Digital image watermarking aims to protect the information in an image without significantly affecting visual quality. In this paper, a new image watermarking technique has been proposed that uses Gaussian filters and first-order partial differential matrix to extort the edge surface of a host image. This paper influence on the edge surface curvelet coefficients as human eyes are not equally sensitive to a smooth and an edged surface. To preserve the quality of the artwork and to increase the resistance against attacks, the author utilizes the edge surface area of an image, coarse levels of curvelet transform, and strength parameters. The selection of host coefficients are conforming to the human visual system (HVS) is the uniqueness of the research. The exploitation of the Gaussian filters and first-order partial differential coarse curvelet coefficients and the watermark strength parameter offers robustness against image processing attacks. The standard visual quality perception of HVS evaluation metrics are used to measure the superiority of the presented work.

Hiding data in electrocardiogram signals are a big challenge due to the embedded information that can hamper the accuracy of disease detection. On the other hand, hiding data into ECG signals provides more security for, and authenticity of, the patient’s data. Some recent studies used non-blind watermarking techniques to embed patient information and data of a patient into ECG signals. However, these techniques are not robust against attacks with noise and show a low performance in terms of parameters such as peak signal to noise ratio (PSNR), normalized correlation (NC), mean square error (MSE), percentage residual difference (PRD), bit error rate (BER), structure similarity index measure (SSIM). In this study, an improved blind ECG-watermarking technique is proposed to embed the information of the patient’s data into the ECG signals using curvelet transform. The Euclidean distance between every two curvelet coefficients was computed to cluster the curvelet coefficients and after this, data were embedded into the selected clusters. This was an improvement not only in terms of extracting a hidden message from the watermarked ECG signals, but also robust against image-processing attacks. Performance metrics of SSIM, NC, PSNR and BER were used to measure the superiority of presented work. KL divergence and PRD were also used to reveal data hiding in curvelet coefficients of ECG without disturbing the original signal. The simulation results also demonstrated that the clustering method in the curvelet domain provided the best performance—even when the hidden messages were large size.

In this paper an efficient & robust non-blind watermarking technique based on multi-resolution geometric analysis named curvelet transform is proposed. Curvelet transform represent edges along curve much more efficiently than the wavelet transform and other traditional transforms. The proposed algorithm of embedding watermark in different scales in curvelet domain is implemented and the results are compared using proper metric. The visual quality of watermarked image, efficiency of data hiding and the quality of extracted watermark of curvelet domain embedding techniques with wavelet Domain at different number of decomposition levels are compared. Experimental results show that embedding in curvelet domain yields best visual quality in watermarked image, the quality of extracted watermark, robustness of the watermark and the data hiding efficiency.

In this paper, a semi-blind watermarking technique of embedding the color watermark using curvelet coefficient in RGB cover image has been proposed. The technique used the concept of HVS that the human eyes are not much sensitive to blue color. So the blue color plane of the cover image is used as embedding domain. A bit planes method is also used, the most significant bit (MSB) plane of watermark image is used as embedding information. Selected scale and orientation of the curvelet coefficients of the blue channel in the cover image has been used for embedding the watermark information. All other 0-