Chihiko Yamada

Visual-Chromatic Spatial and Temporal Frequency Responses in Elderly People

Elderly people tend to perceive color as more yellowish than younger people do, and their ability to discriminate between blueish colors deteriorates as they grow older. This paper describes measurements of visual chromatic spatial and temporal frequency responses in subjects aged 60 to 75 years old to gain a better understanding of age-related changes in color perception and to clarify some differences between young and elderly people. We found that visual chromatic spatial and temporal frequency responses to ayellow-blue (dominant wavelength : 565-445 nm) stimulus were significantly reduced in comparison with those to a red-green (495 nm and its conjugate) stimulus. The results suggest that weakened optical functions in the eye and in the power to send visual signals from the retina to the nervous system are likely causes of this deterioration of color -contrast sensitivity.

50-inch Autostereoscopic 3-D Television.

メガネが不要な50インチ液晶投写型の多眼式3次元カラーテレビジョン装置を試作した.この装置は被写体を4台のテレビカメラで同時に撮像し, 信号処理によって縦縞のストライプ像に合成したあと, 1台の高性能液晶プロジェクタを用いてレンチキュラスクリーンに背面投写する方式である.試作した4眼式3次元テレビジョン装置は, 従来の2眼式に比べて立体視できる観察範囲が拡大し, 自然で見やすい立体カラー動画像を表示することができた.