This paper describes a technique for local thresholding of large digital images, obtained from line drawings of low quality. It is based on two main steps. First, the gray level image is thresholded with a global value, to discard those pixels which surely belong to a non significant background. A suitable run representation is used to compress the resulting image. Then, for each run, a set of connected runs is used to compute a local thresholding value. This threshold is applied to the pixels of the current run, to obtain the final binary image.

Date Published: 1 November 1989
PDF: 5 pages
Proc. SPIE 1199, Visual Communications and Image Processing IV, (1 November 1989); doi: 10.1117/12.970080

Published in SPIE Proceedings Vol. 1199:
Visual Communications and Image Processing IV
William A. Pearlman, Editor(s)