如何将image/tiff;base64字符串转换为image/png;base64字符串？

import base64
from PIL import Image

def convert_tiff_to_png(base64_tiff):
    # 解码base64字符串为二进制数据
    tiff_data = base64.b64decode(base64_tiff)

    # 将二进制数据转换为tiff格式的图像对象
    tiff_image = Image.open(io.BytesIO(tiff_data))
    tiff_image.format = 'TIFF'

    # 将tiff格式的图像对象转换为png格式的图像对象
    png_image = tiff_image.convert('PNG')

    # 将png格式的图像对象转换回base64字符串
    buffered = io.BytesIO()
    png_image.save(buffered, format="PNG")
    base64_png = base64.b64encode(buffered.getvalue()).decode('utf-8')

    return base64_png