The introduction of high-quality image generation models, particularly the StyleGAN family, provides a powerful tool to synthesize and manipulate images. However, existing models are built upon high-quality (HQ) data as desired outputs, making them unfit for in-the-wild low-quality (LQ) images, which are common inputs for manipulation. In this work, we bridge this gap by proposing a novel GAN structure that allows for generating images with controllable quality. The network can synthesize various image degradation and restore the sharp image via a quality control code. Our proposed QC-StyleGAN can directly edit LQ images without altering their quality by applying GAN inversion and manipulation techniques. It also provides for free an image restoration solution that can handle various degradations, including noise, blur, compression artifacts, and their mixtures. Finally, we demonstrate numerous other applications such as image degradation synthesis, transfer, and interpolation.

由于GaN潜在空间的勘探和利用，近年来，现实世界的图像操纵实现了奇妙的进展。 GaN反演是该管道的第一步，旨在忠实地将真实图像映射到潜在代码。不幸的是，大多数现有的GaN反演方法都无法满足下面列出的三个要求中的至少一个：重建质量，可编辑性和快速推断。我们在本研究中提出了一种新的两阶段策略，同时适合所有要求。在第一阶段，我们训练编码器将输入图像映射到StyleGan2 $ \ Mathcal {W} $ - 空间，这被证明具有出色的可编辑性，但重建质量较低。在第二阶段，我们通过利用一系列HyperNetWorks来补充初始阶段的重建能力以在反转期间恢复缺失的信息。这两个步骤互相补充，由于Hypernetwork分支和由于$ \ Mathcal {W} $ - 空间中的反转，因此由于HyperNetwork分支和优异的可编辑性而相互作用。我们的方法完全是基于编码器的，导致极快的推断。关于两个具有挑战性的数据集的广泛实验证明了我们方法的优越性。

Our goal with this survey is to provide an overview of the state of the art deep learning technologies for face generation and editing. We will cover popular latest architectures and discuss key ideas that make them work, such as inversion, latent representation, loss functions, training procedures, editing methods, and cross domain style transfer. We particularly focus on GAN-based architectures that have culminated in the StyleGAN approaches, which allow generation of high-quality face images and offer rich interfaces for controllable semantics editing and preserving photo quality. We aim to provide an entry point into the field for readers that have basic knowledge about the field of deep learning and are looking for an accessible introduction and overview.

Figure 1. The proposed pixel2style2pixel framework can be used to solve a wide variety of image-to-image translation tasks. Here we show results of pSp on StyleGAN inversion, multi-modal conditional image synthesis, facial frontalization, inpainting and super-resolution.

We present a novel image inversion framework and a training pipeline to achieve high-fidelity image inversion with high-quality attribute editing. Inverting real images into StyleGAN's latent space is an extensively studied problem, yet the trade-off between the image reconstruction fidelity and image editing quality remains an open challenge. The low-rate latent spaces are limited in their expressiveness power for high-fidelity reconstruction. On the other hand, high-rate latent spaces result in degradation in editing quality. In this work, to achieve high-fidelity inversion, we learn residual features in higher latent codes that lower latent codes were not able to encode. This enables preserving image details in reconstruction. To achieve high-quality editing, we learn how to transform the residual features for adapting to manipulations in latent codes. We train the framework to extract residual features and transform them via a novel architecture pipeline and cycle consistency losses. We run extensive experiments and compare our method with state-of-the-art inversion methods. Qualitative metrics and visual comparisons show significant improvements. Code: https://github.com/hamzapehlivan/StyleRes

由于简单但有效的训练机制和出色的图像产生质量，生成的对抗网络（GAN）引起了极大的关注。具有生成照片现实的高分辨率（例如$ 1024 \ times1024 $）的能力，最近的GAN模型已大大缩小了生成的图像与真实图像之间的差距。因此，许多最近的作品表明，通过利用良好的潜在空间和博学的gan先验来利用预先训练的GAN模型的新兴兴趣。在本文中，我们简要回顾了从三个方面利用预先培训的大规模GAN模型的最新进展，即1）大规模生成对抗网络的培训，2）探索和理解预训练的GAN模型，以及预先培训的GAN模型，以及3）利用这些模型进行后续任务，例如图像恢复和编辑。有关相关方法和存储库的更多信息，请访问https://github.com/csmliu/pretretaining-gans。

