HOẠT ĐỘNG TRONG TUẦN

Thời gian: 9h, thứ 5 ngày 16/1/2014
Địa điểm: Phòng 301, Nhà A5, Viện Toán học

Tóm tắt:  In this report we introduce some data hiding schemes for images (binary, gray images) based on modules of small characteristics which can reach the limit of theoretical upper bound MSDR  (in embedded bits) of any block-based data hiding scheme.  A comparison between module and correcting code methods shows that in data hiding, correcting code method can be considered as a special case of module method, and with module method we can build flexibly several hiding schemes with higher hidden data ratio than hiding schemes based on correcting codes. For example, by  the scheme (2,12,6) we can hide 6 bits in each block 12 pixels of binary images with at most two pixels are changed which can not reached by correcting code method untill now. Let us remark that with the CPT (Cheng-Pan-Tseng) hiding scheme, in such  blocks ones can hide at most 3 bits per block.