@mattly the mathematical process for genAI to create images is called diffusion. To my knowledge, all image generation models are diffusion models. It's basically a mix of adding and removing complex noise until it reaches a certain result. Some models use tricks like inline generation to generate part of the image at a time, similar to rendering quadrants of a 3D scene on a CPU, instead of doing it all at once to yield more coherent results. When you ask chatGPT to generate an image, your prompt can be processed by an LLM to make it work better with the diffusion model's dataset of labelled imagery. It's also the method for video generation, although other transformer models are used to improve object permanence and other flaws on recent models like Sora and Veo 3. But yeah, you have LLMs for text and Diffusion models for imagery. Highly recommend the wikipedia article and its linked articles to get a good technical overview : https://en.wikipedia.org/wiki/Diffusion_model
@mattly LLM is a slightly weird term but I think it usually means a transformer based language model.
I think in the most part the image generation models are diffusion models (https://en.wikipedia.org/wiki/Diffusion_model), so perhaps it's diffusion generation model or just image generation model?