AI Image Generation Guide: DALL-E, Midjourney & Stable Diffusion

How AI Image Generation Works

Modern AI image generators use diffusion models — a technique that starts with random noise and gradually removes it, guided by your text prompt, until a coherent image emerges. This process typically runs 20–50 denoising steps.

The key components are a text encoder (usually CLIP) that converts your prompt into a vector, a U-Net that iteratively denoises the image, and a VAE (Variational Autoencoder) that converts between pixel space and the compressed latent space where diffusion happens.

DALL-E 3 vs Midjourney vs Stable Diffusion

Writing Effective Image Prompts

Image prompts follow a different structure than text prompts. The most effective formula:

Style Keywords That Work

Using DALL-E 3 via API

import OpenAI from 'openai';

const openai = new OpenAI();

const image = await openai.images.generate({
  model: 'dall-e-3',
  prompt: 'A futuristic city skyline at night with flying cars, cyberpunk aesthetic, neon lights reflecting on wet streets, cinematic lighting, 4K',
  n: 1,                    // DALL-E 3 only supports n=1
  size: '1792x1024',       // 1024x1024 | 1024x1792 | 1792x1024
  quality: 'hd',           // 'standard' | 'hd' (2x cost)
  style: 'vivid',          // 'vivid' | 'natural'
  response_format: 'url',  // 'url' | 'b64_json'
});

console.log(image.data[0].url);
// Returns a temporary URL valid for 1 hour
// Download and store it yourself for permanent access

Image Generation Pricing