Bilkent University Multimedia Database Group
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Content Based Retrieval for Digital Ottoman Archives

The goal of this project is developing content based retrieval techniques for historical Ottoman documents stored as textual images.

Project Members


  • Prof. Özgür Ulusoy (CS)
  • Assoc. Prof. Ugur Gudukbay (CS)
  • Prof. Enis Cetin (EE)
  • Ph.D./M.S. Students

  • İsmail Sengör Altingövde (Ph.D.)
  • Ismet Zeki Yalniz (Ph.D.)
  • Ediz Saykol (Ph.D.)
  • Undergraduates

  • Ali Kemal Sinop (B.S., 2004), I. Zeki Yalniz, Volkan Arici (B.S., 2005)

Project Description

There is an accelerating demand to access the visual content of documents stored in historical and cultural archives. Availability of electronic imaging tools and effective image processing techniques makes it feasible to process the multimedia data in large databases. In this project, a framework for content-based retrieval of historical documents in the Ottoman Empire archives is presented. The documents are stored as textual images, which are compressed by constructing a library of symbols occurring in a document, and the symbols in the original image are then replaced with pointers into the codebook to obtain a compressed representation of the image. The features in wavelet and spatial domain based on angular and distance span of shapes are used to extract the symbols. In order to make content-based retrieval in historical archives, a query is specified as a rectangular region in an input image and the same symbol-extraction process is applied to the query region. The queries are processed on the codebook of documents and the query images are identi.ed in the resulting documents using the pointers in textual images. The querying process does not require decompression of images. The new content-based retrieval framework is also applicable to many other document archives using different scripts.


E. Saykol, A. K. Sinop, U. Gudukbay, Ö. Ulusoy, E. Cetin. Content-Based Retrieval of Historical Ottoman Documents Stored as Textual Images. IEEE Transactions on Image Processing, vol.13, no.3, 2004. PDF outlink


The prototype system developed for content-based retrieval of digital Ottoman Archives can be accessed here outlink.


There are two data sets (including Ottoman document scans) used in our studies: Set1 outlink (38 documents, 118 MB) Set2 outlink (43 documents, 15 MB)

Set1 is obtained from the following recources (please see our publications for detailed information).

  • A. Alparslan, Osmanlı Hat Sanatı Tarihi, Yapı Kredi Yayınları, 1999.
  • M. U. Derman, Hat Koleksiyonundan Seçmeler, Sakıp Sabancı Müzesi, Sabancı Üniversitesi, 2002.
  • H. M. H.Hakkak-zade Mustafa Hilmi Efendi, Mizanü’l-hatt, Istanbul, 1986.
  • M. Ülker, Başlangıçtan Günümüze Türk Hat Sanatı, Türkiye İş¸ Bankası Kültür Yayınları, 1987.
  • E. Çetin,Ö.N. Gerek, and A. H. Tewfik, “The Topkapi Palace Museum,” Museum Int., vol. 1, no. 1, pp. 22–25, 2000.

Set 2 is obtained from a textbook for teaching Ottoman.