Guide complet de la generation d'images par IA pour debutants [2026]
Apprenez a generer des images par IA en partant de zero. Guide couvrant Midjourney, DALL-E, Stable Diffusion et les techniques de prompts.
AI image generation has become accessible to everyone in 2026. This guide covers everything from basics to practical prompt techniques for beginners.
What Is AI Image Generation?
AI image generation creates images automatically from text prompts (instructions). The mainstream technology is diffusion models, which gradually construct images from noise.
Major AI Image Generation Tools
Midjourney
Known for artistic, beautiful image generation. Available via Discord, starting at $10/month. Creative expression quality is top-tier, widely used in advertising and design.
DALL-E 3 (Built into ChatGPT)
Integrated into ChatGPT, DALL-E 3 offers the easiest natural language instructions. Available on ChatGPT's free plan, it automatically optimizes your text instructions, making it the best choice for beginners.
Stable Diffusion
An open-source model that runs locally on your PC for free. Extremely customizable with extensions like LoRA and ControlNet. Accessible via UI tools like ComfyUI and Automatic1111.
Leonardo AI
High-quality image generation with a free tier, plus specialized features for game assets and illustration. The intuitive web interface makes it easy to use.
Prompt Writing Basics
Basic Structure
Effective prompts follow: "Subject + Style + Details + Quality specification"
Example: "A cat walking on a sunset beach, watercolor style, warm tones, high quality, 4K resolution"
Quality-Boosting Keywords
- Quality: masterpiece, best quality, ultra detailed, 8K
- Lighting: cinematic lighting, golden hour, soft light
- Composition: wide angle, close-up, bird's eye view
Negative Prompts
Specifying unwanted elements is also important. Adding "low quality, blurry, distorted" helps avoid poor results.
Recommended Starting Path
1. Start with DALL-E 3: Simply tell ChatGPT "create an image of..." in natural language 2. Move to Midjourney: When you need higher quality, consider Midjourney's paid plan 3. Explore Stable Diffusion: For full customization, set up a local Stable Diffusion environment
Copyright and Commercial Use
AI image copyright remains legally gray. Always check each tool's terms of service for commercial use. Midjourney paid plans and self-generated Stable Diffusion images are generally cleared for commercial use.
Summary
AI image generation is one of the most accessible ways to start using AI in 2026. Begin with DALL-E 3 in ChatGPT and gradually level up.