Block-Based Discrete Wavelet Transform-Singular Value Decomposition Image Watermarking Scheme Using Human Visual System Characteristics

Digital watermarking has been suggested as a way to achieve digital protection. The aim of digital watermarking is to insert the secret data into the image without significantly affecting the visual quality. This study presents a robust block-based image watermarking scheme based on the singular value decomposition (SVD) and human visual system in the discrete wavelet transform (DWT) domain. The proposed method is considered to be a block-based scheme that utilises the entropy and edge entropy as HVS characteristics for the selection of significant blocks to embed the watermark, which is a binary watermark logo. The blocks of the lowest entropy values and edge entropy values are selected as the best regions to insert the watermark. After the first level of DWT decomposition, the SVD is performed on the low-low sub-band to modify several elements in its U matrix according to predefined conditions. The experimental results of the proposed scheme showed high imperceptibility and high robustness against all image processing attacks and several geometrical attacks using examples of standard and real images. Furthermore, the proposed scheme outperformed several previous schemes in terms of imperceptibility and robustness. The security issue is improved by encrypting a portion of the important information using Advanced Standard Encryption a key size of 192-bits (AES-192)

Identification as a mechanism of narrative persuasion

Contains fulltext : M_337499.pdf (publisher's version ) (Closed access)22 p

Radical masculinity: morality, sociality and relationships through recollections of Naxalite activists

In this article I argue that the concern with gender relations and the challenges female activists were facing foreclosed any discussion of the transformation activism signalled for male comrades, and thus for wider society. I am particularly interested in men’s own views of their social roles and personal predicaments as the more subtle processes of transformation in the lives of male activists are often overlooked. The article takes a closer look at relationships between men, whether friendships or kin relations, as important roles and everyday practices former activists were/are involved in—during their phase of active participation, but crucially also before they become militants and in the aftermath of their involvement in the movement