Try this Python script:

from PIL import Image, ImageDraw, ImageFont
import os
from pathlib import Path

def watermark_from_filename(input_dir, output_dir=None, 
                           position='bottom-right', 
                           font_size=36,
                           color='white',
                           opacity=200):
    """
    Add watermark to images using their filename (without extension)
    
    Args:
        input_dir: Directory containing images
        output_dir: Output directory (if None, creates 'watermarked' subfolder)
        position: 'bottom-right', 'bottom-left', 'top-right', 'top-left', 'center'
        font_size: Size of the watermark text
        color: Color of the text ('white', 'black', or RGB tuple)
        opacity: Transparency (0-255, 255 is fully opaque)
    """
    
    # Setup directories
    input_path = Path(input_dir)
    if output_dir is None:
        output_path = input_path / 'watermarked'
    else:
        output_path = Path(output_dir)
    
    output_path.mkdir(exist_ok=True)
    
    # Supported image formats
    supported_formats = {'.jpg', '.jpeg', '.png', '.tiff', '.bmp'}
    
    # Process each image
    for img_file in input_path.iterdir():
        if img_file.suffix.lower() not in supported_formats:
            continue
            
        print(f"Processing: {img_file.name}")
        
        # Open image
        img = Image.open(img_file)
        
        # Convert to RGBA if needed (for transparency support)
        if img.mode != 'RGBA':
            img = img.convert('RGBA')
        
        # Create transparent overlay
        txt_layer = Image.new('RGBA', img.size, (255, 255, 255, 0))
        draw = ImageDraw.Draw(txt_layer)
        
        # Get filename without extension
        watermark_text = img_file.stem
        
        # Try to load a nice font, fall back to default if not available
        try:
            font = ImageFont.truetype("arial.ttf", font_size)
        except:
            try:
                font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", font_size)
            except:
                font = ImageFont.load_default()
        
        # Get text size using textbbox
        bbox = draw.textbbox((0, 0), watermark_text, font=font)
        text_width = bbox[2] - bbox[0]
        text_height = bbox[3] - bbox[1]
        
        # Calculate position
        margin = 20
        if position == 'bottom-right':
            x = img.width - text_width - margin
            y = img.height - text_height - margin
        elif position == 'bottom-left':
            x = margin
            y = img.height - text_height - margin
        elif position == 'top-right':
            x = img.width - text_width - margin
            y = margin
        elif position == 'top-left':
            x = margin
            y = margin
        elif position == 'center':
            x = (img.width - text_width) // 2
            y = (img.height - text_height) // 2
        else:
            x = img.width - text_width - margin
            y = img.height - text_height - margin
        
        # Convert color name to RGB if needed
        if color == 'white':
            rgb_color = (255, 255, 255, opacity)
        elif color == 'black':
            rgb_color = (0, 0, 0, opacity)
        else:
            rgb_color = (*color, opacity) if isinstance(color, tuple) else (255, 255, 255, opacity)
        
        # Draw text
        draw.text((x, y), watermark_text, font=font, fill=rgb_color)
        
        # Composite the watermark onto the image
        watermarked = Image.alpha_composite(img, txt_layer)
        
        # Convert back to RGB for JPEG
        if img_file.suffix.lower() in {'.jpg', '.jpeg'}:
            watermarked = watermarked.convert('RGB')
        
        # Save
        output_file = output_path / img_file.name
        watermarked.save(output_file, quality=95)
        print(f"Saved: {output_file.name}")
    
    print(f"\nDone! Watermarked images saved to: {output_path}")

# Example usage:
if __name__ == "__main__":
    # Watermark all images in current directory
    watermark_from_filename(
        input_dir=".",
        position='bottom-right',
        font_size=48,
        color='white',
        opacity=200
    )

To use this script:

1. Install Pillow: pip install Pillow

2. Save the script as watermark_dates.py

3. Run it in your image directory:

   python watermark_dates.py
   

Customization options:

• position: Choose where the watermark appears
• font_size: Adjust text size
• color: ‘white’, ‘black’, or RGB tuple like (255, 0, 0) for red
• opacity: 0-255 (lower = more transparent)