PART 4 · MODULE 5From text to pictures
Image Generation
AI-powered image creation
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AI-powered image creation
Type "a golden retriever wearing sunglasses on a beach at sunset" and get back a photorealistic image that never existed before. That is the magic of text-to-image generation. Let's see how it works.
Image generation has evolved rapidly. First came GANs (Generative Adversarial Networks) in 2014, which used a clever competition between two networks. Then Diffusion Models arrived around 2020 and quickly became the standard, producing higher quality and more controllable images.
A GAN has two neural networks that compete with each other. The Generator (the artist) creates fake images. The Discriminator (the critic) tries to tell real images from fakes. Over time, the generator gets so good that even the discriminator cannot tell the difference.
GAN: GENERATOR vs DISCRIMINATOR
Diffusion models take a different approach. During training, they gradually add noise to images until they become pure static. Then they learn to reverse the process — removing noise step by step to recreate the image. It is like restoring a damaged painting, except the model studied millions of paintings to learn how.
DIFFUSION: REMOVING NOISE STEP BY STEP
Pure noise
→Shapes emerge
→Details form
→Refinement
→Final image
The model learns to reverse destruction — removing noise to reveal an image
Models like CLIPconnect text and images in a shared space. When you type a prompt, CLIP converts it into a signal that guides the diffusion process. The model "steers" its denoising toward an image that matches your description.
OpenAI
Integrated into ChatGPT. Strong at following detailed text prompts.
Midjourney Inc.
Known for stunning artistic and photorealistic output. Runs via Discord.
Stability AI
Open-source. Can run locally. Huge community of extensions and fine-tunes.
Diffusion models learn to create by learning to reverse destruction — they master the art of denoising. By gradually removing noise, guided by your text prompt, they conjure images that never existed before.