from PIL import Image
import sys

def get_png_info(file_path):
    try:
        with Image.open(file_path) as img:
            if img.format != 'PNG':
                return "This is not a PNG image."
            
            info = img.info
            result = "PNG Information:\n"
            for key, value in info.items():
                result += f"{key}: {value}\n"
            
            return result
    except Exception as e:
        return f"An error occurred: {str(e)}"

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python checkpnginfo.py <path_to_png_file>")
    else:
        file_path = sys.argv[1]
        print(get_png_info(file_path))