Message estimation for universal steganalysis using multi-classification support vector machine

To prevent misusing of the steganography from the terrorists, effective steganalysis schemes which discriminate the stego-images from suspicious images are necessary. Some steganalysis methods can accurately estimate the length of embedded messages but they are only useful in the pre-defined condition. Active steganalysis methods are powerful in length estimation such as regular singular (RS) and sample pairs analysis (SPA) steganalysis schemes, but they would become invalid in frequency domain. Passive steganalysis methods may discriminate stego-images from suspicious images in spatial and frequency domains such as Lyu and Fraid's steganalysis scheme, but they could not estimate the length of hidden messages. Although length estimation has been discussed in the active steganalysis methods for a while, it is a novel study in passive steganalysis method. We improve the Lyu and Fraid's universal steganalysis scheme and design an efficient length estimation policy in passive steganalysis methods. Experimental results demonstrate the efficiency and practicability of the proposed universal steganalysis scheme.     

Efficient relation extraction method based on spatial feature using ELM

Entity relation extraction can be applied in the automatic question answering system, digital library and many other fields. However, the previous works on this topic mainly focused on the features from a sentence itself in the data sets, without considering the links between sentences in the corpus. In this paper, we propose a concept model and obtain a new effective spatial feature based on this concept model. The added feature makes our feature space concerning not only the inherent information of the sentence itself, but also the semantic information connection between sentences. At last, we use ELM as the training classifier in entity relation extraction. The experiment result shows that the precision and recall of the relation extraction both have a significant increase, by using the new feature. Also, the use of ELM significantly reduces the time of relation extraction. It has a better performance than the traditional method based on SVM.     

一种JPEG图像的DCT域隐写分析方法

提出了一种基于JPEG图像DCT系数差分矩阵统计特征的隐写分析方法。该算法保留了以往算法选用的DCT系数水平和竖直方向的差分矩阵相关特征,通过增加其主副对角线方向上差分矩阵来提取和计算特征向量,进而利用SVM分类器进行分类。实验结果表明,该方法能够有效地对JPEG图像进行检测,并且具有较高的检测正确率。     

利用空间相关性的改进HMM模型

语音识别领域中所采用的经典HMM模型,忽略了语音信号间的相关信息.针对这一问题,利用语音信号的空间相关性对经典HMM模型进行补偿,得到一种改进模型.该方法通过空间相关变换,描述了当前语音特征与历史数据之间的空间相关性,从而对联合状态输出分布进行建模.改进模型的解码算法利用空间相关性变换的参数更新算法在经典ⅧⅥM的解码算法基础上得到.实验结果表明,上述方法在说话人无关连续语音识别系统上获得了明显的性能改进.     

Improved estimation of defocus blur and spatial shifts in spatial domain: a homotopy-based approach

This paper presents a homotopy-based algorithm for the recovery of depth cues in the spatial domain. The algorithm specifically deals with defocus blur and spatial shifts, that is 2D motion, stereo disparities and/or zooming disparities. These cues are estimated from two images of the same scene acquired by a camera evolving in time and/or space. We show that they can be simultaneously computed by resolving a system of equations using a homotopy method. The proposed algorithm is tested using synthetic and real images. The results confirm that the use of a homotopy method leads to a dense and accurate estimation of depth cues. This approach has been integrated into an application for relief estimation from remotely sensed images.     

