Image super-resolution is a common task on mobile and IoT devices, where one often needs to upscale and enhance low-resolution images and video frames. While numerous solutions have been proposed for this problem in the past, they are usually not compatible with low-power mobile NPUs having many computational and memory constraints. In this Mobile AI challenge, we address this problem and propose the participants to design an efficient quantized image super-resolution solution that can demonstrate a real-time performance on mobile NPUs. The participants were provided with the DIV2K dataset and trained INT8 models to do a high-quality 3X image upscaling. The runtime of all models was evaluated on the Synaptics VS680 Smart Home board with a dedicated edge NPU capable of accelerating quantized neural networks. All proposed solutions are fully compatible with the above NPU, demonstrating an up to 60 FPS rate when reconstructing Full HD resolution images. A detailed description of all models developed in the challenge is provided in this paper.

基于深度学习的单图像超分辨率（SISR）方法引起了人们的关注，并在现代高级GPU上取得了巨大的成功。但是，大多数最先进的方法都需要大量参数，记忆和计算资源，这些参数通常会显示在当前移动设备CPU/NPU上时显示出较低的推理时间。在本文中，我们提出了一个简单的普通卷积网络，该网络具有快速最近的卷积模块（NCNET），该模块对NPU友好，可以实时执行可靠的超级分辨率。提出的最近的卷积具有与最近的UP采样相同的性能，但更快，更适合Android NNAPI。我们的模型可以很容易地在具有8位量化的移动设备上部署，并且与所有主要的移动AI加速器完全兼容。此外，我们对移动设备上的不同张量操作进行了全面的实验，以说明网络体系结构的效率。我们的NCNET在DIV2K 3X数据集上进行了训练和验证，并且与其他有效的SR方法的比较表明，NCNET可以实现高保真SR结果，同时使用更少的推理时间。我们的代码和预估计的模型可在\ url {https://github.com/algolzw/ncnet}上公开获得。

自我介绍在训练过程中利用自身的非均匀软监管，并在没有任何运行时成本的情况下提高性能。但是，在训练过程中的开销经常被忽略，但是在巨型模型的时代，培训期间的时间和记忆开销越来越重要。本文提出了一种名为ZIPF标签平滑（ZIPF的LS）的有效自我验证方法，该方法使用网络的直立预测来生成软监管，该软监管在不使用任何对比样本或辅助参数的情况下符合ZIPF分布。我们的想法来自经验观察，即当对网络进行适当训练时，在按样品的大小和平均分类后，应遵循分布的分布，让人联想到ZIPF的自然语言频率统计信息，这是在按样品中的大小和平均值进行排序之后进行的。 。通过在样本级别和整个培训期内强制执行此属性，我们发现预测准确性可以大大提高。使用INAT21细粒分类数据集上的RESNET50，与香草基线相比，我们的技术获得了 +3.61％的准确性增长，而与先前的标签平滑或自我验证策略相比，增益增加了0.88％。该实现可在https://github.com/megvii-research/zipfls上公开获得。

从视频中获得地面真相标签很具有挑战性，因为在像素流标签的手动注释非常昂贵且费力。此外，现有的方法试图将合成数据集的训练模型调整到真实的视频中，该视频不可避免地遭受了域差异并阻碍了现实世界应用程序的性能。为了解决这些问题，我们提出了RealFlow，这是一个基于期望最大化的框架，可以直接从任何未标记的现实视频中创建大规模的光流数据集。具体而言，我们首先估计一对视频帧之间的光流，然后根据预测流从该对中合成新图像。因此，新图像对及其相应的流可以被视为新的训练集。此外，我们设计了一种逼真的图像对渲染（RIPR）模块，该模块采用软磁性裂口和双向孔填充技术来减轻图像合成的伪像。在E-Step中，RIPR呈现新图像以创建大量培训数据。在M-Step中，我们利用生成的训练数据来训练光流网络，该数据可用于估计下一个E步骤中的光流。在迭代学习步骤中，流网络的能力逐渐提高，流量的准确性以及合成数据集的质量也是如此。实验结果表明，REALFLOW的表现优于先前的数据集生成方法。此外，基于生成的数据集，我们的方法与受监督和无监督的光流方法相比，在两个标准基准测试方面达到了最先进的性能。我们的代码和数据集可从https://github.com/megvii-research/realflow获得

本文旨在解释刚被二进制标签监督时，深泡检测模型如何学习图像的人工制品特征。为此，从图像匹配的角度提出了三个假设，如下所示。 1. DeepFake检测模型指出了基于既不是与源相关又不相关的视觉概念的真实/假图像，也就是说，考虑到与伪影这样的视觉概念。 2.除了对二进制标签的监督外，DeepFake检测模型还通过训练集中的FST匹配（即匹配的伪造，源，目标图像）隐含地学习与伪影相关的视觉概念。 3.通过原始训练集中的FST匹配，隐式学习的人工构图概念容易受到视频压缩的影响。在实验中，在各种DNN中验证了上述假设。此外，基于这种理解，我们提出了FST匹配的DeepFake检测模型，以提高压缩视频中伪造检测的性能。实验结果表明，我们的方法实现了出色的性能，尤其是在高度压缩的（例如C40）视频上。

