CHAPTER 2: Technical Performance
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Xinggan for Person Image Generation
XingGAN for Person Image Generation Hao Tang1;2, Song Bai2, Li Zhang2, Philip H.S. Torr2, and Nicu Sebe1;3 1University of Trento ([email protected]) 2University of Oxford 3Huawei Research Ireland Abstract. We propose a novel Generative Adversarial Network (Xing- GAN or CrossingGAN) for person image generation tasks, i.e., translat- ing the pose of a given person to a desired one. The proposed Xing gener- ator consists of two generation branches that model the person's appear- ance and shape information, respectively. Moreover, we propose two novel blocks to effectively transfer and update the person's shape and appear- ance embeddings in a crossing way to mutually improve each other, which has not been considered by any other existing GAN-based image genera- tion work. Extensive experiments on two challenging datasets, i.e., Market- 1501 and DeepFashion, demonstrate that the proposed XingGAN ad- vances the state-of-the-art performance both in terms of objective quan- titative scores and subjective visual realness. The source code and trained models are available at https://github.com/Ha0Tang/XingGAN. Keywords: Generative Adversarial Networks (GANs), Person Image Generation, Appearance Cues, Shape Cues 1 Introduction The problem of person image generation aims to generate photo-realistic per- son images conditioned on an input person image and several desired poses. This task has a wide range of applications such as person image/video genera- tion [41,9,2,11,19] and person re-identification [45,28]. Exiting methods such as [21,22,31,45,35] have achieved promising performance on this challenging task. -
Backpropagation and Deep Learning in the Brain
Backpropagation and Deep Learning in the Brain Simons Institute -- Computational Theories of the Brain 2018 Timothy Lillicrap DeepMind, UCL With: Sergey Bartunov, Adam Santoro, Jordan Guerguiev, Blake Richards, Luke Marris, Daniel Cownden, Colin Akerman, Douglas Tweed, Geoffrey Hinton The “credit assignment” problem The solution in artificial networks: backprop Credit assignment by backprop works well in practice and shows up in virtually all of the state-of-the-art supervised, unsupervised, and reinforcement learning algorithms. Why Isn’t Backprop “Biologically Plausible”? Why Isn’t Backprop “Biologically Plausible”? Neuroscience Evidence for Backprop in the Brain? A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: A spectrum of credit assignment algorithms: How to convince a neuroscientist that the cortex is learning via [something like] backprop - To convince a machine learning researcher, an appeal to variance in gradient estimates might be enough. - But this is rarely enough to convince a neuroscientist. - So what lines of argument help? How to convince a neuroscientist that the cortex is learning via [something like] backprop - What do I mean by “something like backprop”?: - That learning is achieved across multiple layers by sending information from neurons closer to the output back to “earlier” layers to help compute their synaptic updates. How to convince a neuroscientist that the cortex is learning via [something like] backprop 1. Feedback connections in cortex are ubiquitous and modify the -
Synthesizing Images of Humans in Unseen Poses
Synthesizing Images of Humans in Unseen Poses Guha Balakrishnan Amy Zhao Adrian V. Dalca Fredo Durand MIT MIT MIT and MGH MIT [email protected] [email protected] [email protected] [email protected] John Guttag MIT [email protected] Abstract We address the computational problem of novel human pose synthesis. Given an image of a person and a desired pose, we produce a depiction of that person in that pose, re- taining the appearance of both the person and background. We present a modular generative neural network that syn- Source Image Target Pose Synthesized Image thesizes unseen poses using training pairs of images and poses taken from human action videos. Our network sepa- Figure 1. Our method takes an input image along with a desired target pose, and automatically synthesizes a new image depicting rates a scene into different body part and background lay- the person in that pose. We retain the person’s appearance as well ers, moves body parts to new locations and refines their as filling in appropriate background textures. appearances, and composites the new foreground with a hole-filled background. These subtasks, implemented with separate modules, are trained jointly using only a single part details consistent with the new pose. Differences in target image as a supervised label. We use an adversarial poses can cause complex changes in the image space, in- discriminator to force our network to synthesize realistic volving several moving parts and self-occlusions. Subtle details conditioned on pose. We demonstrate image syn- details such as shading and edges should perceptually agree thesis results on three action classes: golf, yoga/workouts with the body’s configuration. -
Memristor-Based Approximated Computation
