Leveraging Diffusion Models for Generative Model Training
A framework to enhance generative models using pre-trained diffusion models.
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Table of Contents
In recent years, a type of computer model known as Diffusion Models (DMs) has gained a lot of attention for its ability to create realistic images and other types of data. These models have become popular because they are easy to train, can handle large amounts of data, and produce high-quality samples. Because of these qualities, many researchers are looking for ways to transfer knowledge from these pre-trained diffusion models to other types of models in a more efficient way.
This article discusses a new framework called Diff-Instruct, which aims to make use of the knowledge stored in pre-trained diffusion models without needing much extra data. The goal is to help other models learn better and faster by using information already available in these diffusion models.
Background
Diffusion models work by gradually transforming initial data into more complex forms through a process that adds noise. This approach allows them to learn about different data distributions effectively. Researchers have found that using pre-trained diffusion models can save time and resources when building new models, as they contain valuable information about the data they were trained on.
More recently, there has been a shift toward using Knowledge Transfer in machine learning. This is particularly useful when acquiring new data is challenging or expensive. By leveraging pre-trained models, researchers can help new models improve their performance without starting from scratch.
However, while there has been a lot of research in transferring knowledge between supervised models, doing this for Generative Models, like DMs and GANs (Generative Adversarial Networks), has not been fully explored. This leads to the main questions of this article:
- Can we efficiently transfer knowledge from pre-trained diffusion models to other generative models?
- How can we overcome the challenges involved in this process?
Diff-Instruct Framework
The Diff-Instruct framework is designed to tackle the problem of transferring knowledge from diffusion models to generative models. The main idea is to use the information in pre-trained diffusion models to guide the training of other models without needing additional data.
The framework works in several steps:
Knowledge Transfer: Diff-Instruct uses the learned parameters from pre-trained diffusion models to update the parameters of the target generative model. This helps the new model learn from the strengths of the diffusion model.
Parameter Guidance: The process involves using gradients, which are mathematical tools that indicate the direction in which a function increases or decreases. These gradients help adjust the new model's parameters based on the knowledge extracted from the diffusion model.
Robustness: A key feature of Diff-Instruct is its robustness. It can work well even when the supporting data is not perfectly aligned. This is especially important because many models operate under various conditions, and the data may not always match perfectly.
Generative Models Overview
Generative models are a class of models that aim to create new data points from an existing dataset. They learn the underlying patterns and structures of the data, enabling them to generate realistic new samples. The two main types of generative models discussed here are diffusion models and GANs.
Diffusion Models
Diffusion models work by gradually adding noise to the data until it becomes pure noise and then reversing this process to regenerate data. This two-step process allows them to learn complex distributions effectively and generate high-quality samples. They excel in producing images and other types of data that require a nuanced understanding of the variations within the training data.
GANs
GANs operate differently. They consist of two main components: a generator, which creates new data, and a discriminator, which evaluates the authenticity of the generated data. The generator tries to create realistic samples, while the discriminator learns to distinguish between real and fake data. This adversarial relationship pushes both networks to improve, resulting in high-quality generated samples.
Knowledge Transfer Challenges
Transferring knowledge from diffusion models to other generative models involves overcoming several challenges:
Data Dependency: Traditional methods often rely heavily on real data to function effectively. This can be limiting when real data is scarce or difficult to obtain.
Compatibility: Different generative models have unique architectures and training procedures. Finding a way to adapt the information from a diffusion model to fit a GAN or another model can be complex.
Performance Metrics: Measuring the success of the knowledge transfer often requires specific performance metrics, which may not always align between models.
Addressing the Challenges with Diff-Instruct
Diff-Instruct addresses these challenges by providing a structured approach to knowledge transfer. Here are some of its key features:
Data-Free Learning: By leveraging knowledge from pre-trained diffusion models, Diff-Instruct allows for training without depending on additional real data. This makes it easier to use in various scenarios where data is limited.
Flexibility: The framework can work with different types of generative models. It can adapt its approach to suit the unique needs of various architectures, whether they're diffusion models or GANs.
Integration of Learning: Diff-Instruct integrates learning from multiple sources and time levels within the diffusion model, enhancing the performance of the target model using a comprehensive knowledge base.
