Decoding design based on posterior probabilities in Ternary Error-Correcting Output Codes

  • Authors:
  • Jin Deng Zhou;Xiao Dan Wang;Hong Jian Zhou;Jie Ming Zhang;Ning Jia

  • Affiliations:
  • Department of Computer Science, Air Force Engineering University, 713800 San Yuan, PR China and The Fourth Lab of Complex System, 100076 Beijing, PR China;Department of Computer Science, Air Force Engineering University, 713800 San Yuan, PR China;The Fourth Lab of Complex System, 100076 Beijing, PR China;Department of Computer Science, Air Force Engineering University, 713800 San Yuan, PR China;The Office of Military Representative in the Avionics Company of Shanghai, 200233 Shanghai, PR China

  • Venue:
  • Pattern Recognition
  • Year:
  • 2012

Quantified Score

Hi-index 0.01

Visualization

Abstract

Ternary Error-Correcting Output Codes (ECOC), which can unify most of the state-of-the-art decomposition frameworks such as one-versus-one, one-versus-all, sparse coding, dense coding, etc., is considered more flexible to model multiclass classification problems than Binary ECOC. Meanwhile, there are many corresponding decoding strategies that have been proposed for Ternary ECOC in earlier literatures. Note that there is few working by posterior probabilities, which can be considered as a Bayes decision rule and hence obtain a better performance in usual. Passerini et al. (2004) [16] have recently proposed a decoding strategy based on posterior probabilities. However, according to the analyses of this paper, Passerini et al.'s (2004) [16] method suffers some defects and result in bias. To overcome that, we proposed a variation of it by refining the decomposition process of probability to get smoother estimates. Our bias-variance analysis shows that the decrease in error by our variant is due to a decrease in variance. Besides, we extended an efficient method of obtaining posterior probabilities based on the linear rule for decoding process in Binary ECOC to Ternary ECOC. On ten benchmark datasets, we observe that the two decoding strategies based on posterior probabilities in this paper obtain better performance than other ones in earlier references.