| 摘要 |
<p>A thresholding algorithm selection apparatus for selecting the threshold algorithm to be applied to a specimen in a digital imaging process is disclosed. The specimen is preliminarily scanned and thresholded using a predetermined thresholding algorithm. The resulting preliminary digital image is divided into a number of cells or regions. Each cell is classified according to its optical characteristics; e.g. textual, photographic, etc. The cell classification is effected in the preferred embodiment by comparing the average white and black run-lengths of each cell to experimental average run-length values which are representative of the different types of specimens. The specimen is re-scanned and thresholded with an appropriate thresholding algorithm for each cell. Additionally, the digital imaging system may contain an optical character recognition program in which case the cell characterization step is used to trigger the optical character recognition program in a textual region, while causing the optical character recognition program to ignore non-textual cells.</p> |
