Hello,

Here's a general outline of a potential solution:

Preparing the Environment:
Before you start, make sure you have a working environment with the necessary programming tools and libraries. You might need a programming language like Python, libraries for HTML parsing and image manipulation, and access to your source HTML files.

Parsing HTML Files:
Write a script in a programming language like Python that can parse each HTML file to locate the Base64-encoded image data. You can use libraries like Beautiful Soup for HTML parsing.

Converting Base64 to Images:
For each Base64-encoded image, you'll need to decode the Base64 data and save it as an image file (e.g., JPEG, PNG) in a designated directory. Libraries like Python's base64 and PIL (Pillow) can be helpful for this step.

Updating HTML Files:
As you decode each image and save it to the designated directory, update the HTML file to reference the newly saved image file instead of the Base64 data. Modify the <img> tags' src attributes to point to the new image file paths.

Handling Multiple Files:
Loop through all your HTML files, performing the parsing, decoding, and updating steps for each file.

Here's a simplified example in Python:
from bs4 import BeautifulSoup
import base64
from PIL import Image
import os

source_dir = "path/to/source/html/files"
output_dir = "path/to/output/images"

# Create the output directory if it doesn't exist
os.makedirs(output_dir, exist_ok=True)

for filename in os.listdir(source_dir):
    if filename.endswith(".html"):
        with open(os.path.join(source_dir, filename), "r") as f:
            html_content = f.read()
        
        soup = BeautifulSoup(html_content, "html.parser")
        
        # Find all <img> tags in the HTML
        img_tags = soup.find_all("img")
        
        for img_tag in img_tags:
            if "src" in img_tag.attrs and img_tag["src"].startswith("data:image"):
                # Extract Base64 image data
                base64_data = img_tag["src"].split(",")[1]
                
                # Decode Base64 data and save as an image file
                image_data = base64.b64decode(base64_data)
                image_path = os.path.join(output_dir, f"image_{len(os.listdir(output_dir))}.png")
                
                with open(image_path, "wb") as img_file:
                    img_file.write(image_data)
                
                # Update the img tag's src attribute
                img_tag["src"] = image_path
                
        # Update the HTML file with modified img tags
        with open(os.path.join(output_dir, filename), "w") as f:
            f.write(soup.prettify())
Backup and Testing:
Before running the script on all your files, make sure to create backups of your original HTML files. Test the script on a smaller subset of files to ensure it works as expected.

Considerations:
Keep in mind that this is a simplified example. Depending on the complexity of your HTML files and the variability in the structure of the <img> tags, you might need to fine-tune the script. Additionally, handling error cases, such as different image formats and edge cases in HTML structure, is important. (https://www.mayoclinicpatientportals.com/)