GenAI4ELab/papercli-papers huggingface dataset:
No Token Left Behind: Explainability-Aided Image Classification and Generation
Authors: Roni Paiss; Hila Chefer; Lior Wolf
Venue: ECCV 2022 (main)

Abstract: "The application of zero-shot learning in computer vision has been revolutionized by the use of image-text matching models. The most notable example, CLIP, has been widely used for both zero-shot classification and guiding generative models with a text prompt. However, the zero-shot use of CLIP is unstable with respect to the phrasing of the input text, making it necessary to carefully engineer the prompts used. We find that this instability stems from a selective similarity score, which is based only on a subset of the semantically meaningful input tokens. To mitigate it, we present a novel explainability-based approach, which adds a loss term to ensure that CLIP focuses on all relevant semantic parts of the input, in addition to employing the CLIP similarity loss used in previous works. When applied to one-shot classification through prompt engineering, our method yields an improvement in the recognition rate, without additional training or fine-tuning. Additionally, we show that CLIP guidance of generative models using our method significantly improves the generated images. Finally, we demonstrate a novel use of CLIP guidance for text-based image generation with spatial conditioning on object location, by requiring the image explainability heatmap for each object to be confined to a pre-determined bounding box."
Interpretable Image Classification with Differentiable Prototypes Assignment
Authors: Dawid Rymarczyk; Łukasz Struski; Michał Górszczak; Koryna Lewandowska; Jacek Tabor; Bartosz Zieliński
Venue: ECCV 2022 (main)

Abstract: "Existing prototypical-based models address the black-box nature of deep learning. However, they are sub-optimal as they often assume separate prototypes for each class, require multi-step optimization, make decisions based on prototype absence (so-called negative reasoning process), and derive vague prototypes. To address those shortcomings, we introduce ProtoPool, an interpretable prototype-based model with positive reasoning and three main novelties. Firstly, we reuse prototypes in classes, which significantly decreases their number. Secondly, we allow automatic, fully differentiable assignment of prototypes to classes, which substantially simplifies the training process. Finally, we propose a new focal similarity function that contrasts the prototype from the background and consequently concentrates on more salient visual features. We show that ProtoPool obtains state-of-the-art accuracy on the CUB-200-2011 and the Stanford Cars datasets, substantially reducing the number of prototypes. We provide a theoretical analysis of the method and a user study to show that our prototypes capture more salient features than those obtained with competitive methods. We made the code available at https://github.com/gmum/ProtoPool."
"Contributions of Shape, Texture, and Color in Visual Recognition"
Authors: Yunhao Ge; Yao Xiao; Zhi Xu; Xingrui Wang; Laurent Itti
Venue: ECCV 2022 (main)

Abstract: "We investigate the contributions of three important features of the human visual system (HVS)---shape, texture, and color ---to object classification. We build a humanoid vision engine (HVE) that explicitly and separately computes shape, texture, and color features from images. The resulting feature vectors are then concatenated to support the final classification. We show that HVE can summarize and rank-order the contributions of the three features to object recognition. We use human experiments to confirm that both HVE and humans predominantly use some specific features to support the classification of specific classes (e.g., texture is the dominant feature to distinguish a zebra from other quadrupeds, both for humans and HVE). With the help of HVE, given any environment (dataset), we can summarize the most important features for the whole task (global; e.g., color is the most important feature overall for classification with the CUB dataset), and for each class (local; e.g., shape is the most important feature to recognize boats in the iLab-20M dataset). To demonstrate more usefulness of HVE, we use it to simulate the open-world zero-shot learning ability of humans with no attribute labeling. Finally, we show that HVE can also simulate human imagination ability with the combination of different features."
STEEX: Steering Counterfactual Explanations with Semantics
Authors: Paul Jacob; Éloi Zablocki; Hédi Ben-Younes; Mickaël Chen; Patrick Pérez; Matthieu Cord
Venue: ECCV 2022 (main)

