Generate Image

Gemini 3 Pro Image Generator

Generate 2K resolution images from text prompts using Google's Gemini 3 Pro model (Nano Banana Pro).

Quick Start

python ~/.claude/commands/generate-image/scripts/generate_image.py "A beautiful sunset over mountains" -o sunset.png

Prompting Guide

Reference: Nano Banana Pro Prompting Tips

Key Elements for Effective Prompts

Include these elements for nuanced creative control:

1. Subject: Who or what is in the image? Be specific

   • "a stoic robot barista with glowing blue optics"
   • "a fluffy calico cat wearing a tiny wizard hat"

2. Composition: How elements are arranged

   • "centered", "rule of thirds", "close-up", "wide shot"

3. Action: What is happening

   • "pouring coffee", "reading a book", "running through rain"

4. Location: Where the scene takes place

   • "in a neon-lit Tokyo alley", "on a misty mountain peak"

5. Style: Visual aesthetic

   • "photorealistic", "watercolor painting", "retro 80s poster"

7 Tips for Best Results

1. Use Specific Details: Combine subject, composition, action, location, and style in one prompt

2. Leverage Real-World Knowledge: Gemini 3 Pro understands real-world context - reference real places, products, or cultural elements

3. Translate and Localize: Generate text in multiple languages for international markets, posters, infographics

4. Refine with Technical Terms: Add camera angles, lighting conditions, text integration requirements

5. Blend Multiple Concepts: Combine ideas, translate images, generate visuals with embedded text

6. Maintain Brand Consistency: Apply designs with consistent styling, drape patterns/logos onto 3D objects while preserving lighting and texture

7. Know the Limitations: Complex text rendering and factual diagrams may need iteration

Example Prompts

Product Photography:

"Professional product photo of a minimalist smartwatch on white marble surface,
soft studio lighting, slight reflection, centered composition, 8K detail"

Marketing Banner:

"Modern tech startup banner with text 'Innovation Starts Here',
gradient blue to purple background, geometric shapes, clean typography"

Artistic Portrait:

"Cinematic portrait of a jazz musician in a smoky club,
warm amber lighting, shallow depth of field, 1950s New York aesthetic"

Options

• -o, --output: Output file path (default: generated_image.png)
• -a, --aspect-ratio: Aspect ratio (default: 16:9)
  • Square: 1:1
  • Portrait: 2:3, 3:4, 4:5, 9:16
  • Landscape: 3:2, 4:3, 5:4, 16:9, 21:9

Examples

# 16:9 landscape image (default)
python ~/.claude/commands/generate-image/scripts/generate_image.py "Futuristic city skyline at night, cyberpunk aesthetic, neon lights reflecting on wet streets" -o city.png

# Square image for social media
python ~/.claude/commands/generate-image/scripts/generate_image.py "Flat lay of coffee and pastries on wooden table, morning light, cozy cafe aesthetic" -o product.png -a 1:1

# Portrait for mobile
python ~/.claude/commands/generate-image/scripts/generate_image.py "Fashion editorial, model in avant-garde outfit, dramatic studio lighting, high contrast" -o fashion.png -a 9:16

Requirements

• Python 3.8+
• GEMINI_API_KEY in ~/.env

API Details

• Model: gemini-3-pro-image-preview (fixed)
• Resolution: 2K (fixed)
• Endpoint: Google Generative Language API v1beta
• Output: JPEG format

Troubleshooting

API Key Not Found

Ensure ~/.env contains:

GEMINI_API_KEY=your_api_key_here

Timeout Errors

The default timeout is 120 seconds. For complex prompts, the API may take longer.

No Image in Response

Some prompts may be rejected by safety filters. Try rephrasing the prompt.