IEEE Trans Image Process. 2020;29(1):2094-2107. doi: 10.1109/TIP.2019.2938859. Epub 2019 Sep 9.
To defy the curse of dimensionality, the inputs are always projected from the original high-dimensional space into the target low-dimension space for feature extraction. However, due to the existence of noise and outliers, the feature extraction task for corrupted data is still a challenging problem. Recently, a robust method called low rank embedding (LRE) was proposed. Despite the success of LRE in experimental studies, it also has many disadvantages: 1) The learned projection cannot quantitatively interpret the importance of features. 2) LRE does not perform data reconstruction so that the features may not be capable of holding the main energy of the original "clean" data. 3) LRE explicitly transforms error into the target space. 4) LRE is an unsupervised method, which is only suitable for unsupervised scenarios. To address these problems, in this paper, we propose a novel method to exploit the latent discriminative features. In particular, we first utilize an orthogonal matrix to hold the main energy of the original data. Next, we introduce an l -norm term to encourage the features to be more compact, discriminative and interpretable. Then, we enforce a columnwise l -norm constraint on an error component to resist noise. Finally, we integrate a classification loss term into the objective function to fit supervised scenarios. Our method performs better than several state-of-the-art methods in terms of effectiveness and robustness, as demonstrated on six publicly available datasets.
为了克服维度诅咒,输入总是从原始的高维空间投影到目标的低维空间,以进行特征提取。然而,由于噪声和异常值的存在,对于损坏数据的特征提取任务仍然是一个具有挑战性的问题。最近,提出了一种称为低秩嵌入(LRE)的鲁棒方法。尽管 LRE 在实验研究中取得了成功,但它也有许多缺点:1)学习到的投影不能定量地解释特征的重要性。2)LRE 不进行数据重建,因此特征可能无法保留原始“干净”数据的主要能量。3)LRE 将误差显式地转换到目标空间。4)LRE 是一种无监督方法,仅适用于无监督场景。为了解决这些问题,在本文中,我们提出了一种利用潜在判别特征的新方法。特别是,我们首先利用正交矩阵来保持原始数据的主要能量。接下来,我们引入一个 l -范数项,以鼓励特征更加紧凑、具有判别力和可解释性。然后,我们对误差分量施加列 l -范数约束,以抵抗噪声。最后,我们将分类损失项集成到目标函数中,以适应监督场景。我们的方法在六个公开可用的数据集上的有效性和鲁棒性方面都优于几种最先进的方法。