Machine Lip-Reading of Japanese Vowels Utilizing A Stereoscopic Vision System

Masami Nakano, Tomio Watanabe

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


The lip-shape recognition of Japanese vowels utilizing a stereoscopic vision system has been performed to enhance the discrimination of five vowels by machine lip-reading. The opening angle P4 between the upper lip and the lower lip is selected as the typical three-dimensional feature parameter of lip shape, in addition to the usual feature parameters such as the width P1 and the height P2 of the lip shape and distance P3 between the tips of the upper lip and the chin. Compared with the 3 two-dimensional parameters P1, P2 and P3 used in a single-vision system, the 3 and 4 three-dimensional parameters led to the significant increase of discrimination rate, and in particular, the discrimination rate by the 4 three-dimensional parameters was more than 90% for every tested subject. Recognition for an unspecified subject was also examined, based on the selections of the variance-covariance matrix and the mean vector of feature variables, by which the Mahalanobis' generalized square distance and the maximum likelihood discrimination function were determined.

Original languageEnglish
Pages (from-to)525-530
Number of pages6
Journaltransactions of the japan society of mechanical engineers series c
Issue number570
Publication statusPublished - 1994
Externally publishedYes


  • Human Engineering
  • Lip Reading
  • Lip Shapes
  • Man-Machine Interface
  • Stereoscopic Vision
  • Three-Dimensional Measurement
  • Vowel Recognition

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'Machine Lip-Reading of Japanese Vowels Utilizing A Stereoscopic Vision System'. Together they form a unique fingerprint.

Cite this