We present a novel method to acquire object representations from online image collections, capturing high-quality geometry and material properties of arbitrary objects from photographs with varying cameras, illumination, and backgrounds. This enables various object-centric rendering applications such as novel-view synthesis, relighting, and harmonized background composition from challenging in-the-wild input. Using a multi-stage approach extending neural radiance fields, we first infer the surface geometry and refine the coarsely estimated initial camera parameters, while leveraging coarse foreground object masks to improve the training efficiency and geometry quality. We also introduce a robust normal estimation technique which eliminates the effect of geometric noise while retaining crucial details. Lastly, we extract surface material properties and ambient illumination, represented in spherical harmonics with extensions that handle transient elements, e.g. sharp shadows. The union of these components results in a highly modular and efficient object acquisition framework. Extensive evaluations and comparisons demonstrate the advantages of our approach in capturing high-quality geometry and appearance properties useful for rendering applications.
翻译:我们提出一种新的方法,从在线图像收藏中获取物体表示,捕捉来自不同相机、照明和背景不同照片的任意物体的高质量几何和物质特性,这样可以使各种以物体为中心的应用,例如新视角合成、亮光和来自充满挑战的在野输入的统一背景构成。我们首先采用多阶段的方法,扩大神经光谱场,推断地表几何和完善粗略估计的初步照相参数,同时利用粗浅的地表物体掩体,提高培训效率和几何质量。我们还采用了强有力的正常估计技术,消除几何噪音的影响,同时保留关键细节。最后,我们提取地表材料特性和环境照明,在球形的相容中代表着处理瞬变元素的扩展,例如锐色阴影。这些组成部分的组合结果是一个高度模块化和有效的物体获取框架。广泛的评价和比较表明我们的方法在捕捉高质量几何和外观特性方面的好处,这些特性对于应用是有用的。