Abstract: In order to avoid the error filling problem caused by irregular shape and uneven size of damaged areas in Wutai Mountain murals,a novel block matching algorithm was proposed.First,a dispersion item was introduced in the priority calculation process except for a confidence coefficient and a data item originally,which might guarantee that the most informative block would be inpainted primarily.Then,the covariance factor denoting structural integrity among image blocks was adopted in similarity calculation to reduce error filling rate.Experimental results on Wutai Mountain murals illustrate that the proposed algorithm can solve the error filling problem of the original Criminisi algorithm effectively.