Memristor-based Approximated Computation Boxun Li1, Yi Shan1, Miao Hu2, Yu Wang1, Yiran Chen2, Huazhong Yang1 1Dept. of E.E., TNList, Tsinghua University, Beijing, China 2Dept. of E.C.E., University of Pittsburgh, Pittsburgh, USA 1 Email: [email protected] Abstract—The cessation of Moore’s Law has limited further architectures, which not only provide a promising hardware improvements in power efficiency. In recent years, the physical solution to neuromorphic system but also help drastically close realization of the memristor has demonstrated a promising the gap of power efficiency between computing systems and solution to ultra-integrated hardware realization of neural net- works, which can be leveraged for better performance and the brain. The memristor is one of those promising devices. power efficiency gains. In this work, we introduce a power The memristor is able to support a large number of signal efficient framework for approximated computations by taking connections within a small footprint by taking the advantage advantage of the memristor-based multilayer neural networks. of the ultra-integration density [7]. And most importantly, A programmable memristor approximated computation unit the nonvolatile feature that the state of the memristor could (Memristor ACU) is introduced first to accelerate approximated computation and a memristor-based approximated computation be tuned by the current passing through itself makes the framework with scalability is proposed on top of the Memristor memristor a potential, perhaps even the best, device to realize ACU. We also introduce a parameter configuration algorithm of neuromorphic computing systems with picojoule level energy the Memristor ACU and a feedback state tuning circuit to pro- consumption [8], [9]. -
A Survey of Autonomous Driving: Common Practices and Emerging Technologies
Accepted March 22, 2020 Digital Object Identifier 10.1109/ACCESS.2020.2983149 A Survey of Autonomous Driving: Common Practices and Emerging Technologies EKIM YURTSEVER1, (Member, IEEE), JACOB LAMBERT 1, ALEXANDER CARBALLO 1, (Member, IEEE), AND KAZUYA TAKEDA 1, 2, (Senior Member, IEEE) 1Nagoya University, Furo-cho, Nagoya, 464-8603, Japan 2Tier4 Inc. Nagoya, Japan Corresponding author: Ekim Yurtsever (e-mail: [email protected]). ABSTRACT Automated driving systems (ADSs) promise a safe, comfortable and efficient driving experience. However, fatalities involving vehicles equipped with ADSs are on the rise. The full potential of ADSs cannot be realized unless the robustness of state-of-the-art is improved further. This paper discusses unsolved problems and surveys the technical aspect of automated driving. Studies regarding present challenges, high- level system architectures, emerging methodologies and core functions including localization, mapping, perception, planning, and human machine interfaces, were thoroughly reviewed. Furthermore, many state- of-the-art algorithms were implemented and compared on our own platform in a real-world driving setting. The paper concludes with an overview of available datasets and tools for ADS development. INDEX TERMS Autonomous Vehicles, Control, Robotics, Automation, Intelligent Vehicles, Intelligent Transportation Systems I. INTRODUCTION necessary here. CCORDING to a recent technical report by the Eureka Project PROMETHEUS [11] was carried out in A National Highway Traffic Safety Administration Europe between 1987-1995, and it was one of the earliest (NHTSA), 94% of road accidents are caused by human major automated driving studies. The project led to the errors [1]. Against this backdrop, Automated Driving Sys- development of VITA II by Daimler-Benz, which succeeded tems (ADSs) are being developed with the promise of in automatically driving on highways [12]. -
Video and Audio Deepfakes: What Lawyers Need to Know by Sharon D
Video and Audio Deepfakes: What Lawyers Need to Know by Sharon D. Nelson, Esq., and John W. Simek © 2020 Sensei Enterprises, Inc. If some nefarious person has decent photos of your face, you too (like so many unfortunate Hollywood celebrities) could appear to be the star of a pornographic video. If someone has recordings of your voice (from your website videos, CLEs you have presented, speeches you’ve given, etc.), they can do a remarkably good job of simulating your spoken words and, just as an example, call your office manager and authorize a wire transfer – something the office manager may be willing to do because of “recognizing” your voice. Unnerving? Yes, but it is the reality of today. And if you don’t believe how “white hot” deepfakes are, just put a Google alert on that word and you’ll be amazed at the volume of daily results. Political and Legal Implications We have already seen deepfakes used in the political area (the “drunk” Nancy Pelosi deepfake, a reference to which was tweeted by the president), and many commentators worry that deepfake videos will ramp up for the 2020 election. Some of them, including the Pelosi video, are referred to as “cheapfakes” because they are so poorly done (basically running the video at 75 percent speed to simulate drunkenness), but that really doesn’t matter if large numbers of voters believe it’s real. And the days when you could tell a deepfake video by the fact that the person didn’t blink are rapidly vanishing as the algorithms have gotten smarter. -
Neural Rendering and Reenactment of Human Actor Videos