Abstract: As deep learning models are increasingly used in safety-critical applications, explainability and trustworthiness become major concerns. For simple images, such as low-resolution face portraits, synthesizing visual counterfactual explanations has recently been proposed as a way to uncover the decision mechanisms of a trained classification model. In this work, we address the problem of producing counterfactual explanations for high-quality images and complex scenes. Leveraging recent semantic-to-image models, we propose a new generative counterfactual explanation framework that produces plausible and sparse modifications which preserve the overall scene structure. Furthermore, we introduce the concept of "region-targeted counterfactual explanations", and a corresponding framework, where users can guide the generation of counterfactuals by specifying a set of semantic regions of the query image the explanation must be about. Extensive experiments are conducted on challenging datasets including high-quality portraits (CelebAMask-HQ) and driving scenes (BDD100k).
Are Vision Transformers Robust to Patch Perturbations?
Authors: Jindong Gu; Volker Tresp; Yao Qin
Venue: ECCV 2022 (main)

Abstract: "Recent advances in Vision Transformer (ViT) have demonstrated its impressive performance in image classification, which makes it a promising alternative to Convolutional Neural Network (CNN). Unlike CNNs, ViT represents an input image as a sequence of image patches. The patch-based input image representation makes the following question interesting: How does ViT perform when individual input image patches are perturbed with natural corruptions or adversarial perturbations, compared to CNNs? In this work, we study the robustness of ViT to patch-wise perturbations. Surprisingly, we {find} that ViTs are more robust to naturally corrupted patches than CNNs, whereas they are more vulnerable to adversarial patches. Furthermore, we discover that the attention mechanism greatly affects the robustness of vision transformers. Specifically, the attention module can help improve the robustness of ViT by effectively ignoring natural corrupted patches. However, when ViTs are attacked by an adversary, the attention mechanism can be easily fooled to focus more on the adversarially perturbed patches and cause a mistake. Based on our analysis, we propose a simple temperature-scaling based method to {improve} the robustness of ViT against adversarial patches. Extensive qualitative and quantitative experiments are performed to support our findings, understanding, and improvement of ViT robustness to patch-wise perturbations across a set of transformer-based architectures."
A Dataset Generation Framework for Evaluating Megapixel Image Classifiers & Their Explanations
Authors: Gautam Machiraju; Sylvia Plevritis; Parag Mallick
Venue: ECCV 2022 (main)

Abstract: "Deep learning-based megapixel image classifiers have exceptional prediction performance in a number of domains, including clinical pathology. However, extracting reliable, human-interpretable model explanations has remained challenging. Because real-world megapixel images often contain latent image features highly correlated with image labels, it is difficult to distinguish correct explanations from incorrect ones. Furthering this issue are the flawed assumptions and designs of today’s classifiers. To investigate classification and explanation performance, we introduce a framework to (a) generate synthetic control images that reflect common properties of megapixel images and (b) evaluate average test-set correctness. By benchmarking two commonplace Convolutional Neural Networks (CNNs), we demonstrate how this interpretability evaluation framework can inform architecture selection beyond classification performance -- in particular, we show that a simple Attention-based architecture identifies salient objects in all seven scenarios, while a standard CNN fails to do so in six scenarios. This work carries widespread applicability to any megapixel imaging domain."
Cartoon Explanations of Image Classifiers
Authors: Stefan Kolek; Duc Anh Nguyen; Ron Levie; Joan Bruna; Gitta Kutyniok
Venue: ECCV 2022 (main)

Abstract: "We present CartoonX (Cartoon Explanation), a novel model-agnostic explanation method tailored towards image classifiers and based on the rate-distortion explanation (RDE) framework. Natural images are roughly piece-wise smooth signals---also called cartoon-like images---and tend to be sparse in the wavelet domain. CartoonX is the first explanation method to exploit this by requiring its explanations to be sparse in the wavelet domain, thus extracting the relevant piece-wise smooth part of an image instead of relevant pixel-sparse regions. We demonstrate that CartoonX can reveal novel valuable explanatory information, particularly for misclassifications. Moreover, we show that CartoonX achieves a lower distortion with fewer coefficients than state-of-the-art methods."
Shap-CAM: Visual Explanations for Convolutional Neural Networks Based on Shapley Value
Authors: Quan Zheng; Ziwei Wang; Jie Zhou; Jiwen Lu
Venue: ECCV 2022 (main)

