scholarly journals A Perceptive Approach to Digital Image Watermarking Using a Brightness Model and the Hermite Transform

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Boris Escalante-Ramírez ◽  
S. L. Gomez-Coronel
Keyword(s):  
Vision System ◽  
Image Watermarking ◽  
Human Vision ◽  
Human Observer ◽  
Noise Detection ◽  
Local Orientation ◽  
Image Normalization ◽  
Hermite Transform ◽  
Watermarking Scheme ◽  
Derivatives Of

This work presents a watermarking technique in digital images using a brightness model and the Hermite Transform (HT). The HT is an image representation model that incorporates important properties of the Human Vision System (HVS), such as the analysis of local orientation, and the model of Gaussian derivatives of early vision. The proposed watermarking scheme is based on a perceptive model that takes advantage of the masking characteristics of the HVS, thus allowing the generation of a watermark that cannot be detected by a human observer. The mask is constructed using a brightness model that exploits the limited sensibility of the human visual system for noise detection in areas of high or low brightness. Experimental results show the imperceptibility of the watermark and the fact that the proposed algorithm is robust to most common processing attacks. For the case of geometric distortions, an image normalization stage is carried out prior to the watermarking.

scholarly journals 3D Hermite Transform Optical Flow Estimation in Left Ventricle CT Sequences

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 595 ◽  
Author(s):  
Carlos Mira ◽  
Ernesto Moya-Albor ◽  
Boris Escalante-Ramírez ◽  
Jimena Olveres ◽  
Jorge Brieva ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Optical Flow ◽  
Vision System ◽  
Heart Diseases ◽  
Left Ventricular ◽  
Two Dimensions ◽  
Human Vision ◽  
Three Dimensions ◽  
Hermite Transform ◽  
Cardiac Volumes

Heart diseases are the most important causes of death in the world and over the years, the study of cardiac movement has been carried out mainly in two dimensions, however, it is important to consider that the deformations due to the movement of the heart occur in a three-dimensional space. The 3 D + t analysis allows to describe most of the motions of the heart, for example, the twisting motion that takes place on every beat cycle that allows us identifying abnormalities of the heart walls. Therefore, it is necessary to develop algorithms that help specialists understand the cardiac movement. In this work, we developed a new approach to determine the cardiac movement in three dimensions using a differential optical flow approach in which we use the steered Hermite transform (SHT) which allows us to decompose cardiac volumes taking advantage of it as a model of the human vision system (HVS). Our proposal was tested in complete cardiac computed tomography (CT) volumes ( 3 D + t ), as well as its respective left ventricular segmentation. The robustness to noise was tested with good results. The evaluation of the results was carried out through errors in forwarding reconstruction, from the volume at time t to time t + 1 using the optical flow obtained (interpolation errors). The parameters were tuned extensively. In the case of the 2D algorithm, the interpolation errors and normalized interpolation errors are very close and below the values reported in ground truth flows. In the case of the 3D algorithm, the results were compared with another similar method in 3D and the interpolation errors remained below 0.1. These results of interpolation errors for complete cardiac volumes and the left ventricle are shown graphically for clarity. Finally, a series of graphs are observed where the characteristic of contraction and dilation of the left ventricle is evident through the representation of the 3D optical flow.

scholarly journals A Reliable Image Watermarking Scheme Based on Redistributed Image Normalization and SVD

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Musrrat Ali ◽  
Chang Wook Ahn ◽  
Millie Pant ◽  
Patrick Siarry
Keyword(s):  
Digital Image ◽  
Image Watermarking ◽  
Piecewise Linear ◽  
Chaotic Map ◽  
Scaling Factor ◽  
Image Normalization ◽  
Integer Multiple ◽  
Piecewise Linear Chaotic Map ◽  
Value Decomposition ◽  
Watermarking Scheme

Digital image watermarking is the process of concealing secret information in a digital image for protecting its rightful ownership. Most of the existing block based singular value decomposition (SVD) digital watermarking schemes are not robust to geometric distortions, such as rotation in an integer multiple of ninety degree and image flipping, which change the locations of the pixels but don’t make any changes to the pixel’s intensity of the image. Also, the schemes have used a constant scaling factor to give the same weightage to the coefficients of different magnitudes that results in visible distortion in some regions of the watermarked image. Therefore, to overcome the problems mentioned here, this paper proposes a novel image watermarking scheme by incorporating the concepts of redistributed image normalization and variable scaling factor depending on the coefficient’s magnitude to be embedded. Furthermore, to enhance the security and robustness the watermark is shuffled by using the piecewise linear chaotic map before the embedding. To investigate the robustness of the scheme several attacks are applied to seriously distort the watermarked image. Empirical analysis of the results has demonstrated the efficiency of the proposed scheme.

scholarly journals Statistical Assessment of Discrimination Capabilities of a Fractional Calculus Based Image Watermarking System for Gaussian Watermarks

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 255
Author(s):  
Mario Gonzalez-Lee ◽  
Hector Vazquez-Leal ◽  
Luis J. Morales-Mendoza ◽  
Mariko Nakano-Miyatake ◽  
Hector Perez-Meana ◽  
...  
Keyword(s):  
Fractional Calculus ◽  
Roc Curve ◽  
Gaussian Noise ◽  
False Positive ◽  
Operating Characteristic ◽  
Image Watermarking ◽  
Area Under The Curve ◽  
Statistical Assessment ◽  
Watermarking Scheme ◽  
Fractional Equation

In this paper, we explore the advantages of a fractional calculus based watermarking system for detecting Gaussian watermarks. To reach this goal, we selected a typical watermarking scheme and replaced the detection equation set by another set of equations derived from fractional calculus principles; then, we carried out a statistical assessment of the performance of both schemes by analyzing the Receiver Operating Characteristic (ROC) curve and the False Positive Percentage (FPP) when they are used to detect Gaussian watermarks. The results show that the ROC of a fractional equation based scheme has 48.3% more Area Under the Curve (AUC) and a False Positives Percentage median of 0.2% whilst the selected typical watermarking scheme has 3%. In addition, the experimental results suggest that the target applications of fractional schemes for detecting Gaussian watermarks are as a semi-fragile image watermarking systems robust to Gaussian noise.

Sign in / Sign up

Export Citation Format

Share Document