By name: gemini-image description: Reference guide for using google-genai Python library to generate images with gemini-3-pro-image-preview model. Use this skill when building new projects that need Gemini image generation capabilities, to understand the correct API patterns, configuration options, and best practices.
Gemini Image Generation Guide
Reference for generating images with Google's gemini-3-pro-image-preview model.
Language References
Load the appropriate reference based on the project's language:
| Language | Reference File |
|---|---|
| Python | references/python.md |
Instructions: When implementing Gemini image generation, read the corresponding language reference file for complete code patterns and examples.
Model Information
| Property | Value |
|---|---|
| Model ID | gemini-3-pro-image-preview |
| Cost | ~$0.134 per image (2K) |
| Max Reference Images | 5+ (high fidelity) |
| Resolutions | 1K, 2K, 4K |
Supported Aspect Ratios
| Ratio | Use Case |
|---|---|
1:1 |
Square, social media posts |
2:3 |
Portrait photos |
3:2 |
Landscape photos |
3:4 |
Portrait, mobile screens |
4:3 |
Standard display |
4:5 |
Instagram portrait |
5:4 |
Large format |
9:16 |
Vertical video, stories |
16:9 |
Widescreen, presentations |
21:9 |
Ultra-wide, cinematic |
Image Sizes
| Size | Resolution | Use Case |
|---|---|---|
1K |
~1024px | Thumbnails, previews |
2K |
~2048px | Standard output (recommended) |
4K |
~4096px | High-quality prints |
Important: Use uppercase "K" (not "1k", "2k", "4k").
Environment Setup
export GOOGLE_API_KEY='your-api-key-here'
Core Capabilities
1. Text-to-Image Generation
Generate images from text descriptions with configurable aspect ratio and resolution.
2. Style Transfer with Reference Images
Pass reference images to maintain consistent style across generations. Supports up to 5+ images for high fidelity.
3. Image Editing
Modify existing images based on text instructions (add/remove elements, style changes).
4. Batch Generation
Generate multiple style candidates or variations.
Prompt Engineering Tips
Be Descriptive
Bad: "cat, sunset"
Good: "A fluffy orange tabby cat sitting on a wooden fence,
watching a vibrant sunset over rolling hills.
Warm golden and pink light illuminates the scene.
Photorealistic style with soft focus background."
Specify Visual Elements
- Lighting: "soft morning light", "dramatic side lighting", "golden hour"
- Style: "oil painting", "watercolor", "3D render", "photorealistic"
- Mood: "serene", "dramatic", "whimsical", "mysterious"
- Composition: "close-up portrait", "wide landscape", "bird's eye view"
- Camera: "35mm lens", "shallow depth of field", "wide angle"
For Style Transfer
When using reference images, be explicit about what to transfer:
- "Match the color palette and brushstroke style of the reference"
- "Keep the artistic mood and lighting from the reference image"
Common Issues
| Issue | Solution |
|---|---|
| "No image generated" | Check prompt for content policy violations; simplify prompt |
| "Invalid image_size" | Use uppercase: "1K", "2K", "4K" |
| "API key not found" | Set GOOGLE_API_KEY environment variable |
| Rate limits | Add delays between requests; use exponential backoff |
Pricing Comparison
| Model | Cost per Image |
|---|---|
| gemini-3-pro-image-preview | ~$0.134 |
| gemini-2.5-flash-image | ~$0.039 |