We present a novel scheme for embedding secret data into a binary image without introducing noticeable artifacts.Unlike some block-based methods,the proposed scheme encodes the secret bits directly into boundary pixels by checking each pixel of the cover image in a pseudo-random order for embedding eligibility.A set of rules ensures correct identification of data-carrying pixels in blind extraction.The proposed scheme does not generate isolated dots,and Call incorporate various coding methods such as matrix encoding to further improve the embedding performance.It is shown that up to one fourth of the boundary pixels may be used to carry secret data.Experimental results indicate that the method can achieve good visual quality with fairly large data capacity.