针对移动机器人同步定位与地图构建(SLAM)的闭环检测问题,提出改进闭环检测准确率的特征空间全排列向量匹配方法。使用ORB(Oriented FAST and Rotated BRIEF)方法提取图像特征点,创建基于视觉字典树的词袋,初步筛选出候选闭环图像。将...针对移动机器人同步定位与地图构建(SLAM)的闭环检测问题,提出改进闭环检测准确率的特征空间全排列向量匹配方法。使用ORB(Oriented FAST and Rotated BRIEF)方法提取图像特征点,创建基于视觉字典树的词袋,初步筛选出候选闭环图像。将图像分成4块大小均匀的区域,计算各区域视觉单词向量并全排列,作为特征空间信息。比较特征空间信息方法和词袋方法计算出的图像间距离值,选取最小值对应的图像对作为最佳闭环。相比词袋方法,特征空间信息方法可有效地改善图像特征匹配的感知混淆问题,在保证较高效率的同时,提高了闭环检测的准确率。展开更多
Watermariding system is a complex system requiring both expertise and specialized techniques with security concems.Thus to relieve the multimedia manufactures of the complexities of desgning complicated watermarking s...Watermariding system is a complex system requiring both expertise and specialized techniques with security concems.Thus to relieve the multimedia manufactures of the complexities of desgning complicated watermarking systems,this paper presents a new watermarking model in which watermaiking is provided as a kind of service by the specialized watermarking companies.In order to make this service model work,a simple permutation scheme to hide the true contents is proposed.The paper also proves the security of the scheme against the attacks from the watermarking companies.Finally ,the effectiveness of the scheme is demonstrated through experiments.展开更多
文摘针对移动机器人同步定位与地图构建(SLAM)的闭环检测问题,提出改进闭环检测准确率的特征空间全排列向量匹配方法。使用ORB(Oriented FAST and Rotated BRIEF)方法提取图像特征点,创建基于视觉字典树的词袋,初步筛选出候选闭环图像。将图像分成4块大小均匀的区域,计算各区域视觉单词向量并全排列,作为特征空间信息。比较特征空间信息方法和词袋方法计算出的图像间距离值,选取最小值对应的图像对作为最佳闭环。相比词袋方法,特征空间信息方法可有效地改善图像特征匹配的感知混淆问题,在保证较高效率的同时,提高了闭环检测的准确率。
基金the National Research Fund for the Doctoral Programof Higher Education of China under Grant No.20020248024
文摘Watermariding system is a complex system requiring both expertise and specialized techniques with security concems.Thus to relieve the multimedia manufactures of the complexities of desgning complicated watermarking systems,this paper presents a new watermarking model in which watermaiking is provided as a kind of service by the specialized watermarking companies.In order to make this service model work,a simple permutation scheme to hide the true contents is proposed.The paper also proves the security of the scheme against the attacks from the watermarking companies.Finally ,the effectiveness of the scheme is demonstrated through experiments.
