Hiroshi Yashiro

A high-speed algorithm for propagation-type labeling based on block sorting of runs in binary images

A fast algorithm for component labeling of binary images is proposed. Component labeling is an important method for separation of objects in document image understanding, especially in character and picture extraction. The proposed algorithm is based on sorting and tracking of runs and label propagation to the connected runs. Each scan line is partitioned into small segments, i.e. blocks and runs on the scan line are sorted according to the block sequence to speed up tracking of runs. It was ascertained by experiment that the processing time is 16.7 times faster than that of the conventional pixel-based labeling method.<<ETX>>

A new method of document structure extraction using generic layout knowledge

A method of document structure extraction using generic layout knowledge is described. With this method, it is possible to translate images of multimedia documents, i.e. documents that include pictures, graphics, and color information, to hypertext. Hypertext consists of decomposed elements linked with each other through some logical relationship. The principal components of the method are extraction of logical structure elements using a rectangular set operation and generation of hierarchical links of the logical structure between the extracted document elements. It is shown experimentally that the logical structure of a technical paper can be extracted.<<ETX>>