Compact Shape Portrayal Descriptor
by Konstantinos Zagoris

Democritus University of Thrace - Department of Electrical and Computer Engineering

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This project is a product of Image Processing and Multimedia Laboratory (IPML) by:

Dr Konstantinos Zagoris (email:
Dr Ergina Kavallieratou
Professor Nikos Papamarkos



Shape is one of the most important low-level image features employed in content based retrieval systems. It can be used in a variety of a ways. One such way is the document image retrieval through word spotting.

The block diagram of the CSPD calculationThe CSPD is a MPEG-like descriptor that contains conventional contour and region shape features with a wide applicability from any arbitrary shape to document retrieval through word spotting. It is also, compact (it less than 16 bytes) and requires low computational cost. The retrieval results obtained are satisfactory in comparison with other MPEG-7 shapes descriptors. Particular, it has been designed with attention to its size and storage requirements, keeping it as small as possible without limiting its discriminating ability.

More specifically, the Compact Shape Portrayal Descriptor is a forty one dimension vector that it is created from five distinct features that capture satisfactory the shape of an object. Also, the values of the vector are quantized for binary representation in three bits for each so its storage requirements are only 123 bits per shape. As the block diagram portrays, the computation of the CSPD can be easily parallize as each feature can be calculated separately.

The advantage of this descriptor is its balance between its size, its calculation time and its retrieval results. It is suitable for existing retrieval systems that they need to add shape information to their descriptors without compromising theirs storing and computational requirements.

Reference/Citation Journal Paper

K. Zagoris, Ε. Kavallieratou and N. Papamarkos, «Image Retrieval Systems Based On Compact Shape Descriptor and Relevance Feedback Information», Journal of Visual Communication and Image Representation , 22 (2011), pp. 378-390 DOI information:10.1016/j.jvcir.2011.03.002,2011

We provide the CSPD descriptor free to download as a .NET DLL here. In addition to the CSPD DLL file, an example solution for the Visual Studio 2010 is provided, which it is an extension to the TSRD example solution. You can download the example solution from here.

You can download, the stand-alone version of the above program:

Filename Type Version Date
CSPD DLL zip file 1.0.4 20/08/2015
Shape Retrieval System zip file 26/06/2009


  • Microsoft .NET 3.5 SP1 and above (you can download it from here)
  • Windows XP/Vista/7