Auto-focusing technique in a projector-camera system

Projector-camera system has been researched for years and it has become more and more popular in 3D vision and many other applications. However, with pre-determined position of projector´s lens, projector based researches were not able to deal with the scenes that have objects with different distances from the projector. In this paper, we present a projector autofocusing technique based on local blur information of the image that can overcome above limitation. The algorithm is implemented on projector-camera system, in order to focus the pattern which is projected by projector on all objects in the scene sequentially. The proposed algorithm first obtains a blur-map of the scene on the image by using a robust local blur estimator, and then the region of interest is decided by thresholding the obtained blur-map. Since the main light source is provided by projector, the proposed auto-focusing algorithm achieves a good performance with different light conditions.