg,