Dual purpose FWT domain spread spectrum image watermarking in real time

Spread spectrum (SS) watermarking for multimedia signal becomes appealing due to its high robustness attribute and is used widely for various applications. Some of these applications essentially demand development of low cost algorithms so that they can be used for real time services such as broadcast monitoring, security in communication etc. In recent time one popular non-conventional application of digital watermarking becomes promising that assesses blindly the QoS (quality of services) of the multimedia services which is expected to be offered by the future generation mobile radio network. Majority of the existing SS watermarking schemes suffer from high computation cost and complexity leading to the difficulty for real time implementation and limits their usage for the above mentioned applications. This paper proposes fast Walsh transform (FWT) based SS image watermarking scheme that serves the dual purposes of authentication in data transmission as well as QoS assessment for digital media through dynamic estimation of the wireless channel condition. Fast Walsh transform offers low computation cost for implementation, smaller change in image (multimedia signal) information due to data embedding and ease of hardware realization. VLSI implementation using field programmable gate array (FPGA) has been developed to make it suitable for real time implementation.