title: Approach of self-adaptive illumination for optical imaging systems.
abstract: An optical imaging signal is vulnerable to undesired features such as ambient light illumination and partial specular reflection from the target; the success of extracting target features from images depends largely on appropriate design of illumination. This paper presents an approach for self-adaptive illumination for optical imaging systems. The proposed illumination system projects a reference image to a target surface as an initial structured illumination, and then adjusts the projected image automatically to compensate the negative influences of undesired features. After this self-adaptive control process, undesired features would appear mostly invisible in the captured images. The signal-to-noise ratio would be improved dramatically well before subsequent image processing. In the validation experiments, several images with uniform brightness were offered as reference images; the captured images could achieve high brightness uniformity, even when the target surface was uneven or was illuminated by ambient light. In a further experiment of selective vessel illumination on a human palm, simulated vessel regions were selectively illuminated. Undesired features, like palm prints, almost disappeared in the images captured.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhou
authors.forename: Jim
authors.initials: J
authors.lastname: Goodliffe
authors.forename: Hao
authors.initials: H
authors.lastname: Cai
authors.forename: Kui
authors.initials: K
authors.lastname: Zhou
authors.forename: Xianglin
authors.initials: X
authors.lastname: Zhang