反转生成对抗网络（GAN）可以使用预训练的发电机来促进广泛的图像编辑任务。现有方法通常采用gan的潜在空间作为反转空间，但观察到空间细节的恢复不足。在这项工作中，我们建议涉及发电机的填充空间，以通过空间信息补充潜在空间。具体来说，我们替换具有某些实例感知系数的卷积层中使用的恒定填充（例如，通常为零）。通过这种方式，可以适当地适当地适应了预训练模型中假定的归纳偏差以适合每个单独的图像。通过学习精心设计的编码器，我们设法在定性和定量上提高了反演质量，超过了现有的替代方案。然后，我们证明了这样的空间扩展几乎不会影响天然甘纳的歧管，因此我们仍然可以重复使用甘斯（Gans）对各种下游应用学到的先验知识。除了在先前的艺术中探讨的编辑任务外，我们的方法还可以进行更灵活的图像操纵，例如对面部轮廓和面部细节的单独控制，并启用一种新颖的编辑方式，用户可以高效地自定义自己的操作。

edu.hk (a) Image Reconstruction (b) Image Colorization (c) Image Super-Resolution (d) Image Denoising (e) Image Inpainting (f) Semantic Manipulation Figure 1: Multi-code GAN prior facilitates many image processing applications using the reconstruction from fixed PGGAN [23] models.

Face Restoration (FR) aims to restore High-Quality (HQ) faces from Low-Quality (LQ) input images, which is a domain-specific image restoration problem in the low-level computer vision area. The early face restoration methods mainly use statistic priors and degradation models, which are difficult to meet the requirements of real-world applications in practice. In recent years, face restoration has witnessed great progress after stepping into the deep learning era. However, there are few works to study deep learning-based face restoration methods systematically. Thus, this paper comprehensively surveys recent advances in deep learning techniques for face restoration. Specifically, we first summarize different problem formulations and analyze the characteristic of the face image. Second, we discuss the challenges of face restoration. Concerning these challenges, we present a comprehensive review of existing FR methods, including prior based methods and deep learning-based methods. Then, we explore developed techniques in the task of FR covering network architectures, loss functions, and benchmark datasets. We also conduct a systematic benchmark evaluation on representative methods. Finally, we discuss future directions, including network designs, metrics, benchmark datasets, applications,etc. We also provide an open-source repository for all the discussed methods, which is available at https://github.com/TaoWangzj/Awesome-Face-Restoration.

In this work, we propose TediGAN, a novel framework for multi-modal image generation and manipulation with textual descriptions. The proposed method consists of three components: StyleGAN inversion module, visual-linguistic similarity learning, and instance-level optimization. The inversion module maps real images to the latent space of a well-trained StyleGAN. The visual-linguistic similarity learns the text-image matching by mapping the image and text into a common embedding space. The instancelevel optimization is for identity preservation in manipulation. Our model can produce diverse and high-quality images with an unprecedented resolution at 1024 2 . Using a control mechanism based on style-mixing, our Tedi-GAN inherently supports image synthesis with multi-modal inputs, such as sketches or semantic labels, with or without instance guidance. To facilitate text-guided multimodal synthesis, we propose the Multi-Modal CelebA-HQ, a large-scale dataset consisting of real face images and corresponding semantic segmentation map, sketch, and textual descriptions. Extensive experiments on the introduced dataset demonstrate the superior performance of our proposed method. Code and data are available at https://github.com/weihaox/TediGAN.

Recent 3D-aware GANs rely on volumetric rendering techniques to disentangle the pose and appearance of objects, de facto generating entire 3D volumes rather than single-view 2D images from a latent code. Complex image editing tasks can be performed in standard 2D-based GANs (e.g., StyleGAN models) as manipulation of latent dimensions. However, to the best of our knowledge, similar properties have only been partially explored for 3D-aware GAN models. This work aims to fill this gap by showing the limitations of existing methods and proposing LatentSwap3D, a model-agnostic approach designed to enable attribute editing in the latent space of pre-trained 3D-aware GANs. We first identify the most relevant dimensions in the latent space of the model controlling the targeted attribute by relying on the feature importance ranking of a random forest classifier. Then, to apply the transformation, we swap the top-K most relevant latent dimensions of the image being edited with an image exhibiting the desired attribute. Despite its simplicity, LatentSwap3D provides remarkable semantic edits in a disentangled manner and outperforms alternative approaches both qualitatively and quantitatively. We demonstrate our semantic edit approach on various 3D-aware generative models such as pi-GAN, GIRAFFE, StyleSDF, MVCGAN, EG3D and VolumeGAN, and on diverse datasets, such as FFHQ, AFHQ, Cats, MetFaces, and CompCars. The project page can be found: \url{https://enisimsar.github.io/latentswap3d/}.

尽管使用StyleGan进行语义操纵的最新进展，但对真实面孔的语义编辑仍然具有挑战性。 $ W $空间与$ W $+空间之间的差距需要重建质量与编辑质量之间的不良权衡。为了解决这个问题，我们建议通过用基于注意的变压器代替Stylegan映射网络中的完全连接的层来扩展潜在空间。这种简单有效的技术将上述两个空间整合在一起，并将它们转换为一个名为$ W $ ++的新的潜在空间。我们的修改后的Stylegan保持了原始StyleGan的最新一代质量，并具有中等程度的多样性。但更重要的是，提议的$ W $ ++空间在重建质量和编辑质量方面都取得了卓越的性能。尽管有这些显着优势，但我们的$ W $ ++空间支持现有的反转算法和编辑方法，仅由于其与$ w/w $+空间的结构相似性，因此仅可忽略不计的修改。 FFHQ数据集上的广泛实验证明，我们提出的$ W $ ++空间显然比以前的$ w/w $+空间更可取。该代码可在https://github.com/anonsubm2021/transstylegan上公开提供。

In this work, we are dedicated to text-guided image generation and propose a novel framework, i.e., CLIP2GAN, by leveraging CLIP model and StyleGAN. The key idea of our CLIP2GAN is to bridge the output feature embedding space of CLIP and the input latent space of StyleGAN, which is realized by introducing a mapping network. In the training stage, we encode an image with CLIP and map the output feature to a latent code, which is further used to reconstruct the image. In this way, the mapping network is optimized in a self-supervised learning way. In the inference stage, since CLIP can embed both image and text into a shared feature embedding space, we replace CLIP image encoder in the training architecture with CLIP text encoder, while keeping the following mapping network as well as StyleGAN model. As a result, we can flexibly input a text description to generate an image. Moreover, by simply adding mapped text features of an attribute to a mapped CLIP image feature, we can effectively edit the attribute to the image. Extensive experiments demonstrate the superior performance of our proposed CLIP2GAN compared to previous methods.

通过利用预熟gan的潜在空间，已经提出了许多最近的作品来进行面部图像编辑。但是，很少有尝试将它们直接应用于视频，因为1）他们不能保证时间一致性，2）他们的应用受到视频的处理速度的限制，3）他们无法准确编码面部运动和表达的细节。为此，我们提出了一个新颖的网络，将面部视频编码到Stylegan的潜在空间中，以进行语义面部视频操纵。基于视觉变压器，我们的网络重复了潜在向量的高分辨率部分，以实现时间一致性。为了捕捉微妙的面部运动和表情，我们设计了涉及稀疏面部地标和密集的3D脸部网眼的新颖损失。我们已经彻底评估了我们的方法，并成功证明了其对各种面部视频操作的应用。特别是，我们提出了一个新型网络，用于3D坐标系中的姿势/表达控制。定性和定量结果都表明，我们的方法可以显着优于现有的单图方法，同时实现实时（66 fps）速度。

现有的GAN倒置和编辑方法适用于具有干净背景的对齐物体，例如肖像和动物面孔，但通常会为更加困难的类别而苦苦挣扎，具有复杂的场景布局和物体遮挡，例如汽车，动物和室外图像。我们提出了一种新方法，以在gan的潜在空间（例如stylegan2）中倒转和编辑复杂的图像。我们的关键想法是用一系列层的集合探索反演，从而将反转过程适应图像的难度。我们学会预测不同图像段的“可逆性”，并将每个段投影到潜在层。更容易的区域可以倒入发电机潜在空间中的较早层，而更具挑战性的区域可以倒入更晚的特征空间。实验表明，与最新的复杂类别的方法相比，我们的方法获得了更好的反转结果，同时保持下游的编辑性。请参阅我们的项目页面，网址为https://www.cs.cmu.edu/~saminversion。

近年来，面部语义指导（包括面部地标，面部热图和面部解析图）和面部生成对抗网络（GAN）近年来已广泛用于盲面修复（BFR）。尽管现有的BFR方法在普通案例中取得了良好的性能，但这些解决方案在面对严重降解和姿势变化的图像时具有有限的弹性（例如，在现实世界情景中看起来右，左看，笑等）。在这项工作中，我们提出了一个精心设计的盲人面部修复网络，具有生成性面部先验。所提出的网络主要由非对称编解码器和stylegan2先验网络组成。在非对称编解码器中，我们采用混合的多路残留块（MMRB）来逐渐提取输入图像的弱纹理特征，从而可以更好地保留原始面部特征并避免过多的幻想。 MMRB也可以在其他网络中插入插件。此外，多亏了StyleGAN2模型的富裕和多样化的面部先验，我们采用了微调的方法来灵活地恢复自然和现实的面部细节。此外，一种新颖的自我监督训练策略是专门设计用于面部修复任务的，以使分配更接近目标并保持训练稳定性。关于合成和现实世界数据集的广泛实验表明，我们的模型在面部恢复和面部超分辨率任务方面取得了卓越的表现。

The primary aim of single-image super-resolution is to construct a high-resolution (HR) image from a corresponding low-resolution (LR) input. In previous approaches, which have generally been supervised, the training objective typically measures a pixel-wise average distance between the super-resolved (SR) and HR images. Optimizing such metrics often leads to blurring, especially in high variance (detailed) regions. We propose an alternative formulation of the super-resolution problem based on creating realistic SR images that downscale correctly. We present a novel super-resolution algorithm addressing this problem, PULSE (Photo Upsampling via Latent Space Exploration), which generates high-resolution, realistic images at resolutions previously unseen in the literature. It accomplishes this in an entirely self-supervised fashion and is not confined to a specific degradation operator used during training, unlike previous methods (which require training on databases of LR-HR image pairs for supervised learning). Instead of starting with the LR image and slowly adding detail, PULSE traverses the high-resolution natural image manifold, searching for images that downscale to the original LR image. This is formalized through the "downscaling loss," which guides exploration through the latent space of a generative model. By leveraging properties of high-dimensional Gaussians, we restrict the search space to guarantee that our outputs are realistic. PULSE thereby generates super-resolved images that both are realistic and downscale correctly. We show extensive experimental results demonstrating the efficacy of our approach in the domain of face super-resolution (also known as face hallucination). We also present a discussion of the limitations and biases of the method as currently implemented with an accompanying model card with relevant metrics. Our method outperforms state-of-the-art methods in perceptual quality at higher resolutions and scale factors than previously pos-sible.

Recent work has shown that a variety of semantics emerge in the latent space of Generative Adversarial Networks (GANs) when being trained to synthesize images. However, it is difficult to use these learned semantics for real image editing. A common practice of feeding a real image to a trained GAN generator is to invert it back to a latent code. However, existing inversion methods typically focus on reconstructing the target image by pixel values yet fail to land the inverted code in the semantic domain of the original latent space. As a result, the reconstructed image cannot well support semantic editing through varying the inverted code. To solve this problem, we propose an in-domain GAN inversion approach, which not only faithfully reconstructs the input image but also ensures the inverted code to be semantically meaningful for editing. We first learn a novel domain-guided encoder to project a given image to the native latent space of GANs. We then propose domain-regularized optimization by involving the encoder as a regularizer to fine-tune the code produced by the encoder and better recover the target image. Extensive experiments suggest that our inversion method achieves satisfying real image reconstruction and more importantly facilitates various image editing tasks, significantly outperforming start-of-the-arts. 1

我们表明，诸如Stylegan和Biggan之类的预训练的生成对抗网络（GAN）可以用作潜在银行，以提高图像超分辨率的性能。尽管大多数现有面向感知的方法试图通过以对抗性损失学习来产生现实的产出，但我们的方法，即生成的潜在银行（GLEAN），通过直接利用预先训练的gan封装的丰富而多样的先验来超越现有实践。但是，与需要在运行时需要昂贵的图像特定优化的普遍的GAN反演方法不同，我们的方法只需要单个前向通行证才能修复。可以轻松地将Glean合并到具有多分辨率Skip连接的简单编码器银行decoder架构中。采用来自不同生成模型的先验，可以将收集到各种类别（例如人的面孔，猫，建筑物和汽车）。我们进一步提出了一个轻巧的Glean，名为Lightglean，该版本仅保留Glean中的关键组成部分。值得注意的是，Lightglean仅由21％的参数和35％的拖鞋组成，同时达到可比的图像质量。我们将方法扩展到不同的任务，包括图像着色和盲图恢复，广泛的实验表明，与现有方法相比，我们提出的模型表现出色。代码和模型可在https://github.com/open-mmlab/mmediting上找到。

尽管在预验证的GAN模型的潜在空间中表现出的编辑能力，但倒置现实世界的图像被陷入困境，即重建不能忠于原始输入。这样做的主要原因是，训练和现实世界数据之间的分布未对准，因此，对于真实图像编辑而言，它不稳定。在本文中，我们提出了一个基于GAN的新型编辑框架，以通过组成分解范式解决室外反转问题。特别是，在构图阶段，我们引入了一个差分激活模块，用于从全局角度\ ie（IE）检测语义变化，这是编辑和未编辑图像的特征之间的相对差距。借助生成的diff-cam掩模，配对的原始图像和编辑图像可以直观地进行粗糙的重建。这样，几乎整体可以生存属性，而这种中间结果的质量仍然受到不可避免的幽灵效果的限制。因此，在分解阶段，我们进一步提出了一个基于GAN的基于GAN的DEGHOSTING网络，用于将最终的精细编辑图像与粗糙重建分开。在定性和定量评估方面，广泛的实验比最新方法具有优势。我们方法的鲁棒性和灵活性在两个属性和多属性操作的方案上也得到了验证。