Rule Line Detection and Removal in Handwritten Text Images

Analysis of handwritten document images is one of the key areas of research in image processing domain. The objective of the analysis is to recognize the text components in an image and extract the intended information. However, inscription of handwriting usually would be on documents with rule lines, since they act as guide lines to the writer to ensure the writing remains straight and is of uniform size. These lines make the task of recognition difficult and hence removing them automatically becomes a major issue in text image processing. To accomplish this objective, an attempt is being made in this paper to remove the horizontal rule lines and vertical margin line for efficient recognition and analysis of the foreground text. Using mathematical morphology, predominant horizontal and vertical lines are removed leaving out stray lines which hinder the further processing of text. The stray lines are identified and removed using entropy with sliding window based on dynamic thresholding.