Figure 1: Dense pose estimation aims at mapping all human pixels of an RGB image to the 3D surface of the human body. We introduce DensePose-COCO, a large-scale ground-truth dataset with image-to-surface correspondences manually annotated on 50K COCO images and train DensePose-RCNN, to densely regress part-specific UV coordinates within every human region at multiple frames per second. Left: The image and the regressed correspondence by DensePose-RCNN, Middle: DensePose COCO Dataset annotations, Right: Partitioning and UV parametrization of the body surface. AbstractIn this work, we establish dense correspondences between an RGB image and a surface-based representation of the human body, a task we refer to as dense human pose estimation. We first gather dense correspondences for 50K persons appearing in the COCO dataset by introducing an efficient annotation pipeline. We then use our dataset to train CNN-based systems that deliver dense correspondence 'in the wild', namely in the presence of background, occlusions and scale variations. We improve our training set's effectiveness by training an 'inpainting' network that can fill in missing ground truth values, and report clear improvements with respect to the best results that would be achievable in the past. We experiment with fullyconvolutional networks and region-based models and observe a superiority of the latter; we further improve accuracy through cascading, obtaining a system that delivers highly-accurate results in real time. Supplementary materials and videos are provided on the project page http: //densepose.org.
Abstract-We present a method for gesture detection and localisation based on multi-scale and multi-modal deep learning. Each visual modality captures spatial information at a particular spatial scale (such as motion of the upper body or a hand), and the whole system operates at three temporal scales. Key to our technique is a training strategy which exploits: i) careful initialization of individual modalities; and ii) gradual fusion involving random dropping of separate channels (dubbed ModDrop) for learning cross-modality correlations while preserving uniqueness of each modality-specific representation. We present experiments on the ChaLearn 2014 Looking at People Challenge gesture recognition track, in which we placed first out of 17 teams. Fusing multiple modalities at several spatial and temporal scales leads to a significant increase in recognition rates, allowing the model to compensate for errors of the individual classifiers as well as noise in the separate channels. Futhermore, the proposed ModDrop training technique ensures robustness of the classifier to missing signals in one or several channels to produce meaningful predictions from any number of available modalities. In addition, we demonstrate the applicability of the proposed fusion scheme to modalities of arbitrary nature by experiments on the same dataset augmented with audio.
The ability to predict and therefore to anticipate the future is an important attribute of intelligence. It is also of utmost importance in real-time systems, e.g. in robotics or autonomous driving, which depend on visual scene understanding for decision making. While prediction of the raw RGB pixel values in future video frames has been studied in previous work, here we introduce the novel task of predicting semantic segmentations of future frames. Given a sequence of video frames, our goal is to predict segmentation maps of not yet observed video frames that lie up to a second or further in the future. We develop an autoregressive convolutional neural network that learns to iteratively generate multiple frames. Our results on the Cityscapes dataset show that directly predicting future segmentations is substantially better than predicting and then segmenting future RGB frames. Prediction results up to half a second in the future are visually convincing and are much more accurate than those of a baseline based on warping semantic segmentations using optical flow.
