Immersive Hemisphere Projection Teaching System Oriented Image Pre-distortion Algorithm

To meet the needs of practical teaching, we’d add virtual reality systems to some process in it. Those systems provide a simulation-based and immersive environment for students’study, deepening their awareness and understanding of knowledge, so as to enhance the quality of teaching. However, the existing systems have several problems, such as integration of complex and high costs, being unable to meet the actual teaching targets. All those make creating a new system with new technology become urgent, one with integration of simple, low costs, being easy to use and can achieve the desired effect.This article established an immersive hemisphere projection teaching system composed of hardware and software. The system consists of a single projector, a spherical mirror, and a large-scale hemispheric screen, effectively provides a high degree of immersion and broad visual space which owns120degrees in the vertical direction and180degrees in the horizontal direction.This article focuses on the software which is especially important to the image display on the wide screen. Owing to ordinary projector being designed for flat screen projection, to get the right image shows, the projected image should have a pre-deformation progress. We firstly got an accurate pre-abnormal image through manual tests, and then designed the three-dimensional rotation algorithm for mapping from the original image to the pre-abnormal image. Through simulation tests of the algorithm in matlab, we confirmed it with high calibration accuracy.We lastly discussed the application of this system in teaching, listing some examples of it, and analyzed its advantages and potential applications.