"Generative AI: Transformers, Diffusion & GANs"

Transformers, Diffusion Models, and GANs are key generative AI architectures, each excelling in tasks like text generation, image synthesis, and data modeling. While Transformers revolutionize NLP with attention mechanisms, Diffusion Models excel in high-fidelity image generation, and GANs leverage adversarial training for creative outputs.

Generative AI Models Description
Transformers
Transformers are foundational architectures in generative AI, introduced through the seminal paper "Attention is All You Need." They rely on the attention mechanism, which allows the model to weigh the importance of different input tokens (words, characters, etc.) when generating output. Transformers are particularly effective for sequential data like text and have revolutionized natural language processing (NLP). Key components of Transformers include:
  • Encoder-Decoder Architecture: The encoder processes input data, and the decoder generates output. However, models like GPT (Generative Pre-trained Transformer) use only the decoder for text generation.
  • Self-Attention: This mechanism helps the model focus on relevant parts of the input sequence while generating output.
  • Positional Encoding: Since Transformers lack a natural sequence structure, positional encodings are added to input embeddings to preserve order.
Transformers power many state-of-the-art models like GPT, BERT, and T5, and they are widely employed for tasks like text generation, translation, and summarization.
Diffusion Models
Diffusion models are a class of generative models designed to create high-quality data by modeling the gradual addition and removal of noise. Drawing inspiration from physical processes like gas diffusion, these models learn to reverse a noising process to generate new samples. The process can be summarized in two main stages:
  • Forward Process: Noise is progressively added to the data over several steps until the data becomes indistinguishable from pure noise.
  • Reverse Process: The model learns to reverse this noising process step-by-step, reconstructing data from noise.
Diffusion models have gained popularity in image generation tasks. For example, DALL-E and Stable Diffusion employ these models to generate high-fidelity images from textual descriptions. Their ability to generate diverse and detailed outputs makes them a powerful alternative to GANs in certain applications.
Generative Adversarial Networks (GANs)
Generative Adversarial Networks (GANs) consist of two neural networks: a Generator and a Discriminator, which work in opposition to improve the quality of generated data. This adversarial setup was introduced by Ian Goodfellow in 2014 and has since become a cornerstone of generative AI models. Here's how GANs work:
  • Generator: The generator creates fake data samples (e.g., images) from random noise.
  • Discriminator: The discriminator evaluates whether a given sample is real (from the training dataset) or fake (produced by the generator).
  • Adversarial Training: The generator tries to fool the discriminator by improving its fake samples, while the discriminator becomes better at distinguishing real from fake data. This iterative process continues until the generator produces data indistinguishable from the real dataset.
GANs are widely used for tasks like image synthesis, video generation, and style transfer. However, they are known for challenges like mode collapse and instability during training, which researchers continue to address.