Generation of PDF with vector symbols from scanned document
Ilya V. Kurilin, Ilia V. Safonov, Michael N. Rychagov, Ho‐Keun Lee, Sangho Kim, Don-Chul Choi · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2013
The paper is devoted to the algorithm for generation of PDF with vector symbols from scanned documents. The complex multi-stage technique includes segmentation of the document to text/drawing areas and background, conversion of symbols to lines and Bezier curves, storing compressed background and foreground. In the paper we concentrate on symbol conversion that comprises segmentation of symbol bodies with resolution enhancement, contour tracing and approximation. Presented method outperforms competitive solutions and secures the best compression rate/quality ratio. Scaling of initial document to other sizes as well as several printing/scanning-to-PDF iterations expose advantages of proposed way for handling with document images. Numerical vectorization quality metric was elaborated. The outcomes of OCR software and user opinion survey confirm high quality of proposed method.