scholarly journals Towards Robust Invariant Commutative Watermarking-Encryption Based on Image Histograms

2014 ◽  
Vol 5 (4) ◽  
pp. 36-52 ◽  
Author(s):  
Roland Schmitz ◽  
Shujun Li ◽  
Christos Grecos ◽  
Xinpeng Zhang
Keyword(s):  
Feature Space ◽  
Calibration Point ◽  
Jpeg2000 Compression ◽  
The Mean ◽  
Histogram Bins ◽  
Watermarking Scheme

Invariant Commutative Watermarking-Encryption means to use a cipher that does not have any impact on a certain feature space, which can thus be used for embedding watermarks either before or after encryption. For example, histogram-based watermarking schemes are invariant to pixel permutations and can be combined with permutation-based ciphers to form a Commutative Watermarking-Encryption (CWE) scheme. However, typical histogram-based watermarking schemes based on comparison of histogram bins are prone to de-synchronization attacks, where the whole histogram is shifted by a certain amount. In this paper the authors investigate the possibility to avoid this kind of attacks by synchronizing the embedding and detection processes, using the mean of the histogram as a calibration point. The resulting watermarking scheme is resistant to three common types of shifts of the histogram, while the advantages of previous histogram-based schemes, especially commutativity of watermarking and permutation-based encryption, are preserved. The authors also report on the results of testing robustness of the scheme against JPEG and JPEG2000 compression.

Commutative Watermarking-Encryption of Multimedia Data Based on Histograms

2019 ◽  
pp. 141-163
Author(s):  
Roland Schmitz ◽  
Shujun Li ◽  
Christos Grecos ◽  
Xinpeng Zhang
Keyword(s):  
Image Data ◽  
Multimedia Data ◽  
Encryption Scheme ◽  
Calibration Point ◽  
Still Image ◽  
Audio Data ◽  
The Mean ◽  
Histogram Bins ◽  
Watermarking Scheme ◽  
Desynchronization Attacks

Histogram-based watermarking schemes are invariant to pixel permutations and can thus be combined with permutation-based ciphers to form a commutative watermarking-encryption scheme. In this chapter, the authors demonstrate the feasibility of this approach for audio data and still image data. Typical histogram-based watermarking schemes based on comparison of histogram bins are prone to desynchronization attacks, where the whole histogram is shifted by a certain amount. These kind of attacks can be avoided by synchronizing the embedding and detection processes, using the mean of the histogram as a calibration point. The resulting watermarking scheme is resistant to three common types of shifts of the histogram, while the advantages of previous histogram-based schemes, especially commutativity of watermarking and permutation-based encryption, are preserved. The authors also report on the results of testing robustness of the still image watermark against JPEG and JPEG2000 compression and on the possibility of using histogram-based watermarks for authenticating the content of an image.

Best Architecture of an Artificial Neural Network to Model Prefilming Airblast Atomization: Not So Deep Learning

2021 ◽  
Author(s):  
Geoffroy Chaussonnet ◽  
Sebastian Gepperth ◽  
Simon Holz ◽  
Rainer Koch ◽  
Hans-Jörg Bauer
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Feature Space ◽  
Middle Layer ◽  
Ann Model ◽  
Deformation Velocity ◽  
The Mean ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Domain Of Parameters

Abstract A fully connected Artificial Neural Network (ANN) is used to predict the mean spray characteristics of prefilming airblast atomization. The model is trained from the planar prefilmer experiment from the PhD thesis of Gepperth (2020). The output of the ANN model are the Sauter Mean Diameter, the mean droplet axial velocity, the mean ligament length and the mean ligament deformation velocity. The training database contains 322 different operating points. Two types of model input quantities are investigated and compared. First, nine dimensional parameters are used as inputs for the model. Second, nine non-dimensional groups commonly used for liquid atomization are derived from the first set of inputs. The best architecture is determined after testing over 10000 randomly drawn ANN architectures, with up to 10 layers and up to 128 neurons per layer. The striking results is that for both types of model, the best architectures consist of only 3 hidden layer in the shape of a diabolo. This shape recalls the shape of an autoencoder, where the middle layer would be the feature space of reduced dimensionality. It was found that the model with dimensional input quantities always shows a lower test and validation errors than the one with non-dimensional input quantities. In general, the two types of models provide comparable accuracy, better than typical correlations of SMD and droplet velocity. Finally the extrapolation capability of the models was assessed by a training them on a confined domain of parameters and testing them outside this domain.

An Improved Representation for Object Tracking Algorithm

2009 ◽  
Vol 16-19 ◽  
pp. 1020-1024
Author(s):  
Yu Ming Gu ◽  
Jie Liu ◽  
Kuo Liu ◽  
Zhao Yao
Keyword(s):  
Object Tracking ◽  
Spatial Information ◽  
Target Location ◽  
Mean Shift ◽  
Feature Space ◽  
Candidate Region ◽  
Space Representation ◽  
Improved Method ◽  
The Mean ◽  
Model Region

Aiming at the shortcoming of feature space representation in traditional mean shift, we propose an improved object tracking method. At first, the target model region is segmented into overlapped square, and their histograms are computed. Then, the feature space is constituted which has introduced spatial information into. So the accuracy is enhanced. After computing the feature space of target candidate region, the mean shift is employed to find the new target location. The result shows that the improved method can track the object more robust, accurately and quickly.

An Improved Print-Scan Resistant Watermarking Scheme

2015 ◽  
Vol 731 ◽  
pp. 153-158
Author(s):  
Wei Guo ◽  
Wen Fa Qi
Keyword(s):  
Data Extraction ◽  
Visual Quality ◽  
Mapping Method ◽  
Local Complexity ◽  
Before And After ◽  
Dct Coefficients ◽  
The Mean ◽  
Image Pixels ◽  
Watermarking Scheme ◽  
Better Than

As an improvement of Cheng etal.’s print-and-scan (PS) digital watermarking scheme, the proposed method solves the data extraction failure problem caused by pixel displacement. We propose to embed the watermark into the middle band of DCT coefficients based on the fact that the mean of DCT coefficients (MDC) is zero before and after PS. Besides, a mapping method is designed which can distribute the change of average to the original image pixels according to the local complexity. Meanwhile, we use the JND model mentioned in Cheng et al.’s scheme to guarantee the visual quality. Extensive experiments show that the proposed scheme is effective to resist PS, and the performance of the proposed scheme is better than that of Cheng et al.’s scheme.

scholarly journals Multiple watermarking technique using optimal threshold

2020 ◽  
Vol 18 (1) ◽  
pp. 368
Author(s):  
Noruhida Alias ◽  
Ferda Ernawan
Keyword(s):  
Cross Correlation ◽  
Orthogonal Matrix ◽  
Arnold Transform ◽  
High Demand ◽  
Trade Off ◽  
Multiple Watermarking ◽  
Jpeg2000 Compression ◽  
Optimal Thresholds ◽  
Multiple Watermarks ◽  
Watermarking Scheme

<span>The multiple watermarking technique has drawn more attention due to high demand for embedding more than one copyright. This paper proposes a multiple watermarking scheme using DWT-SVD by utilizing HVS characteristics. Our scheme embeds multiple watermarks in red and blue colors. The proposed scheme examines the coefficients of U orthogonal matrix for embedding and extracting watermarks. Watermarks are scrambled by Arnold transform before embedded in the host image in order provide additional security. The optimal thresholds for red and blue colors are revealed by finding a trade-off between normalized-cross correlation and imperceptibility from quantization steps. The experimental results demonstrate that our scheme achieves high resistant under JPEG and JPEG2000 compression for both inserted watermarks. </span>

A Robust Wavelet Based Watermarking Scheme For Digital Audio

2012 ◽  
Vol 8 (8) ◽  
pp. 65-72
Author(s):  
Ayad Abdulsada
Keyword(s):  
Signal Processing ◽  
Experimental Results ◽  
Digital Audio ◽  
The Mean ◽  
Watermarking Scheme

In this paper, a robust wavelet based watermarking scheme has been proposed for digital audio. A single bit is embedded in the approximation part of each frame. The watermark bits are embedded in two subsets of indexes randomly generated by using two keys for security purpose. The embedding process is done in adaptively fashion according to the mean of each approximation part. The detection of watermark does not depend on the original audio. To measure the robustness of the algorithm, different signal processing operations have been applied on the watermarked audio. Several experimental results have been conducted to illustrate the robustness and efficiency of the proposed watermarked audio scheme.

scholarly journals A Robust Watermarking Scheme Based on the Mean Modulation of DWT Coefficients

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Zied Kricha ◽  
Anis Kricha ◽  
Anis Sakly
Keyword(s):  
Signal Processing ◽  
Wavelet Transformation ◽  
State Of The Art ◽  
Mean Value ◽  
Chaotic Sequence ◽  
Computational Algorithms ◽  
Robust Watermarking ◽  
The Mean ◽  
Extraction Stage ◽  
Watermarking Scheme

In an endeavor to deal with image copyright infringement, robust watermarking approaches are commonly used. However, most of the existing approaches either present a limited robustness or rely on highly computational algorithms, thereby limiting the efficiency of these solutions. In this paper, a novel blind and robust watermarking method is presented. First, the vertical and horizontal subbands coefficients, resulting from the wavelet transformation, are scrambled using a chaotic sequence and then gathered into individual blocks. Next, the mean value of each block is modulated according to watermark bit. At the extraction stage, based on the sign of the blocks’ mean, a blind watermark extractor is suggested. The imperceptibility, security, complexity, and robustness of the proposed approach have been evaluated and compared with state of the art solutions. Experimental results prove that the proposed approach successfully satisfies the watermarking requirement and outperforms existing methods against both geometric and signal processing attacks.

Representing Color Ensembles

2017 ◽  
Vol 28 (10) ◽  
pp. 1510-1517 ◽  
Author(s):  
Andrey Chetverikov ◽  
Gianluca Campana ◽  
Árni Kristjánsson
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Feature Space ◽  
Striking Similarity ◽  
Color Distribution ◽  
Internal Representations ◽  
Distractor Color ◽  
Mean And Variance ◽  
The Mean ◽  
Actual Shape

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

scholarly journals Use of SHDM in Commutative Watermarking-Encryption

2020 ◽  
Author(s):  
Roland Schmitz
Keyword(s):  
Spatial Domain ◽  
The Other ◽  
Encryption Scheme ◽  
Large Capacity ◽  
Security Applications ◽  
Dither Modulation ◽  
Jpeg2000 Compression ◽  
Medium Security ◽  
The Cost ◽  
Watermarking Scheme

Abstract SHDM stands for Sphere Hardening Dither Modulation and is a watermarking algorithm based on quantizing the norm of a vector extracted from the cover work. We show how SHDM can be integrated into a fully commutative watermarking encryption scheme and investigate implementations in the spatial, DCT- and DWT-domain with respect to their delity, robustness, capacity and security of encryption. The watermarking scheme, when applied in the DCT- or DWT-domain, proves to be very robust against JPEG/JPEG2000 compression. On the other hand, the spatial domain-based approach offers a large capacity. The increased robustness of the watermarking schemes, however, comes at the cost of rather weak encryption primitives, making the proposed CWE scheme suited for low - medium security applications with high robustness requirements.

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