A Novel (2, 2) Visual Secret Sharing without the Pixel Expansion

Pixel expansion is a common drawback of traditional (2,2) visual secret sharing (VSS), unexpanded shares can decrease the bandwidth and save storage. In the literature, we introduce a novel (2,2) VSS scheme, that solved the pixel expansion and visual quality is almost equal with traditional (2,2) VSS. Our scheme not only can apply to (2,2) VSS, but also to (k, k) VSS. At last, analyse and experiment are conducted to evaluate the efficiency of the proposed method.