Radiative Gaussian Splatting for Efficient X-ray Novel View Synthesis
Authors: name: Yuanhao Cai, name: Yixun Liang, name: Jiahao Wang, name: Angtian Wang, name: Yulun Zhang, name: Xiaokang Yang, name: Zongwei Zhou, name: Alan Yuille

X-ray is widely applied for transmission imaging due to its stronger
penetration than natural light. When rendering novel view X-ray projections,
existing methods mainly based on NeRF suffer from long training time and slow
inference speed. In this paper, we propose a 3D Gaussian splatting-based
framework, namely X-Gaussian, for X-ray novel view synthesis. Firstly, we
redesign a radiative Gaussian point cloud model inspired by the isotropic
nature of X-ray imaging. Our model excludes the influence of view direction
when learning to predict the radiation intensity of 3D points. Based on this
model, we develop a Differentiable Radiative Rasterization (DRR) with CUDA
implementation. Secondly, we customize an Angle-pose Cuboid Uniform
Initialization (ACUI) strategy that directly uses the parameters of the X-ray
scanner to compute the camera information and then uniformly samples point
positions within a cuboid enclosing the scanned object. Experiments show that
our X-Gaussian outperforms state-of-the-art methods by 6.5 dB while enjoying
less than 15% training time and over 73x inference speed. The application on
sparse-view CT reconstruction also reveals the practical values of our method.
Code and models will be publicly available at
https://github.com/caiyuanhao1998/X-Gaussian . A video demo of the training
process visualization is at https://www.youtube.com/watch?v=gDVf_Ngeghg .