A novel voting ensemble model for spatial prediction of landslides using GIS

ABSTRACT

Inherent complex topography and drastic weather patterns together have concocted various natural disasters worldwide. In difficult terrains such as those prevalent in the North-Eastern regions of India, coupled with the factors such as population explosion and improper land use, lead them to witness some of the world’s most drastic landslides with an astonishing frequency, reckoning landslide susceptibility assessment crucial in such regions. This paper focuses on exploring a promising machine learning ensemble technique of Majority-based voting which has seldom been employed for landslide susceptibility assessment. The ensemble comprises Logistic Regression (LR), Gradient Boosted Decision Trees (GBDT) and Voting Feature Interval (VFI) to prepare landslide susceptibility zonation maps for the Brahmaputra valley region (Assam & Nagaland) and its close vicinity. In the first stage of the study, a landslide inventory for the area comprising 436 landslide locations was prepared in geographic information system (GIS), substantiated by news reports and remote sensing data. In the second stage, 16 landslide causative thematic maps including Elevation, Slope, Slope Aspect, General Curvature, Plan Curvature, Profile Curvature, Surface Roughness, Topographic Wetness Index (TWI), Stream Power Index (SPI), Slope Length, Normalized Difference Vegetation Index (NDVI), Land Use/Land Cover (LULC), Distance from Roads, Rivers, Faults and Railways were prepared. In the third stage, the landslide inventory was annexed with the causative factor maps to obtain a dataset comprising coordinates of the locations and the values of aforementioned causative factors on the corresponding coordinates. The proposed model was then trained and tested on the prepared dataset (70%:30% split). Finally, the efficiency of the new model was tested using the area under receiver operating characteristic curve (AUC of ROC). The validation results demonstrate the mettle of the proposed majority-based voting ensemble LR-GBDT-VFI (AUC: 0.98) against the conventional techniques such as Decision Trees, Support Vector Machines, Random Forest, etc. Altogether, the study offers an approach with wide scope across the field of landslide hazard assessment.     

改进的基于R树的空问连接代价模型

针对Yannis Theodoridis等人提出的空间连接代价模型存在比较理想化的限制条件--假设数据均匀分布,缓冲策略使用简单的缺点,利用划分子空间并抽样获取非均匀数据实际密度的策略,提出了优先保存查询集合树的最新访问路径的有效中问节点的缓冲区算法,给出了改进后的评估公式.实验结果表明,改进后的模型比原模型提高了评估的精确度.     

Classification of paint on metallic surfaces using spatial domain analysis of laser images

In this paper a classification method is described for painted surfaces using laser image clarity meter (LIC)^†. In this method extracted features from reflected images of size (512 × 512 × 8 bits) from painted surfaces are used for classification purpose. The distance measured between the features of the test samples and the reference sample, which is smooth black glass, determines the deviation of the test sample from the reference. In comparing the result of 500 of the painted panels classified by the proposed method with the result of visual inspection, we have shown that this method is quite effective.     

Entropy-based texture analysis in the spatial frequency domain

An approach which uses regional entropy measures in the spatial frequency domain for texture discrimination is presented. The measures provide texture discriminating information independent of that contained in the usual summed energy within based frequency domain features. Performance of the entropy features as measured by a between-to-within-class scatter criterion is comparable to that of traditional frequency domain features and gray level co-occurrence contrast features. A method of frequency scaling is introduced to enable the comparison of texture samples of different subimage size. The resulting regional entropy measures are subimage size-invariant subject to certain constraints which arise from properties of the discrete Fourier transform.     

小波域中的鲁棒性盲水印算法

提出了自适应的鲁棒性图像水印方案。用密钥选择嵌入的位置,增加水印的安全性,并只对有嵌入要求的图像块进行离散小波变换,这样算法的计算复杂度只与水印容量有关,与宿主图像无关,相对减少了计算的复杂度。在水印嵌入过程中,对相应的有嵌入要求的图像块进行分类来决定不同的嵌入强度,达到了自适应的嵌入要求。为了更好地增加方案的鲁棒性,采用基因算法对阈值进行了优化。实验结果表明,此方案具有很好的透明性,对通常的图像处理具有很好的鲁棒性。     

Malicious inter-frame video tampering detection in MPEG videos using time and spatial domain analysis of quantization effects

In this paper, a new algorithm is proposed for forgery detection in MPEG videos using spatial and time domain analysis of quantization effect on DCT coefficients of I and residual errors of P frames. The proposed algorithm consists of three modules, including double compression detection, malicious tampering detection and decision fusion. Double compression detection module employs spatial domain analysis using first significant digit distribution of DCT coefficients in I frames to detect single and double compressed videos using an SVM classifier. Double compression does not necessarily imply the existence of malignant tampering in the video. Therefore, malicious tampering detection module utilizes time domain analysis of quantization effect on residual errors of P frames to identify malicious inter-frame forgery comprising frame insertion or deletion. Finally, decision fusion module is used to classify input videos into three categories, including single compressed videos, double compressed videos without malicious tampering and double compressed videos with malicious tampering. The experimental results and the comparison of the results of the proposed method with those of other methods show the efficiency of the proposed algorithm.     

