针对复制-移动篡改,本文提出基于SURF(Speeded Up Robust Features)特征匹配篡改区域快速自动探测与定位方法。首先应用SURF算法提取待检测图像的特征点和特征向量并进行特征匹配,然后估计匹配对之间的仿射变换参数并消除错配,最后通过...针对复制-移动篡改,本文提出基于SURF(Speeded Up Robust Features)特征匹配篡改区域快速自动探测与定位方法。首先应用SURF算法提取待检测图像的特征点和特征向量并进行特征匹配,然后估计匹配对之间的仿射变换参数并消除错配,最后通过仿射变换找出趋近完整的复制-移动区域。实验结果证明了该方法对复制-移动篡改探测的有效性。展开更多
Most existing methods for image copy-move forgery detection(CMFD)operate on grayscale images. Although the keypoint-based methods have the advantages of strong robustness and low computational cost,they cannot identif...Most existing methods for image copy-move forgery detection(CMFD)operate on grayscale images. Although the keypoint-based methods have the advantages of strong robustness and low computational cost,they cannot identify the flat duplicated regions without reliable extracted features. In this paper, we propose a new CMFD method by using speeded-up robust feature(SURF)in the opponent color space. Our method starts by converting the inspected image from RGB to the opponent color space. The color gradient per pixel is calculated and taken as the work space for SURF to extract the keypoints. The matched keypoints are clustered and their geometric transformations are estimated. Finally, the false matches are removed. Experimental results show that the proposed technique can effectively expose the duplicated regions with various transformations, even when the duplication regions are flat.展开更多
A new passive wheel type of leg-wheeled mobile robot based on rolling principle was introduced. To enhance the stability and maintain vertical to the ground of wheels, four passive wheels were installed at the end of ...A new passive wheel type of leg-wheeled mobile robot based on rolling principle was introduced. To enhance the stability and maintain vertical to the ground of wheels, four passive wheels were installed at the end of four legs respectively and parallel mechanisms were used as legs. And an inertia coordinate system and a robot coordinate system were established, the related kinematic equation of the robot was gotten according to some assumptions after the configuration or the posture of wheels and legs was analyzed. At the same time, the turning conditions of the robot were also obtained. Based on the motion principle, the VSS-based logic control system was designed and the skating straight experiments and the turning experiments were conducted. And some conclusions were drawn.展开更多
针对当前图像伪造检测准确率低、适应性弱等问题,提出支持向量机耦合多分辨率韦伯局部描述符(WLD-multiresolution Weber local descriptor)的图像伪造检测技术。将图像转换为YCrCb模型,以亮度和色度的形式保存图像,利用人眼对色度的敏...针对当前图像伪造检测准确率低、适应性弱等问题,提出支持向量机耦合多分辨率韦伯局部描述符(WLD-multiresolution Weber local descriptor)的图像伪造检测技术。将图像转换为YCrCb模型,以亮度和色度的形式保存图像,利用人眼对色度的敏感性弱于亮度的特点,根据色度分量提取图像特征;根据当前像素的差分激励和梯度方向,构造WLD计算模型,判断图像的灰度值变化和纹理变化信息;分析优化WLD参数,采用像素点的差分激励和梯度方向在不同分辨率下形成WLD直方图;引入支持向量机(SVM)分类算法对提取的伪造图像进行分类学习。在大量图像数据库进行伪造检测的实验结果表明,多分辨率WLD相对单分辨率WLD具有更好的检测效果,在拼接伪造图像和复制-移动伪造图像的检测中,多分辨率WLD都有较好的检测性能。展开更多
The threshold control of safety blasting vibration velocity is a significant process for the underground mining of complicated ore deposit under construction,road,and water.According to the equivalent principle of dis...The threshold control of safety blasting vibration velocity is a significant process for the underground mining of complicated ore deposit under construction,road,and water.According to the equivalent principle of displacement and velocity of mass point,differential evolution is put forward based on 3DEC dynamic analysis,making the calculation more efficient and accurate.The 3DEC model of the complicated orebody under railway is established according to the topographic maps and geological data of the eastern Pyrite Mine.The stimulus-response distribution of internal stress and displacement fields are demonstrated by analyzing the on-site monitoring vibration displacement and velocity data of the mass point.The reliability of parameter selection,such as blasting simulation waveforms,rock damping,is identified.The safety vibration velocity of railway is set to 4.5 cm/s in line with the requirement of safety blasting rules.Thus,the maximum amount of single-stage explosive in this region is 44.978 kg.The simulation result is in good agreement with the on-site monitoring datum.No displacement and settlement of the 701 railway special line was achieved by choosing the critical amount of the single-stage explosive.展开更多
