import os def create_output_directory(directory="output"): """Create output directory if it doesn't exist""" if not os.path.exists(directory): os.makedirs(directory) return directory def allowed_file(filename): """Check if file has allowed extension""" ALLOWED_EXTENSIONS = {'png', 'jpg', 'jpeg'} return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS