EDGE-SHRINKING INTERPOLATION FOR MEDICAL IMAGES

A new algorithm for interpolating the missing data between two adjacen t medical images is presented. Our method is useful for solving the in terpolation of any region-represented images of an object to be recons tructed, even when the object is stretched abruptly, branched or hollo w, as often occurs in medical images, which cases can not be handled w ell by existing methods. When this algorithm is applied, the nonoverla pped regions of the same object in the two base images are first extra cted and encoded by chamfer distance code on every pixel in these regi ons. Then, the outer edges of the nonoverlapping regions are shrunk in ward simultaneously so that the stretched edges reach the edges of the overlapping regions at the same time. The distance codes in nonoverla pping regions are used to limit the shrinking of these edges in the in terpolation process. The proposed method also provides object centrali zation and enlargement operations to obtain stable and reasonable resu lts in complicated case. The experimental results show that the propos ed method is more effective and efficient in resolving general interpo lation tasks than the existing methods (S. P. Raya and J. K. Udupa, IE EE Trans. Med. Imag. 9, 32-42, 1990; G. T. Herman ef al., IEEE Comput. Graph. Appl. 12, 69-79, 1992; J. F. Guo et al., Comput. Med. Imag. Gr aph. 19, 267-279, 1995). (C) 1997 Elsevier Science Ltd.