该文针对行人识别中的特征表示问题,提出一种混合结构的分层特征表示方法,这种混合结构结合了具有表示能力的词袋结构和学习适应性的深度分层结构。首先利用基于梯度的HOG局部描述符提取局部特征,再通过一个由空间聚集受限玻尔兹曼机组成的深度分层编码方法进行编码。对于每个编码层,利用稀疏性和选择性正则化进行无监督受限玻尔兹曼机学习,再应用监督微调来增强分类任务中视觉特征表示,采用最大池化和空间金字塔方法得到高层图像特征表示。最后采用线性支持向量机进行行人识别,提取深度分层特征遮挡等与目标无关部分自然分离,有效提高了后续识别的准确性。实验结果证明了所提出方法具有较高的识别率。
For feature representation of pedestrian recognition, a hybrid hierarchical feature representation method which combines representation ability of the bag of words model and depth layered with learning adaptability is presented. This method first uses HOG local descriptor gradient-based for local features extraction, and then encoding the feature by a depth of layered coding method, the layered coding method by spatial aggregating Restricted Boltzmann Machine(RBM). For each coding layer, the sparse and selective regularization are used for the unsupervised RBM learning and supervision fine-tuning is used to enhance the visual features representation in classification task. Finally, high-level image feature representation is obtained by the maximum pool and space of Pyramid method, and then the linear support vector machine is used for pedestrian recognition, feature extraction of depth architecture. It improves effectively the accuracy of subsequent recognition. Experimental results show that the proposed method has a high recognition rate.