$k$ Out of $n$ Region Incrementing Scheme in Visual Cryptography. - Ching-Nung Yang; Hsiang-Wen Shih; Chih-Cheng Wu; Lein Harn (IEEE Trans. Circuits Syst. Video Technol., 2012)

Aspect ratio invariant visual cryptography by image filtering and resizing. - Ching-Nung Yang; Pin-Wei Chen; Hsiang-Wen Shih; Cheonshik Kim (Pers. Ubiquitous Comput., 2013)