DIFFUSION | AI | GENERATIVE MODELING |

Transforming Data into Art: The Influence of Diffusion in AI Generative Modeling

The basic introduction of Diffusion and its working with use cases and references to study diffusion in detail

Chinmay Bhalerao
Data And Beyond

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Generated by stable diffusion by the author

Diffusion is now in many applications for image processing, image generating applications, and image editing applications. let's understand it in detail.

Introduction

Diffusion is a concept that has gained significant popularity in the field of artificial intelligence (AI), particularly in the domain of generative modeling.

It refers to a class of algorithms and techniques that involve iterative processes for generating realistic and high-quality synthetic data. Diffusion models have revolutionized the field of AI by enabling the creation of diverse and complex data samples, ranging from images to text and audio.

Diffusion in AI

In the context of AI, diffusion refers to a generative modeling approach that leverages iterative processes to transform a simple initial distribution into a more complex target distribution. It involves the gradual transformation of random noise into realistic samples that resemble the data distribution being modeled. Diffusion models utilize a diffusion process to generate high-quality synthetic data that captures the complexity and diversity of real-world data.

Structure of Diffusion Models

Fig: The architecture of latent diffusion model. (Image source: Rombach & Blattmann, et al. 2022)

1. Diffusion Equation: The core component of diffusion models is the diffusion equation, which governs the transformation of the data distribution over time. The equation describes the process of gradually spreading or diffusing the information in the input noise to generate realistic samples. It typically involves a series of diffusion steps, where each step introduces controlled noise into the data.

2. Noise Level Schedule: A crucial aspect of diffusion models is the noise level schedule. It determines the amount of noise to be added at each diffusion step. Initially, the noise level is high, allowing for greater exploration of the data space. As the diffusion progresses, the noise level decreases, leading to a refinement of the generated samples. The noise level schedule is carefully designed to strike a balance between exploration and exploitation during the generation process.

3. Inference Network: Diffusion models often employ an inference network to estimate the posterior distribution of the data given a generated sample. The inference network is responsible for reverse-mapping the generated data back to the latent space. It helps in tasks such as data reconstruction, denoising, and generating high-quality samples from the learned latent space.

The diffusion model uses a forward diffusion process. The forward diffusion process is used because it allows for the generation of realistic and high-quality samples, provides control over exploration and exploitation, captures complex dependencies, offers flexibility and adaptability, provides interpretability and insights, and has demonstrated state-of-the-art performance. These advantages make the forward diffusion process an attractive choice for generative modeling tasks.

The Markov chain of forward/backward diffusion process of generating a sample by slowly adding /removing noise.

In this process, the goal is to transform an initial distribution into a target distribution by iteratively updating the samples in a forward direction. The forward diffusion process plays a crucial role in generating realistic and high-quality synthetic data.

Real-life use cases of Diffusion in AI

1. Image Synthesis: Diffusion models have shown remarkable success in image synthesis tasks. By gradually transforming random noise into realistic images, diffusion models can generate diverse samples that exhibit intricate details, textures, and structures.

2. Text Generation: Diffusion models have also been applied to text generation tasks, enabling the generation of coherent and contextually rich textual data. By iteratively updating the latent representations of text, diffusion models can produce diverse and high-quality text samples.

3. Audio Generation: Diffusion models have started to make inroads into audio generation as well. By employing diffusion processes, these models can generate realistic audio samples, capturing the nuances and variations present in real-world audio data. Research papers like “Diffusion Models for Audio Synthesis” are interesting to work with diffusion.

Image Links and Additional Resources
To gain a deeper understanding of diffusion and explore its applications, the following resources can be valuable:

  1. “Image Synthesis with a Single (Stochastic) Encoder” by Ho et al. (2020)
  2. “Diffusion Models Beat GANs on Image Synthesis” by Zhai et al. (2021)
  3. “Diffusion Models for Audio Synthesis” by Kim et al. (2021)

These resources provide detailed insights into the structure of diffusion models, their applications, and the advancements made in the field of AI.

Conclusion:

Diffusion has emerged as a powerful paradigm in AI, enabling the generation of realistic and diverse synthetic data. By leveraging iterative processes and the diffusion equation, diffusion models have made significant contributions to image synthesis, text generation, and audio generation. These models provide a framework for transforming random noise into high-quality samples that capture the complexity and diversity of real-world data distribution. As research in diffusion models continues to advance, we can expect further breakthroughs and applications across various domains of AI.

References:

[0] Weng, Lilian. (Jul 2021). What are diffusion models? Lil’Log. https://lilianweng.github.io/posts/2021-07-11-diffusion-models/.
[1] Ho, J., Jaini, P., Abbeel, P., Song, D., & Mordatch, I. (2020). Image Synthesis with a Single (Stochastic) Encoder. arXiv preprint arXiv:2010.05855.
[2] Zhai, X., Ye, J., Yang, X., & Lin, L. (2021). Diffusion Models Beat GANs on Image Synthesis. arXiv preprint arXiv:2105.05233.
[3] Kim, H., Son, H., & Kim, J. (2021). Diffusion Models for Audio Synthesis. arXiv preprint arXiv:2106.02852.

I gave a very basic idea for diffusion but you can find a detailed explanation of diffusion models and Markov processes in my 0th reference.

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Chinmay Bhalerao
Data And Beyond

AI-ML Researcher & Developer | 3 X Top writer in Artificial intelligence, Computer vision & Object detection | Mathematical Modelling & Simulations