1. A vertex processing device applied in an image processing system having an image capture module that generates a plurality of camera images, comprising: a coefficient interpolation unit for generating an interpolated warping coefficient for each camera image with respect to each vertex from a vertex list based on n number of warping coefficients and its original texture coordinates in each camera image; and a coordinate modifying unit coupled to coefficient interpolation unit for calculating modified texture coordinates in each camera image for each vertex according to the interpolated warping coefficient and its original texture coordinates in each camera image; wherein the vertex list comprises a plurality of vertices with their data structures that define a vertex mapping between the camera images and a panoramic image; and wherein the n number of warping coefficients respectively denote warping degrees for n number of overlap regions in the panoramic image and n>=1.