Joint Optimal Object Shape Estimation and Encoding

Lisimachos P. Kondi*, Gerry Melnikov, Aggelos K. Katsaggelos

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


A major problem in object-oriented video coding and MPEG-4 is the encoding of object boundaries. Traditionally this problem is treated separately from the texture encoding problem. In this paper, we present a vertex-based shape coding method which is optimal in the operational rate-distortion sense and takes into account the texture information of the video frames. This is accomplished by utilizing a variable-width tolerance band whose width is a function of the texture profile. As an example, this width is inversely proportional to the magnitude of the image gradient. Thus, in areas where the confidence in the estimation of the boundary is low and/or coding errors in the boundary will not affect the application (e.g., object-oriented coding and MPEG-4) significantly, a larger boundary approximation error is allowed. We present experimental results which demonstrate the effectiveness of the proposed algorithm.

Original languageEnglish (US)
Pages (from-to)528-533
Number of pages6
JournalIEEE Transactions on Circuits and Systems for Video Technology
Issue number4
StatePublished - Apr 2004


  • Boundary coding
  • MPEG-4
  • Operational rate-distortion (ORD) theory
  • Shape coding
  • Shape-adaptive DCT

ASJC Scopus subject areas

  • Media Technology
  • Electrical and Electronic Engineering


Dive into the research topics of 'Joint Optimal Object Shape Estimation and Encoding'. Together they form a unique fingerprint.

Cite this