A little Python script to brighten an image.

import os
from PIL import ImageEnhance, Image

def brightenImage(input_dir, output_dir):
    os.makedirs(output_dir, exist_ok=True)                                          # output directory
    for filename in os.listdir(input_dir):                                          # loop through files
        if filename.lower().endswith('.jpg'):                                       # check if jpg
            with Image.open(os.path.join(input_dir, filename)) as img:              # open jpg  
                enhanced_img = ImageEnhance.Contrast(img).enhance(1.25)             # enhance contrast
                enhanced_img = ImageEnhance.Brightness(enhanced_img).enhance(1.5)   # enhance brightness
                enhanced_img.save(os.path.join(output_dir, filename))               # save output

if __name__ == '__main__':
    input_directory = '.'                                                           # input directory
    output_directory = 'output'                                                     # output directory
    brightenImage(input_directory, output_directory)                                # brighten image