为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平...为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平矩和二进制位图;基于LBP(local binary pattern)算子,设计邻域空间LBP模式,获取位图的特征矩阵;构造量化函数,得到高、低电平矩阵对应的紧凑二值序列,利用主成分分析处理特征矩阵,输出二值序列,组合这些二值序列,获取图像哈希。根据Hamming距离,对图像真伪进行认证。实验数据表明,与当前哈希算法相比,所提哈希算法具有更好的抗碰撞性能与感知鲁棒。展开更多
In expression recognition, feature representation is critical for successful recognition since it contains distinctive information of expressions. In this paper, a new approach for representing facial expression featu...In expression recognition, feature representation is critical for successful recognition since it contains distinctive information of expressions. In this paper, a new approach for representing facial expression features is proposed with its objective to describe features in an effective and efficient way in order to improve the recognition performance. The method combines the facial action coding system(FACS) and 'uniform' local binary patterns(LBP) to represent facial expression features from coarse to fine. The facial feature regions are extracted by active shape models(ASM) based on FACS to obtain the gray-level texture. Then, LBP is used to represent expression features for enhancing the discriminant. A facial expression recognition system is developed based on this feature extraction method by using K nearest neighborhood(K-NN) classifier to recognize facial expressions. Finally, experiments are carried out to evaluate this feature extraction method. The significance of removing the unrelated facial regions and enhancing the discrimination ability of expression features in the recognition process is indicated by the results, in addition to its convenience.展开更多
目的抑郁症是一种严重的精神类障碍,会显著影响患者的日常生活和工作。目前的抑郁症临床评估方法几乎都依赖于临床访谈或问卷调查,缺少系统有效地挖掘与抑郁症密切相关模式信息的手段。为了有效帮助临床医生诊断患者的抑郁症严重程度,...目的抑郁症是一种严重的精神类障碍,会显著影响患者的日常生活和工作。目前的抑郁症临床评估方法几乎都依赖于临床访谈或问卷调查,缺少系统有效地挖掘与抑郁症密切相关模式信息的手段。为了有效帮助临床医生诊断患者的抑郁症严重程度,情感计算领域涌现出越来越多的方法进行自动化的抑郁症识别。为了有效挖掘和编码人们面部含有的具有鉴别力的情感信息,本文提出了一种基于动态面部特征和稀疏编码的抑郁症自动识别框架。方法在面部特征提取方面,提出了一种新的可以深层次挖掘面部宏观和微观结构信息的动态特征描述符,即中值鲁棒局部二值模式—3D正交平面(median robust local binary patterns from three orthogonal planes,MRELBP-TOP)。由于MRELBP-TOP帧级特征的维度较高,且含有部分冗余信息。为了进一步去除冗余信息和保留关键信息,采用随机映射(random projection,RP)对帧级特征MRELBP-TOP进行降维。此外,为了进一步表征经过降维后的高层模式信息,采用稀疏编码(sparse coding,SC)来抽象紧凑的特征表示。最后,采用支持向量机进行抑郁程度的估计,即预测贝克抑郁分数(the Beck depression inventory-II,BDI-II)。结果在AVEC2013(the continuous audiovisual emotion and depression 2013)和AVEC2014测试集上,抑郁程度估计值与真实值之间的均方根误差(root mean square error,RMSE)分别为9.70和9.22,相比基准算法,识别精度分别提高了29%和15%。实验结果表明,本文方法优于当前大多数基于视频的抑郁症识别方法。结论本文构建了基于面部表情的抑郁症识别框架,实现了抑郁程度的有效估计;提出了帧级特征描述子MRELBP-TOP,有效提高了抑郁症识别的精度。展开更多
