Pantiltzoom camera calibration and high-resolution mosaic generation
In this paper, we discuss the problem of estimating parameters of a calibration model for active pantiltzoom cameras. The variation of the intrinsic parameters of each camera over its full range of zoom settings is estimated through a two step procedure. We first determine the intrinsic parameters at the cameras lowest zoom setting very accurately by capturing an extended panorama. The camera intrinsics and radial distortion parameters are then determined at discrete steps in a monotonically increasing zoom sequence that spans the full zoom range of the camera. Our model incorporates the variation of radial distortion with camera zoom. Both calibration phases are fully automatic and do not assume any knowledge of the scene structure. High-resolution calibrated panoramic mosaics are also computed during this process. These fully calibrated panoramas are represented as multi-resolution pyramids of cube-maps. We describe a hierarchical approach for building multiple levels of detail in panoramas, by aligning hundreds of images captured within a 112 zoom range. Results are shown from datasets captured from two types of pantiltzoom cameras placed in an uncontrolled outdoor environment. The estimated camera intrinsics model along with the cube-maps provides a calibration reference for images captured on the fly by the active pantiltzoom camera under operation making our approach promising for active camera network calibration.
pantiltzoom camera calibration radial distortion active camera networks image mosaicing zoom calibration radiometric alignment