Recent state-of-the-art face recognition (FR) approaches have achieved impressive performance, yet unconstrained face recognition still represents an open problem. Face image quality assessment (FIQA) approaches aim to estimate the quality of the input samples that can help provide information on the confidence of the recognition decision and eventually lead to improved results in challenging scenarios. While much progress has been made in face image quality assessment in recent years, computing reliable quality scores for diverse facial images and FR models remains challenging. In this paper, we propose a novel approach to face image quality assessment, called FaceQAN, that is based on adversarial examples and relies on the analysis of adversarial noise which can be calculated with any FR model learned by using some form of gradient descent. As such, the proposed approach is the first to link image quality to adversarial attacks. Comprehensive (cross-model as well as model-specific) experiments are conducted with four benchmark datasets, i.e., LFW, CFP-FP, XQLFW and IJB-C, four FR models, i.e., CosFace, ArcFace, CurricularFace and ElasticFace, and in comparison to seven state-of-the-art FIQA methods to demonstrate the performance of FaceQAN. Experimental results show that FaceQAN achieves competitive results, while exhibiting several desirable characteristics.

Face image quality assessment (FIQA) attempts to improve face recognition (FR) performance by providing additional information about sample quality. Because FIQA methods attempt to estimate the utility of a sample for face recognition, it is reasonable to assume that these methods are heavily influenced by the underlying face recognition system. Although modern face recognition systems are known to perform well, several studies have found that such systems often exhibit problems with demographic bias. It is therefore likely that such problems are also present with FIQA techniques. To investigate the demographic biases associated with FIQA approaches, this paper presents a comprehensive study involving a variety of quality assessment methods (general-purpose image quality assessment, supervised face quality assessment, and unsupervised face quality assessment methods) and three diverse state-of-theart FR models. Our analysis on the Balanced Faces in the Wild (BFW) dataset shows that all techniques considered are affected more by variations in race than sex. While the general-purpose image quality assessment methods appear to be less biased with respect to the two demographic factors considered, the supervised and unsupervised face image quality assessment methods both show strong bias with a tendency to favor white individuals (of either sex). In addition, we found that methods that are less racially biased perform worse overall. This suggests that the observed bias in FIQA methods is to a significant extent related to the underlying face recognition system.

尽管最近的面部识别（FR）系统在许多部署场景中取得了出色的成果，但它们在挑战现实世界中的表现仍在质疑。因此，面部图像质量评估（FIQA）技术旨在通过为它们提供示例质量信息来支持FR系统，这些信息可用于拒绝不适合识别目的的质量差数据。文献中已经提出了几组依赖不同概念的FIQA方法，所有这些方法都可以用于生成质量的面部图像，这些面部图像可以用作伪造的（质量）标签，并可以利用进行训练（回归 - 基于）质量估计模型。几个fiqa批准\ - 表明可以从与某些面部匹配器生成的配对相似度分布中提取大量样本质量信息。基于这种见解，我们在本文中提出了一种质量标签优化方法，该方法将来自配对配置的相似性的样本质量信息纳入现有现成的FIQA技术的质量预测。我们使用三种不同数据集的三种最先进的FIQA方法评估了建议的方法。我们的实验结果表明，提出的优化过程在很大程度上取决于执行的优化迭代次数。在十个迭代中，该方法似乎执行了最佳，始终超过三种FIQA方法的基本质量得分，这是为实验所选择的。

该卷包含来自机器学习挑战的选定贡献“发现玛雅人的奥秘”，该挑战在欧洲机器学习和数据库中知识发现的欧洲挑战赛曲目（ECML PKDD 2021）中提出。遥感大大加速了古代玛雅人森林地区的传统考古景观调查。典型的探索和发现尝试，除了关注整个古老的城市外，还集中在单个建筑物和结构上。最近，已经成功地尝试了使用机器学习来识别古代玛雅人定居点。这些尝试虽然相关，但却集中在狭窄的区域上，并依靠高质量的空中激光扫描（ALS）数据，该数据仅涵盖古代玛雅人曾经定居的地区的一小部分。另一方面，由欧洲航天局（ESA）哨兵任务制作的卫星图像数据很丰富，更重要的是公开。旨在通过执行不同类型的卫星图像（Sentinel-1和Sentinel-2和ALS）的集成图像细分来定位和识别古老的Maya架构（建筑物，Aguadas和平台）的“发现和识别古代玛雅体系结构（建筑物，Aguadas和平台）的挑战的“发现和识别古老的玛雅体系结构（建筑物，阿吉达斯和平台）的“发现玛雅的奥秘”的挑战， （LIDAR）数据。