State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.
Sensors (Basel). 2018 Jun 14;18(6):1937. doi: 10.3390/s18061937.
In this paper, we carry out researches on randomized local binary features. Randomized local binary features have been used in many methods like RandomForests, RandomFerns, BRIEF, ORB and AKAZE to matching keypoints. However, in those existing methods, the randomness of feature operators only reflects in sampling position. In this paper, we find the quality of the binary feature space can be greatly improved by increasing the randomness of the basic sampling operator. The key idea of our method is to use a Randomized Intensity Difference operator (we call it RID operator) as a basic sampling operator to observe image patches. The randomness of RID operators are reflected in five aspects: grids, position, aperture, weights and channels. Comparing with the traditional incompletely randomized binary features (we call them RIT features), a completely randomized sampling manner can generate higher quality binary feature space. The RID operator can be used on both gray and color images. We embed different kinds of RID operators into RandomFerns and RandomForests classifiers to test their recognition rate on both image and video datasets. The experiment results show the excellent quality of our feature method. We also propose the evaluation criteria for robustness and distinctiveness to observe the effects of randomization on binary feature space.
在本文中，我们对随机局部二进制特征进行了研究。随机局部二进制特征已被广泛应用于许多方法中，如 RandomForests、RandomFerns、BRIEF、ORB 和 AKAZE 等，用于匹配关键点。然而，在这些现有的方法中，特征算子的随机性仅反映在采样位置上。在本文中，我们发现通过增加基本采样算子的随机性，可以大大提高二进制特征空间的质量。我们方法的关键思想是使用随机强度差算子（我们称之为 RID 算子）作为基本采样算子来观察图像补丁。RID 算子的随机性体现在五个方面：网格、位置、孔径、权重和通道。与传统的不完全随机二进制特征（我们称之为 RIT 特征）相比，完全随机的采样方式可以生成更高质量的二进制特征空间。RID 算子可用于灰度和彩色图像。我们将不同类型的 RID 算子嵌入到 RandomFerns 和 RandomForests 分类器中，以测试它们在图像和视频数据集上的识别率。实验结果表明了我们特征方法的优异性能。我们还提出了稳健性和独特性的评估标准，以观察随机化对二进制特征空间的影响。
