| name | gemini-image |
| description | Generate images using Google Gemini and Imagen models via scripts/. Use for AI image generation, text-to-image, creating visuals from prompts, generating multiple images, custom aspect ratios, and high-resolution output up to 4K. Triggers on "generate image", "create image", "imagen", "text to image", "AI art", "nano banana". |
| license | MIT |
| version | 1.0.0 |
| keywords | image generation, imagen, gemini-3-pro, gemini-2.5, text-to-image, AI art, nano banana, 4K resolution, aspect ratio |
Gemini Image Generation
Generate high-quality images from text prompts using Google's Gemini and Imagen models through executable scripts.
When to Use This Skill
Use this skill when you need to:
- Create visual content from text descriptions
- Generate multiple image variations
- Create images at specific resolutions (1K, 2K, 4K)
- Produce images for different aspect ratios (social media, banners, etc.)
- Generate photorealistic images or artistic visuals
- Create images with person generation controls
- Batch generate multiple images at once
- Combine with text generation for complete content creation
Available Scripts
scripts/generate_image.js
Purpose: Generate images using Gemini 3 Pro Image or Imagen 4 models
When to use:
- Any image generation task
- Multiple image generation (1-4 per request)
- Custom resolution and aspect ratio needs
- Professional asset creation
- Photorealistic or artistic image generation
Key parameters:
| Parameter | Description | Example |
|---|
prompt | Text description (required) | "A futuristic city at sunset" |
--model, -m | Model to use | gemini-3.1-flash-image-preview |
--output-dir, -o | Output directory for images | images/ |
--name, -n | Base name for output files | artwork |
--no-timestamp | Disable auto timestamp | Flag |
--aspect, -a | Aspect ratio | 16:9 |
--size, -s | Resolution | 2K or 4K |
--num | Number of images (1-4) | 4 |
--person | Person generation policy | allow_adult |
Output: List of saved PNG file paths
Workflows
Workflow 1: Basic Image Generation
node scripts/generate_image.js "A futuristic city at sunset with flying cars"
- Best for: Quick image generation, prototypes
- Model:
gemini-3.1-flash-image-preview (default, Nano Banana 2)
- Output:
images/generated_image_YYYYMMDD_HHMMSS.png
Workflow 2: Social Media (Instagram, Facebook)
node scripts/generate_image.js "Minimalist coffee shop interior" --aspect 1:1 --size 2K --name coffee-shop
- Best for: Instagram posts, profile pictures
- Aspect: 1:1 (square format)
- Resolution: 2K (2048x2048)
- Output:
images/coffee-shop_YYYYMMDD_HHMMSS.png
Workflow 3: YouTube Thumbnails (16:9)
node scripts/generate_image.js "Tech gadget review thumbnail with vibrant colors" --aspect 16:9 --size 2K --name thumbnail
- Best for: YouTube, video thumbnails
- Aspect: 16:9 (widescreen)
- Resolution: 2K (2752x1536)
- Output:
images/thumbnail_YYYYMMDD_HHMMSS.png
Workflow 4: Multiple Variations
node scripts/generate_image.js "Abstract geometric patterns in blue and gold" --num 4 --name abstract
- Best for: A/B testing, design options
- Generates: 4 distinct variations
- Output:
images/abstract_YYYYMMDD_HHMMSS_0.png, images/abstract_YYYYMMDD_HHMMSS_1.png, etc.
Workflow 5: Custom Output Directory
node scripts/generate_image.js "Detailed architectural rendering of modern museum" --aspect 16:9 --size 4K --output-dir ./professional/ --name museum
- Best for: Print materials, high-end assets, organized projects
- Model:
gemini-3.1-flash-image-preview or gemini-3-pro-image-preview (for 4K)
- Resolution: 4K (5504x3072 for 16:9)
- Directory created automatically if it doesn't exist
Workflow 6: Photorealistic Images (Imagen 4)
node scripts/generate_image.js "Robot holding a red skateboard in urban setting" --model imagen-4.0-generate-001 --aspect 16:9 --size 2K --num 2 --name robot-skate
- Best for: Realistic photos, product shots
- Model:
imagen-4.0-generate-001 (photorealistic)
- Notes: English prompts only
- Max 4 images per request
Workflow 7: Blog Post Featured Image
node scripts/generate_image.js "Serene mountain lake at sunrise with reflections" --aspect 16:9 --size 2K --output-dir ./blog-images/ --name featured-image
- Best for: Blog headers, article images
- Combines well with: gemini-text for blog content generation
Workflow 8: Content Creation Pipeline (Text + Image)
node skills/gemini-text/scripts/generate.js "Write a product description for smart home device"
node scripts/generate_image.js "Sleek modern smart home device on white background" --aspect 4:3 --size 2K --name product
- Best for: E-commerce, marketing campaigns
- Combines with: gemini-text, gemini-batch for batch production
Workflow 9: Disable Timestamp
node scripts/generate_image.js "Fixed filename image" --name my-image --no-timestamp
- Best for: When you want complete control over filename
- Output:
images/my-image.png (no timestamp)
- Use when: Generating files for specific naming schemes or automated pipelines
Parameters Reference
Model Selection
