Steganalysis of Low Embedding Rates LSB Speech Based on Histogram Moments in Frequency Domain

As wavelet packet transform is able to focus on minute change of signals, this study proposes an analytic approach of low embedding steganograpy based on high order Histogram moments in frequency domain (HMFD), which provides a key solution to the feature selection and extraction of HMFD. The detection results are tested with the LSB matching steganograpy of different embedding rates in speech signals, respectively, it is proved that the detection performance with HMFD applied is greater than that of histogram statistical moments. HMFD by Wavelet packet decomposition (WPD) can effectively detect low embedding rates Least significant bit (LSB) speech steganography, its accuracy can be 60.8％ while the embedding rate is only 3％.     

Robust frontal view search using extended manifold learning

Many 2D face processing algorithms can perform better using frontal or near frontal faces. In this paper, we present a robust frontal view search method based on manifold learning, with the assumption that with the pose being the only variable, face images should lie in a smooth and low-dimensional manifold. In 2D embedding, we find that manifold geometry of face images with varying poses has the shape of a parabola with the frontal view in the vertex. However, background clutter and illumination variations make frontal view deviate from the vertex. To address this problem, we propose a pairwise K-nearest neighbor protocol to extend manifold learning. In addition, we present an illumination-robust localized edge orientation histogram to represent face image in the extended manifold learning. The experimental results show that the extended algorithms have higher search accuracy, even under varying illuminations.     

一种自适应FCM彩色图像分割算法

针对FCM彩色图像分割算法需要给定聚类数且受初始值影响较大的缺点,提出一种自适应FCM彩色图像分割算法.该方法首先引入主分量变换,通过直方图分析,在RGB彩色空间上自动确定聚类数目,其次引入2D直方图,分析对角线投影1D直方图,并采用最大最小距离法选取初始聚类中心.利用该算法对各种彩色图像进行分割实验,实验结果表明:该算法能够有效且自适应地分割彩色图像.     

基于分层最大熵的航拍图像增强

针对恶劣的天气条件使航拍图像的对比度低、细 节模糊的问题,提出了一种基于分层最大熵的图像 增强算法。首先将图像的直方图平均分割成4个子层;然后根据分割后子层的特征求取每个 子层 的自适应函数;最后根据该函数完成每个子层的规定化处理。实 验结果表明,经过本文算法处理后图像的对比度得到了提高,同时图像的细节和纹理信息也 得到了增强。     

基于线列红外探测器的图像增强算法研究

针对线列红外探测器扫描成像特点,提出了一种基于平台直方图统计的红外图像增强算法。仿真结果表明,该算法能够校正扫描型热像仪由盲、闪元引起的黑白道,提高图像的对比度,修正全局灰度等级,锐化图像中的边缘细节,对扫描成像系统的红外图像具有较好的增强效果。     

重叠视野域内多摄像机目标交换算法

多摄像机之间重叠视野区域内目标交接问题是实现多摄像机监控系统持续目标跟踪的关键,传统方法是在摄像机重叠视野区域内采用特征匹配方法或基于视野分界线的目标交接算法。但是特征匹配计算量较大,受摄像机参数设置因素影响较大,实用性不高。而基于视野分界线的目标交接算法由于新目标的检测存在延时,仅利用该方法来实现一致性标号容易出错。近年来,出现了利用投影不变量,计算目标在相邻摄像机中的投影位置来进行目标交接的方法,取得较好效果。但在多个目标相距较近的情况下,投影过程中产生的误差会造成目标对应错误。文中提出一种投影不变量     

基于图像边缘增强组合算法的研究

通过分析函数的一阶导数与二阶导数图像的特征,提出了一种含有权值的图像边缘锐化的新算法.通过设定不同的权值可以实现不同的增强效果,经增强后的图像再用直方图均衡化处理.仿真结果显示此方法可以使图像更加清晰,且具有较好的灵活性和普遍的适用性.     

Audio steganalysis of DSSS based on statistical moments of histogram

Compared with the histogram of Discrete Cosine Transform (DCT) coefficients before the Direct Sequence Spread Spectrum (DSSS) embedding, the peak value of the histogram after the em-bedding decreases and expands toward the border. Based on the property, an audio steganalysis of DSSS based on statistical moments of histogram is proposed. The statistical moments of the histogram in DCT domain and its frequency domain and the statistical moments of the histogram of the wavelet coefficients of every level in frequency domain are calculated as the features of classification. Support Vector Machine (SVM) is exploited as the classifier. Experimental results show that the proposed technique is effective on the DSSS embedding in DCT domain using different embedding length, and the average detection rate is 91.75%.     

直方图均衡增强算法在实时图像处理中的实现

介绍了直方图均衡增强算法在显示系统中的应用,提出利用FPGA(Field Programmable Gate Array)并行处理海量数据的能力来实现显示系统,与采用DSP等传统方法相比,在处理实时图像及工作效率方面优势明显.给出了主要模块的设计方法,整个系统设计紧凑、简单、可靠性高.     

红外图像灰度直方图统计分析的研究

数字图像的直方图反映了其像素强度值的分布情况.作为图像处理中最简单和最有用的一种工具,直方图方法用于许多图像操作中,例如对比度拉伸、直方图均衡化等.用灰度直方图方法对150幅不同类型的红外图像进行了统计分析.结果表明,在这些图像中,大多数图像没有灰度值小于16的像素,或者此类像素数量很少.这意味着A/D数据流的低4位对红外图像质量的影响较小.