Most includeding techniques of digital watermark even now working through the direct inclusion in the pixel without taking into account the level of compression (attack) that can go wrong, which makes digital watermark can be discarded easily. In this research, a method was proposed to overcome this problem, which is based on DCT (after image partitioned into non overlapped blocks with size 8×8 pixel), accompanied by a quantization method. The watermark (digital image) is embedded in DCT frequency domain seeking the blocks have highest standard deviation (the checking is only on the AC coefficients) within a predetermined threshold value, then the covered image will compressed (attacked) varying degrees of compression. The suggested methodology enables user to extract digital watermark even when the digital image compressed to low level bit ratios was showed in tables.
Effective Image Watermarking Method Based on DCT
Digital Watermarking
JPEG compression
DCT
Coefficients Quantization
Publication Date
Thu Jun 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Nahrain Mobile Learning System (NMLS)
Nahrain mobile learning system
short message service
wireless application protocols
multimedia messaging service
mobile learning
personal digital assistant
wireless fidelity
general packet radio service
extensible hypertext markup language
java database connectivity
The work in this paper involves the planning, design and implementation of a mobile learning system called Nahrain Mobile Learning System (NMLS). This system provides complete teaching resources, which can be accessed by the students, instructors and administrators through the mobile phones. It presents a viable alternative to Electronic learning. It focuses on the mobility and flexibility of the learning practice, and emphasizes the interaction between the learner and learning content. System users are categorized into three categories: administrators, instructors and students. Different learning activities can be carried out throughout the system, offering necessary communication tools to allow the users to communicate with each other
... Show More