Abstract: In this paper, a novel concept, rayset, is proposed. A new image based representation, object centered concentric mosaics (OCCM), is derived based on this concept. The rayset is a parametric function, which consists of two mapping relations. The first mapping relation maps from a parameter space to the ray space. The second one maps from the parameter space to the attribute space. We show that different image-based scene representations can all be cast as different kinds of raysets, and image-based rendering approaches can be regarded as attempts to sample and reconstruct the scene using different raysets. A collection of OCCM is a 3-D rayset, which can be used to represent an object. The storage size for OCCM is about the same as an animation sequence generated with a virtual camera rotated around the object. However, comparing with such an animation sequence, OCCM provide a much richer experience because the user can move back and forth freely in the scene and observe the changes in parallax.