在本文中,我们发现两个因素抑制POMS从实现高感感性质量:1)方向优化(COO)问题和2)模型的低频趋势。首先,POMS倾向于生成SR图像,其位置空间中的位置最接近所有潜在的高分辨率(HR)图像的分配中心,导致这种POMS失去高频细节。其次,图像的90美元\%$区域由低频信号组成;相比之下,人类感知依赖于图像的高频细节。然而,POMS应用相同的计算来处理不同频率区域,使POM倾向于恢复低频区域。基于这两个因素,我们提出了一种细节,通过组合高频增强模块和空间对比学习模块来降低COO问题的影响和低频趋势来提高对比损失(DECHROSTS)。实验结果表明,在若干常规SR模型上施加DROCKS时的效率和有效性。例如,在EDSR中,与基于GAN的方法相比,我们所提出的方法与视觉质量微妙降级的基于GAN的方法实现了3.60美元。此外,我们的最终结果表明,与最先进的方法相比,配备了我们的DECHROSS的SR网络更具现实和视觉上令人愉悦的纹理。 %拟议方法的源代码包含在补充材料中,并将在将来公开。
translated by 谷歌翻译
为了弥合深度神经网络的复杂性和硬件能力之间不断增加的差距,网络量化引起了越来越多的研究关注。混合精度量化的最新趋势利用硬件的多个位宽度算术运算来释放网络量化的全部潜力。然而,这也导致困难的整数编程配方,并且即使使用各种放松,大多数现有方法也能使用极其耗时的搜索过程。我们建议优化一个代理度量,而不是解决原始整数编程的问题,而是与整数编程的丢失高度相关的网络正交性的概念,而是用线性编程易于优化。该方法通过数量级的秩序减少了搜索时间和所需的数据量,符合量化精度几乎没有妥协。具体而言,我们在Reset-18上获得72.08%的前1个精度,6.7MB不需要任何搜索迭代。鉴于我们的算法的高效率和低数据依赖性,我们将其用于训练后量化,该量化仅在MobileNetv2上实现71.27%的前1个精度,只有1.5MB。我们的代码可在https://github.com/mac-automl/oppq上获得。
translated by 谷歌翻译
尽管在许多计算机视觉任务上具有卓越的性能,但深度卷积神经网络众所周知,在具有资源限制的设备上被压缩。大多数现有的网络修剪方法需要艰苦的人类努力和禁止的计算资源,特别是当约束改变时。当需要部署在各种设备上时,这实际上限制了模型压缩的应用。此外,现有的方法仍然受到缺失的理论指导挑战。在本文中,我们提出了一种信息理论启发的自动模型压缩策略。我们的方法背后的原理是信息瓶颈理论,即隐藏的表示应该彼此压缩信息。因此,我们在网络激活中介绍了标准化的Hilbert-Schmidt独立性标准(NHSIC),作为层重要性的稳定和广义指标。当给出某个资源约束时,我们将HSIC指示器与约束将架构搜索问题转换为具有二次约束的线性编程问题。这种问题很容易通过几秒钟的凸优化方法解决。我们还提供严格的证据,揭示优化归一化的HSIC同时最小化不同层之间的相互信息。没有任何搜索过程,我们的方法实现了与最先进的压缩算法相比的更好的压缩权衡。例如,通过Reset-50,我们达到了45.3%的杂志,在想象中有75.75前1个精度。代码是在https://github.com/mac-automl/itpruner/tree/master上的途径。
translated by 谷歌翻译
Masked image modeling (MIM) performs strongly in pre-training large vision Transformers (ViTs). However, small models that are critical for real-world applications cannot or only marginally benefit from this pre-training approach. In this paper, we explore distillation techniques to transfer the success of large MIM-based pre-trained models to smaller ones. We systematically study different options in the distillation framework, including distilling targets, losses, input, network regularization, sequential distillation, etc, revealing that: 1) Distilling token relations is more effective than CLS token- and feature-based distillation; 2) An intermediate layer of the teacher network as target perform better than that using the last layer when the depth of the student mismatches that of the teacher; 3) Weak regularization is preferred; etc. With these findings, we achieve significant fine-tuning accuracy improvements over the scratch MIM pre-training on ImageNet-1K classification, using all the ViT-Tiny, ViT-Small, and ViT-base models, with +4.2%/+2.4%/+1.4% gains, respectively. Our TinyMIM model of base size achieves 52.2 mIoU in AE20K semantic segmentation, which is +4.1 higher than the MAE baseline. Our TinyMIM model of tiny size achieves 79.6% top-1 accuracy on ImageNet-1K image classification, which sets a new record for small vision models of the same size and computation budget. This strong performance suggests an alternative way for developing small vision Transformer models, that is, by exploring better training methods rather than introducing inductive biases into architectures as in most previous works. Code is available at https://github.com/OliverRensu/TinyMIM.
