Score SDE: Dissect

The discrete version of diffusion models (DDPM, DDIM) are easier to understand and implement, but the same may not be said about their continuous counterpart. Here I attempt to take a dive into the official implementation of the score based generative model through stochastic differential equations paper and try to map the implementation with the paper. This would help me (and potentially others) to adapt and modify the code base for my own use....

18 May 2024 · Fred Xu

PDE-Refiner: Implementation

Quick Overview of Main Result The work PDE Refiner is about ensuring stable long time rollouts of dynamical systems. In this work, they identified empirically that the neglect of non-dominant spatial frequency information (high frequency modes in PDE solution) is the primary reason for the inability of existing models for long temporal rollouts. To address this issue, they force the model to learn these modes by actively injecting noises at each step and predicting noise, just like the mechanism in diffuion models....

23 Apr 2024 · Fred Xu

DDIM: Implementation

Note: found out a more detailed code go-over tool, annotated deep learning implementations . However, it seems that as a researcher, it is better to read the paper and read the code yourself before looking for illustrations from this site. In this post I go over the implementation of the DDIM sampling method (for Implicit models) and also some variants of the implicit diffusion model paradigm. It is advised to first take a read at the ddpm post about the general training setup of the diffusion model; DDIM changes the inference / sampling process to make it more efficient....

19 Apr 2024 · Fred Xu

DDPM: Implementation

A diffusion model’s standard implementation contains two parts: The backbone model (in the standard DDPM setting, this is the UNet). The diffusion process (in the standard setting, this is Gaussian Diffusion). The goal of this post is to gauge the standard practice in implementing the basic Denoising Diffusion Probabilistic Model (DDPM), from their official Github implementation. Unconditional DDPM This is the basic version of DDPM, not used for conditional generation. The way the repository structure was set up for DDPM is that each python module under the denoising_diffusion_pytorch folder is self-contained....

18 Apr 2024 · Fred Xu