Reviewerly/exHarmony huggingface dataset:
FLOAT: Fast Learnable Once-for-All Adversarial Training for Tunable Trade-off between Accuracy and Robustness

Existing models that achieve state-of-the-art (SOTA) performance on both clean and adversarially-perturbed images rely on convolution operations conditioned with feature-wise linear modulation (FiLM) layers. These layers require additional parameters and are hyperparameter sensitive. They significantly increase training time, memory cost, and potential latency which can be costly for resource-limited or real-time applications. In this paper, we present a fast learnable once-for-all adversarial training (FLOAT) algorithm, which instead of the existing FiLM-based conditioning, presents a unique weight conditioned learning that requires no additional layer, thereby incurring no significant increase in parameter count, training time, or network latency compared to standard adversarial training. In particular, we add configurable scaled noise to the weight tensors that enables a trade-off between clean and adversarial performance. Extensive experiments show that FLOAT can yield SOTA performance improving both clean and perturbed image classification by up to ~6% and ~10%, respectively. Moreover, real hardware measurement shows that FLOAT can reduce the training time by up to 1.43× with fewer model parameters of up to 1.47× on iso-hyperparameter settings compared to the FiLM-based alternatives. Additionally, to further improve memory effi ciency we introduce FLOAT sparse (FLOATS), a form of non-iterative model pruning and provide detailed empirical analysis in yielding a three-way accuracy-robustness-complexity trade-off for these new class of pruned conditionally trained models.
Unsupervised Audio-Visual Lecture Segmentation

Over the last decade, online lecture videos have become increasingly popular and have experienced a meteoric rise during the pandemic. However, video-language research has primarily focused on instructional videos or movies, and tools to help students navigate the growing online lectures are lacking. Our first contribution is to facilitate research in the educational domain by introducing AVLectures, a large-scale dataset consisting of 86 courses with over 2,350 lectures covering various STEM subjects. Each course contains video lectures, transcripts, OCR outputs for lecture frames, and optionally lecture notes, slides, assignments, and related educational content that can inspire a variety of tasks. Our second contribution is introducing video lecture segmentation that splits lectures into bite-sized topics. Lecture clip representations leverage visual, textual, and OCR cues and are trained on a pretext self-supervised task of matching the narration with the temporally aligned visual content. We formulate lecture segmentation as an unsupervised task and use these representations to generate segments using a temporally consistent 1-nearest neighbor algorithm, TW-FINCH [44]. We evaluate our method on 15 courses and compare it against various visual and textual baselines, outperforming all of them. Our comprehensive ablation studies also identify the key factors driving the success of our approach.
A Deep Neural Framework to Detect Individual Advertisement (Ad) from Videos

Detecting commercial Ads from a video is important. For example, the commercial break frequency and duration are two metrics to measure the user experience for streaming service providers such as Amazon Freevee. The detection can be done intrusively by intercepting the network traffic and then parsing the service providers data and logs, or non-intrusively by capturing the videos streamed by content providers and then analyzing using the computer vision technologies. In this paper, we present a non-intrusive framework that is able to not only detect an Ad section, but also segment out individual Ads. We show that our algorithm is scalable because it uses light weight audio data to do global segmentation, as well as is domain crossing (movies, TVs and live streaming sports) captured from the popular streaming services such as the Freevee and the Prime Video (PV) live sports.
Patch-level Gaze Distribution Prediction for Gaze Following

Gaze following aims to predict where a person is looking in a scene, by predicting the target location, or indicating that the target is located outside the image. Recent works detect the gaze target by training a heatmap regression task with a pixel-wise mean-square error (MSE) loss, while formulating the in/out prediction task as a binary classification task. This training formulation puts a strict, pixel-level constraint in higher resolution on the single annotation available in training, and does not consider annotation variance and the correlation between the two subtasks. To address these issues, we introduce the patch distribution prediction (PDP) method. We replace the in/out prediction branch in previous models with the PDP branch, by predicting a patch-level gaze distribution that also considers the outside cases. Experiments show that our model regularizes the MSE loss by predicting better heatmap distributions on images with larger annotation variances, meanwhile bridging the gap between the target prediction and in/out prediction subtasks, showing a significant improvement in performance on both subtasks on public gaze following datasets.
LineEX: Data Extraction from Scientific Line Charts

In this paper, we introduce LineEX that extracts data from scientific line charts. We adapt existing vision transformers and pose detection methods and showcase significant performance gains over existing SOTA baselines. We also propose a new loss function and present its effectiveness against existing loss functions. In addition, we synthetically created the largest line chart dataset comprising 430K images. The code is available at https: //github.com/Shiva-sankaran/LineEX.
GeoFill: Reference-Based Image Inpainting with Better Geometric Understanding

