Naslov
An Assessment of the Video Image Quality Required in a Remote Vision Guidance System for Visually Impaired Pedestrians

Autori
Hunaiti, Ziad ; Garaj, Vanja ; Balachandran, Wamadeva

Izvornik
Journal of Telemedicine and Telecare (1357-633X) 12 (2006), 8; 400-403

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Video Image Quality, Remote Vision, Navigation, Visually Impaired Pedestrians

Sažetak
A study was carried out to determine the most acceptable quality of video images for use in remote guidance of visually impaired pedestrians. A video image clip of 20 s duration was captured using a digital camera, while walking a sample route. The video image clip was encoded at bit rates of 30 and 48 kbit/s and frame rates of 10, 7.5, 5 and 2.7 fps. Two standard resolutions were used: Quarter Common Intermediate Format (QCIF) (176 × 144 pixels) and Common Intermediate Format (CIF) (352 × 288 pixels). Twelve participants gave their judgment on the picture update rate (smoothness of movement), the bit rate and the static resolution. The mean scores for total quality (five-point scale) ranged from 3.3 to 4.8, but there was no significant difference between them. The mean scores for smoothness (five-point scale) ranged from 3.0 to 4.7, but there was no significant difference between them. The mean score for the resolution of the QCIF video clips was 2.9 (SD = 0.9) and for the CIF recordings were 4.1 (SD = 0.7), but there was no significant difference between them. The majority of the participants were most comfortable with video which was transmitted at 48 kbit/s and 7.5 fps. Therefore, this quality can be considered satisfactory for remote guidance.

Izvorni jezik
Engleski

Znanstvena područja
Računarstvo

POVEZANOST RADA