Abstract: "Explaining deep convolutional neural networks has been recently drawing increasing attention since it helps to understand the networks’ internal operations and why they make certain decisions. Saliency maps, which emphasize salient regions largely connected to the network’s decision-making, are one of the most common ways for visualizing and analyzing deep networks in the computer vision community. However, saliency maps generated by existing methods cannot represent authentic information in images due to the unproven proposals about the weights of activation maps which lack solid theoretical foundation and fail to consider the relations between each pixels. In this paper, we develop a novel post-hoc visual explanation method called Shap-CAM based on class activation mapping. Unlike previous gradient-based approaches, Shap-CAM gets rid of the dependence on gradients by obtaining the importance of each pixels through Shapley value. We demonstrate that Shap-CAM achieves better visual performance and fairness for interpreting the decision making process. Our approach outperforms previous methods on both recognition and localization tasks."
Privacy-Preserving Face Recognition with Learnable Privacy Budgets in Frequency Domain
Authors: Jiazhen Ji; Huan Wang; Yuge Huang; Jiaxiang Wu; Xingkun Xu; Shouhong Ding; ShengChuan Zhang; Liujuan Cao; Rongrong Ji
Venue: ECCV 2022 (main)

Abstract: "Face recognition technology has been used in many fields due to its high recognition accuracy, including the face unlocking of mobile devices, community access control systems, and city surveillance. As the current high accuracy is guaranteed by very deep network structures, facial images often need to be transmitted to third-party servers with high computational power for inference. However, facial images visually reveal the user’s identity information. In this process, both untrusted service providers and malicious users can significantly increase the risk of a personal privacy breach. Current privacy-preserving approaches to face recognition are often accompanied by many side effects, such as a significant increase in inference time or a noticeable decrease in recognition accuracy. This paper proposes a privacy-preserving face recognition method using differential privacy in the frequency domain. Due to the utilization of differential privacy, it offers a guarantee of privacy in theory. Meanwhile, the loss of accuracy is very slight. This method first converts the original image to the frequency domain and removes the direct component termed DC. Then a privacy budget allocation method can be learned based on the loss of the back-end face recognition network within the differential privacy framework. Finally, it adds the corresponding noise to the frequency domain features. Our method performs very well with several classical face recognition test sets according to the extensive experiments."
Contrast-Phys: Unsupervised Video-Based Remote Physiological Measurement via Spatiotemporal Contrast
Authors: Zhaodong Sun; Xiaobai Li
Venue: ECCV 2022 (main)

Abstract: "Video-based remote physiological measurement utilizes face videos to measure the blood volume change signal, which is also called remote photoplethysmography (rPPG). Supervised methods for rPPG measurements achieve state-of-the-art performance. However, supervised rPPG methods require face videos and ground truth physiological signals for model training. In this paper, we propose an unsupervised rPPG measurement method that does not require ground truth signals for training. We use a 3DCNN model to generate multiple rPPG signals from each video in different spatiotemporal locations and train the model with a contrastive loss where rPPG signals from the same video are pulled together while those from different videos are pushed away. We test on five public datasets, including RGB videos and NIR videos. The results show that our method outperforms the previous unsupervised baseline and achieves accuracies very close to the current best supervised rPPG methods on all five datasets. Furthermore, we also demonstrate that our approach can run at a much faster speed and is more robust to noises than the previous unsupervised baseline. Our code is available at https://github.com/zhaodongsun/contrast-phys."
Source-Free Domain Adaptation with Contrastive Domain Alignment and Self-Supervised Exploration for Face Anti-Spoofing
Authors: Yuchen Liu; Yabo Chen; Wenrui Dai; Mengran Gou; Chun-Ting Huang; Hongkai Xiong
Venue: ECCV 2022 (main)

Abstract: "Despite promising success in intra-dataset tests, existing face anti-spoofing (FAS) methods suffer from poor generalization ability under domain shift. This problem can be solved by aligning source and target data. However, due to privacy and security concerns of human faces, source data are usually inaccessible during adaptation for practical deployment, where only a pre-trained source model and unlabeled target data are available. In this paper, we propose a novel Source-free Domain Adaptation framework for Face Anti-Spoofing, namely SDA-FAS, that addresses the problems of source knowledge adaptation and target data exploration under the source-free setting. For source knowledge adaptation, we present novel strategies to realize self-training and domain alignment. We develop a contrastive domain alignment module to align conditional distribution across different domains by aggregating the features of fake and real faces separately. We demonstrate in theory that the pre-trained source model is equivalent to the source data as source prototypes for supervised contrastive learning in domain alignment. The source-oriented regularization is also introduced into self-training to alleviate the self-biasing problem. For target data exploration, self-supervised learning is employed with specified patch shuffle data augmentation to explore intrinsic spoofing features for unseen attack types. To our best knowledge, SDA-FAS is the first attempt that jointly optimizes the source-adapted knowledge and target self-supervised exploration for FAS. Extensive experiments on thirteen cross-dataset testing scenarios show that the proposed framework outperforms the state-of-the-art methods by a large margin."
On Mitigating Hard Clusters for Face Clustering
Authors: Yingjie Chen; Huasong Zhong; Chong Chen; Chen Shen; Jianqiang Huang; Tao Wang; Yun Liang; Qianru Sun
Venue: ECCV 2022 (main)

Abstract: "Face clustering is a promising way to scale up face recognition systems using large-scale unlabeled face images. It remains challenging to identify small or sparse face image clusters that we call hard clusters, which is caused by the heterogeneity, i.e., high variations in size and sparsity, of the clusters. Consequently, the conventional way of using a uniform threshold (to identify clusters) often leads to a terrible misclassification for the samples that should belong to hard clusters. We tackle this problem by leveraging the neighborhood information of samples and inferring the cluster memberships (of samples) in a probabilistic way. We introduce two novel modules, Neighborhood-Diffusion-based Density (NDDe) and Transition-Probability-based Distance (TPDi), based on which we can simply apply the standard Density Peak Clustering algorithm with a uniform threshold. Our experiments on multiple benchmarks show that each module contributes to the final performance of our method, and by incorporating them into other advanced face clustering methods, these two modules can boost the performance of these methods to a new state-of-the-art."
OneFace: One Threshold for All
Authors: Jiaheng Liu; Zhipeng Yu; Haoyu Qin; Yichao Wu; Ding Liang; Gangming Zhao; Ke Xu
Venue: ECCV 2022 (main)

Abstract: "Face recognition (FR) has witnessed remarkable progress with the surge of deep learning. Current FR evaluation protocols usually adopt different thresholds to calculate the True Accept Rate (TAR) under a pre-defined False Accept Rate (FAR) for different datasets. How- ever, in practice, when the FR model is deployed on industry systems (e.g., hardware devices), only one fixed threshold is adopted for all scenarios to distinguish whether a face image pair belongs to the same identity. Therefore, current evaluation protocols using different thresholds for different datasets are not fully compatible with the practical evaluation scenarios with one fixed threshold, and it is critical to measure the performance of FR models by using one threshold for all datasets. In this paper, we rethink the limitations of existing evaluation protocols for FR and propose to evaluate the performance of FR models from a new perspective. Specifically, in our OneFace, we first propose the One- Threshold-for-All (OTA) evaluation protocol for FR, which utilizes one fixed threshold called as Calibration Threshold to measure the performance on different datasets. Then, to improve the performance of FR models under the OTA protocol, we propose the Threshold Consistency Penalty (TCP) to improve the consistency of the thresholds among multiple domains, which includes Implicit Domain Division (IDD) as well as Calibration and Domain Thresholds Estimation (CDTE). Extensive experimental results on multiple benchmark datasets demonstrate the effectiveness of our proposed method for FR."
Label2Label: A Language Modeling Framework for Multi-Attribute Learning
Authors: Wanhua Li; Zhexuan Cao; Jianjiang Feng; Jie Zhou; Jiwen Lu
Venue: ECCV 2022 (main)

