pixelNeRF: Neural Radiance Fields from One or Few Images
Yu et al., CVPR 2021
We propose pixelNeRF, a learning framework that predicts a continuous neural scene representation conditioned on one or few input images. The existing approach for constructing neural radiance fields [27] involves optimizing the representation to every scene independently, requiring many calibrated views and significant compute time. We take a step towards resolving these shortcomings by introducing an architecture that conditions a NeRF on image inputs in a fully convolutional manner. This allows the network to be trained across multiple scenes to learn a scene prior, enabling it to perform novel view synthesis in a feed-forward manner from a sparse set of views (as few as one). Leveraging the volume rendering approach of NeRF, our model can be trained directly from images with no explicit 3D supervision. We conduct extensive experiments on ShapeNet benchmarks for single image novel view synthesis tasks with held-out objects as well as entire unseen categories. We further demonstrate the flexibility of pixelNeRF by demonstrating it on multi-object ShapeNet scenes and real scenes from the DTU dataset. In all cases, pixelNeRF outperforms current state-of-the-art baselines for novel view synthesis and single image 3D reconstruction. For the video and code, please visit the project website: https://alexyu.net/pixelnerf.
🔑 Key idea:
For a few-shot (one- or two-shot) setting of NeRFs, a sampling coordinate is paired with the bilinear interpolation of projected CNN features.
💪 Strength:
Exploit pre-trained 2d representations for the generalized photometric information.
For multiple views, the average pooling operator can be applied before the final layers.
😵 Weakness:
Use an external source
ResNet34 pretrained on ImageNet for experiments
Mainly for the ShapeNet dataset
🤔 Confidence:
Medium
✏️ Memo:
Leave a memo if needed. Otherwise, please remove this section.
pixelNeRF: Neural Radiance Fields from One or Few Images
Yu et al., CVPR 2021
🔑 Key idea:
💪 Strength:
😵 Weakness:
🤔 Confidence:
✏️ Memo: