Gemini Vision — "Nano Banana"
Analyze images using Google Gemini Flash (vision model) for detailed visual understanding, layout analysis, text detection, and defect identification.
When to Use
ALWAYS use this when:
- User says "analiza imagen", "nano banana", "qué ves", "describe la imagen"
- User drags/pastes an image into VS Code chat
- You need to "see" an image to make decisions (layout, overlap, colors, etc.)
- Visual verification of generated documents (PDF, DOCX, slides)
Priority over image-analyzer: If GEMINI_API_KEY is available, prefer this skill over the GPT-4o-based image-analyzer. Falls back to image-analyzer if no Gemini key.
Auth
Requires GEMINI_API_KEY in env or ~/.env.
Get one at: https://aistudio.google.com/apikey
Quick Reference
SCRIPT=~/.claude/skills/gemini-vision/scripts/gemini_vision.py
# Load API key from ~/.env
export $(grep GEMINI_API_KEY ~/.env | xargs)
# Describe one image
python3 "$SCRIPT" photo.jpg
# Custom prompt for specific analysis
python3 "$SCRIPT" footer.png --prompt "Is the blue line overlapping the date text?"
# Analyze latest VS Code chat image
python3 "$SCRIPT" --vscode-latest --prompt "Describe what you see"
# Batch analyze directory
python3 "$SCRIPT" photos/ --batch
# JSON output
python3 "$SCRIPT" img1.png img2.png --json
# Use specific model (default: gemini-2.0-flash)
python3 "$SCRIPT" img.png --model gemini-2.5-flash
VS Code Chat Images
When users drag images into VS Code Copilot Chat:
~/.var/app/com.visualstudio.code/config/Code/User/workspaceStorage/vscode-chat-images/image-<timestamp>.png
Use --vscode-latest to auto-find the most recent one:
python3 "$SCRIPT" --vscode-latest --prompt "What do you see?"
Workflow Integration
1. Document Verification (PDF/DOCX)
After generating a PDF or DOCX, render to image and verify:
# Render PDF page to PNG
flatpak-spawn --host pdftoppm -f 1 -l 1 -r 150 -png document.pdf preview
# Analyze with Gemini
python3 "$SCRIPT" preview-1.png --prompt "Check the footer: is the date text overlapping the blue line?"
2. Before/After Comparison
python3 "$SCRIPT" before.png after.png --prompt "Compare these two images. What changed? Are there improvements or regressions?"
3. Architecture Diagram Review
python3 "$SCRIPT" diagram.svg --prompt "Review this architecture diagram for completeness and accuracy"
Models Available
| Model | Best For | Speed |
|---|---|---|
gemini-2.0-flash |
General vision, fast | Fast |
gemini-2.5-flash |
Complex analysis | Medium |
gemini-2.5-pro |
Highest quality | Slower |
Default: gemini-2.0-flash (best speed/quality balance)
Fallback Chain
- Gemini Flash (this skill) — preferred when
GEMINI_API_KEYavailable - GPT-4o (
image-analyzerskill) — fallback whenOPENAI_API_KEYorGITHUB_TOKENavailable - Pixel analysis (Pillow) — last resort, programmatic color/position analysis
Lessons Learned
- Gemini Flash is particularly good at detecting text overlap, layout issues, and spatial relationships in documents
- For PDF footer verification, use specific prompts like "Is the blue line overlapping the date text?" rather than generic "describe"
- VS Code Flatpak stores chat images at a non-standard path — use
--vscode-latestto handle automatically - Always
export $(grep GEMINI_API_KEY ~/.env | xargs)before calling if key isn't in environment
Source: CarlosCaPe/octorato — distributed by TomeVault.