Automatische Schwellwertbestimmung für numerische Abtaster

摘要

A computer-based system and method automatically determines a threshold level for each cell of a digital document having one or more cells. Each cell of the document has a plurality of pixels and each pixel has associated therewith a plurality of bits to represent a graylevel for that pixel. A co-occurrence matrix (200) indicating a quantity of each pixel graylevel pair (220) in the cell is constructed (104). From this matrix, a first histogram (600) is constructed (504) and used to determine (112) a background and a foreground peak for the cell and the features (116) for these peaks. The center of mass for the cell is determined (120) based on these features and is used to determine (124) the threshold level for the cell.