6. Image Enhancement and Restoration

  1. Tinku Acharya and
  2. Ajoy K. Ray

Published Online: 20 SEP 2005

DOI: 10.1002/0471745790.ch6

Image Processing: Principles and Applications

Image Processing: Principles and Applications

How to Cite

Acharya, T. and Ray, A. K. (2005) Image Enhancement and Restoration, in Image Processing: Principles and Applications, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471745790.ch6

Publication History

  1. Published Online: 20 SEP 2005
  2. Published Print: 19 AUG 2005

ISBN Information

Print ISBN: 9780471719984

Online ISBN: 9780471745792



  • histogram equalization;
  • histogram hyperbolization;
  • unsharp masking;
  • restoration;
  • inverse filtering;
  • Wiener filtering


Image enhancement techniques deal with accentuation or sharpening of image features, such as contrast, boundaries, edges, etc. Image enhancement techniques both in spatial domain and frequency domain have been discussed in this chapter. Interesting spatial domain strategies like unsharp masking, spatial filtering etc have been briefly discussed. Widely used techniques like histogram equalization and histogram hyperbolization have been presented. Frequency domain strategies which include frequency domain filtering have also been discussed. The primary difference between the enhancement and restoration techniques have been brought out here. Some of the important techniques of image restoration like inverse filtering, Wiener filter, restoration of impulse noise embedded image and blurred image have been discussed in this chapter.