An adaptive correction algorithm of non-linear distorted document

作者：Li Bo; Wang Jiangqing; Xu Shengzhou; Xu Ning; Li Fan; Deng Ying

来源：Journal of Computational Methods in Sciences and Engineering, 2016, 16(4): 807-820.

DOI：10.3233/JCM-160693

• Document image correction
• non-linear distortion
• text lines
• two-level structure
• document region partition

Document images tend to warp when scanned or photocopied in document processing, resulting in non-linear distortion which can cause a decrease in image quality, and bring errors to image analysis and recognition. This paper treats the warped text lines as curves of non-linear function, and proposes an adaptive non-linear correction model to rectify the distorted document images. The model is based on a novel character and word two-level structure and flexible parameters calculation method which are robust to various kinds of distortions of text lines. After pre-processing, character-based connected domains are detected and merged. Some methods are used to locate the heads of text lines, trace them and extract each text line accurately. Character connected domains are then sorted via insertion sort algorithm, and important parameters are adaptively calculated by adopting statistics method related to document region partition. Finally, tilt angle is calculated using angle calculation model, which is based on word-level unit, and curled text lines are corrected adaptively based on character-level unit. Experimental results show that the method proposed is effective and robust in correcting the curl of text lines in various degrees and directions.

• 出版日期2016
• 单位武汉理工大学