A compact covering method to exploit embedding capacity for matrix encoding

Recently, a number of covering schemes proposed to exploit embedding capacity in covering images using matrix encoding. When binary secret data include a high frequency of repeated bit-blocks, a preprocessing phase is employed to compress secret data prior to the embedding process regardless of whether the compressed secret data still contain some repeated bit-blocks. This paper proposes two novel compact covering schemes, compact covering scheme (CCS) and intelligent compact covering scheme (ICCS), which directly compress and conceal the repeated bit-blocks of secret data bits into covering images within a single phase. The proposed schemes can exploit the embedding capacity and increase the embedding efficiency by reducing the required encoding operations. In addition, the proposed ICCS scheme can indicate up to which degree of repeated bit-blocks of secret data it can take advantage of in order to improve the embedding capacity. Experimental results demonstrate that the proposed ICCS method can significantly improve the embedding capacity when the ratio of the repeated bit-blocks over the total number of blocks is low. The proposed schemes are feasible for actual data-hiding applications.