An optimizing iterative approach with objective sharpness evaluation in adaptive projection system. (October 2018)

• Record Type: Journal Article
• Authors: Lyu, Chengang; Chang, Yuqing; Liu, Yuxiang; Gao, Jiale; Liu, Ning; Yang, Jiachen
• Is Part Of: Optics & laser technology. Volume 106(2018)
• Page Start: 481
• Page End: 486
• Publication Date: 2018-10
• Subjects: Adaptive illumination -- Exposure compensation -- Iteration -- Sharpness evaluation; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2018.04.035
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: A optimizing iterative approach based on adaptive projection system is proposed. An objective evaluation system is introduced to evaluate the experimental results. The new iterative method is convergent. The random two-step phase-shifting profilmetry makes the depth information more accurate. This approach could limit the number of iterations, and achieve better iterative result with fewer iterations. Abstract: In order to modify the local luminance heterogeneity of target object image, restrain the phenomenon of overexposure and preserve enough original image information, we analyzed the adaptability of the adjustable projection which is applied to exposure compensation. In this paper, a novel iterative method by using the improved algorithm for absolute center moment (IACM) is proposed. A projector-camera system with the iterative algorithm is built to adjust the adaptive projection according to the inversion theory, the differences of depth information and the illumination intensity. Among them, the role of depth information is correspond to different light intensity at different heights. Through the experiment, the result shows that the camera could achieve uniform luminance and the index convergence is evaluated by IACM. This system can output the image with better definition based on iterative stop criterion, thereby the number of iterations is limited and objectively countable. This technique is suitable for industrial measurement, defect detection and quality control in real-time measurement.