Experimental Evaluation
To validate the effectiveness of Diff-Instruct, experiments were conducted in two main areas: distilling knowledge from pre-trained diffusion models and improving the performance of existing GAN models.
Distillation of Pre-Trained Diffusion Models
The first experiment focused on refining generative models based on knowledge from pre-trained diffusion models. The goal was to train new models that can generate high-quality samples efficiently.
Methodology: The new models were trained using the gradients derived from the pre-trained diffusion models. This process allowed the new models to learn the essential features while relying on the rich data distributions learned by the diffusion models.
Results: The results showed that the new models achieved state-of-the-art performance in generating samples that were consistent with the quality of the pre-trained diffusion models. This demonstrated the effectiveness of the knowledge transfer process through Diff-Instruct.
Improvement of GANs
The second experiment aimed to show how Diff-Instruct could enhance existing GAN models, which typically rely on adversarial training.
Methodology: In this case, existing GAN models were initially trained to convergence using traditional methods. Afterward, Diff-Instruct was applied to improve the generators by using the knowledge extracted from the pre-trained diffusion models.
Results: The experiments indicated significant improvements in the quality of the generated samples. The GAN models exhibited better performance metrics than when initially trained without the infusion of diffusion model knowledge.
Conclusions
The Diff-Instruct framework opens new possibilities for leveraging pre-trained diffusion models to enhance the performance of various generative models. By allowing for data-free training, flexibility, and robust learning techniques, it paves the way for ongoing research and applications in the field of generative modeling.
The experiments conducted validate the effectiveness of Diff-Instruct, demonstrating that it can successfully transfer knowledge to create high-quality samples efficiently. Researchers can benefit from this methodology, especially in scenarios where data is limited, making Diff-Instruct a significant step forward in the utilization of generative models.
Future Directions
While the results are promising, there are still several areas for future exploration:
Multi-Model Integration: Leveraging multiple pre-trained models simultaneously could enhance the knowledge transfer process. This area of research remains largely unexplored.
Hybrid Approaches: Exploring how Diff-Instruct can be effectively combined with real data could yield even better results and improvements in model performance.
Direct Learning from Data: Investigating methods for directly using data to train new diffusion models in conjunction with Diff-Instruct could lead to innovative solutions for generative modeling challenges.
The ongoing development of the Diff-Instruct framework has the potential to significantly advance the field of generative modeling, facilitating the creation of more powerful and efficient models in various applications.
Title: Diff-Instruct: A Universal Approach for Transferring Knowledge From Pre-trained Diffusion Models
Abstract: Due to the ease of training, ability to scale, and high sample quality, diffusion models (DMs) have become the preferred option for generative modeling, with numerous pre-trained models available for a wide variety of datasets. Containing intricate information about data distributions, pre-trained DMs are valuable assets for downstream applications. In this work, we consider learning from pre-trained DMs and transferring their knowledge to other generative models in a data-free fashion. Specifically, we propose a general framework called Diff-Instruct to instruct the training of arbitrary generative models as long as the generated samples are differentiable with respect to the model parameters. Our proposed Diff-Instruct is built on a rigorous mathematical foundation where the instruction process directly corresponds to minimizing a novel divergence we call Integral Kullback-Leibler (IKL) divergence. IKL is tailored for DMs by calculating the integral of the KL divergence along a diffusion process, which we show to be more robust in comparing distributions with misaligned supports. We also reveal non-trivial connections of our method to existing works such as DreamFusion, and generative adversarial training. To demonstrate the effectiveness and universality of Diff-Instruct, we consider two scenarios: distilling pre-trained diffusion models and refining existing GAN models. The experiments on distilling pre-trained diffusion models show that Diff-Instruct results in state-of-the-art single-step diffusion-based models. The experiments on refining GAN models show that the Diff-Instruct can consistently improve the pre-trained generators of GAN models across various settings.
Authors: Weijian Luo, Tianyang Hu, Shifeng Zhang, Jiacheng Sun, Zhenguo Li, Zhihua Zhang
Last Update: 2024-01-15 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2305.18455
Source PDF: https://arxiv.org/pdf/2305.18455
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
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