Calvin Murdock

dblp:127/0454 · DBLP profile ↗
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17ranked-venue papers
10as first author
9since 2021 · last 2025
0000-0002-9560-4506ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 15 · 8 first-author · 8 since 2021Graphics, computer vision, multimedia, augmented reality and games · 15 · 9 first-author · 7 since 2021
YearPublicationVenuePosition
2025 Hearing Anywhere in Any Environment
abstract
In mixed reality applications, a realistic acoustic experience in spatial environments is as crucial as the visual experience for achieving true immersion. Despite recent advances in neural approaches for Room Impulse Response (RIR) estimation, most existing methods are limited to the single environment on which they are trained, lacking the ability to generalize to new rooms with different geometries and surface materials. We aim to develop a unified model capable of reconstructing the spatial acoustic experience of any environment with minimum additional measurements. To this end, we present xRIR, a framework for cross-room RIR prediction. The core of our generalizable approach lies in combining a geometric feature extractor, which captures spatial context from panorama depth images, with a RIR encoder that extracts detailed acoustic features from only a few reference RIR samples. To evaluate our method, we introduce AcousticRooms, a new dataset featuring high-fidelity simulation of over 300,000 RIRs from 260 rooms. Experiments show that our method strongly outperforms a series of baselines. Furthermore, we successfully perform sim-to-real transfer by evaluating our model on four real-world environments, demonstrating the generalizability of our approach and the realism of our dataset.
Xiulong Liu 0002, Anurag Kumar 0003, Paul Calamia, Sebastià Vicenc Amengual Garí, Calvin Murdock, Ishwarya Ananthabhotla, Philip W. Robinson, Eli Shlizerman, Vamsi K. Ithapu, Ruohan Gao
CVPR5
2025 EgoAdapt: Adaptive Multisensory Distillation and Policy Learning for Efficient Egocentric Perception
abstract
Modern perception models, particularly those designed for multisensory egocentric tasks, have achieved remarkable performance but often come with substantial computational costs. These high demands pose challenges for real-world deployment, especially in resource-constrained environments. In this paper, we introduce EgoAdapt, a framework that adaptively performs cross-modal distillation and policy learning to enable efficient inference across different egocentric perception tasks, including egocentric action recognition, active speaker localization, and behavior anticipation. Our proposed policy module is adaptable to task-specific action spaces, making it broadly applicable. Experimental results on three challenging egocentric datasets EPIC-Kitchens, EasyCom, and Aria Everyday Activities demonstrate that our method significantly enhances efficiency, reducing GMACs by up to 89.09%, parameters up to 82.02%, and energy up to 9.6x, while still on-par and in many cases outperforming, the performance of corresponding state-of-the-art models.
Sanjoy Chowdhury, Subrata Biswas, Sayan Nag, Tushar Nagarajan, Calvin Murdock, Ishwarya Ananthabhotla, Yijun Qian, Vamsi K. Ithapu, Dinesh Manocha, Ruohan Gao
ICCV5
2025 Gaze-Enhanced Multimodal Turn-Taking Prediction in Triadic Conversations
Seongsil Heo, Christi Miller, Calvin Murdock, Michael J. Proulx
INTERSPEECH3
2025 Gaze Beyond the Frame: Forecasting Egocentric 3D Visual Span
abstract
People continuously perceive and interact with their surroundings based on underlying intentions that drive their exploration and behaviors. While research in egocentric user and scene understanding has focused primarily on motion and contact-based interaction, forecasting human visual perception itself remains less explored despite its fundamental role in guiding human actions and its implications for AR/VR and assistive technologies. We address the challenge of egocentric 3D visual span forecasting, predicting where a person's visual perception will focus next within their three-dimensional environment. To this end, we propose EgoSpanLift, a novel method that transforms egocentric visual span forecasting from 2D image planes to 3D scenes. EgoSpanLift converts SLAM-derived keypoints into gaze-compatible geometry and extracts volumetric visual span regions. We further combine EgoSpanLift with 3D U-Net and unidirectional transformers, enabling spatio-temporal fusion to efficiently predict future visual span in the 3D grid. In addition, we curate a comprehensive benchmark from raw egocentric multisensory data, creating a testbed with 364.6K samples for 3D visual span forecasting. Our approach outperforms competitive baselines for egocentric gaze anticipation and 3D localization, while achieving comparable results even when projected back onto 2D image planes without additional 2D-specific training.
Heeseung Yun, Joonil Na, Jaeyeon Kim, Calvin Murdock, Gunhee Kim
NeurIPS4
2024 Spherical World-Locking for Audio-Visual Localization in Egocentric Videos
Heeseung Yun, Ruohan Gao, Ishwarya Ananthabhotla, Anurag Kumar 0003, Jacob Donley, Gunhee Kim, Vamsi K. Ithapu, Calvin Murdock
ECCV (24)9
2024 Self-Motion As Supervision For Egocentric Audiovisual Localization
abstract
Sound source localization is a key requirement for many assistive applications of augmented reality, such as speech enhancement. In conversational settings, potential sources of interest may be approximated by active speaker detection. However, localizing speakers in crowded, noisy environments is challenging, particularly without extensive ground truth annotations. Still, people are often able to communicate effectively in these scenarios through orienting behavioral responses, such as head motion and eye gaze, which have been shown to correlate with directions of auditory sources. In the absence of ground truth annotations, we propose joint training of egocentric audiovisual localization with behavioral pseudolabels to relate audiovisual stimuli with directional information extracted from future behavior. We evaluate this method as a technique for unsupervised egocentric active speaker localization and compare pseudolabels derived from head and gaze directions against fully-supervised alternatives.
