量化浮点重量和深度卷积神经网络的激活到定点表示产生降低的存储器占用尺寸和推理时间。最近，努力已经进入零拍量量，不需要原始未标记的训练样本给定任务。这些最佳发布的作品依赖于学习批量归一化（BN）参数来推断出量化的激活范围。特别地，这些方法是基于经验估计框架或数据蒸馏方法而构建的，用于计算激活的范围。然而，当呈现不容纳BN层的网络时，这种方案的性能严重降低。在这一思路中，我们提出了广泛的零拍量化（GZSQ）框架，既不需要原始数据也不依赖于BN层统计。我们利用了数据蒸馏方法并仅利用模型的预先训练的重量来估计激活的范围校准的丰富数据。据我们所知，这是利用预制权重的分布以协助零射量量化的过程。拟议的计划显着优于现有的零点工程，例如，MobileNetv2的分类准确性的提高〜33％，以及各种任务的其他一些型号。我们还展示了拟议的工作跨多个开源量化框架的功效。重要的是，我们的作品是第一次尝试训练未来派零击中量化的零击中量化的深度神经网络。

混合精确的深神经网络达到了硬件部署所需的能源效率和吞吐量，尤其是在资源有限的情况下，而无需牺牲准确性。但是，不容易找到保留精度的最佳每层钻头精度，尤其是在创建巨大搜索空间的大量模型，数据集和量化技术中。为了解决这一困难，最近出现了一系列文献，并且已经提出了一些实现有希望的准确性结果的框架。在本文中，我们首先总结了文献中通常使用的量化技术。然后，我们对混合精液框架进行了彻底的调查，该调查是根据其优化技术进行分类的，例如增强学习和量化技术，例如确定性舍入。此外，讨论了每个框架的优势和缺点，我们在其中呈现并列。我们最终为未来的混合精液框架提供了指南。

模型量化已成为加速深度学习推理的不可或缺的技术。虽然研究人员继续推动量化算法的前沿，但是现有量化工作通常是不可否认的和不可推销的。这是因为研究人员不选择一致的训练管道并忽略硬件部署的要求。在这项工作中，我们提出了模型量化基准（MQBench），首次尝试评估，分析和基准模型量化算法的再现性和部署性。我们为实际部署选择多个不同的平台，包括CPU，GPU，ASIC，DSP，并在统一培训管道下评估广泛的最新量化算法。 MQBENCK就像一个连接算法和硬件的桥梁。我们进行全面的分析，并找到相当大的直观或反向直观的见解。通过对齐训练设置，我们发现现有的算法在传统的学术轨道上具有大致相同的性能。虽然用于硬件可部署量化，但有一个巨大的精度差距，仍然不稳定。令人惊讶的是，没有现有的算法在MQBench中赢得每一项挑战，我们希望这项工作能够激发未来的研究方向。

Zero-shot quantization is a promising approach for developing lightweight deep neural networks when data is inaccessible owing to various reasons, including cost and issues related to privacy. By utilizing the learned parameters (statistics) of FP32-pre-trained models, zero-shot quantization schemes focus on generating synthetic data by minimizing the distance between the learned parameters ($\mu$ and $\sigma$) and distributions of intermediate activations. Subsequently, they distill knowledge from the pre-trained model (\textit{teacher}) to the quantized model (\textit{student}) such that the quantized model can be optimized with the synthetic dataset. In general, zero-shot quantization comprises two major elements: synthesizing datasets and quantizing models. However, thus far, zero-shot quantization has primarily been discussed in the context of quantization-aware training methods, which require task-specific losses and long-term optimization as much as retraining. We thus introduce a post-training quantization scheme for zero-shot quantization that produces high-quality quantized networks within a few hours on even half an hour. Furthermore, we propose a framework called \genie~that generates data suited for post-training quantization. With the data synthesized by \genie, we can produce high-quality quantized models without real datasets, which is comparable to few-shot quantization. We also propose a post-training quantization algorithm to enhance the performance of quantized models. By combining them, we can bridge the gap between zero-shot and few-shot quantization while significantly improving the quantization performance compared to that of existing approaches. In other words, we can obtain a unique state-of-the-art zero-shot quantization approach.

