Robust image adaptive watermarking scheme with strength factor analysis

Abstract

Towards the end of 20th century digitalization had started to spread in all forms of the technology related areas. Around the same time internet had also begun to turn the whole world into a global village. Though digital form of data had many benefits over its analog counterpart like ease of storage and transmission, still a lot of multimedia content providers were skeptical of it due to the fear of probable copyright violation by the high quality duplication possible with the digital data. As necessity breeds the invention, watermarking techniques came in the forefront to tackle this problem. In watermarking a secret and invisible data is hidden in the digital content. This secret data could be a logo or some other information for correctly identifying the original owner of the content. At the time of conflict the original owner could easily prove his ownership by extracting the hidden information from the digital content. A lot of research work carried out in the watermarking field, emphasized the use of perceptually significant areas of the image for robust watermarking. HVS models facilitated the use of certain frequencies and chromatic components for embedding the watermark, towards which the human eyes have low sensitivity. Many image-adaptive techniques espousing these two doctrines of robustness and imperceptibility have been proposed. Following the footsteps of the preceding researchers, the presented work is an effort to provide better and less complicated robust watermarking techniques by applying image-adaptive measures. In the available literature there is no study to suggest if any one size of block segmentation in image could provide better robustness than the other size of block segmentation for the same watermarking technique. In the presented work three sizes of block segmentations (8×8, 16×16 and 32×32) have been used in the proposed DWT based semi-blind image-adaptive watermarking technique.