A Structured Dictionary Perspective on Implicit Neural Representations

This is the source code to reproduce the experiments of the CVPR 2022 paper "A structured dictionary perspective on implicit neural representations" by Gizem Yüce*, Guillermo Ortiz-Jimenez*, Beril Besbinar and Pascal Frossard.

Dependencies

To run the code, please install all its dependencies by running:

$ pip install -r requirements.txt

This assumes that you have access to a Linux machine with an NVIDIA GPU with CUDA>=11.1. Otherwise, please check the instructions to install JAX with your setup in the corresponding repository.

Experiments

The repository contains code to reproduce each figure in the paper, as well as to pretrain a SIREN on the CelebA dataset using meta-learning:

• Figure 2: Imperfect reconstruction
• Figure 3: Aliasing
• Figure 4: NTK alignment
• Figure 5: NTK eigenvectors
• Meta-learning pretraining

Figure 2: Imperfect reconstruction

Figure 2 shows examples of imperfect reconstruction of an image using INRs with a limited frequency support. To reproduce this figure you can run

$ python figure_2.py

This script will save the resulting pdf figures under figures/figure_2/.

Figure 3: Aliasing

Figure 3 shows an example of induced aliasing when reconstructing an ambiguous single-tone signal using an INR with a high-frequency emphasis. To reproduce this figure you can run

$ python figure_3.py

This script will save the resulting pdf figures under figures/figure_3/.

Figure 4: NTK alignment

Figure 3 compares the alignment of the eigenvectors of the NTK at initialization with 100 CelebA images for different INR architectures. To reproduce this figure you can run

$ python figure_4.py

This script will save the resulting pdf figures under figures/figure_4/.

⚠️ Need to run meta_learn.py first! figure_4.py assumes that you have access to the pretrained weights of a meta-learned SIREN. In this repository, we provide such weights for our default hyperparameters. However, if you want to experiment with other configurations, you will need to run meta_learn.py.

Figure 5: NTK eigenvectors

Figure 5 plots the eigenvectors of the NTK at initialization for different architectures. To reproduce this figure you can run

$ python figure_5.py

This script will save the resulting pdf figures under figures/figure_5/.

⚠️ Need to run meta_learn.py first! figure_5.py assumes that you have access to the pretrained weights of a meta-learned SIREN. In this repository, we provide such weights for our default hyperparameters. However, if you want to experiment with other configurations, you will need to run meta_learn.py.

Meta-learning pretraining

For completeness we provide a standalone script meta_learn.py to meta-train a SIREN network on the CelebA dataset. The code of this script has been taken from Tancik et al. 2021.. Running this script will override the weights in maml_celebA_5000.pickle.

Reference

If you use this code, please cite the following paper:

@InCollection{inr_dictionaries2022,
  title = {A structured dictionary perspective on implicit neural representations},
  author = {Y\"uce, Gizem, and {Ortiz-Jimenez}, Guillermo and Besbinar, Beril and Frossard, Pascal},
  booktitle = {Proc. IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR 2022)},
  month = Jun,
  year = {2022}
}