Reference-guided image inpainting restores image pixels by leveraging the content from another single reference image. The primary challenge is how to precisely place the pixels from the reference image into the hole region. Therefore, understanding the 3D geometry that relates pixels between two views is a crucial step towards building a better model. Given the complexity of handling various types of reference images, we focus on the scenario where the images are captured by freely moving the same camera around. Compared to the previous work, we propose a principled approach that does not make heuristic assumptions about the planarity of the scene. We lever-age a monocular depth estimate and predict relative pose between cameras, then align the reference image to the target by a differentiable 3D reprojection and a joint optimization of relative pose and depth map scale and offset. Our approach achieves state-of-the-art performance on both RealEstate10K and MannequinChallenge dataset with large baselines, complex geometry and extreme camera motions. We experimentally verify our approach is also better at handling large holes.
Contrastive Knowledge-Augmented Meta-Learning for Few-Shot Classification

Model agnostic meta-learning algorithms aim to infer priors from several observed tasks that can then be used to adapt to a new task with few examples. Given the inherent diversity of tasks arising in existing benchmarks, recent methods have resorted to task-specific adaptation of the prior. Our goal is to improve generalization of meta learners when the task distribution contains challenging distribution shifts and semantic disparities. To this end, we introduce CAML (Contrastive Knowledge-Augmented Meta Learning), a knowledge-enhanced few-shot learning approach that evolves a knowledge graph to encode historical experience, and employs a contrastive distillation strategy to leverage the encoded knowledge for task-aware modulation of the base learner. In addition to the standard few-shot task adaptation, we also consider the more challenging multi-domain task adaptation and few-shot dataset generalization settings in our evaluation with standard benchmarks. Our empirical study shows that CAML (i) enables simple task encoding schemes; (ii) eliminates the need for knowledge extraction at inference time; and most importantly, (iii) effectively aggregates historical experience thus leading to improved performance in both multi-domain adaptation and dataset generalization.
An Embedding-Dynamic Approach to Self-Supervised Learning

A number of recent self-supervised learning methods have shown impressive performance on image classification and other tasks. A somewhat bewildering variety of techniques have been used, not always with a clear understanding of the reasons for their benefits, especially when used in combination. Here we treat the embeddings of images as point particles and consider model optimization as a dynamic process on this system of particles. Our dynamic model combines an attractive force for similar images, a locally dispersive force to avoid local collapse, and a global dispersive force to achieve a globally-homogeneous distribution of particles. The dynamic perspective highlights the advantage of using a delayed-parameter image embedding (a la BYOL) together with multiple views of the same image. It also uses a purely-dynamic local dispersive force (Brownian motion) that shows improved performance over other methods and does not require knowledge of other particle coordinates. The method is called MSBReg which stands for (i) a Multiview centroid loss, which applies an attractive force to pull different image view embeddings toward their centroid, (ii) a Singular value loss, which pushes the particle system toward spatially homogeneous density, (iii) a Brownian diffusive loss. We evaluate downstream classification performance of MSBReg on ImageNet as well as transfer learning tasks including fine-grained classification, multi-class object classification, object detection, and instance segmentation. In addition, we also show that applying our regularization term to other methods further improves their performance and stabilize the training by preventing a mode collapse.
Towards Discriminative and Transferable One-Stage Few-Shot Object Detectors

Recent object detection models require large amounts of annotated data for training a new classes of objects. Few-shot object detection (FSOD) aims to address this problem by learning novel classes given only a few samples. While competitive results have been achieved using two-stage FSOD detectors, typically one-stage FSODs under-perform compared to them. We make the observation that the large gap in performance between two-stage and one-stage FSODs are mainly due to their weak discriminability, which is explained by a small post-fusion receptive field and a small number of foreground samples in the loss function. To address these limitations, we propose the Few-shot RetinaNet (FSRN) that consists of: a multi-way support training strategy to augment the number of foreground samples for dense meta-detectors, an early multi-level feature fusion providing a wide receptive field that covers the whole anchor area and two augmentation techniques on query and source images to enhance transferability. Extensive experiments show that the proposed approach addresses the limitations and boosts both discriminability and transferability. FSRN is almost two times faster than two-stage FSODs while remaining competitive in accuracy, and it outperforms the state-of-the-art of one-stage meta-detectors and also some two-stage FSODs on the MS-COCO and PASCAL VOC benchmarks.
RIFT: Disentangled Unsupervised Image Translation via Restricted Information Flow

Unsupervised image-to-image translation methods aim to map images from one domain into plausible examples from another domain while preserving the structure shared across two domains. In the many-to-many setting, an additional guidance example from the target domain is used to determine the domain-specific factors of variation of the generated image. In the absence of attribute annotations, methods have to infer which factors of variation are specific to each domain from data during training. In this paper, we show that many state-of-the-art architectures implicitly treat textures and colors as always being domain-specific, and thus fail when they are not. We propose a new method called RIFT that does not rely on such inductive architectural biases and instead infers which attributes are domain-specific vs shared directly from data. As a result, RIFT achieves consistently high cross-domain manipulation accuracy across multiple datasets spanning a wide variety of domain-specific and shared factors of variation.
Adversarial robustness in discontinuous spaces via alternating sampling &amp; descent

Several works have shown that deep learning models are vulnerable to adversarial attacks where seemingly simple label-preserving changes to the input image lead to incorrect predictions. To combat this, gradient based adversarial training is generally employed as a standard defense mechanism. However, in cases where the loss landscape is discontinuous with respect to a given perturbation set, first order methods get stuck in local optima, and fail to defend against threat. This is often a problem for many physically realizable perturbation sets such as 2D affine transformations and 3D scene parameters. To work in such settings, we introduce a new optimization framework that alternates between global zeroth order sampling and local gradient updates to compute strong adversaries that can be used to harden the model against attack. Further, we design a powerful optimization algorithm using this framework, called Alternating Evolutionary Sampling and Descent (ASD), which combines an evolutionary search strategy (viz. covariance matrix adaptation) with gradient descent. We consider two settings with discontinuous/discrete and non-convex loss landscapes to evaluate ASD: a) 3D scene parameters and b) 2D patch attacks, and find that it achieves state-of-the-art results on adversarial robustness.
RSF: Optimizing Rigid Scene Flow From 3D Point Clouds Without Labels

We present a method for optimizing object-level rigid 3D scene flow over two successive point clouds without any annotated labels in autonomous driving settings. Rather than using pointwise flow vectors, our approach represents scene flow as the composition a global ego-motion and a set of bounding boxes with their own rigid motions, exploiting the multi-body rigidity commonly present in dynamic scenes. We jointly optimize these parameters over a novel loss function based on the nearest neighbor distance using a differentiable bounding box formulation. Our approach achieves state-of-the-art accuracy on KITTI Scene Flow and nuScenes without requiring any annotations, outperforming even supervised methods. Additionally, we demonstrate the effectiveness of our approach on motion segmentation and ego-motion estimation. Lastly, we visualize our predictions and validate our loss function design with an ablation study.
Contrastive Learning of Semantic Concepts for Open-set Cross-domain Retrieval

We consider the problem of image retrieval where query images during testing belong to classes and domains both unseen during training. This requires learning a feature space that has the ability to generalize across both classes and domains together. To this end, we propose semantic contrastive concept network (SCNNet), a new learning framework that helps take a step towards class and domain generalization in a principled fashion. Unlike existing methods that rely on global object representations, SCNNet proposes to learn local feature vectors to facilitate unseen-class generalization. To this end, SCNNet’s key innovations include (a) a novel trainable local concept extraction module that learns an orthonormal set of basis vectors, and (b) computes local features for any unseen-class data as a linear combination of the learned basis set. Next, to enable unseen-domain generalization, SCNNet proposes to generate supervisory signals from an adjacent data modality, i.e., natural language, by mining freely available textual label information associated with images. SCNNet derives these signals from our novel trainable semantic ordinal distance constraints that ensure semantic consistency between pairs of images sampled from different domains. Both the proposed modules above enable end-to-end training of the SC-NNet, resulting in a model that helps establish state-of-the-art performance on the standard DomainNet, PACS, and Sketchy benchmark datasets with average Prec@200 improvements of 42.6%, 6.5%, and 13.6% respectively over the most recently reported results.
A Suspect Identification Framework using Contrastive Relevance Feedback

Suspect Identification is one of the most pivotal aspects of a forensic and criminal investigation. A significant amount of time and skill is devoted to creating sketches for it and requires a fair amount of recollections from the witness to provide a useful sketch. We devise a method that aims to automate the process of suspect identification and model this problem by iteratively retrieving images from feedback provided by the user. Compared to standard image retrieval tasks, interactive facial image retrieval is specifically more challenging due to the high subjectivity involved in describing a person’s facial attributes and appropriately evolving with the preferences put forward by the user. Our method uses a relatively simpler form of supervision by utilizing the user’s feedback to label images as either similar or dissimilar to their mental image of the suspect based on which we propose a loss function using the contrastive learning paradigm that is optimized in an online fashion. We validate the efficacy of our proposed approach using a carefully designed testbed to simulate user feedback and a large-scale user study. We empirically show that our method iteratively improves personalization, leading to faster convergence and enhanced recommendation relevance, thereby, improving user satisfaction. Our proposed framework is being designed for real-time use in the metropolitan crime investigation department, and thus is also equipped with a user-friendly web interface with a real-time experience for suspect retrieval.
CNN2Graph: Building Graphs for Image Classification

