Can not save Image File

Dear, all

Board Model: Maixpy Go Suit
Firmware Version: MicroPython v0.4.0-96-gc0bee2c on 2019-11-26;
SD: Fat32, ext4 and ext3 tested

First of all, sorry for being too basic a question.

We are experimenting with saving images to the SD card.

// Code
import sensor, lcd, image

print (“init”)
lcd.init (freq = 15000000)
sensor.reset ()
sensor.set_pixformat (sensor.RGB565)
sensor.set_framesize (sensor.VGA)
sensor.run (1)
sensor.skip_frames (40)
print (“init ok”)

path = “/sd/image.jpg”
img = sensor.snapshot ()
img.save (path)

print (“read image”)
img_read = image.Image (path)
lcd.display (img_read)
print (“ok”)

-Error Message-
Traceback (most recent call last):
File “”, line 14, in
OSError: [Errno 22] EINVAL
MicroPython v0.4.0-96-gc0bee2c on 2019-11-26; Sipeed_M1 with kendryte-k210

How can I save to an SD card?

Thanks a lot