Neural Rendering and Reenactment of Human Actor Videos LINGJIE LIU, University of Hong Kong, Max Planck Institute for Informatics WEIPENG XU, Max Planck Institute for Informatics MICHAEL ZOLLHÖFER, Stanford University, Max Planck Institute for Informatics HYEONGWOO KIM, FLORIAN BERNARD, and MARC HABERMANN, Max Planck Institute for Informatics WENPING WANG, University of Hong Kong CHRISTIAN THEOBALT, Max Planck Institute for Informatics (real) Driving motion (synth.) Output Fig. 1. We propose a novel learning-based approach for the animation and reenactment of human actor videos. The top row shows some frames of the video from which the source motion is extracted, and the bottom row shows the corresponding synthesized target person imagery reenacting the source motion. We propose a method for generating video-realistic animations of real hu- images are then used to train a conditional generative adversarial network mans under user control. In contrast to conventional human character render- that translates synthetic images of the 3D model into realistic imagery of ing, we do not require the availability of a production-quality photo-realistic the human. We evaluate our method for the reenactment of another person 3D model of the human, but instead rely on a video sequence in conjunction that is tracked in order to obtain the motion data, and show video results with a (medium-quality) controllable 3D template model of the person. With generated from artist-designed skeleton motion. Our results outperform the that, our approach significantly reduces production cost compared to conven- state-of-the-art in learning-based human image synthesis. tional rendering approaches based on production-quality 3D models, and can CCS Concepts: • Computing methodologies → Computer graphics; also be used to realistically edit existing videos. -
CSE 152: Computer Vision Manmohan Chandraker
CSE 152: Computer Vision Manmohan Chandraker Lecture 15: Optimization in CNNs Recap Engineered against learned features Label Convolutional filters are trained in a Dense supervised manner by back-propagating classification error Dense Dense Convolution + pool Label Convolution + pool Classifier Convolution + pool Pooling Convolution + pool Feature extraction Convolution + pool Image Image Jia-Bin Huang and Derek Hoiem, UIUC Two-layer perceptron network Slide credit: Pieter Abeel and Dan Klein Neural networks Non-linearity Activation functions Multi-layer neural network From fully connected to convolutional networks next layer image Convolutional layer Slide: Lazebnik Spatial filtering is convolution Convolutional Neural Networks [Slides credit: Efstratios Gavves] 2D spatial filters Filters over the whole image Weight sharing Insight: Images have similar features at various spatial locations! Key operations in a CNN Feature maps Spatial pooling Non-linearity Convolution (Learned) . Input Image Input Feature Map Source: R. Fergus, Y. LeCun Slide: Lazebnik Convolution as a feature extractor Key operations in a CNN Feature maps Rectified Linear Unit (ReLU) Spatial pooling Non-linearity Convolution (Learned) Input Image Source: R. Fergus, Y. LeCun Slide: Lazebnik Key operations in a CNN Feature maps Spatial pooling Max Non-linearity Convolution (Learned) Input Image Source: R. Fergus, Y. LeCun Slide: Lazebnik Pooling operations • Aggregate multiple values into a single value • Invariance to small transformations • Keep only most important information for next layer • Reduces the size of the next layer • Fewer parameters, faster computations • Observe larger receptive field in next layer • Hierarchically extract more abstract features Key operations in a CNN Feature maps Spatial pooling Non-linearity Convolution (Learned) . Input Image Input Feature Map Source: R. -
Automated Elastic Pipelining for Distributed Training of Transformers
PipeTransformer: Automated Elastic Pipelining for Distributed Training of Transformers Chaoyang He 1 Shen Li 2 Mahdi Soltanolkotabi 1 Salman Avestimehr 1 Abstract the-art convolutional networks ResNet-152 (He et al., 2016) and EfficientNet (Tan & Le, 2019). To tackle the growth in The size of Transformer models is growing at an model sizes, researchers have proposed various distributed unprecedented rate. It has taken less than one training techniques, including parameter servers (Li et al., year to reach trillion-level parameters since the 2014; Jiang et al., 2020; Kim et al., 2019), pipeline paral- release of GPT-3 (175B). Training such models lel (Huang et al., 2019; Park et al., 2020; Narayanan et al., requires both substantial engineering efforts and 2019), intra-layer parallel (Lepikhin et al., 2020; Shazeer enormous computing resources, which are luxu- et al., 2018; Shoeybi et al., 2019), and zero redundancy data ries most research teams cannot afford. In this parallel (Rajbhandari et al., 2019). paper, we propose PipeTransformer, which leverages automated elastic pipelining for effi- T0 (0% trained) T1 (35% trained) T2 (75% trained) T3 (100% trained) cient distributed training of Transformer models. In PipeTransformer, we design an adaptive on the fly freeze algorithm that can identify and freeze some layers gradually during training, and an elastic pipelining system that can dynamically Layer (end of training) Layer (end of training) Layer (end of training) Layer (end of training) Similarity score allocate resources to train the remaining active layers. More specifically, PipeTransformer automatically excludes frozen layers from the Figure 1. Interpretable Freeze Training: DNNs converge bottom pipeline, packs active layers into fewer GPUs, up (Results on CIFAR10 using ResNet). -
