Use of the Hough transform to separate merged text/graphics in forms

Abstract

Presents a new method for the separation of merged text/form-structure components in forms. The technique described uses a modified version of the Hough transform to detect the structure of the form. The closed contours of the connected components are approximated by piecewise linear line segments. The parameters of the Hesse normal form of each line segment serve as input for the Hough transform. Compared to the vectorized boundary of characters, the lines of the form structure consist of appreciable more line segments with the same orientation and distance. So, the problem of the form structure detection in the database of line segments can be reduced to the detection of local peaks in the Hough space. Subsequent processing steps reconstruct the remaining contour fragments to characters.<>