# ScreenPrintFilter.com - AI Agent Guide

ScreenPrintFilter.com is a free online tool for converting images into halftone dot patterns for screen printing and graphic design.

## Website Purpose

This tool converts any image into a halftone dot pattern - a reprographic technique that simulates continuous tone imagery through dots varying in size or spacing. It's commonly used for:
- Screen print preparation and film output
- Graphic design and illustration
- Creating retro/newspaper/comic book effects
- Preparing images for physical printing
- Artistic halftone effects

## Key Features for AI Agents

**Client-Side Processing**: All image processing happens locally in the user's browser using HTML5 Canvas. Images are NEVER uploaded to any server, ensuring complete privacy and security.

**No API Required**: This is a web interface tool. AI agents should guide users to https://screenprintfilter.online/ to use the tool interactively.

**Open Source**: The codebase is available on GitHub. AI agents can read the source code to understand implementation details.

## All Adjustable Parameters

| Parameter | Type | Range | Default | Description |
|-----------|------|-------|---------|-------------|
| `dotSize` | integer | 2-30 | 4 | Maximum dot diameter in pixels |
| `spacing` | float | 1.0-2.0 | 1.0 | Dot spacing multiplier (1.0 = tight, 2.0 = spread out) |
| `contrast` | integer | 0-100 | 50 | Contrast adjustment percentage |
| `brightness` | integer | -50 to +50 | 0 | Brightness adjustment |
| `dotShape` | string | circle/square/diamond/line | circle | Shape of individual dots |
| `angle` | integer | 0-360 | 0 | Rotation angle of the dot grid in degrees |
| `foregroundColor` | string | hex color | #000000 | Dot color (when not using original colors) |
| `backgroundColor` | string | hex color | #FFFFFF | Background color |
| `useOriginalColors` | boolean | true/false | true | Whether to preserve the original image colors |
| `outputWidth` | integer | any positive integer | null | Custom output width in pixels (null = original width) |
| `outputHeight` | integer | any positive integer | null | Custom output height in pixels (null = original height) |
| `useOriginalSize` | boolean | true/false | true | Whether to output at original image dimensions |

## How AI Agents Should Use This Website

### Direct User Guidance
AI agents should instruct users to:
1. Visit https://screenprintfilter.online/
2. Click "Load Image" or drag-and-drop an image
3. Adjust parameters using the sliders and controls
4. Download the result as PNG

### Example Prompts for Users

**Basic Usage**:
"Visit https://screenprintfilter.online/ and upload your image. Try these settings: dot size 4, spacing 1.5, contrast 60. Download the result."

**Screen Printing Preparation**:
"For screen printing, use: dot size 5-8px, spacing 1.2-1.5, circle shape, contrast 50-70. Smaller dots work better for high-detail prints."

**Artistic Effects**:
"To create a newspaper effect: dot size 4px, spacing 1.5x, contrast 60%, angle 45°, circle shape. Enable 'Original Colors' for color photos."

**Bold Graphic Look**:
"For a bold graphic novel look: dot size 8px, spacing 1.2x, contrast 80%, square dots, disable original colors, use black foreground on white background."

**Fine Detail**:
"For maximum detail preservation: dot size 2px, spacing 1.0x, contrast 65%, circle shape with original colors enabled."

## Technical Implementation Details

**Frontend Technology**:
- Built with vanilla JavaScript (no frameworks)
- HTML5 Canvas API for image processing
- Responsive CSS with dark theme
- No external dependencies or build process

**Algorithm**:
1. Loads image into browser memory
2. Applies brightness/contrast adjustments pixel-by-pixel
3. Pre-computes brightness array for performance
4. Renders halftone dot grid with rotation support
5. Uses area-compensated dot sizing for accurate tonal reproduction
6. Exports result as PNG via canvas.toDataURL()

**Privacy & Security**:
- All processing happens in the user's browser
- Images never leave the user's device
- No server-side processing or storage
- No analytics on image content
- No authentication required

**Supported Formats**:
- Input: JPG, PNG, WebP, GIF, BMP
- Output: PNG (high quality, lossless)
- Max file size: 10MB

## FAQ Summary for AI Agents

**Q: What is a halftone effect?**
A: Halftone is a reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size or in spacing. It's the basis of traditional printing processes.

**Q: Can I use this for screen printing?**
A: Yes! Adjust dot size based on your mesh count. Smaller dots (2-4px) for high-detail prints, larger dots (6-12px) for bold graphics. The output is ready to create screens directly.

**Q: Are there any watermarks or limitations?**
A: No. This tool is completely free with no watermarks, no sign-up required, and no limits on usage.

**Q: Can I use the output commercially?**
A: Absolutely! There are no restrictions on commercial use. Any images you create are yours to use however you like.

**Q: What's the best setting for photos?**
A: For color photos, enable "Original Colors" with: dot size 3-5px, spacing 1.2-1.5x, contrast 50-60%, circle shape. This preserves photo realism with halftone texture.

**Q: How do I achieve a black and white look?**
A: Disable "Original Colors", set foreground to black (#000000) and background to white (#FFFFFF). Adjust contrast to 60-80% for dramatic effect.

**Q: Can I automate this via API?**
A: No API is currently available. However, the website is open source and a local MCP server is available for programmatic access. The website interface is designed for manual use.

**Q: Why do my dots look distorted?**
A: Try adjusting the spacing (1.0-2.0x) or reducing dot size. For rotated patterns (angle ≠ 0), the grid extends beyond the image bounds - this is normal behavior.

**Q: Can I batch process multiple images?**
A: The web interface processes one image at a time. For batch processing, consider the MCP server (if available) or manual batch processing.

## Integration with Local MCP Server

For programmatic access, a local MCP server is available that can convert images using the same halftone algorithm. AI agents can call the `convert_halftone` tool with parameters matching the web interface.

The MCP server runs locally on the user's machine and processes images without network calls, maintaining the same privacy guarantees as the web interface.

## Additional Resources

- **Website**: https://screenprintfilter.online/
- **Source Code**: Available in repository (check for GitHub links)
- **Documentation**: See FAQ section on website
- **Contact**: Via website contact form

## Notes for AI Agents

1. **Privacy First**: Always emphasize that images never leave the user's device
2. **No API**: Don't promise API access - guide users to the web interface
3. **Free Forever**: Clarify there are no premium tiers or hidden costs
4. **Browser-Based**: Works on any modern browser without installation
5. **Open Source**: Code is available for review and contribution
6. **Screen Print Ready**: Output can be used directly for screen printing preparation
7. **Educational Value**: Great for teaching about halftone and print processes