论文标题
使用带有蒙版特征和感知损失的CNN进行单图HDR重建
Single Image HDR Reconstruction Using a CNN with Masked Features and Perceptual Loss
论文作者
论文摘要
数码相机只能捕获有限的现实场景的亮度,从而产生具有饱和像素的图像。现有的单图像高动态范围(HDR)重建方法试图扩大亮度范围,但不能幻觉可见的纹理,从而在饱和区域中产生伪像的结果。在本文中,我们提出了一种基于学习的新方法来通过以视觉上令人愉悦的方式恢复输入LDR图像的饱和像素来重建HDR图像。以前的基于深度学习的方法在曝光良好和饱和的像素上应用相同的卷积过滤器,在训练过程中产生模棱两可,并导致棋盘和光环伪像。为了克服这个问题,我们提出了一种特征掩盖机制,可降低饱和区域的特征的贡献。此外,我们将基于VGG的感知损失函数调整到应用程序中,以便能够合成视觉上令人愉悦的纹理。由于用于培训的HDR图像的数量有限,因此我们建议在两个阶段进行训练。具体来说,我们首先在大量图像上训练系统,以进行图像介绍任务,然后在HDR重建中对其进行微调。由于大多数HDR示例都包含易于重建的平滑区域,因此我们提出了一种抽样策略,以在HDR微调阶段选择具有挑战性的训练补丁。我们通过实验结果证明,我们的方法可以在各种场景中重建视觉上令人愉悦的HDR结果,比目前的最新情况要好。
Digital cameras can only capture a limited range of real-world scenes' luminance, producing images with saturated pixels. Existing single image high dynamic range (HDR) reconstruction methods attempt to expand the range of luminance, but are not able to hallucinate plausible textures, producing results with artifacts in the saturated areas. In this paper, we present a novel learning-based approach to reconstruct an HDR image by recovering the saturated pixels of an input LDR image in a visually pleasing way. Previous deep learning-based methods apply the same convolutional filters on well-exposed and saturated pixels, creating ambiguity during training and leading to checkerboard and halo artifacts. To overcome this problem, we propose a feature masking mechanism that reduces the contribution of the features from the saturated areas. Moreover, we adapt the VGG-based perceptual loss function to our application to be able to synthesize visually pleasing textures. Since the number of HDR images for training is limited, we propose to train our system in two stages. Specifically, we first train our system on a large number of images for image inpainting task and then fine-tune it on HDR reconstruction. Since most of the HDR examples contain smooth regions that are simple to reconstruct, we propose a sampling strategy to select challenging training patches during the HDR fine-tuning stage. We demonstrate through experimental results that our approach can reconstruct visually pleasing HDR results, better than the current state of the art on a wide range of scenes.