A comment on “Sharing secrets in stegoimages with authentication”

Recently, Chang et al.'s image secret sharing (ISS) scheme enhanced the weak authentication of two previous ISS schemes—Lin et al.'s scheme and Yang et al.'s scheme. Also, the authors claimed that the visual qualities of stegoimages were superior to the previous two schemes; however, their qualities were not really that improved. Contrarily, the qualities are significantly degraded when compared with those in Yang et al.'s scheme. This miscalculation is owing to a misunderstanding of Yang et al.'s scheme.