| Presentation | 2007-03-15 A Study of Rectification of Digital Camera Document Image using Shape from Parallel Geodesics Katsuhito Fujimoto, Hiroaki Takebe, Misako Suwa, Satoshi Naoi, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Methods to rectify distortion of digital camera document images of curved papers have become important for camera-based document image recognition. In this paper we propose a novel distortion rectification method based on "shape from parallel geodesics." This method considers the following features: parallel lines corresponding to character strings or ruled lines of tables on extended surface become parallel geodesics on a curved paper surface and a smoothly curved paper can be modeled by a ruled surface, that is, a sweep surface of rulings. The projected geodesics and the projected rulings exist in the input image derived from perspective transformation. The presented method extracts the projected geodesics, estimates the projected rulings in the input image, estimates the ruled surface that models the curved paper, and generates the corrected image, in this order. Continuous dynamic programming is used for the estimation of the projected rulings by the condition derived from parallelism of geodesics on the curved paper. It can estimate the ruled surface model directly by numerical operations of differentiation, integration and matrix inversion without any iterative calculation. We also report on experiments that show the effectiveness of the proposed method. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | distorted image rectification / document images / digital camera images / shape from parallel geodesics |
| Paper # | PRMU2006-252 |
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| Conference Information | |
| Committee | PRMU |
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| Conference Date | 2007/3/8(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Pattern Recognition and Media Understanding (PRMU) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Study of Rectification of Digital Camera Document Image using Shape from Parallel Geodesics |
| Sub Title (in English) | |
| Keyword(1) | distorted image rectification |
| Keyword(2) | document images |
| Keyword(3) | digital camera images |
| Keyword(4) | shape from parallel geodesics |
| 1st Author's Name | Katsuhito Fujimoto |
| 1st Author's Affiliation | Fujitsu Laboratories Ltd.() |
| 2nd Author's Name | Hiroaki Takebe |
| 2nd Author's Affiliation | Fujitsu Laboratories Ltd. |
| 3rd Author's Name | Misako Suwa |
| 3rd Author's Affiliation | Fujitsu Laboratories Ltd. |
| 4th Author's Name | Satoshi Naoi |
| 4th Author's Affiliation | Fujitsu Laboratories Ltd. |
| Date | 2007-03-15 |
| Paper # | PRMU2006-252 |
| Volume (vol) | vol.106 |
| Number (no) | 605 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |