GEOMETRIC AND RADIOMETRIC IMAGE WARPING DUE TO OPTICAL-SYSTEM DISPLACEMENT

This article undertakes an analytical and computational investigation of the image warping resulting from optical system displacement. Such image warping has implications for the registration of sequences of im ages acquired from a moving camera. The analysis covers optical system s with arbitrary amounts of distortion, with arbitrarily wide fields o f view, and subject to general rigid body displacements (i.e. translat ion and rotation). Image warping naturally separates into a geometric and radiometric, or intensity, component. Uniform image translation is excluded from geometric warping; and uniform image amplitude scaling is excluded from radiometric warping. For pure camera rotation, the tw o warping components are analysed separately, and simulations of both are presented for both segmented and unsegmented image domains. Image segmentation permits different translation vectors and scaling factors to be applied to different regions of the image, before the residual warping is evaluated. The simulations demonstrate a significant reduct ion in both warping components, with its attendant benefits for image registration, arising from domain segmentation. Further analysis revea ls the consequences for both warping components of including camera tr anslation in addition to rotation.