顔領域の違いが読話性能に与える影響について

摘要

Lipreading is the technique to recognize speaker's utterances from the motion with changing shape of the mouth. Although most of previous approaches to lipreading focus on the limited region of the mouth, utterances of some phonemes often accompany with the motion of surrounding areas together with the mouth movement. In this paper, we have compared four regions: (A) entire face region, (B) the region that the eyes and the nose are removed from the entire face region, (C) mouth and adjacent region, and (D) mouth region. Experimental results of word recognition and vowel/consonant recognition show that most of vowel recognition using the region (B) results in the highest performance, while different regions output the best performance on consonant recognition.%読話とは口の動きや形状を読み取り発話内容を理解する技術のことを指す．従来の読話の研究の多くは口唇領域に対して行われてきた．しかし，発話する音によっては口の動作が大きく周辺の奴や顎の形状の変化が大きい音や，口の動作が小さい音など，様々である．そこで本論文では（A）顔全体領域，（B）顔全体領域から目と鼻を除いた領域，（C）口唇領域と顎から鼻孔までの高さを含んだ領域，（D）口唇領域の4つの領域を用いて単語認識，母音・子音認識を行った．実験の結果，ほとんどの母音について領域（B）が最も高い性能を示し，一方で子音については音素ごとに認識性能が高い領域が異なることが分かった．