| Model | Nickname | Quality | Max Size | Best For |
|---|
gemini-3.1-flash-image-preview | Nano Banana 2 | Pro-level | 4K | New default, fast + strong quality |
gemini-3-pro-image-preview | Nano Banana Pro | Highest | 4K | Maximum quality and complex text rendering |
gemini-2.5-flash-image | Nano Banana | Good | 2K | High-volume, low-latency |
imagen-4.0-generate-001 | Imagen 4 | Photorealistic | 2K | Realistic photos, product shots |
Aspect Ratios
| Ratio | Use Case | 1K Size | 2K Size |
|---|
| 1:1 | Instagram, avatars | 1024x1024 | 2048x2048 |
| 16:9 | YouTube, presentations | 1376x768 | 2752x1536 |
| 9:16 | Instagram Stories, TikTok | 768x1376 | 1536x2752 |
| 4:3 | Traditional displays | 1024x768 | 2048x1536 |
| 3:4 | Portrait orientation | 768x1024 | 1536x2048 |
| 21:9 | Ultrawide | - | 5504x2400 |
Note: 4K resolution is available with gemini-3.1-flash-image-preview and gemini-3-pro-image-preview
Resolution Guide
| Size | Use Case | Best Model |
|---|
| 1K (1024px) | Web thumbnails, previews | Any model |
| 2K (2048px) | Standard web, social media | Any model |
| 4K (4096px) | Print, high-end assets | gemini-3-pro only |
Person Generation Policy
| Policy | Description | Restrictions |
|---|
dont_allow | No people in images | None |
allow_adult | Adults only | Recommended default |
allow_all | All ages | Restricted in EU, UK, CH, MENA |
Output Interpretation
File Naming
- Default format:
{name}_YYYYMMDD_HHMMSS.png (auto timestamp)
- Single image example:
artwork_20260130_031643.png
- Multiple images:
{name}_YYYYMMDD_HHMMSS_0.png, {name}_YYYYMMDD_HHMMSS_1.png, etc.
- Without timestamp (
--no-timestamp): {name}.png
- Script prints: "Saved: /path/to/file.png"
Image Quality
- All images include SynthID watermark for authenticity
- PNG format for lossless quality
- Can be converted to JPEG/WEBP if needed
- 4K images are significantly larger file sizes
Error Messages
- "Model not available": Check model name spelling
- "Unsupported size": Verify size/model combination
- "Aspect ratio error": Use supported ratios for selected model
Common Issues
"google-genai or pillow not installed"
cd scripts && npm install
"Image generation failed"
- Check prompt length (too verbose can fail)
- Try simpler, more focused prompts
- Verify model availability in your region
- Check API quota limits
"Unsupported aspect ratio"
- Check if ratio is supported by selected model
- Imagen 4 has fewer ratio options than Gemini
- Use 16:9 or 1:1 for best compatibility
"4K not supported"
- 4K works best with
gemini-3.1-flash-image-preview or gemini-3-pro-image-preview
- Use
--size 2K for older models
- Try
--model gemini-3.1-flash-image-preview --size 4K
"Imagen prompt language error"
- Imagen models support English prompts only
- Use
gemini-3.1-flash-image-preview for other languages
- Translate prompt to English for Imagen
File too large for storage
- Use
--size 1K for smaller files
- Compress images after generation
- Convert PNG to JPEG for web use
Best Practices
Prompt Engineering
- Be specific and descriptive
- Include style descriptors (e.g., "photorealistic", "digital art")
- Mention lighting, mood, and composition
- Use analogies for complex concepts
- Avoid negative prompts (describe what you want, not what to avoid)
Model Selection
- Use
gemini-3.1-flash-image-preview for: Best default balance, quality, speed, 4K
- Use
gemini-3-pro-image-preview for: Maximum quality, complex text rendering
- Use
gemini-2.5-flash-image for: Speed, high volume
- Use
imagen-4.0-generate-001 for: Photorealism, product shots
Performance Optimization
- Generate multiple images at once with
--num
- Use lower resolution for previews
- Batch requests for high-volume needs (gemini-batch skill)
- Cache results for repeated requests
Quality Tips
- Use 2K resolution for most web uses
- 4K only when maximum detail is needed
- Combine specific prompts with style guidance
- Test prompts with
--num 1 before generating batches
Cost Management
- Use flash models for cost efficiency
- 4K generation costs significantly more
- Batch multiple requests when possible
- Generate at 1K for testing, 2K/4K for final
Related Skills
- gemini-text: Generate text content alongside images
- gemini-tts: Create audio for image-based content
- gemini-batch: Process multiple image requests efficiently
- gemini-embeddings: Generate image embeddings for similarity search
Quick Reference
node scripts/generate_image.js "Your prompt"
node scripts/generate_image.js "Prompt" --aspect 1:1 --size 2K --name social-post
node scripts/generate_image.js "Prompt" --aspect 16:9 --size 2K --name thumbnail
node scripts/generate_image.js "Prompt" --aspect 16:9 --size 4K --name high-res
node scripts/generate_image.js "Prompt" --num 4 --name variations
node scripts/generate_image.js "Prompt" --output-dir ./my-images/ --name custom
node scripts/generate_image.js "Prompt" --model imagen-4.0-generate-001 --aspect 16:9 --size 2K --name photo
node scripts/generate_image.js "Prompt" --name fixed-name --no-timestamp
Reference