To obtain lower inference latency and less memory footprint of deep neural networks, model quantization has been widely employed in deep model deployment, by converting the floating points to low-precision integers. However, previous methods (such as quantization aware training and post training quantization) require original data for the fine-tuning or calibration of quantized model, which makes them inapplicable to the cases that original data are not accessed due to privacy or security. This gives birth to the data-free quantization method with synthetic data generation. While current data-free quantization methods still suffer from severe performance degradation when quantizing a model into lower bit, caused by the low inter-class separability of semantic features. To this end, we propose a new and effective data-free quantization method termed ClusterQ, which utilizes the feature distribution alignment for synthetic data generation. To obtain high inter-class separability of semantic features, we cluster and align the feature distribution statistics to imitate the distribution of real data, so that the performance degradation is alleviated. Moreover, we incorporate the diversity enhancement to solve class-wise mode collapse. We also employ the exponential moving average to update the centroid of each cluster for further feature distribution improvement. Extensive experiments based on different deep models (e.g., ResNet-18 and MobileNet-V2) over the ImageNet dataset demonstrate that our proposed ClusterQ model obtains state-of-the-art performance.

最近，生成的数据无量子化作为一种​​实用的方法，将神经网络压缩到低位宽度而不访问真实数据。它通过利用其全精密对应物的批量归一化（BN）统计来生成数据来量化网络。然而，我们的研究表明，在实践中，BN统计的合成数据在分布和样品水平时严重均匀化，这导致量化网络的严重劣化。本文提出了一种通用不同的样本生成（DSG）方案，用于生成无数据的训练后量化和量化感知培训，以减轻有害的均质化。在我们的DSG中，我们首先将统计对齐缩写为BN层中的功能，以放宽分配约束。然后，我们加强特定BN层对不同样品的损失影响，并抑制了生成过程中样品之间的相关性，分别从统计和空间角度分别多样化样本。广泛的实验表明，对于大规模的图像分类任务，我们的DSG可以始终如一地优于各种神经结构上的现有数据无数据量化方法，尤其是在超低比特宽度下（例如，在W4A4设置下的22％的增益下）。此外，由我们的DSG引起的数据多样化引起了各种量化方法的一般增益，证明了多样性是无数据量化的高质量合成数据的重要特性。

量化已成为压缩和加速神经网络最普遍的方法之一。最近，无数据量化已被广泛研究作为实用和有前途的解决方案。它根据FP32批量归一化（BN）统计，合成校准量化模型的数据，并显着降低了传统量化方法中实际训练数据的沉重依赖性。不幸的是，我们发现在实践中，BN统计的合成数据在分配水平和样品水平上具有严重均匀化，并且进一步引起量化模型的显着性能下降。我们提出了各种样品生成（DSG）方案，以减轻均质化引起的不利影响。具体而言，我们松弛BN层中的特征统计的对准，以在分配水平处放宽约束，并设计一个层状增强，以加强针对不同的数据样本的特定层。我们的DSG方案是多功能的，甚至能够应用于现代训练后的训练后的量化方法，如亚马逊。我们评估大规模图像分类任务的DSG方案，并始终如一地获得各种网络架构和量化方法的显着改进，特别是当量化到较低位时（例如，在W4A4上的高达22％）。此外，从增强的多样性受益，综合数据校准的模型均接近通过实际数据校准的那些，甚至在W4A4上越优于它们。

While machine learning is traditionally a resource intensive task, embedded systems, autonomous navigation, and the vision of the Internet of Things fuel the interest in resource-efficient approaches. These approaches aim for a carefully chosen trade-off between performance and resource consumption in terms of computation and energy. The development of such approaches is among the major challenges in current machine learning research and key to ensure a smooth transition of machine learning technology from a scientific environment with virtually unlimited computing resources into everyday's applications. In this article, we provide an overview of the current state of the art of machine learning techniques facilitating these real-world requirements. In particular, we focus on deep neural networks (DNNs), the predominant machine learning models of the past decade. We give a comprehensive overview of the vast literature that can be mainly split into three non-mutually exclusive categories: (i) quantized neural networks, (ii) network pruning, and (iii) structural efficiency. These techniques can be applied during training or as post-processing, and they are widely used to reduce the computational demands in terms of memory footprint, inference speed, and energy efficiency. We also briefly discuss different concepts of embedded hardware for DNNs and their compatibility with machine learning techniques as well as potential for energy and latency reduction. We substantiate our discussion with experiments on well-known benchmark datasets using compression techniques (quantization, pruning) for a set of resource-constrained embedded systems, such as CPUs, GPUs and FPGAs. The obtained results highlight the difficulty of finding good trade-offs between resource efficiency and predictive performance.

