Gradient Estimation Using Wide Support Operators


Senel H. G.

IEEE TRANSACTIONS ON IMAGE PROCESSING, cilt.18, sa.4, ss.867-878, 2009 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 18 Sayı: 4
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1109/tip.2008.2011758
  • Dergi Adı: IEEE TRANSACTIONS ON IMAGE PROCESSING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.867-878
  • Anahtar Kelimeler: Edge detection, fuzzy topology, fuzzy connectedness, gradient estimation, EDGE-DETECTION, DIFFERENTIATORS, CONNECTEDNESS, DESIGN
  • Anadolu Üniversitesi Adresli: Evet

Özet

One of the fastest methods of localizing edges in images is based on small gradient kernels, such as Sobel, Prewitt, and Roberts. Although small gradient kernels provide a fast way of computing the gradients, they have little control over noise, edge location, and edge orientation. They are known to be only sensitive to step edges and fail to detect smooth boundaries. On the other hand, large kernels provide superior noise suppression characteristics, but they suffer from wide response area around edges. They cause edges or neighboring objects to merge due to their wide support. Problems associated with large gradient kernels prevent their widespread usage. This paper presents a fuzzy topology-based method to facilitate the use of larger gradient kernels. The new method effectively limits the response area around the edge and prevents neighboring objects to affect each other. Synthetic Images are used to show the superior noise suppression properties and response characteristics to both step and ramp edges. Natural images are also used to assess the performance of the newly proposed topological gradient estimation qualitatively.