title: New developments in low-bit rate videotelephony for people who are deaf.
abstract: This study was designed to evaluate the picture quality requirements for three visual communication modes: speechreading, fingerspelling, and sign language. Video recordings of everyday spoken, fingerspelled, and signed sentences were made, and some recordings were processed using a computer simulation of the IBIDEM technology: a videophone based on a novel type of visual sensor. This retina-like sensor, implemented in the camera, has a high resolution in the central part and a degrading resolution in the peripheral part of the picture. Two independent variables were examined: frame rate (10 and 15 frames per second) and spatial resolution (6000 and 8000 pixels per frame). Twenty-four people who were prelingually deaf participated, 8 in each communication mode. The results showed a marked effect of frame rate on speechreading. Fingerspelling and sign language were not affected by frame rate, and spatial resolution had no effect on any of the three communication modes.
authors.affiliation: Instituut voor Doven, Sint-Michielsgestel, The Netherlands.
authors.forename: W W
authors.initials: WW
authors.lastname: Woelders
authors.forename: H W
authors.initials: HW
authors.lastname: Frowein
authors.forename: J
authors.initials: J
authors.lastname: Nielsen
authors.forename: P
authors.initials: P
authors.lastname: Questa
authors.forename: G
authors.initials: G
authors.lastname: Sandini
mesh_terms: D000293:Adolescent; D000328:Adult; D003638:Deafness; D005260:Female; D006801:Humans; D008085:Lipreading; D008297:Male; D008875:Middle Aged; D012813:Sign Language; D013685:Telecommunications / Q000592:standards*; D014743:Videotape Recording