Enhancement and restoration of documents, text images and videos has become increasingly important in many areas of electronic imaging. Designing and developing computer automated systems to restore low-resolution and degraded documentation and text images is highly desirable. Dr. Paul Thouin and I have developed a system that makes use of resolution expansion to enhance low-resolution text images so as to improve Optical Character Recognition (OCR) accuracy and quality of degraded images. This system can be also used to restore both binary and grayscale images as well as video frames. An ongoing research project is to extend the current work to enhancement and restoration of color text images. It has been filed by UMBC for a US patent.

Ph.D. Dissertation

  1. Paul Thouin, Image Restoration of Low Resolution Text and Document Images, May 2000.
  2. Yingze Du, Text Detection and Restoration for Color Video Images, May, 2003

Patent Pending

  1. C.-I Chang and P. Thouin, Method and Apparatus of Resolution Restoration and Enhancement of Bimodal-Like Images, March 31, 2000.

Disclosure of Invention

  1. Thouin, Paul and Chang, Chein-I, Methods and Apparatus of Low-Resolution Digital Documentation and Text Images, November 10, 1998.

Journal Publications

  1. P. Thouin and C.-I Chang, New technique restores text from 8x8 block DCT-compressed gray-scale images, Special Section on J. Electronic Imaging, OE Report, no. 179, p. 11, November 1998.
  2. P. Thouin and C.-I Chang, A method for restoration of low-resolution text images, International Journal on Document Analysis and Recognition, Vol. 2, No. 4, pp. 200-210, June 2000.
  3. P. Thouin and C.-I Chang, A computer-automated system for restoration of documents and text images, Journal of Electronic Imaging, vol. 10, no. 2, pp. 535-547, April 2001.
  4. Y. Du, C.-I Chang and P. Thouin, an automatic system for text detection in single video images, J. Electronic Imaging. (to appear)

Conference Publications

  1. Y.Z. Du, P.Thouin and C.-I Chang,"Low-Resolution Expansion of Color Text Images Using HSI Approach", The 5th World Multi-Conference on Systemics, Cybernetics and Informatics,Orlando, FL,July,2001
  2. P. Thouin, Y. Du, C. -I Chang, "Low Resolution Expansion of Gray Scale Text Images Using Gibbs-Markov Random Field Model",2001 Symposium on Document Image Understanding Technology, Columbia, MD, pp. 41-47,2001.
  3. P. Thouin and C.-I Chang, "Constrained nonlinear restoration of JPEG compressed low-resolution text from gray-level images using a Gibbs-Markov random fields," IS T/SPIE 10th Annual Symposium, Electronic Imaging '98: Science Technology, Documentation V, San Jose, pp. 220-229, Jan. 24-30, 1998.
  4. P. Thouin and C.-I Chang, "A method for restoration of low-resolution text images," SPIE Proc. 1999 Symposium on Documentation Image Understanding Technology , Annapolis, MD, pp. 143-148, April 14-16, 1999.