Abstract: Objects are usually associated with multiple attributes, and these attributes often exhibit high correlations. Modeling complex relationships between attributes poses a great challenge for multi-attribute learning. This paper proposes a simple yet generic framework named Label2Label to exploit the complex attribute correlations. Label2Label is the first attempt for multi-attribute prediction from the perspective of language modeling. Specifically, it treats each attribute label as a "word" describing the sample. As each sample is annotated with multiple attribute labels, these "words" will naturally form an unordered but meaningful "sentence", which depicts the semantic information of the corresponding sample. Inspired by the remarkable success of pre-training language models in NLP, Label2Label introduces an image-conditioned masked language model, which randomly masks some of the "word" tokens from the label "sentence" and aims to recover them based on the masked "sentence" and the context conveyed by image features. Our intuition is that the instance-wise attribute relations are well grasped if the neural net can infer the missing attributes based on the context and the remaining attribute hints. Label2Label is conceptually simple and empirically powerful. Without incorporating task-specific prior knowledge and highly specialized network designs, our approach achieves state-of-the-art results on three different multi-attribute learning tasks, compared to highly customized domain-specific methods. Code is available at https://github.com/Li-Wanhua/Label2Label.
AgeTransGAN for Facial Age Transformation with Rectified Performance Metrics
Authors: Gee-Sern Hsu; Rui-Cang Xie; Zhi-Ting Chen; Yu-Hong Lin
Venue: ECCV 2022 (main)

Abstract: "We propose the AgeTransGAN for facial age transformation and the improvements to the metrics for performance evaluation. The AgeTransGAN is composed of an encoder-decoder generator and a conditional multitask discriminator with an age classifier embedded. The generator exploits cycle-generation consistency, age classification and cross-age identity consistency to disentangle the identity and age characteristics during training. The discriminator fuses age features with the target age group label and collaborates with the embedded age classifier to warrant the desired age traits made on the generated images. As many previous work use the Face++ APIs as the metrics for performance evaluation, we reveal via experiments the inappropriateness of using the Face++ as the metrics for the face verification and age estimation of juniors. To rectify the Face++ metrics, we made the Cross-Age Face (CAF) dataset which contains 4000 face images of 520 individuals taken from their childhood to seniorhood. The CAF is one of the very few datasets that offer much more images of the same individuals across large age gaps than the popular FG-Net. We use the CAF to rectify the face verification thresholds of the Face++ APIs across different age gaps. We also use the CAF and the FFHQ-Aging datasets to compare the age estimation performance of the Face++ APIs and an age estimator made by our own, and propose rectified metrics for performance evaluation. We compare the performance of the AgeTransGAN and state-of-the-art approaches by using the existing and rectified metrics."
Hierarchical Contrastive Inconsistency Learning for Deepfake Video Detection
Authors: Zhihao Gu; Taiping Yao; Yang Chen; Shouhong Ding; Lizhuang Ma
Venue: ECCV 2022 (main)

Abstract: "With the rapid development of Deepfake techniques, the capacity of generating hyper-realistic faces has aroused public concerns in recent years. The temporal inconsistency which derives from the contrast of facial movements between pristine and forged videos can serve as an efficient cue in identifying Deepfakes. However, most existing approaches tend to impose binary supervision to model it, which restricts them to only focusing on the category-level discrepancies. In this paper, we propose a novel Hierarchical Contrastive Inconsistency Learning framework (HCIL) with a two-level contrastive paradigm. Specially, sampling multiply snippets to form the input, HCIL performs contrastive learning from both local and global perspectives to capture more general and intrinsical temporal inconsistency between real and fake videos. Moreover, we also incorporate a region-adaptive module for intra-snippet inconsistency mining and an inter-snippet fusion module for cross-snippet information fusion, which further facilitates the inconsistency learning. Extensive experiments and visualizations demonstrate the effectiveness of our method against SOTA competitors on four Deepfake video datasets, \emph{i.e.,} FaceForensics++, Celeb-DF, DFDC, and Wild-Deepfake."