Complement the Broken Pose in Human Image Synthesis
Focus and retain: Complement the Broken Pose in Human Image Synthesis Pu Ge†, Qiushi Huang†, Wei Xiang‡, Xue Jing, Yule Li, Yiyong Li, Zhun Sun Bigo Technology PTE. LTD, Singapore {gepu,huangqiushi,xiangwei1}@bigo.sg Abstract Given a target pose, how to generate an image of a spe- cific style with that target pose remains an ill-posed and thus complicated problem. Most recent works treat the human pose synthesis tasks as an image spatial transformation prob- lem using flow warping techniques. However, we observe that, due to the inherent ill-posed nature of many compli- cated human poses, former methods fail to generate body parts. To tackle this problem, we propose a feature-level flow attention module and an Enhancer Network. The flow attention module produces a flow attention mask to guide the combination of the flow-warped features and the structural pose features. Then, we apply the Enhancer Network to re- fine the coarse image by injecting the pose information. We present our experimental evaluation both qualitatively and quantitatively on DeepFashion, Market-1501, and Youtube dance datasets. Quantitative results show that our method has 12.995 FID at DeepFashion, 25.459 FID at Market-1501, 14.516 FID at Youtube dance datasets, which outperforms some state-of-the-arts including Guide-Pixe2Pixe, Global- Flow-Local-Attn, and CocosNet. 1. Introduction Figure 1: (a) The inputs of the task: a reference image with a target pose. (b) The outputs of the task: a generated human in Conditional image generation and synthesis becomes a the target pose. From left to right: the ground truth, results popular computer vision task recent years [29]. -
1 Convolution
CS1114 Section 6: Convolution February 27th, 2013 1 Convolution Convolution is an important operation in signal and image processing. Convolution op- erates on two signals (in 1D) or two images (in 2D): you can think of one as the \input" signal (or image), and the other (called the kernel) as a “filter” on the input image, pro- ducing an output image (so convolution takes two images as input and produces a third as output). Convolution is an incredibly important concept in many areas of math and engineering (including computer vision, as we'll see later). Definition. Let's start with 1D convolution (a 1D \image," is also known as a signal, and can be represented by a regular 1D vector in Matlab). Let's call our input vector f and our kernel g, and say that f has length n, and g has length m. The convolution f ∗ g of f and g is defined as: m X (f ∗ g)(i) = g(j) · f(i − j + m=2) j=1 One way to think of this operation is that we're sliding the kernel over the input image. For each position of the kernel, we multiply the overlapping values of the kernel and image together, and add up the results. This sum of products will be the value of the output image at the point in the input image where the kernel is centered. Let's look at a simple example. Suppose our input 1D image is: f = 10 50 60 10 20 40 30 and our kernel is: g = 1=3 1=3 1=3 Let's call the output image h. -
Convolutional Neural Network Transfer Learning for Robust Face
Convolutional Neural Network Transfer Learning for Robust Face Recognition in NAO Humanoid Robot Daniel Bussey1, Alex Glandon2, Lasitha Vidyaratne2, Mahbubul Alam2, Khan Iftekharuddin2 1Embry-Riddle Aeronautical University, 2Old Dominion University Background Research Approach Results • Artificial Neural Networks • Retrain AlexNet on the CASIA-WebFace dataset to configure the neural • VGG-Face Shows better results in every performance benchmark measured • Computing systems whose model architecture is inspired by biological networf for face recognition tasks. compared to AlexNet, although AlexNet is able to extract features from an neural networks [1]. image 800% faster than VGG-Face • Capable of improving task performance without task-specific • Acquire an input image using NAO’s camera or a high resolution camera to programming. run through the convolutional neural network. • Resolution of the input image does not have a statistically significant impact • Show excellent performance at classification based tasks such as face on the performance of VGG-Face and AlexNet. recognition [2], text recognition [3], and natural language processing • Extract the features of the input image using the neural networks AlexNet [4]. and VGG-Face • AlexNet’s performance decreases with respect to distance from the camera where VGG-Face shows no performance loss. • Deep Learning • Compare the features of the input image to the features of each image in the • A subfield of machine learning that focuses on algorithms inspired by people database. • Both frameworks show excellent performance when eliminating false the function and structure of the brain called artificial neural networks. positives. The method used to allow computers to learn through a process called • Determine whether a match is detected or if the input image is a photo of a training.