GA Based Robust Blind Digital Watermarking

A genetic algorithm based robust blind digital watermarking scheme is presented. The experimental results show that our scheme keeps invisibility, security and robustness more likely than other proposals in the literature, thanks to the GA pretreatment.Junta de Andalucía FQM-01

A novel perceptually adaptive image watermarking scheme by selecting adaptive threshold in dht domain

This paper proposed a novel image watermarking technique by applying the characteristics of the human visual system, in Hadamard transform domain. Statistical information measures were used to select proper blocks for data embedding. Watermark was embedded by the modification of Discrete Hadamard transform (DHT) coefficients of selected blocks. Threshold and modification value were selected adaptively for each image block, which improved robustness and transparency. The proposed algorithm was able to withstand a variety of attacks and image processing operations like rotation, cropping, noise addition, resizing, lossy compression and etc. The experimental results showed good performance of the proposed scheme in comparison with some of the recently reported watermarking techniques.Keywords: Digital image watermarking, Hadamard transform, Entropy, Lossy compression, Adaptive Threshol

Hybrid multiple watermarking technique for securing medical images of modalities MRI, CT scan, and X-ray

In order to contribute to the security of sharing and transferring medical images, we had presented a multiple watermarking technique for multiple protections; it was based on the combination of three transformations: the discrete wavelet transform (DWT), the fast Walsh-Hadamard transform (FWHT) and, the singular value decomposition (SVD). In this paper, three watermark images of sizes 512x 512 were inserted into a single medical image of various modalities such as magnetic resonance imaging (MRI), computed tomography (CT), and X-Radiation (X-ray). After applying DWT up to the third level on the original image, the high-resolution sub-bands were being selected subsequently to apply FWHT and then SVD. The singular values of the three watermark images were inserted into the singular values of the cover medical image. The experimental results showed the effectiveness of the proposed method in terms of quality and robustness compared to other reported techniques cited in the literature