DOI QR코드

DOI QR Code

Text Detection and Binarization using Color Variance and an Improved K-means Color Clustering in Camera-captured Images

카메라 획득 영상에서의 색 분산 및 개선된 K-means 색 병합을 이용한 텍스트 영역 추출 및 이진화

  • 송영자 (숙명여자대학교 컴퓨터과학과) ;
  • 최영우 (숙명여자대학교 컴퓨터과학과)
  • Published : 2006.06.01

Abstract

Texts in images have significant and detailed information about the scenes, and if we can automatically detect and recognize those texts in real-time, it can be used in various applications. In this paper, we propose a new text detection method that can find texts from the various camera-captured images and propose a text segmentation method from the detected text regions. The detection method proposes color variance as a detection feature in RGB color space, and the segmentation method suggests an improved K-means color clustering in RGB color space. We have tested the proposed methods using various kinds of document style and natural scene images captured by digital cameras and mobile-phone camera, and we also tested the method with a portion of ICDAR[1] contest images.

이미지에 포함된 텍스트는 이미지의 내용을 함축적이고 구체적으로 표현하는 정보로서 이러한 정보를 실시간에 찾아내서 인식한다면 다양한 응용에 활용할 수 있다. 본 논문에서는 카메라로 취득한 다양한 종류의 이미지로부터 텍스트를 추출하는 방법과 추출된 영역에서 텍스트를 분리하는 방법을 새롭게 제안한다. 텍스트 영역 추출을 위해서 RGB 색 공간에서 색 분산을 특징으로 제안하며, 텍스트 영역 분리를 위해서 RGB 색 공간에서 개선된 K-means 병합을 제안한다. 실험은 디지털 카메라와 핸드폰 카메라로 취득한 다양한 종류의 문서유형 이미지와 실내외의 일반적인 자연이미지를 사용하였으며, ICDAR 콘테스트[1] 이미지의 일부도 사용하였다.

Keywords

References

  1. S. M. Lucas, A. Panaretos, L. Sosa, A. Tang, S. Wong and R. Young, 'ICDAR 2003 Robust Reading Competition,' Proceeding of International Conference on Document Analysis and Recognition, Vol.2, pp.682-687, 2003
  2. Anil K. Jain and Bin Yu, 'Automatic Text Location in Images and Video Frames,' Pattern Recognition, Vol.31, No.12, pp.2055-2076, 1998 https://doi.org/10.1016/S0031-3203(98)00067-3
  3. H. K. Kim, 'Efficient Automatic Text Location Method and Content-based Indexing and Structuring of Video Database,' Journal of Visual Communications and Image Representation, Vol.7, pp.336-344, 1996 https://doi.org/10.1006/jvci.1996.0029
  4. J. Ohya, A. Shio and S. Akamatsu, 'Recognizing Characters in Scene images,' IEEE Transactions on Pattern Analysis and Machine Intelligence, PAMI-16(2), pp.67-82, 1994 https://doi.org/10.1109/34.273729
  5. N. Ezaki, M. Bulacu and L.Schomaker, 'Text Detection from Natural Scene Images : Towards a System for Visually Impaired Persons,' Proceedings of 17th International Conference on Pattern Recognition, Vol.Ⅱ, pp.683-686, 2004 https://doi.org/10.1109/ICPR.2004.1334351
  6. Hao Wang, 'Automatic Character Location and Segmentation in Color Scene Images,' Proceedings of 11th International Conference on Image Analysis and Processing, pp.2-7, 2001 https://doi.org/10.1109/ICIAP.2001.956977
  7. Rafael C. Gonzalez and Richard E. Woods, Digital Image Processing, Addison Wesley, 1993
  8. N. Otsu, 'A thresholding selection method from gray-level histogram,' IEEE Transactions on System, Man, and Cybernetics, No.9, pp.62-66, 1979
  9. M. Seeger and C. Dance, 'Binarizing camera images for OCR,' Proceeding of International Conference on Document Analysis and Recognition, Vol.1, pp.54-58, 2001
  10. 김계경, 지수영, 정연구, 박상규, '조명이 적은 카메라기반 문서 영상 인식시스템,' 컴퓨터비젼 및 패턴인식 연구회 워크샵, pp.90-92, 2002
  11. C. Garcia and X. Apostolidis, 'Text detection and segmentation in complex color images,' Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing, Vol.4, pp.2326-2329, 2000 https://doi.org/10.1109/ICASSP.2000.859306
  12. B. Wang, X-F. Li, F. Liu and F-Q. Hu, 'Color text image binarization based on binary texture analysis,' Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing, Vol.3, pp.585-588, 2004 https://doi.org/10.1109/ICASSP.2004.1326612
  13. J. Matas and J. Kittler, 'Spatial and feature space clustering: Applications in image analysis,' Proceedings of 6th International Conference on Computer Analysis of Images and Patterns, pp.162-173, 1995
  14. M. Junker and R. Hoch, 'On the Evaluation of Document Analysis Components by Recall, Precision, and Accuracy,' Proceeding of International Conference on Document Analysis and Recognition, pp.713-716, 1999 https://doi.org/10.1109/ICDAR.1999.791887
  15. Simon M. Lucas, 'ICDAR 2005 Text Locating Competition Results,' Proceeding of International Conference on Document Analysis and Recognition, pp.80-84, 2005 https://doi.org/10.1109/ICDAR.2005.231