Matrix embedding for large payloads

Matrix embedding is a general coding method that can be applied to most steganographic schemes to improve their embedding efficiency - the number of message bits embedded per one embedding change. Because smaller number of embedding changes is less likely to disrupt statistic properties of the cover object, schemes that employ matrix embedding generally have better steganographic security. This gain is more important for long messages than for shorter ones because longer messages are easier to detect. Previously introduced approaches to matrix embedding based on Hamming codes are, however, not efficient for long messages. In this paper, we present novel matrix embedding schemes that are efficient for embedding messages close to the embedding capacity. One is based on a family of codes constructed from simplex codes and the second one on random linear codes of small dimension. The embedding efficiency of the proposed methods is evaluated with respect to theoretically achievable bounds.