Generate Image
Generate and edit high-quality images using OpenRouter's image generation models including FLUX.2 Pro and Gemini 3 Pro.
When to Use This Skill
Use generate-image for:
- •Photos and photorealistic images
- •Artistic illustrations and artwork
- •Concept art and visual concepts
- •Visual assets for presentations or documents
- •Image editing and modifications
- •Any general-purpose image generation needs
Use scientific-schematics instead for:
- •Flowcharts and process diagrams
- •Circuit diagrams and electrical schematics
- •Biological pathways and signaling cascades
- •System architecture diagrams
- •CONSORT diagrams and methodology flowcharts
- •Any technical/schematic diagrams
Quick Start
Use the scripts/generate_image.py script to generate or edit images:
# Generate a new image python scripts/generate_image.py "A beautiful sunset over mountains" # Edit an existing image python scripts/generate_image.py "Make the sky purple" --input photo.jpg
This generates/edits an image and saves it as generated_image.png in the current directory.
API Key Setup
CRITICAL: The script requires an OpenRouter API key. Before running, check if the user has configured their API key:
- •Look for a
.envfile in the project directory or parent directories - •Check for
OPENROUTER_API_KEY=<key>in the.envfile - •If not found, inform the user they need to:
- •Create a
.envfile withOPENROUTER_API_KEY=your-api-key-here - •Or set the environment variable:
export OPENROUTER_API_KEY=your-api-key-here - •Get an API key from: https://openrouter.ai/keys
- •Create a
The script will automatically detect the .env file and provide clear error messages if the API key is missing.
Model Selection
Default model: google/gemini-3-pro-image-preview (high quality, recommended)
Available models for generation and editing:
- •
google/gemini-3-pro-image-preview- High quality, supports generation + editing - •
black-forest-labs/flux.2-pro- Fast, high quality, supports generation + editing
Generation only:
- •
black-forest-labs/flux.2-flex- Fast and cheap, but not as high quality as pro
Select based on:
- •Quality: Use gemini-3-pro or flux.2-pro
- •Editing: Use gemini-3-pro or flux.2-pro (both support image editing)
- •Cost: Use flux.2-flex for generation only
Common Usage Patterns
Basic generation
python scripts/generate_image.py "Your prompt here"
Specify model
python scripts/generate_image.py "A cat in space" --model "black-forest-labs/flux.2-pro"
Custom output path
python scripts/generate_image.py "Abstract art" --output artwork.png
Edit an existing image
python scripts/generate_image.py "Make the background blue" --input photo.jpg
Edit with a specific model
python scripts/generate_image.py "Add sunglasses to the person" --input portrait.png --model "black-forest-labs/flux.2-pro"
Edit with custom output
python scripts/generate_image.py "Remove the text from the image" --input screenshot.png --output cleaned.png
Multiple images
Run the script multiple times with different prompts or output paths:
python scripts/generate_image.py "Image 1 description" --output image1.png python scripts/generate_image.py "Image 2 description" --output image2.png
Script Parameters
- •
prompt(required): Text description of the image to generate, or editing instructions - •
--inputor-i: Input image path for editing (enables edit mode) - •
--modelor-m: OpenRouter model ID (default: google/gemini-3-pro-image-preview) - •
--outputor-o: Output file path (default: generated_image.png) - •
--api-key: OpenRouter API key (overrides .env file)
Example Use Cases
For Scientific Documents
# Generate a conceptual illustration for a paper python scripts/generate_image.py "Microscopic view of cancer cells being attacked by immunotherapy agents, scientific illustration style" --output figures/immunotherapy_concept.png # Create a visual for a presentation python scripts/generate_image.py "DNA double helix structure with highlighted mutation site, modern scientific visualization" --output slides/dna_mutation.png
For Presentations and Posters
# Title slide background python scripts/generate_image.py "Abstract blue and white background with subtle molecular patterns, professional presentation style" --output slides/background.png # Poster hero image python scripts/generate_image.py "Laboratory setting with modern equipment, photorealistic, well-lit" --output poster/hero.png
For General Visual Content
# Website or documentation images python scripts/generate_image.py "Professional team collaboration around a digital whiteboard, modern office" --output docs/team_collaboration.png # Marketing materials python scripts/generate_image.py "Futuristic AI brain concept with glowing neural networks" --output marketing/ai_concept.png
Error Handling
The script provides clear error messages for:
- •Missing API key (with setup instructions)
- •API errors (with status codes)
- •Unexpected response formats
- •Missing dependencies (requests library)
If the script fails, read the error message and address the issue before retrying.
Critical Prompt Requirements
IMPORTANT: No Meta Instructions in Output
When generating prompts for the AI image generation models, ensure the generated image does NOT contain any visible text showing:
- •The prompt or instructions that were given to generate it
- •System instructions or AI-related metadata
- •Any "meta" text describing how the image was created
- •Watermarks or labels indicating AI generation
- •Layout descriptions (e.g., "left panel", "right panel", "center panel")
- •Font specifications or typography instructions
- •Color scheme descriptions or palette information
The image should only contain the requested visual content. Always include this instruction in your prompts: "Do not include any text showing the prompt, instructions, layout descriptions, font/color specifications, or metadata in the generated image."
Notes
- •Images are returned as base64-encoded data URLs and automatically saved as PNG files
- •The script supports both
imagesandcontentresponse formats from different OpenRouter models - •Generation time varies by model (typically 5-30 seconds)
- •For image editing, the input image is encoded as base64 and sent to the model
- •Supported input image formats: PNG, JPEG, GIF, WebP
- •Check OpenRouter pricing for cost information: https://openrouter.ai/models
Image Editing Tips
- •Be specific about what changes you want (e.g., "change the sky to sunset colors" vs "edit the sky")
- •Reference specific elements in the image when possible
- •For best results, use clear and detailed editing instructions
- •Both Gemini 3 Pro and FLUX.2 Pro support image editing through OpenRouter
Integration with Other Skills
- •scientific-schematics: Use for technical diagrams, flowcharts, circuits, pathways
- •generate-image: Use for photos, illustrations, artwork, visual concepts
- •scientific-slides: Combine with generate-image for visually rich presentations
- •latex-posters: Use generate-image for poster visuals and hero images