We introduce a new class of panoramic images, called polycentric panoramic images, which is a generalization from more specific classes such as single-center, multiple-center, or concentric panoramic images. This paper focuses on the derivation of an epipolar curve equation for polycentric panoramic images. The epipolar curve equation derived provides a unified approach for the epipolar geometry in any of the more specific classes of panoramic images. 1 The University of Auckland, Tamaki Campus, Centre for Image Technology and Robotics, Computer Vision Unit, Auckland, New Zealand