3D image registration (IR) aims to map one image to another image of a same scene

widely used in medical diagnosis and other applications. The existing methods mostly use feature to registration and have specific constraint condition which have many problems such as time-consuming

strong random in feature extraction and not flexible under constraint condition. For those problems

an intensity-based method for non-feature 3D rigid IR is proposed in this paper. The method uses Taylor expansion and the least squares (LS) to directly get the transformation parameters and has advantage of high processing speed with less processed data. It is shown by numerous experiments that the proposed IR method has high accuracy and only uses very small proportion data to process.