Department of Energy, grant DE FG02 92ER14261 and by Sandia National Laboratories, contract AU 9640. More recently, several thresholding methods have been evaluated by . D. Trier and A. K . The method introduced in this paper can be classified as a thresholding scheme. Image thresholding can be handled globally, determining a single threshold for the entire image, or locally, applying different thresholds in different spatial regions.
Binary analysis is based on a locally adaptive thresholding of the gray scale image.
It is even possible that almost all the essential information in the map image is preserved with this method. Then , a sequence of segmentation steps extracts long lines, symbol candidates, and split connected symbol candidate pairs. Finally , the individual symbol candidates are classified using the binary raster representation. Locally Adaptive Binarization. Pattern Analysis and Machine Intelligence, vol.