Gemini Image Generator

Gemini NanoBananaを使った汎用AI画像生成スキル。

When to Use This Skill

Trigger when user:

• Asks to generate/create images with AI
• Mentions "Gemini image", "generate picture", "create artwork"
• Requests visual content from text descriptions
• Wants to produce illustrations or graphics
• Wants to create images matching a reference image's style (NEW!)

For specific use cases, use specialized skills:

• LP/セールスレター画像 → gemini-lp-generator
• ウェビナースライド → gemini-slide-generator

Quick Start

cd /path/to/gemini-image-generator

# 1. Check authentication
python scripts/run.py auth_manager.py status

# 2. Authenticate (if needed)
python scripts/run.py auth_manager.py setup

# 3. Generate image (basic)
python scripts/run.py image_generator.py \
  --prompt "sunset over mountains, watercolor style" \
  --output output/my_image.png

# 4. Generate with reference image (NEW!)
python scripts/run.py image_generator.py \
  --prompt "犬を描いて" \
  --reference-image "/path/to/reference.png" \
  --output output/styled_dog.png

How It Works

Basic Mode (テキストのみ)

1. Navigate to gemini.google.com
2. Click "ツール" (Tools) button
3. Select "画像を作成" (Create Image) - Activates NanoBanana
4. Enter prompt and generate
5. Download generated image

Reference Image Mode (参考画像あり) - NEW!

1. Upload reference image to Gemini
2. AI analyzes visual elements (style, colors, lighting, etc.)
3. Extract analysis as YAML format
4. Generate optimized meta-prompt
5. Create new image with matching style

┌────────────────┐     ┌────────────────┐     ┌────────────────┐
│  📷 Reference  │ →   │  📋 YAML       │ →   │  📝 Optimized  │
│     Image      │     │    Analysis    │     │     Prompt     │
└────────────────┘     └────────────────┘     └────────────────┘
                                                      │
                                                      ▼
                                              ┌────────────────┐
                                              │  🖼️ Generated  │
                                              │     Image      │
                                              └────────────────┘

Parameters

Prompt Examples

Basic Examples (テキストのみ)

# Landscape
python scripts/run.py image_generator.py \
  --prompt "serene sunset over snow-capped mountains, warm orange sky, photorealistic"

# Art style
python scripts/run.py image_generator.py \
  --prompt "watercolor painting of a cat sitting by window, soft colors"

# Product photo
python scripts/run.py image_generator.py \
  --prompt "professional product photography, white background, soft lighting"

Reference Image Examples (参考画像あり) - NEW!

# Match style of reference image
python scripts/run.py image_generator.py \
  --prompt "犬を描いて" \
  --reference-image "examples/watercolor_cat.png" \
  --output output/watercolor_dog.png

# Save YAML analysis for review
python scripts/run.py image_generator.py \
  --prompt "森の風景" \
  --reference-image "examples/sunset.jpg" \
  --yaml-output output/analysis.yaml \
  --output output/forest.png

# Debug mode with browser visible
python scripts/run.py image_generator.py \
  --prompt "カフェの内装" \
  --reference-image "examples/cozy_room.png" \
  --show-browser \
  --output output/cafe.png

Standalone Tools

# Extract YAML only (without generating image)
python scripts/run.py prompt_extractor.py \
  --image "examples/reference.png" \
  --output analysis.yaml

# Generate prompt from YAML
python scripts/run.py meta_prompt.py \
  --yaml analysis.yaml \
  --request "猫を描いて"

Authentication

This skill manages browser authentication for all Gemini-based skills:

• gemini-slide-generator (shares browser profile)
• gemini-lp-generator (shares browser profile)

# Check status
python scripts/run.py auth_manager.py status

# Setup (opens browser for Google login)
python scripts/run.py auth_manager.py setup

# Clear session
python scripts/run.py auth_manager.py clear

Troubleshooting

Data Storage

• data/browser_profile/ - Browser session (shared with other Gemini skills)
• data/state.json - Authentication state
• output/ - Generated images

Architecture

scripts/
├── config.py           # Centralized settings
├── browser_utils.py    # BrowserFactory and StealthUtils
├── auth_manager.py     # Authentication management
├── image_generator.py  # Image generation (with reference image support)
├── prompt_extractor.py # Extract visual elements as YAML (NEW!)
├── meta_prompt.py      # Generate optimized prompts from YAML (NEW!)
└── run.py              # Wrapper script for venv

docs/
└── UPGRADE_SPEC.md     # Feature specification with diagrams

Notes

• First generation takes longer (browser startup)
• Subsequent generations faster (session reuse)
• Authentication persists ~7 days
• UI selectors may break when Gemini updates