161L. Alem and W. Huang (eds.), Recent Trends of Mobile Collaborative Augmented Reality Systems, DOI 10.1007/978-1-4419-9845-3_13,

Abstract Spatial Augmented Reality (SAR) superimposes computer generated virtual objects directly on physical objects ’ surfaces. This enables user to interact with real world objects in a natural manner. This chapter investigates SAR tech-niques and summarizes advantages with the difficulties of SAR in presenting digital information to users. The chapter then presents a concept of portable collaborative SAR. The concept utilizes both projector-based SAR and Head-Mounted-Display (HMD) based Augmented Reality (AR) in a single environment to assist collabora-tions within multiple users. The concept combines advantages of both projector-based SAR for collaboration and HMD-based AR display in personalization to improve the efficiency of collaborative tasks. The presented concept is explored in a case study of industrial quality assurance scenario to show its effectiveness.