神经网络量化能够在边缘设备上部署模型。对其硬件效率的基本要求是平衡器是硬件友好的：均匀，对称，以及两个阈值的功率。据我们所知，目前的训练后量化方法不同时支持所有这些约束。在这项工作中，我们引入了硬件友好的训练量化（HPTQ）框架，通过协同组合几种已知的量化方法来解决这个问题。我们对四个任务进行了大规模的研究：在各种网络架构上进行分类，对象检测，语义分割和姿势估计。我们广泛的实验表明，可以在硬件友好的限制下获得竞争结果。

无数据量化是一项将神经网络压缩到低位的任务，而无需访问原始培训数据。大多数现有的无数据量化方法导致由于不准确的激活剪辑范围和量化误差而导致严重的性能降解，尤其是对于低位宽度。在本文中，我们提出了一种简单而有效的无数据量化方法，具有准确的激活剪辑和自适应批准化。精确的激活剪辑（AAC）通过利用完全精确模型的准确激活信息来提高模型的准确性。自适应批准归一化首先建议通过自适应更新批处理层次来解决分布更改中的量化误差。广泛的实验表明，所提出的无数据量化方法可以产生令人惊讶的性能，在Imagenet数据集上达到RESNET18的64.33％的TOP-1准确性，绝对改进的3.7％优于现有的最新方法。

量化的神经网络通常需要较小的内存占用和较低的计算复杂性，这对于有效部署至关重要。然而，量化不可避免地导致原始网络的分布分发，这通常会降低性能。为了解决这个问题，已经制定了大规模的努力，但大多数现有方法缺乏统计因素，依赖于几种手动配置。在本文中，我们提出了一种自适应映射量化方法，以学习模型内固有的最佳潜在子分布，并用混凝土高斯混合物（GM）平稳地近似。特别地，网络权重被符合GM - 近似的子分布。该子分布随着直接任务客观优化引导的共同调整模式中的重量更新而发展。在各种现代架构上的图像分类和物体检测的充分实验证明了所提出的方法的有效性，泛化性能和可转移性。此外，开发了用于移动CPU的有效部署流，在Octa-Core ARM CPU上实现高达7.46 $ \ Times $推理加速。代码在https://github.com/runpeidong/dgms公开发布。

Deep neural networks (DNNs) are currently widely used for many artificial intelligence (AI) applications including computer vision, speech recognition, and robotics. While DNNs deliver state-of-the-art accuracy on many AI tasks, it comes at the cost of high computational complexity. Accordingly, techniques that enable efficient processing of DNNs to improve energy efficiency and throughput without sacrificing application accuracy or increasing hardware cost are critical to the wide deployment of DNNs in AI systems.This article aims to provide a comprehensive tutorial and survey about the recent advances towards the goal of enabling efficient processing of DNNs. Specifically, it will provide an overview of DNNs, discuss various hardware platforms and architectures that support DNNs, and highlight key trends in reducing the computation cost of DNNs either solely via hardware design changes or via joint hardware design and DNN algorithm changes. It will also summarize various development resources that enable researchers and practitioners to quickly get started in this field, and highlight important benchmarking metrics and design considerations that should be used for evaluating the rapidly growing number of DNN hardware designs, optionally including algorithmic co-designs, being proposed in academia and industry.The reader will take away the following concepts from this article: understand the key design considerations for DNNs; be able to evaluate different DNN hardware implementations with benchmarks and comparison metrics; understand the trade-offs between various hardware architectures and platforms; be able to evaluate the utility of various DNN design techniques for efficient processing; and understand recent implementation trends and opportunities.