文摘针对复制-移动篡改,本文提出基于SURF(Speeded Up Robust Features)特征匹配篡改区域快速自动探测与定位方法。首先应用SURF算法提取待检测图像的特征点和特征向量并进行特征匹配,然后估计匹配对之间的仿射变换参数并消除错配,最后通过仿射变换找出趋近完整的复制-移动区域。实验结果证明了该方法对复制-移动篡改探测的有效性。
基金Supported by the Natural Science Foundation of Tianjin(No.15JCYBJC15500)
文摘Most existing methods for image copy-move forgery detection(CMFD)operate on grayscale images. Although the keypoint-based methods have the advantages of strong robustness and low computational cost,they cannot identify the flat duplicated regions without reliable extracted features. In this paper, we propose a new CMFD method by using speeded-up robust feature(SURF)in the opponent color space. Our method starts by converting the inspected image from RGB to the opponent color space. The color gradient per pixel is calculated and taken as the work space for SURF to extract the keypoints. The matched keypoints are clustered and their geometric transformations are estimated. Finally, the false matches are removed. Experimental results show that the proposed technique can effectively expose the duplicated regions with various transformations, even when the duplication regions are flat.
文摘A new passive wheel type of leg-wheeled mobile robot based on rolling principle was introduced. To enhance the stability and maintain vertical to the ground of wheels, four passive wheels were installed at the end of four legs respectively and parallel mechanisms were used as legs. And an inertia coordinate system and a robot coordinate system were established, the related kinematic equation of the robot was gotten according to some assumptions after the configuration or the posture of wheels and legs was analyzed. At the same time, the turning conditions of the robot were also obtained. Based on the motion principle, the VSS-based logic control system was designed and the skating straight experiments and the turning experiments were conducted. And some conclusions were drawn.
文摘针对当前图像伪造检测准确率低、适应性弱等问题,提出支持向量机耦合多分辨率韦伯局部描述符(WLD-multiresolution Weber local descriptor)的图像伪造检测技术。将图像转换为YCrCb模型,以亮度和色度的形式保存图像,利用人眼对色度的敏感性弱于亮度的特点,根据色度分量提取图像特征;根据当前像素的差分激励和梯度方向,构造WLD计算模型,判断图像的灰度值变化和纹理变化信息;分析优化WLD参数,采用像素点的差分激励和梯度方向在不同分辨率下形成WLD直方图;引入支持向量机(SVM)分类算法对提取的伪造图像进行分类学习。在大量图像数据库进行伪造检测的实验结果表明,多分辨率WLD相对单分辨率WLD具有更好的检测效果,在拼接伪造图像和复制-移动伪造图像的检测中,多分辨率WLD都有较好的检测性能。
基金Fund for New Teacher of the Doctoral Program of Higher Education(No. 200805611092)the Fundamental Research Funds for the Central Universities(No.2009zm0064)the Key Program of the National Natural Science Foundation of China(No.50934002) for its financial support
文摘The threshold control of safety blasting vibration velocity is a significant process for the underground mining of complicated ore deposit under construction,road,and water.According to the equivalent principle of displacement and velocity of mass point,differential evolution is put forward based on 3DEC dynamic analysis,making the calculation more efficient and accurate.The 3DEC model of the complicated orebody under railway is established according to the topographic maps and geological data of the eastern Pyrite Mine.The stimulus-response distribution of internal stress and displacement fields are demonstrated by analyzing the on-site monitoring vibration displacement and velocity data of the mass point.The reliability of parameter selection,such as blasting simulation waveforms,rock damping,is identified.The safety vibration velocity of railway is set to 4.5 cm/s in line with the requirement of safety blasting rules.Thus,the maximum amount of single-stage explosive in this region is 44.978 kg.The simulation result is in good agreement with the on-site monitoring datum.No displacement and settlement of the 701 railway special line was achieved by choosing the critical amount of the single-stage explosive.
