基于深度哈希学习的商标图像检索研究

摘要 大规模图像检索具有广泛的应用前景，其核心在于图像特征提取和高效相似性计算.深度学习技术在图像特征提取具有较强的特征表示能力，同时哈希技术在高维数据近似计算方面具有较好的性能.目前，基于哈希学习的技术在大规模图像检索及相似性查询方面获得了广泛的研究和应用.本文结合卷积神经网络和哈希技术实现商标图像检索，通过深度学习技术提取商标图像特征，使用位哈希对数据对象编码，在海明空间折中查询的质量和效率.基于卷积神经网络模型，提出了深度哈希算法，并研究了损失函数和该数据集上的优化器选择，通过获取符合哈希编码规范的位编码实现对在二元空间对商标图像数据快速检索，该方法分为离线深度哈希学习和在线查询两个阶段.在真实商标数据集上进行实验，实验结果表明，本文方法能够在商标数据集上获得较高质量的位编码，并具有较高的检索精确度和在线查询效率.
Abstract：Large-scale image retrieval has great potential for a vast number of applications. The fundamentals of image retrieval lie in image feature extraction and high-efficiency similarity evaluation. Deep learning has great capability for feature representation in image objects, while the Hashing technique has better efficiency for high-dimensional data approximation queries. At present, hash learning technology has been widely researched and applied in large-scale image retrieval for the similarity query. This paper extracts trademark image features using convolutional neural network techniques; the data objects are then encoded with bit codes and an approximate query is applied in Hamming space with high efficiency. In this paper, the convolutional neural network is employed and a deep learning based Hash algorithm is proposed; in addition, the loss function and optimizer for the trademark dataset are studied. By obtaining the bit codes that satisfy the Hash coding criterion, the retrieval of trademark data is efficient. Our method can be divided into offline deep Hash learning and online query stages. Experiments are conducted on real trademark data sets, and the results show that our method can obtain high-quality bit code, which has high retrieval accuracy and online query efficiency.