As a neural network compression technique, post-training quantization (PTQ) transforms a pre-trained model into a quantized model using a lower-precision data type. However, the prediction accuracy will decrease because of the quantization noise, especially in extremely low-bit settings. How to determine the appropriate quantization parameters (e.g., scaling factors and rounding of weights) is the main problem facing now. Many existing methods determine the quantization parameters by minimizing the distance between features before and after quantization. Using this distance as the metric to optimize the quantization parameters only considers local information. We analyze the problem of minimizing local metrics and indicate that it would not result in optimal quantization parameters. Furthermore, the quantized model suffers from overfitting due to the small number of calibration samples in PTQ. In this paper, we propose PD-Quant to solve the problems. PD-Quant uses the information of differences between network prediction before and after quantization to determine the quantization parameters. To mitigate the overfitting problem, PD-Quant adjusts the distribution of activations in PTQ. Experiments show that PD-Quant leads to better quantization parameters and improves the prediction accuracy of quantized models, especially in low-bit settings. For example, PD-Quant pushes the accuracy of ResNet-18 up to 53.08% and RegNetX-600MF up to 40.92% in weight 2-bit activation 2-bit. The code will be released at https://github.com/hustvl/PD-Quant.

深度神经网络（DNN）的记录断裂性能具有沉重的参数化，导致外部动态随机存取存储器（DRAM）进行存储。 DRAM访问的禁用能量使得在资源受限的设备上部署DNN是不普遍的，呼叫最小化重量和数据移动以提高能量效率。我们呈现SmartDeal（SD），算法框架，以进行更高成本的存储器存储/访问的较低成本计算，以便在推理和培训中积极提高存储和能量效率。 SD的核心是一种具有结构约束的新型重量分解，精心制作以释放硬件效率潜力。具体地，我们将每个重量张量分解为小基矩阵的乘积以及大的结构稀疏系数矩阵，其非零被量化为-2的功率。由此产生的稀疏和量化的DNN致力于为数据移动和重量存储而大大降低的能量，因为由于稀疏的比特 - 操作和成本良好的计算，恢复原始权重的最小开销。除了推理之外，我们采取了另一次飞跃来拥抱节能培训，引入创新技术，以解决培训时出现的独特障碍，同时保留SD结构。我们还设计专用硬件加速器，充分利用SD结构来提高实际能源效率和延迟。我们在不同的设置中对多个任务，模型和数据集进行实验。结果表明：1）应用于推理，SD可实现高达2.44倍的能效，通过实际硬件实现评估; 2）应用于培训，储存能量降低10.56倍，减少了10.56倍和4.48倍，与最先进的训练基线相比，可忽略的准确性损失。我们的源代码在线提供。

由于神经网络变得更加强大，因此在现实世界中部署它们的愿望是一个上升的愿望;然而，神经网络的功率和准确性主要是由于它们的深度和复杂性，使得它们难以部署，尤其是在资源受限的设备中。最近出现了神经网络量化，以满足这种需求通过降低网络的精度来降低神经网络的大小和复杂性。具有较小和更简单的网络，可以在目标硬件的约束中运行神经网络。本文调查了在过去十年中开发的许多神经网络量化技术。基于该调查和神经网络量化技术的比较，我们提出了该地区的未来研究方向。

Although weight and activation quantization is an effective approach for Deep Neural Network (DNN) compression and has a lot of potentials to increase inference speed leveraging bit-operations, there is still a noticeable gap in terms of prediction accuracy between the quantized model and the full-precision model. To address this gap, we propose to jointly train a quantized, bit-operation-compatible DNN and its associated quantizers, as opposed to using fixed, handcrafted quantization schemes such as uniform or logarithmic quantization. Our method for learning the quantizers applies to both network weights and activations with arbitrary-bit precision, and our quantizers are easy to train. The comprehensive experiments on CIFAR-10 and ImageNet datasets show that our method works consistently well for various network structures such as AlexNet, VGG-Net, GoogLeNet, ResNet, and DenseNet, surpassing previous quantization methods in terms of accuracy by an appreciable margin. Code available at https://github.com/Microsoft/LQ-Nets