Neural Network classifiers generally operate via the i.i.d. assumption where examples are passed through independently during training. We propose CNN2GNN and CNN2Transformer which instead leverage inter-example information for classification. We use Graph Neural Networks (GNNs) to build a latent space bipartite graph and compute cross-attention scores between input images and a proxy set. Our approach addresses several challenges of existing methods. Firstly, it is end-to-end differentiable despite the generally discrete nature of graph construction. Secondly, it allows inductive inference at no extra cost. Thirdly, it presents a simple method to construct graphs from arbitrary datasets that captures both example level and class level information. Finally, it addresses the proxy collapse problem by combining contrastive and cross-entropy losses rather than separate clustering algorithms. Our results increase classification performance over baseline experiments and outperform other methods. We also conduct an empirical investigation showing that Transformer style attention scales better than GAT attention with dataset size.
FaceOff: A Video-to-Video Face Swapping System

Doubles play an indispensable role in the movie industry. They take the place of the actors in dangerous stunt scenes or scenes where the same actor plays multiple characters. The double's face is later replaced with the actor's face and expressions manually using expensive CGI technology, costing millions of dollars and taking months to complete. An automated, inexpensive, and fast way can be to use face-swapping techniques that aim to swap an identity from a source face video (or an image) to a target face video. However, such methods cannot preserve the source expressions of the actor important for the scene's context. To tackle this challenge, we introduce video-to-video (V2V) face-swapping, a novel task of face-swapping that can preserve (1) the identity and expressions of the source (actor) face video and (2) the background and pose of the target (double) video. We propose FaceOff, a V2V face-swapping system that operates by learning a robust blending operation to merge two face videos following the constraints above. It reduces the videos to a quantized latent space and then blends them in the reduced space. FaceOff is trained in a self-supervised manner and robustly tackles the non-trivial challenges of V2V face-swapping. As shown in the experimental section, FaceOff significantly outperforms alternate approaches qualitatively and quantitatively.
Single Stage Weakly Supervised Semantic Segmentation of Complex Scenes

The costly process of obtaining semantic segmentation labels has driven research towards weakly supervised semantic segmentation (WSSS) methods, using only image-level, point, or box labels. Such annotations introduce limitations and challenges that results in overly-tuned methods specialized in specific domains or scene types. The over reliance of image-level based methods on generation of high quality class activation maps (CAMs) results in limited applicable dataset complexity range, mostly focusing on object centric scenes. Additionally, the lack of dense annotations requires methods to increase network complexity to obtain additional semantic information, often done through multiple stages of training and refinement. Here, we present a single-stage approach generalizable to a wide range of dataset complexities, that is trainable from scratch, without any dependency on pre-trained backbones, classification, or separate refinement tasks. We utilize point annotations to generate reliable, on-the-fly pseudo-masks through refined and spatially filtered features. We are to demonstrate SOTA performance on benchmark datasets (PascalVOC 2012), as well as significantly outperform other SOTA WSSS methods on recent real-world datasets (CRAID, CityPersons, IAD, ADE20K, CityScapes) with up to 28.1% and 22.6% performance boosts compared to our single-stage and multi-stage baselines respectively.
Lightweight Video Denoising using Aggregated Shifted Window Attention

Video denoising is a fundamental problem in numerous computer vision applications. State-of-the-art attention-based denoising methods typically yield good results, but require vast amounts of GPU memory and usually suffer from very long computation times. Especially in the field of restoring digitized high-resolution historic films, these techniques are not applicable in practice. To overcome these issues, we introduce a lightweight video denoising network that combines efficient axial-coronal-sagittal (ACS) convolutions with a novel shifted window attention formulation (ASwin), which is based on the memory-efficient aggregation of self- and cross-attention across video frames. We numerically validate the performance and efficiency of our approach on synthetic Gaussian noise. Moreover, we train our network as a general-purpose blind denoising model for real-world videos, using a realistic noise synthesis pipeline to generate clean-noisy video pairs. A user study and non-reference quality assessment prove that our method outperforms the state-of-the-art on real-world historic videos in terms of denoising performance and temporal consistency.