Python Imaging Library

import os
from PIL import Image


def convert_jpegs_to_pngs(folder_path):
    # Checks if the provided path is a folder
    if not os.path.isdir(folder_path):
        print(f"Error: {folder_path} is not a valid folder.")
        return

    # Iterates over all files in the folder
    for filename in os.listdir(folder_path):
        # Checks if the file has a .jpg or .jpeg extension
        if filename.lower().endswith(".jpg") or filename.lower().endswith(".jpeg"):
            # Full path of the file
            jpeg_path = os.path.join(folder_path, filename)
            # Path for the converted file
            png_path = os.path.join(folder_path, os.path.splitext(filename)[0] + ".png")

            try:
                # Opens the JPEG image
                with Image.open(jpeg_path) as img:
                    # Converts and saves as PNG
                    img.save(png_path, "PNG")
                    print(f"Converted {jpeg_path} to {png_path}")
            except Exception as e:
                print(f"Error converting {jpeg_path}: {e}")