Image Watermarker

A Python package for embedding and extracting watermarks in various image formats (PNG, JPEG, WebP, AVIF, HEIC/HEIF). It provides a simple and flexible way to protect your images by adding hidden or invisible watermarks.

Features

• Multiple Image Formats: Supports PNG, JPEG, WebP, AVIF, and HEIC/HEIF image formats.
• Different Watermarking Techniques:
  • PNG & WebP: Embeds the watermark text into the least significant bit (LSB) of the alpha channel. This is a steganographic technique, making the watermark invisible to the naked eye.
  • JPEG: Embeds the watermark text into the EXIF metadata (Artist field). This method doesn't alter the visual appearance of the image.
  • AVIF & HEIC/HEIF: Appends a custom watermark marker and the watermark text to the end of the file bytes. This method is simpler but may be more easily detectable.
• Easy-to-Use API: Simple functions for adding and checking watermarks.
• Handles Bytes and File Paths: Functions accept image data as bytes, PIL.Image objects, or file paths.
• Error Handling: Includes error handling and informative error messages.
• Dependencies handled: Minimal external dependencies for maximum compatibility.

Installation

pip install image-invisible-watermarker

Usage

The package provides separate functions for each supported image format:

• add_watermark_png(image, watermark_text) and check_watermark_png(image, watermark_text)
• add_watermark_jpeg(image_bytes, watermark_text) and check_watermark_jpeg(image_bytes, watermark_text)
• add_watermark_webp(image, watermark_text, output_path=None) and check_watermark_webp(image, watermark_text)
• add_watermark_avif_heic_heif(file_bytes, watermark_text) and extract_watermark_avif_heic_heif(file_bytes, watermark_text)

PNG Example

from image_watermarker import add_watermark_png, check_watermark_png

# Add watermark to a PNG image
image_bytes = add_watermark_png("input.png", "My Watermark")
if image_bytes:
    with open("output.png", "wb") as f:
        f.write(image_bytes)

# Check for the watermark
result = check_watermark_png("output.png", "My Watermark")
print("IsDetected:", result[0])  # Output: IsDetected: True
print("Detected Text:", result[1])  # Output: Detected Text: My Watermark

# You can also pass image bytes directly:
with open("input.png", "rb") as f:
    image_bytes = f.read()
watermarked_bytes = add_watermark_png(image_bytes, "Another Watermark")
# ...

JPEG Example

from image_watermarker import add_watermark_jpeg, check_watermark_jpeg

# Add watermark to a JPEG image
image_bytes = add_watermark_jpeg("input.jpg", "JPEG Watermark")
if image_bytes:
    with open("output.jpg", "wb") as f:
        f.write(image_bytes)

# Check for the watermark
result = check_watermark_jpeg("output.jpg", "JPEG Watermark")
print("IsDetected:", result[0])
print("Detected Text:", result[1])

# Using file paths:
image_bytes = add_watermark_jpeg("input.jpg", "Another JPEG Watermark") # Pass file path directly

WebP Example

from image_watermarker import add_watermark_webp, check_watermark_webp

# Add watermark to a WebP image
image_bytes = add_watermark_webp("input.webp", "WebP Watermark")
if image_bytes:
    with open("output.webp", "wb") as f:
        f.write(image_bytes)

# Check for the watermark
result = check_watermark_webp("output.webp", "WebP Watermark")
print("IsDetected:", result[0])
print("Detected Text:", result[1])

AVIF/HEIC/HEIF Example

from image_watermarker import add_watermark_avif_heic_heif, extract_watermark_avif_heic_heif

# Add watermark
image_bytes = add_watermark_avif_heic_heif("input.avif", "AVIF Watermark") # or .heic, .heif
if image_bytes:
    with open("output.avif", "wb") as f:
        f.write(image_bytes)

# Check watermark
result = extract_watermark_avif_heic_heif("output.avif", "AVIF Watermark")
print("IsDetected:", result[0])
print("Detected Text:", result[1])

# Example with file path:
image_bytes = add_watermark_avif_heic_heif("input.heic", "HEIC Watermark")

Important Notes

• Alpha Channel (PNG & WebP): The PNG and WebP watermarking methods require images to have an alpha channel. If your image doesn't have one, it will be converted to RGBA.
• LSB Watermarking (PNG & WebP): LSB watermarking is generally robust to minor image manipulations (e.g., resizing, slight color adjustments). However, significant changes to the alpha channel or lossy compression can remove or corrupt the watermark.
• EXIF Metadata (JPEG): Watermarks stored in EXIF metadata can be easily removed by stripping the metadata from the image. This method is less secure than LSB watermarking. Consider it more of a visible attribution than a robust protection mechanism.
• AVIF and HEIC:
  • AVIF and HEIC/HEIF watermarking relies on appending data. This is not a robust watermarking technique. It's easily removed. It's mainly intended for simple cases where a basic, easily detectable watermark is sufficient.
• Error Handling: The functions return None or raise exceptions if errors occur. Check the return values and handle potential exceptions appropriately. Error messages are also printed to the console.
• Dependencies: The package relies on Pillow (PIL), numpy, and piexif. These are automatically installed when you install image-watermarker via pip.

Contributing

Contributions are welcome! If you find a bug or have a feature request, please open an issue on the GitHub repository. If you'd like to contribute code, please fork the repository and submit a pull request.

License

This project is licensed under the Creative Commons Attribution-NoDerivatives (CC BY-ND) License