模型架构
Normalizing flows
Transform a simple distribution into a complex data distribution through a sequence of invertible mappings with tractable Jacobians.
思维模型
A reversible deformation of probability space: data can map to noise and noise can map back to data.
数据流
- Data sample
- Invertible transformations
- Simple latent distribution
- Exact change-of-variables likelihood
- Reverse transforms for sampling
训练方式
Maximum likelihood is optimized exactly under architectural constraints that make inversion and the Jacobian determinant tractable.
推理运行方式
Density evaluation runs data toward the latent; generation samples the base distribution and applies every transform in reverse.
优势
- Exact likelihood under the model
- Invertible encoding and generation
- Useful when density estimation is itself important
权衡
- Invertibility constrains network design
- High-dimensional media can require deep, memory-heavy flows
- Likelihood does not necessarily track perceived sample quality
适用场景
- Exact density or reversible transforms are requirements
- The domain fits available invertible architectures
- You will evaluate both likelihood and task utility
应避免或质疑的场景
- Only perceptual generation quality matters
- Architectural flexibility is more important than exact likelihood
- A simpler discriminative uncertainty method is sufficient
已发表的示例系列
- • Real NVP
- • Glow-style image flows
常见组合
Variational inferenceHybrid latent-variable models