Why Generating Images Is Hard — The Problem Diffusion Solved
Every text-to-image system — Stable Diffusion, Midjourney, DALL·E, Imagen — rests on one idea: destroy an image with noise, then learn to run the destruction backwards. Before that idea, a decade of generative modeling fought a three-way trade-off between sample quality, training stability, and diversity — and every architecture picked two. This series builds diffusion models from first principles: what problem they solve, why the math works, and how the pieces (latents, guidance, transformers, flow matching) assembled into the systems generating images and video today.
Every text-to-image system rests on one idea: destroy an image with noise, then learn to run the destruction backwards. Why generation is sampling (not prediction), how VAEs blur and GANs collapse, the quality/diversity/stability trilemma — and the iterative-refinement move that escaped it, opening a 10-post series.