A new environment mapping method using equirectangular panorama from unordered images

Cube Mapping is a popular and promising environment mapping technology in which six cubic images containing the information of entire environment are used to enhance the reality of the virtual object in the Augmented Reality system. In this paper, a new method is proposed, which generate the six cubic images in real time from a pre-process unplanned image sequence gotten by a calibrated camera. As a part of system initialization, a series of unplanned image sequences were recorded, as well as the camera extrinsic-parameter of each image. While every virtual object is rendered, several images are chosen according to the camera's position and attitude information to build an environment sphere model whose center is same as the virtual object's. Each of the select images is filled to corresponding area of the sphere model's surface due to its orientation and the upper direction of the camera. After the surface of the sphere is full of filling, the model is constructed to reflect the all surrounding scene like a mirrored sphere. According to the equirectangular projection algorithm, the surface of the sphere model with longitude and latitude coordinate system can be unfold to rectangular image which is called equirectangular panoramic image. Then the six cubic images can be segmented from the equirectangular panoramic image by a special algorithm.