translated by 谷歌翻译
Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
translated by 谷歌翻译
Benefiting from the intrinsic supervision information exploitation capability, contrastive learning has achieved promising performance in the field of deep graph clustering recently. However, we observe that two drawbacks of the positive and negative sample construction mechanisms limit the performance of existing algorithms from further improvement. 1) The quality of positive samples heavily depends on the carefully designed data augmentations, while inappropriate data augmentations would easily lead to the semantic drift and indiscriminative positive samples. 2) The constructed negative samples are not reliable for ignoring important clustering information. To solve these problems, we propose a Cluster-guided Contrastive deep Graph Clustering network (CCGC) by mining the intrinsic supervision information in the high-confidence clustering results. Specifically, instead of conducting complex node or edge perturbation, we construct two views of the graph by designing special Siamese encoders whose weights are not shared between the sibling sub-networks. Then, guided by the high-confidence clustering information, we carefully select and construct the positive samples from the same high-confidence cluster in two views. Moreover, to construct semantic meaningful negative sample pairs, we regard the centers of different high-confidence clusters as negative samples, thus improving the discriminative capability and reliability of the constructed sample pairs. Lastly, we design an objective function to pull close the samples from the same cluster while pushing away those from other clusters by maximizing and minimizing the cross-view cosine similarity between positive and negative samples. Extensive experimental results on six datasets demonstrate the effectiveness of CCGC compared with the existing state-of-the-art algorithms.
translated by 谷歌翻译
As one of the prevalent methods to achieve automation systems, Imitation Learning (IL) presents a promising performance in a wide range of domains. However, despite the considerable improvement in policy performance, the corresponding research on the explainability of IL models is still limited. Inspired by the recent approaches in explainable artificial intelligence methods, we proposed a model-agnostic explaining framework for IL models called R2RISE. R2RISE aims to explain the overall policy performance with respect to the frames in demonstrations. It iteratively retrains the black-box IL model from the randomized masked demonstrations and uses the conventional evaluation outcome environment returns as the coefficient to build an importance map. We also conducted experiments to investigate three major questions concerning frames' importance equality, the effectiveness of the importance map, and connections between importance maps from different IL models. The result shows that R2RISE successfully distinguishes important frames from the demonstrations.
translated by 谷歌翻译
Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.
translated by 谷歌翻译
Transformer has achieved impressive successes for various computer vision tasks. However, most of existing studies require to pretrain the Transformer backbone on a large-scale labeled dataset (e.g., ImageNet) for achieving satisfactory performance, which is usually unavailable for medical images. Additionally, due to the gap between medical and natural images, the improvement generated by the ImageNet pretrained weights significantly degrades while transferring the weights to medical image processing tasks. In this paper, we propose Bootstrap Own Latent of Transformer (BOLT), a self-supervised learning approach specifically for medical image classification with the Transformer backbone. Our BOLT consists of two networks, namely online and target branches, for self-supervised representation learning. Concretely, the online network is trained to predict the target network representation of the same patch embedding tokens with a different perturbation. To maximally excavate the impact of Transformer from limited medical data, we propose an auxiliary difficulty ranking task. The Transformer is enforced to identify which branch (i.e., online/target) is processing the more difficult perturbed tokens. Overall, the Transformer endeavours itself to distill the transformation-invariant features from the perturbed tokens to simultaneously achieve difficulty measurement and maintain the consistency of self-supervised representations. The proposed BOLT is evaluated on three medical image processing tasks, i.e., skin lesion classification, knee fatigue fracture grading and diabetic retinopathy grading. The experimental results validate the superiority of our BOLT for medical image classification, compared to ImageNet pretrained weights and state-of-the-art self-supervised learning approaches.
translated by 谷歌翻译
When using LiDAR semantic segmentation models for safety-critical applications such as autonomous driving, it is essential to understand and improve their robustness with respect to a large range of LiDAR corruptions. In this paper, we aim to comprehensively analyze the robustness of LiDAR semantic segmentation models under various corruptions. To rigorously evaluate the robustness and generalizability of current approaches, we propose a new benchmark called SemanticKITTI-C, which features 16 out-of-domain LiDAR corruptions in three groups, namely adverse weather, measurement noise and cross-device discrepancy. Then, we systematically investigate 11 LiDAR semantic segmentation models, especially spanning different input representations (e.g., point clouds, voxels, projected images, and etc.), network architectures and training schemes. Through this study, we obtain two insights: 1) We find out that the input representation plays a crucial role in robustness. Specifically, under specific corruptions, different representations perform variously. 2) Although state-of-the-art methods on LiDAR semantic segmentation achieve promising results on clean data, they are less robust when dealing with noisy data. Finally, based on the above observations, we design a robust LiDAR segmentation model (RLSeg) which greatly boosts the robustness with simple but effective modifications. It is promising that our benchmark, comprehensive analysis, and observations can boost future research in robust LiDAR semantic segmentation for safety-critical applications.
translated by 谷歌翻译