模型二进制化是一种压缩神经网络并加速其推理过程的有效方法。但是，1位模型和32位模型之间仍然存在显着的性能差距。实证研究表明，二进制会导致前进和向后传播中的信息损失。我们提出了一个新颖的分布敏感信息保留网络（DIR-NET），该网络通过改善内部传播和引入外部表示，将信息保留在前后传播中。 DIR-NET主要取决于三个技术贡献：（1）最大化二进制（IMB）的信息：最小化信息损失和通过重量平衡和标准化同时同时使用权重/激活的二进制误差； （2）分布敏感的两阶段估计器（DTE）：通过共同考虑更新能力和准确的梯度来通过分配敏感的软近似来保留梯度的信息； （3）代表性二进制 - 意识蒸馏（RBD）：通过提炼完整精确和二元化网络之间的表示来保留表示信息。 DIR-NET从统一信息的角度研究了BNN的前进过程和后退过程，从而提供了对网络二进制机制的新见解。我们的DIR-NET中的三种技术具有多功能性和有效性，可以在各种结构中应用以改善BNN。关于图像分类和客观检测任务的综合实验表明，我们的DIR-NET始终优于主流和紧凑型体系结构（例如Resnet，vgg，vgg，EfficityNet，darts和mobilenet）下最新的二进制方法。此外，我们在现实世界中的资源有限设备上执行DIR-NET，该设备可实现11.1倍的存储空间和5.4倍的速度。

无数据量化可以潜在地解决模型压缩中的数据隐私和安全问题，因此已得到广泛研究。最近，PSAQ-VIT设计了一个相对值度量，贴片相似性，以生成预训练视觉变压器（VIT）的数据，从而实现了VIT的第一次无数据量化尝试。在本文中，我们提出了PSAQ-VIT V2，这是在PSAQ-VIT之上建立的更准确，无数据的VIT的更准确和无数据的量化框架。更具体地说，按照PSAQ-VIT中的贴片相似性度量，我们引入了一种自适应的教师学生策略，该策略促进了生成的样品的持续环节演变和量化的模型（学生），并在竞争性和互动方式下以竞争性和互动方式进行。完整的模型（教师），因此显着提高了量化模型的准确性。此外，没有辅助类别指导，我们采用了任务和模型独立的先验信息，使通用方案与广泛的视觉任务和模型兼容。对图像分类，对象检测和语义分割任务和PSAQ-VIT V2进行了各种模型进行了广泛的实验，并具有幼稚的量化策略，并且没有访问现实世界数据，从而始终取得了竞争性的结果，显示出潜力作为强大的基线的潜力关于VIT的无数据量化。例如，使用SWIN-S作为（骨干）模型，8位量化达到ImageNet上的82.13 TOP-1精度，50.9盒AP和可可的44.1 Mask AP，而ADE20K上的47.2 miOU。我们希望准确，一般的PSAQ-VIT V2可以作为涉及敏感数据的现实应用程序中的潜在和实践解决方案。代码将在以下网址发布并合并：https：//github.com/zkkli/psaq-vit。

量化图像超分辨率的深卷积神经网络大大降低了它们的计算成本。然而，现有的作品既不患有4个或低位宽度的超低精度的严重性能下降，或者需要沉重的微调过程以恢复性能。据我们所知，这种对低精度的漏洞依赖于特征映射值的两个统计观察。首先，特征贴图值的分布每个通道和每个输入图像都变化显着变化。其次，特征映射具有可以主导量化错误的异常值。基于这些观察，我们提出了一种新颖的分布感知量化方案（DAQ），其促进了超低精度的准确训练量化。 DAQ的简单功能确定了具有低计算负担的特征图和权重的动态范围。此外，我们的方法通过计算每个通道的相对灵敏度来实现混合精度量化，而无需涉及任何培训过程。尽管如此，量化感知培训也适用于辅助性能增益。我们的新方法优于最近的培训甚至基于培训的量化方法，以超低精度为最先进的图像超分辨率网络。