Method of restoring the shadow distortion in a bounded book scan...
需积分: 7 45 浏览量
2014-05-04
00:09:27
上传
评论
收藏 2.88MB PDF 举报
A Restoration Method for Distorted Image
Scanned From a Bound Book
HyungSoo Ohk, HyeonSeok Seo, KiMin Kang , Sangho Kim and DonChul Choi
Samsung Electronics
416, Maetan dong Yeongtong-gu Suwon
Abstract
When a bound document such as a book is scanned or copied with a flat-bed scanner, there are two kinds of defects in the scanned
image; the geometric and photometric distortion. The root cause of the defects is the imperfect contact between the book to be scanned
and the scanner glass plate. The long gap between the book center and the glass plate causes the optical path from the surface of the
book and the imaging unit(CCD/CIS) to be different from the optimal condition.
In this paper, we propose a method for restoring bound document scan images without any additional information or sensor. We
correct the bound document images based on the estimation of the boundary feature and background profile. Boundary Feature is
obtained after calculating and analyzing the Minimum Boundary Rectangle which encloses the whole foreground contents with
minimum size and the extracted feature is used for correcting geometric distortion; de-skew, warping, and page separation.
Background profile is estimated from the gradient map and it is utilized to correct photometric distortion; exposure problem.
Experimental results show effectiveness of our proposed method.
Keyword: Image Processing, Book, Document, Copy, Scan.
1. INTRODUCTION
When scanning pages from a bound book, the image to be scanned is distorted because it is not flat on the document
glass of scanner.
The purpose of our research is providing an automatic and effective method to correct distorted image scanned from
bound books. Photometric and geometric distortions are corrected. Moreover, each page of the book is separated
automatically. This algorithm can be used for MFP, Scanner, OCR system and so on.
The rest of the paper is organized as followed. In the next section we present an analysis about distortion of book copy
image. Section 3 explains image analysis and Section 4 provide image correction. The experimental results and
conclusion are presented in Section 5.
2. DISTORTION OF BOOK COPY
The difference of scanning or copying a book and a paper is that the page of the book to be scanned cannot be laid flat
on the document glass of scanner. There are two kinds of degradation in book image, photometric and geometric
distortion.
Fig. 1. Scanned Image
Color Imaging XVI: Displaying, Processing, Hardcopy, and Applications, edited by Reiner Eschbach,
Gabriel G. Marcu, Alessandro Rizzi, Proc. of SPIE-IS&T Electronic Imaging, SPIE Vol. 7866
78661T · © 2011 SPIE-IS&T · CCC code: 0277-786X/11/$18 doi: 10.1117/12.876758
SPIE-IS&T/ Vol. 7866 78661T-1
资源评论
