In order to remove the high density of salt %pepper noise

this paper proposes an efficient two-step denoising algorithm (TSDA)

which is based the standard median filtering and the mean filter. Numerical experiment shows that TSDA is able to preserve edges and remove the high density salt %pepper noise efficiently. TSDA has more improvement on MSE

PSNR and IEF than SMF and New Decision-Based Algorithm (NDBA).