In the traditional examplar-based algorithm

the image completion effect is greatly degraded due to the fixed patch-size

which cannot change together with an image automatically in the process of completing.So in this paper we propose an adaptive patch-size determining method to solve this problem.By analyzing the image changes in the gradient domain

this method acquires the structure information of each pixel

and then automatically adjusts the patch-size.The simulation results show that this method can overcome many shortcomings of traditional methods

such as structural error propagation and whole structure loss

and realizes perfect completion effect for images with obvious changed structure.