Hiding data in spatial domain images with distortion tolerance

Data hiding is a technique that is used to embed secret information into a cover media. It has been widely used in protecting copyright and transmitting sensitive data over an insecure channel. Conventional data hiding schemes only focus on how to reduce the distortion when sensitive data is embedded into the cover image. However, the transmitted images may be compressed or occur transmitting errors. If such errors occur, the receiver cannot extract the correct information from the stego-image. In this paper, we proposed a novel hiding data scheme with distortion tolerance. The proposed scheme not only can prevent the quality of the processed image from being seriously degraded, but also can simultaneously achieve distortion tolerance. Experimental results show that the proposed scheme indeed can obtain a good image quality and is superior to the other schemes in terms of its distortion tolerance.     

Detecting outliers in industrial systems using a hybrid ensemble scheme

Neural Computing and Applications - The massive growth of process data in industrial systems has promoted the development of data-driven techniques, while the presence of outliers in process data...     

Joint damage identification using Improved Radial Basis Function (IRBF) networks in frequency and time domain

In this paper, a novel two-stage Improved Radial Basis Function (IRBF) neural network technique is proposed to predict the joint damage of a fifty member frame structure with semi-rigid connections in both frequency and time domain. The effective input patterns as normalized design signature indices (NDSIs) in frequency domain and acceleration responses in time domain are simulated numerically from finite element analysis (FEA) by considering different levels of damage severity using Latin hypercube sampling (LHS) technique. The conventional RBF network is used in the first stage of IRBF network and in the second stage reduced search space moving technique is employed for accurate prediction with less than 3% error. The numerical simulation of the substructural joint damage identification of a fifty member frame structure with and without addition of 5% Gaussian random noise to the input patterns is presented and compared with conventional CPN–BPN hybrid method. The two-stage IRBF method is found to be superior in accuracy to conventional hybrid methods as well as to conventional RBF method. An important benefit of the proposed novel IRBF method is the significant reduction in the computational time with good accuracy of joint damage identification.     

抗差分检测的高位空域隐藏方法

针对HSBH的特点对其进行分析,提出一种区间差分检测的方法(DMID),可以准确检测其隐藏量,进而提出了改进的HSBH算法,使其可以抗击DMID的检测.实验结果表明,DMID方法可以测量出HSBH算法隐藏量,检测准确率达到95%以上,改进的HSBH算法使DMID分析得出的估计值低于判决门限2%,从而做出错误判决,可以很好地抗击区间差分检测.     

空域中基于正则化的自适应超分辨率图像复原

对于模糊图像的复原问题,从正则化技术克服问题病态性的思想出发,研究了一种有效的超分辨率图像复原方法.在Nguyen等人的正则图像复原框架的基础上,根据Roberts交叉梯度算子构造正则项,从自适应的角度生成正则化参数,并用共轭梯度法求解该模型的目标泛函极小值.计算机仿真结果表明,该方法可较好的再现图像的重要信息,复原图像的相对误差降低,同时,峰值信噪比和主观视觉效果方面都有明显的提高.     

Evaluate mobile video quality in hybrid spatial and temporal domain

Mobile video quality assessment plays an essential role in multimedia systems and services. In the case of scalable video coding, which enables dynamic adaptation based on terminal capabilities and heterogeneous network, variable resolution is one of the most prominent types of video distortions. In this paper, we propose a new hybrid spatial and temporal distortion metric for evaluating video streaming quality with variable spatio-temporal resolution. The key idea is to project video sequence into feature domain and calculate the distortion of content information from the projected principal component matrix and its eigenvectors. This metric can measures the degree of content information degradation especially in spatio-temporal resolution scalable video. The performance of the proposed metric is evaluated and compared to some state-of-the-art quality evaluation metrics in the literature. Our results show that the proposed metric achieves good correlations with the subjective evaluations of the EPFL scale video database.