geometric transformation
Adversarial Attacks on Black Box Video Classifiers: Leveraging the Power of Geometric Transformations (Supplementary Material)
We observe that our method outperforms the baseline methods in a statistically significant way. We consider four state-of-the-art video classification models, representing diverse methodologies of learning from videos, i.e., C3D [1], SlowFast [2], TPN [3] and I3D [4], as our black-box victim models to perform adversarial attack. The C3D model applies 3D convolution to learn spatio-temporal features from videos. SlowFast uses a two-pathway architecture where the slow pathway operates at a low frame rate to capture spatial semantics and the fast pathway operates at a high frame rate to capture motion at fine temporal resolution. I3D proposes the Inflated 3DConvNet(I3D) with Inflated 2D filters and pooling kernels of traditional 2DCNNs.
Adversarial Attacks on Black Box Video Classifiers: Leveraging the Power of Geometric Transformations
When compared to the image classification models, black-box adversarial attacks against video classification models have been largely understudied. This could be possible because, with video, the temporal dimension poses significant additional challenges in gradient estimation. Query-efficient black-box attacks rely on effectively estimated gradients towards maximizing the probability of misclassifying the target video. In this work, we demonstrate that such effective gradients can be searched for by parameterizing the temporal structure of the search space with geometric transformations.
Functional Indirection Neural Estimator for Better Out-of-distribution Generalization
Kha Pham1 Hung Le1 Man Ngo2 Truyen Tran1, 1 Applied Artificial Intelligence Institute, Deakin University, 2 Faculty of Mathematics and Computer Science, VNUHCM-University of Science, , 1 {phti, thai.le, truyen.tran}@deakin.edu.au, 2 nmman@hcmus.edu.vn
The capacity to achieve out-of-distribution (OOD) generalization is a hallmark of human intelligence and yet remains out of reach for machines. This remarkable capability has been attributed to our abilities to make conceptual abstraction and analogy, and to a mechanism known as indirection, which binds two representations and uses one representation to refer to the other. Inspired by these mechanisms, we hypothesize that OOD generalization may be achieved by performing analogymaking and indirection in the functional space instead of the data space as in current methods. To realize this, we design FINE(Functional Indirection Neural Estimator), a neural framework that learns to compose functions that map data input to output on-the-fly. FINE consists of a backbone network and a trainable semantic memory of basis weight matrices.
Functional Indirection Neural Estimator for Better Out-of-distribution Generalization
Kha Pham1 Hung Le1 Man Ngo2 Truyen Tran1, 1 Applied Artificial Intelligence Institute, Deakin University, 2 Faculty of Mathematics and Computer Science, VNUHCM-University of Science, , 1 {phti, thai.le, truyen.tran}@deakin.edu.au, 2 nmman@hcmus.edu.vn
Certifying Geometric Robustness of Neural Networks
The use of neural networks in safety-critical computer vision systems calls for their robustness certification against natural geometric transformations (e.g., rotation, scaling). However, current certification methods target mostly norm-based pixel perturbations and cannot certify robustness against geometric transformations. In this work, we propose a new method to compute sound and asymptotically optimal linear relaxations for any composition of transformations. Our method is based on a novel combination of sampling and optimization. We implemented the method in a system called DeepG and demonstrated that it certifies significantly more complex geometric transformations than existing methods on both defended and undefended networks while scaling to large architectures.