Non-rigid image registration plays an important role in computer vision and medical image.Demons algorithm has been proved to be effective for non-rigid image registration;however

the existing Demons algorithms are limited in registration image for intensity uniformity or weak textile region

which always results in low registration accuracy and efficiency.Aiming at the problem

this paper applies R-L(Riemann-Liouville) fractional differentiation to active Demons

and proposes a new image registration based on fractional differentiation active Demons.In this paper we calculate image gradient using R-L fractional differentiation instead of the traditional gradient function

not only detail feature is strengthened but also image gradient of intensity uniformity and weak textile area is enhanced

thus registration accuracy and efficiency are improved.Additionally

we give the relation curve between registration accuracy and mask parameters

which can guide one to select optimal parameters.Though optimal parameter (order) is different for different images

it is proved the optimal interval is between 0~1.Theoretical analysis and experiment results show the effectiveness of the proposed method.It is a significant extension of Demons algorithm.