Fig. 9.

Visually assessed performance of formulated ratio images compared to existing technology. Ratio image $\mathrm{R}21=\mathrm{F}440\mathrm{red}/\mathrm{F}440$ approximates the red/green ratio used for polyp discrimination by LIFE-GI (Zeng, 1998). Image $\mathrm{R}22=\mathrm{R}555/\mathrm{F}440$ approximates the published G/R ratio used by the AFI system (Aihara, 2009). Bars represent the percentage of low contrast lesion images for which the ratio image was deemed “adequate” for lesion identification by at least four of eight observers. Diamonds represent the percentage of specimen images for which the ratio image was deemed “exceptional” by three or more of eight observers. The rightmost bar indicates the performance that might be achieved using R27 and R30 in parallel.