Error while printing image with 2 or 3 channels

[ogir-ok]

If you print image with 2 or 3 channels, it fails
Traceback (most recent call last):
File "test_print.py", line 5, in
p.receipt(receipt)
File "/home/ubuntu/venv/local/lib/python2.7/site-packages/xmlescpos/escpos.py", line 699, in receipt
raise e
IndexError: tuple index out of range