/generate-image

name: generate-image
description: Generate or edit images using AI models (FLUX, Nano Banana 2). Use for general-purpose image generation including photos, illustrations, artwork, visual assets, concept art, and any image that is not a technical diagram or schematic. For flowcharts, circuits, pathways, and technical diagrams, use the scientific-schematics skill instead.
license: MIT license
compatibility: Requires an OpenRouter API key
metadata:
    skill-author: K-Dense Inc.

Generate Image

Generate and edit high-quality images using OpenRouter's image generation models including FLUX.2 Pro and Gemini 3.1 Flash Image Preview.

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:

1. Look for a `.env` file in the project directory or parent directories 2. Check for `OPENROUTER_API_KEY=<key>` in the `.env` file 3. If not found, inform the user they need to:

• Create a `.env` file with `OPENROUTER_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

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-3.1-flash-image-preview` (high quality, recommended)

**Available models for generation and editing**:

• `google/gemini-3.1-flash-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-3.1-flash-image-preview or flux.2-pro
• **Editing**: Use gemini-3.1-flash-image-preview 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
• `--input` or `-i`: Input image path for editing (enables edit mode)
• `--model` or `-m`: OpenRouter model ID (default: google/gemini-3.1-flash-image-preview)
• `--output` or `-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.

Notes

• Images are returned as base64-encoded data URLs and automatically saved as PNG files
• The script supports both