Factorization network Te s t Train ϕ 3D shape and viewpoint (α, θ ) (Y, v) 2D keypoints and visibility Dense keypoints Non-rigid objects Rigid objects Monocular reconstruction of:ϕ Figure 1: Our method learns a 3D model of a deformable object category from 2D keypoints in unconstrained images. It comprises a deep network that learns to factorize shape and viewpoint and, at test time, performs monocular reconstruction. AbstractWe propose C3DPO, a method for extracting 3D models of deformable objects from 2D keypoint annotations in unconstrained images. We do so by learning a deep network that reconstructs a 3D object from a single view at a time, accounting for partial occlusions, and explicitly factoring the effects of viewpoint changes and object deformations. In order to achieve this factorization, we introduce a novel regularization technique. We first show that the factorization is successful if, and only if, there exists a certain canonicalization function of the reconstructed shapes. Then, we learn the canonicalization function together with the reconstruction one, which constrains the result to be consistent. We demonstrate stateof-the-art reconstruction results for methods that do not use ground-truth 3D supervision for a number of benchmarks, including Up3D and PASCAL3D+. Source code has been made available at https
Human activity recognition is typically addressed by detecting key concepts like global and local motion, features related to object classes present in the scene, as well as features related to the global context. The next open challenges in activity recognition require a level of understanding that pushes beyond this and call for models with capabilities for fine distinction and detailed comprehension of interactions between actors and objects in a scene. We propose a model capable of learning to reason about semantically meaningful spatio-temporal interactions in videos. The key to our approach is a choice of performing this reasoning at the object level through the integration of state of the art object detection networks. This allows the model to learn detailed spatial interactions that exist at a semantic, object-interaction relevant level. We evaluate our method on three standard datasets (Twenty-BN Something-Something, VLOG and EPIC Kitchens) and achieve state of the art results on all of them. Finally, we show visualizations of the interactions learned by the model, which illustrate object classes and their interactions corresponding to different activity classes.
Dense Pose Transfer 5 details is left to the supplemental material. We start by presenting the architecture of the predictive stream, and then turn to the surface-based stream, corresponding to the upper and lower rows of Fig. 1, respectively. Predictive streamThe predictive module is a conditional generative model that exploits the Dense-Pose system results for pose transfer. Existing conditional models indicate the target pose in the form of heat-maps from keypoint detectors [4], or part segmentations [3]. Here we condition on the concatenation of the input image and Dense-Pose results for the input and target images, resulting in an input of dimension 256×256×9. This provides conditioning that is both global (part-classification), and point-level (continuous coordinates), allowing the remaining network to exploit a richer source of information.The remaining architecture includes an encoder followed by a stack of residual blocks and a decoder at the end, along the lines of [28]. In more detail, this network comprises (a) a cascade of three convolutional layers that encode the 256×256×9 input into 64×64×256 activations, (b) a set of six residual blocks with 3×3×256×256 kernels, (c) a cascade of two deconvolutional and one convolutional layer that deliver an output of the same spatial resolution as the input. All intermediate convolutional layers have 3×3 filters and are followed by instance normalization [36] and ReLU activation. The last layer has tanh non-linearity and no normalization. Warping streamOur warping module performs pose transfer by performing explicit texture mapping between the input and the target image on the common surface UV-system. The core of this component is a Spatial Transformer Network (STN) [37] that warps according to DensePose the image observations to the UV-coordinate system of each surface part; we use a grid with 256×256 UV points for each of the 24 surface parts, and perform scattered interpolation to handle the continuous values of the regressed UV coordinates. The inverse mapping from UV to the output image space is performed by a second STN with a bilinear kernel. As shown in Fig. 3, a direct implementation of this module would often deliver poor results: the part of the surface that is visible on the source image is typically small, and can often be entirely non-overlapping with the part of the body that is visible on the target image. This is only exacerbated by DensePose failures or systematic errors around the part seams. These problems motivate the use of an inpainting network within the warping module, as detailed below.Inpainting autoencoder. This model allows us to extrapolate the body appearance from the surface nodes populated by the STN to the remainder of the surface. Our setup requires a different approach to the one of other deep inpainting methods [33], because we never observe the full surface texture during training. We handle the partially-observed nature of our training signal by using
We present a large-scale study exploring the capability of temporal deep neural networks to interpret natural human kinematics and introduce the first method for active biometric authentication with mobile inertial sensors. At Google, we have created a first-of-its-kind data set of human movements, passively collected by 1500 volunteers using their smartphones daily over several months. We compare several neural architectures for efficient learning of temporal multi-modal data representations, propose an optimized shift-invariant dense convolutional mechanism, and incorporate the discriminatively trained dynamic features in a probabilistic generative framework taking into account temporal characteristics. Our results demonstrate that human kinematics convey important information about user identity and can serve as a valuable component of multi-modal authentication systems. Finally, we demonstrate that the proposed model can also be successfully applied in a visual context.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.