在本文中，我们提出了D2C-SR，这是一个新颖的框架，用于实现现实世界图像超级分辨率的任务。作为一个不适的问题，超分辨率相关任务的关键挑战是给定的低分辨率输入可能会有多个预测。大多数基于经典的深度学习方法都忽略了基本事实，缺乏对基础高频分布的明确建模，从而导致结果模糊。最近，一些基于GAN或学习的超分辨率空间的方法可以生成模拟纹理，但不能保证具有低定量性能的纹理的准确性。重新思考这两者，我们以离散形式了解了基本高频细节的分布，并提出了两阶段的管道：分歧阶段到收敛阶段。在发散阶段，我们提出了一个基于树的结构深网作为差异骨干。提出了发散损失，以鼓励基于树的网络产生的结果，以分解可能的高频表示，这是我们对基本高频分布进行离散建模的方式。在收敛阶段，我们分配空间权重以融合这些不同的预测，以获得更准确的细节，以获取最终输出。我们的方法为推理提供了方便的端到端方式。我们对几个现实世界基准进行评估，包括具有X8缩放系数的新提出的D2CrealSR数据集。我们的实验表明，D2C-SR针对最先进的方法实现了更好的准确性和视觉改进，参数编号明显较少，并且我们的D2C结构也可以作为广义结构应用于其他一些方法以获得改进。我们的代码和数据集可在https://github.com/megvii-research/d2c-sr上找到

Generation of 3D data by deep neural network has been attracting increasing attention in the research community. The majority of extant works resort to regular representations such as volumetric grids or collection of images; however, these representations obscure the natural invariance of 3D shapes under geometric transformations, and also suffer from a number of other issues. In this paper we address the problem of 3D reconstruction from a single image, generating a straight-forward form of output -point cloud coordinates. Along with this problem arises a unique and interesting issue, that the groundtruth shape for an input image may be ambiguous. Driven by this unorthodox output form and the inherent ambiguity in groundtruth, we design architecture, loss function and learning paradigm that are novel and effective. Our final solution is a conditional shape sampler, capable of predicting multiple plausible 3D point clouds from an input image. In experiments not only can our system outperform state-ofthe-art methods on single image based 3d reconstruction benchmarks; but it also shows strong performance for 3d shape completion and promising ability in making multiple plausible predictions.

The miniaturization and mobility of computer vision systems are limited by the heavy computational burden and the size of optical lenses. Here, we propose to use a ultra-thin diffractive optical element to implement passive optical convolution. A division adjoint opto-electronic co-design method is also proposed. In our simulation experiments, the first few convolutional layers of the neural network can be replaced by optical convolution in a classification task on the CIFAR-10 dataset with no power consumption, while similar performance can be obtained.

In this paper, we propose a robust 3D detector, named Cross Modal Transformer (CMT), for end-to-end 3D multi-modal detection. Without explicit view transformation, CMT takes the image and point clouds tokens as inputs and directly outputs accurate 3D bounding boxes. The spatial alignment of multi-modal tokens is performed implicitly, by encoding the 3D points into multi-modal features. The core design of CMT is quite simple while its performance is impressive. CMT obtains 73.0% NDS on nuScenes benchmark. Moreover, CMT has a strong robustness even if the LiDAR is missing. Code will be released at https://github.com/junjie18/CMT.

Different people speak with diverse personalized speaking styles. Although existing one-shot talking head methods have made significant progress in lip sync, natural facial expressions, and stable head motions, they still cannot generate diverse speaking styles in the final talking head videos. To tackle this problem, we propose a one-shot style-controllable talking face generation framework. In a nutshell, we aim to attain a speaking style from an arbitrary reference speaking video and then drive the one-shot portrait to speak with the reference speaking style and another piece of audio. Specifically, we first develop a style encoder to extract dynamic facial motion patterns of a style reference video and then encode them into a style code. Afterward, we introduce a style-controllable decoder to synthesize stylized facial animations from the speech content and style code. In order to integrate the reference speaking style into generated videos, we design a style-aware adaptive transformer, which enables the encoded style code to adjust the weights of the feed-forward layers accordingly. Thanks to the style-aware adaptation mechanism, the reference speaking style can be better embedded into synthesized videos during decoding. Extensive experiments demonstrate that our method is capable of generating talking head videos with diverse speaking styles from only one portrait image and an audio clip while achieving authentic visual effects. Project Page: https://github.com/FuxiVirtualHuman/styletalk.