为提高传统局部二值模式(local binary pattern,LBP)算法提取目标图像特征时的识别率,提出一种基于掩膜迭代感兴趣区域(region of interest,ROI)改进LBP算法的特征提取方法。使用掩膜迭代ROI的提取方法,减少对干扰信息或者无效区域的处...为提高传统局部二值模式(local binary pattern,LBP)算法提取目标图像特征时的识别率,提出一种基于掩膜迭代感兴趣区域(region of interest,ROI)改进LBP算法的特征提取方法。使用掩膜迭代ROI的提取方法,减少对干扰信息或者无效区域的处理,缩短缺陷区域的提取时间。在LBP的基础上根据预设的半径确定所述中心像素点的圆形区域,将邻域采样点之间的灰度值大小关系加入考虑范围,与中心阈值共同作为决定LBP编码情况的影响因子,充分利用邻域点之间所隐藏的方向特征,进一步提高了图像识别的准确率。实验表明,以PASCAL VOC齿轮缺陷数据集中缺陷图像为验证样本,实验所拍摄缺陷图像由SVM识别准确率相较传统LBP算法提升2%,最高识别率99.32%;Manhattan识别准确率相较传统LBP算法提升0.67%,最高识别率98.54%;European识别准确率相较传统LBP算法提升0.44%,最高识别率97.87%。展开更多
文摘为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平矩和二进制位图;基于LBP(local binary pattern)算子,设计邻域空间LBP模式,获取位图的特征矩阵;构造量化函数,得到高、低电平矩阵对应的紧凑二值序列,利用主成分分析处理特征矩阵,输出二值序列,组合这些二值序列,获取图像哈希。根据Hamming距离,对图像真伪进行认证。实验数据表明,与当前哈希算法相比,所提哈希算法具有更好的抗碰撞性能与感知鲁棒。
基金supported by National Natural Science Foundation of China(No.61273339)
文摘In expression recognition, feature representation is critical for successful recognition since it contains distinctive information of expressions. In this paper, a new approach for representing facial expression features is proposed with its objective to describe features in an effective and efficient way in order to improve the recognition performance. The method combines the facial action coding system(FACS) and 'uniform' local binary patterns(LBP) to represent facial expression features from coarse to fine. The facial feature regions are extracted by active shape models(ASM) based on FACS to obtain the gray-level texture. Then, LBP is used to represent expression features for enhancing the discriminant. A facial expression recognition system is developed based on this feature extraction method by using K nearest neighborhood(K-NN) classifier to recognize facial expressions. Finally, experiments are carried out to evaluate this feature extraction method. The significance of removing the unrelated facial regions and enhancing the discrimination ability of expression features in the recognition process is indicated by the results, in addition to its convenience.
文摘目的抑郁症是一种严重的精神类障碍,会显著影响患者的日常生活和工作。目前的抑郁症临床评估方法几乎都依赖于临床访谈或问卷调查,缺少系统有效地挖掘与抑郁症密切相关模式信息的手段。为了有效帮助临床医生诊断患者的抑郁症严重程度,情感计算领域涌现出越来越多的方法进行自动化的抑郁症识别。为了有效挖掘和编码人们面部含有的具有鉴别力的情感信息,本文提出了一种基于动态面部特征和稀疏编码的抑郁症自动识别框架。方法在面部特征提取方面,提出了一种新的可以深层次挖掘面部宏观和微观结构信息的动态特征描述符,即中值鲁棒局部二值模式—3D正交平面(median robust local binary patterns from three orthogonal planes,MRELBP-TOP)。由于MRELBP-TOP帧级特征的维度较高,且含有部分冗余信息。为了进一步去除冗余信息和保留关键信息,采用随机映射(random projection,RP)对帧级特征MRELBP-TOP进行降维。此外,为了进一步表征经过降维后的高层模式信息,采用稀疏编码(sparse coding,SC)来抽象紧凑的特征表示。最后,采用支持向量机进行抑郁程度的估计,即预测贝克抑郁分数(the Beck depression inventory-II,BDI-II)。结果在AVEC2013(the continuous audiovisual emotion and depression 2013)和AVEC2014测试集上,抑郁程度估计值与真实值之间的均方根误差(root mean square error,RMSE)分别为9.70和9.22,相比基准算法,识别精度分别提高了29%和15%。实验结果表明,本文方法优于当前大多数基于视频的抑郁症识别方法。结论本文构建了基于面部表情的抑郁症识别框架,实现了抑郁程度的有效估计;提出了帧级特征描述子MRELBP-TOP,有效提高了抑郁症识别的精度。
