Extraction of courtesy amount item from Chinese check

In Chinese, thousands of bankchecks are validated due to manual processing every day to find out the bankchecks, which are invalidate to the bank´s rules or contain error input information. It is necessary to relieve people from these intensive and tedious works. This paper presents a technique, which is the preprocess stage in our auto-validating system, for extracting the user-entered courtesy amount item from Chinese bankcheck images. Seal imprints in different types and positions cause the main difficulty in the extracting procedure. Instead of removing lines in bi-level images, we proposed a line removal algorithm based on crossing shape analysis in gray-level image. The handwritten information is extracted by a new recursive thresholding algorithm, which can continue removing the brighter background until only the darkest object is left. The proposed methods have been evaluated on real-life Chinese checks. And the results demonstrate the effectiveness of the proposed preprocessing techniques.