Diagram to Image
Convert Mermaid diagrams and Markdown tables to images (PNG/SVG) for use in platforms that don't support rich formatting, like X (Twitter).
When to Use
Use this skill when:
- User has a Mermaid diagram that needs to be converted to an image
- User has a Markdown table that needs to be converted to an image
- User is writing content for X/Twitter and needs visual exports
- User asks to "convert to image", "export as PNG", "make this an image", or similar
Prerequisites
Ensure dependencies are installed:
bash
# Check if mermaid-cli is installed
which mmdc || npm install -g @mermaid-js/mermaid-cli
Smart Output Location
IMPORTANT: Determine the best output location based on context. Follow this decision tree:
1. User Specifies Path
If user explicitly mentions a path or filename, use that.
2. Project Context Detection
Check for common image/asset directories in the current project:
bash
# Check for existing image directories (in order of preference)
ls -d ./images ./assets ./img ./static ./public/images ./assets/images 2>/dev/null | head -1
Use the first existing directory found. Common patterns:
- - General projects
- - Web projects
- - Structured web projects
- - Next.js, React projects
- - Hugo, other static site generators
- - Short form convention
3. Article/Document Context
If user is writing an article or document:
- Look for the document's directory
- Create subdirectory if appropriate
- Name the image based on the document name + descriptor
4. Conversation Context
Analyze the conversation to determine:
- What the diagram represents → Use for filename (e.g., , )
- Related file being discussed → Place image near that file
- Topic being discussed → Use for naming
5. Default Fallback
If no context clues:
- Use current working directory
- Generate descriptive filename from diagram content
Filename Generation
Create meaningful filenames based on content analysis:
| Content Pattern | Example Filename |
|---|
| with auth/login | |
| with API | |
| |
| chart about X | |
| chart | |
| Table with comparison | |
| Table with data | |
Rules:
- Use kebab-case (lowercase with hyphens)
- Keep names concise but descriptive (2-4 words)
- Avoid generic names like or
- Include topic/subject when identifiable
Conversion Process
Step 1: Analyze Context
Before converting, gather context:
- Check current working directory
- Look for existing image directories
- Analyze diagram/table content for naming
- Consider any files or topics mentioned in conversation
Step 2: Determine Output Path
bash
# Example logic (implement mentally, not as literal script)
if user_specified_path:
output_path = user_specified_path
elif exists("./images"):
output_path = "./images/{generated_name}.png"
elif exists("./assets"):
output_path = "./assets/{generated_name}.png"
elif exists("./public/images"):
output_path = "./public/images/{generated_name}.png"
else:
output_path = "./{generated_name}.png"
Step 3: Create Temporary Input File
bash
# For Mermaid
cat > /tmp/diagram.mmd << 'DIAGRAM_EOF'
<mermaid content>
DIAGRAM_EOF
# For Markdown table
cat > /tmp/table.md << 'TABLE_EOF'
<table content>
TABLE_EOF
Step 4: Convert
Mermaid to PNG:
bash
mmdc -i /tmp/diagram.mmd -o <output_path>.png -b white -s 2
Mermaid to SVG:
bash
mmdc -i /tmp/diagram.mmd -o <output_path>.svg -b transparent
Table to PNG:
bash
python3 ~/.claude/skills/diagram-to-image/scripts/table_to_image.py /tmp/table.md <output_path>.png
Step 5: Report Result
After conversion, tell the user:
- Full path where image was saved
- Why that location was chosen (briefly)
- Image dimensions or file size
- Suggest they can specify a different location if needed
Examples
Example 1: Project with images/ directory
Context: User is in a project that has
directory, discussing authentication.
User: "Convert this to an image"
flowchart TD
A[Login] --> B{Valid?}
B -->|Yes| C[Dashboard]
B -->|No| D[Error]
Action:
- Detect exists
- Analyze content → authentication flow
- Generate filename:
- Output:
Example 2: Writing X article about AI
Context: User mentioned writing an article about AI agents for X.
User: "Make this a PNG"
flowchart LR
User --> Agent --> Tools --> Response
Action:
- No standard image directory found
- Context: AI agents article for X
- Generate filename:
- Output:
Example 3: Data comparison table
User: "Export this table as image"
| Model | Speed | Accuracy |
|-------|-------|----------|
| GPT-4 | Slow | High |
| Claude | Fast | High |
Action:
- Check for image directories
- Analyze content → model comparison
- Generate filename:
- Output to appropriate location
Example 4: User specifies location
User: "Save this diagram to ~/Desktop/my-chart.png"
Action: Use exactly
as specified.
Error Handling
- If output directory doesn't exist, create it (with user confirmation for new directories)
- If file already exists, append number:
- If mmdc not installed:
npm install -g @mermaid-js/mermaid-cli
- If Pillow not installed: