In this paper

a SIFT feature based fundus image automatic mosaic algorithm is presented

according to the characteristics of low contrast and the geometric distortion between different fields of the view of the fundus image. The SIFT features of fundus images are extracted and described using vector to determine the feature points matching between two images

and outlier points are removed using MLESAC algorithm. A distance-slope similarity measure method is put forward to purify feature points

then the perspective transformation matrix is computed according to matching points between images

and image registration and image mosaic is implemented finally. The mosaic results of multiple images obtained by fundus camera show that the algorithm has good robustness and stability

and high-precision automatic fundus image mosaic can be achieved.