# QR Code Generator with Logo

This utility generates a QR code from text or a URL and optionally embeds a logo image in the center. It uses high error correction to ensure the QR code remains scannable even with the logo covering part of the data.

**Modules Used:**
*   `qrcode`: To generate the QR code matrix.
*   [[programming/python/modules/pillow-module|Pillow]]: To manipulate images (resize logo, paste onto QR code).
*   [[programming/python/modules/argparse-module|argparse]]: To handle command-line arguments.

## Installation

```bash
pip install "qrcode[pil]" pillow
```

## The Code

Save this as `qr_logo.py`.

```python
import qrcode
from PIL import Image
import argparse
import sys
import os

def generate_qr_with_logo(data, logo_path, output_path, fill_color="black", back_color="white"):
    try:
        # 1. Generate QR Code
        # We use High Error Correction (H) to allow up to 30% damage (covered by logo)
        qr = qrcode.QRCode(
            version=1,
            error_correction=qrcode.constants.ERROR_CORRECT_H,
            box_size=10,
            border=4,
        )
        qr.add_data(data)
        qr.make(fit=True)

        qr_img = qr.make_image(fill_color=fill_color, back_color=back_color).convert('RGB')

        # 2. Add Logo
        if logo_path and os.path.exists(logo_path):
            logo = Image.open(logo_path)
            
            # Calculate logo size
            # The logo should not cover more than 25-30% of the QR code area
            qr_width, qr_height = qr_img.size
            logo_max_size = qr_width // 4  # 25% of QR code size
            
            # Resize logo maintaining aspect ratio
            logo.thumbnail((logo_max_size, logo_max_size))
            
            # Calculate position to center the logo
            logo_pos = ((qr_width - logo.size[0]) // 2, (qr_height - logo.size[1]) // 2)
            
            # Paste logo
            # If logo has transparency (RGBA), use it as a mask
            if logo.mode == 'RGBA':
                qr_img.paste(logo, logo_pos, mask=logo)
            else:
                qr_img.paste(logo, logo_pos)
                
            print(f"Logo embedded: {logo_path}")
        elif logo_path:
            print(f"Warning: Logo file '{logo_path}' not found. Generating standard QR code.")

        # 3. Save
        qr_img.save(output_path)
        print(f"QR Code saved to: {output_path}")

    except Exception as e:
        print(f"Error: {e}")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="QR Code Generator with Logo")
    parser.add_argument("data", help="Data to encode (URL, text, etc.)")
    parser.add_argument("-l", "--logo", help="Path to the logo image file")
    parser.add_argument("-o", "--output", default="qrcode.png", help="Output filename (default: qrcode.png)")
    
    args = parser.parse_args()
    
    generate_qr_with_logo(args.data, args.logo, args.output)
```

## Usage

```bash
# Generate a standard QR code
python qr_logo.py "https://www.example.com"

# Generate with a logo
python qr_logo.py "https://www.python.org" --logo python_logo.png --output python_qr.png
```

[[programming/python/python]]