Calvin Murdock, Ishwarya Ananthabhotla, Vamsi K. Ithapu
ICASSP1
2023 Reframing Neural Networks: Deep Structure in Overcomplete Representations
abstract
In comparison to classical shallow representation learning techniques, deep neural networks have achieved superior performance in nearly every application benchmark. But despite their clear empirical advantages, it is still not well understood what makes them so effective. To approach this question, we introduce deep frame approximation: a unifying framework for constrained representation learning with structured overcomplete frames. While exact inference requires iterative optimization, it may be approximated by the operations of a feed-forward deep neural network. We indirectly analyze how model capacity relates to frame structures induced by architectural hyperparameters such as depth, width, and skip connections. We quantify these structural differences with the deep frame potential, a data-independent measure of coherence linked to representation uniqueness and stability. As a criterion for model selection, we show correlation with generalization error on a variety of common deep network architectures and datasets. We also demonstrate how recurrent networks implementing iterative optimization algorithms can achieve performance comparable to their feed-forward approximations while improving adversarial robustness. This connection to the established theory of overcomplete representations suggests promising new directions for principled deep network architecture design with less reliance on ad-hoc engineering.
Calvin Murdock, George Cazenavette, Simon Lucey
IEEE Trans. Pattern Anal. Mach. Intell.1
2022 Egocentric Deep Multi-Channel Audio-Visual Active Speaker Localization
abstract
Augmented reality devices have the potential to enhance human perception and enable other assistive functionalities in complex conversational environments. Effectively capturing the audio-visual context necessary for understanding these social interactions first requires detecting and localizing the voice activities of the device wearer and the surrounding people. These tasks are challenging due to their egocentric nature: the wearer's head motion may cause motion blur, surrounding people may appear in difficult viewing angles, and there may be occlusions, visual clutter, audio noise, and bad lighting. Under these conditions, previous state-of-the-art active speaker detection methods do not give satisfactory results. Instead, we tackle the problem from a new setting using both video and multi-channel microphone array audio. We propose a novel end-to-end deep learning approach that is able to give robust voice activity detection and localization results. In contrast to previous methods, our method localizes active speakers from all possible directions on the sphere, even outside the camera's field of view, while simultaneously detecting the device wearer's own voice activity. Our experiments show that the proposed method gives superior results, can run in real time, and is robust against noise and clutter.
Hao Jiang 0007, Calvin Murdock, Vamsi K. Ithapu
CVPR2
2021 Architectural Adversarial Robustness: The Case for Deep Pursuit
abstract
Despite their unmatched performance, deep neural networks remain susceptible to targeted attacks by nearly imperceptible levels of adversarial noise. While the underlying cause of this sensitivity is not well understood, theoretical analyses can be simplified by reframing each layer of a feed-forward network as an approximate solution to a sparse coding problem. Iterative solutions using basis pursuit are theoretically more stable and have improved adversarial robustness. However, cascading layer-wise pursuit implementations suffer from error accumulation in deeper networks. In contrast, our new method of deep pursuit approximates the activations of all layers as a single global optimization problem, allowing us to consider deeper, real-world architectures with skip connections such as residual networks. Experimentally, our approach demonstrates improved robustness to adversarial noise.
George Cazenavette, Calvin Murdock, Simon Lucey
CVPR2
2020 Dataless Model Selection With the Deep Frame Potential
abstract
Choosing a deep neural network architecture is a fundamental problem in applications that require balancing performance and parameter efficiency. Standard approaches rely on ad-hoc engineering or computationally expensive validation on a specific dataset. We instead attempt to quantify networks by their intrinsic capacity for unique and robust representations, enabling efficient architecture comparisons without requiring any data. Building upon theoretical connections between deep learning and sparse approximation, we propose the deep frame potential: a measure of coherence that is approximately related to representation stability but has minimizers that depend only on network structure. This provides a framework for jointly quantifying the contributions of architectural hyper-parameters such as depth, width, and skip connections. We validate its use as a criterion for model selection and demonstrate correlation with generalization error on a variety of common residual and densely connected network architectures.
Calvin Murdock, Simon Lucey
CVPR1
2018 Deep Component Analysis via Alternating Direction Neural Networks
Calvin Murdock, Ming-Fang Chang, Simon Lucey
ECCV (15)1
2017 Additive Component Analysis
abstract
Principal component analysis (PCA) is one of the most versatile tools for unsupervised learning with applications ranging from dimensionality reduction to exploratory data analysis and visualization. While much effort has been devoted to encouraging meaningful representations through regularization (e.g. non-negativity or sparsity), underlying linearity assumptions can limit their effectiveness. To address this issue, we propose Additive Component Analysis (ACA), a novel nonlinear extension of PCA. Inspired by multivariate nonparametric regression with additive models, ACA fits a smooth manifold to data by learning an explicit mapping from a low-dimensional latent space to the input space, which trivially enables applications like denoising. Furthermore, ACA can be used as a drop-in replacement in many algorithms that use linear component analysis methods as a subroutine via the local tangent space of the learned manifold. Unlike many other nonlinear dimensionality reduction techniques, ACA can be efficiently applied to large datasets since it does not require computing pairwise similarities or storing training data during testing. Multiple ACA layers can also be composed and learned jointly with essentially the same procedure for improved representational power, demonstrating the encouraging potential of nonparametric deep learning. We evaluate ACA on a variety of datasets, showing improved robustness, reconstruction performance, and interpretability.
Calvin Murdock, Fernando De la Torre
CVPR1
2017 Approximate Grassmannian Intersections: Subspace-Valued Subspace Learning
Calvin Murdock, Fernando De la Torre
ICCV1
2016 Blockout: Dynamic Model Selection for Hierarchical Deep Networks
abstract
Most deep architectures for image classification-even those that are trained to classify a large number of diverse categories-learn shared image representations with a single model. Intuitively, however, categories that are more similar should share more information than those that are very different. While hierarchical deep networks address this problem by learning separate features for subsets of related categories, current implementations require simplified models using fixed architectures specified via heuristic clustering methods. Instead, we propose Blockout, a method for regularization and model selection that simultaneously learns both the model architecture and parameters. A generalization of Dropout, our approach gives a novel parametrization of hierarchical architectures that allows for structure learning via back-propagation. To demonstrate its utility, we evaluate Blockout on the CIFAR and Image Net datasets, demonstrating improved classification accuracy, better regularization performance, faster training, and the clear emergence of hierarchical network structures.
Calvin Murdock, Zhen Li 0028, Howard Zhou, Tom Duerig
CVPR1
2015 Building Dynamic Cloud Maps from the Ground Up
abstract
Satellite imagery of cloud cover is extremely important for understanding and predicting weather. We demonstrate how this imagery can be constructed "from the ground up" without requiring expensive geo-stationary satellites. This is accomplished through a novel approach to approximate continental-scale cloud maps using only ground-level imagery from publicly-available webcams. We collected a year's worth of satellite data and simultaneously-captured, geo-located outdoor webcam images from 4388 sparsely distributed cameras across the continental USA. The satellite data is used to train a dynamic model of cloud motion alongside 4388 regression models (one for each camera) to relate ground-level webcam data to the satellite data at the camera's location. This novel application of large-scale computer vision to meteorology and remote sensing is enabled by a smoothed, hierarchically-regularized dynamic texture model whose system dynamics are driven to remain consistent with measurements from the geo-located webcams. We show that our hierarchical model is better able to incorporate sparse webcam measurements resulting in more accurate cloud maps in comparison to a standard dynamic textures implementation. Finally, we demonstrate that our model can be successfully applied to other natural image sequences from the DynTex database, suggesting a broader applicability of our method.
Calvin Murdock, Nathan Jacobs, Robert Pless
ICCV1
2015 Semantic Component Analysis
abstract
Unsupervised and weakly-supervised visual learning in large image collections are critical in order to avoid the time-consuming and error-prone process of manual labeling. Standard approaches rely on methods like multiple-instance learning or graphical models, which can be computationally intensive and sensitive to initialization. On the other hand, simpler component analysis or clustering methods usually cannot achieve meaningful invariances or semantic interpretability. To address the issues of previous work, we present a simple but effective method called Semantic Component Analysis (SCA), which provides a decomposition of images into semantic components. Unsupervised SCA decomposes additive image representations into spatially-meaningful visual components that naturally correspond to object categories. Using an overcomplete representation that allows for rich instance-level constraints and spatial priors, SCA gives improved results and more interpretable components in comparison to traditional matrix factorization techniques. If weakly-supervised information is available in the form of image-level tags, SCA factorizes a set of images into semantic groups of superpixels. We also provide qualitative connections to traditional methods for component analysis (e.g. Grassmann averages, PCA, and NMF). The effectiveness of our approach is validated through synthetic data and on the MSRC2 and Sift Flow datasets, demonstrating competitive results in unsupervised and weakly-supervised semantic segmentation.
Calvin Murdock, Fernando De la Torre
ICCV1
2013 Webcam2Satellite: Estimating cloud maps from webcam imagery
abstract
We consider the problem of estimating the current satellite cloud map from a collection of broadly distributed, ground-based webcams. The approach uses historical, geo-referenced satellite imagery to learn a mapping between the satellite image and the ground imagery. We explore representational choices for inferring the cloud status based on the ground-level imagery and consider several alternatives for spatially interpolating these sparse measurements to give a complete map. Proof of concept results show that this gives plausible estimates of satellite imagery.
Calvin Murdock, Nathan Jacobs, Robert Pless
WACV1