>Please add the --verbose flag to scanimage, and attach the output.
The outputs is as below
scanimage --mode color --format=pdf --batch-count=1 --verbose
Scanning 1 page, incrementing by 1, numbering from 1
Scanning page 1
scanimage: scanning image of size 424x774 pixels at 24 bits/pixel
scanimage
Public bug reported:
When batch-count is set to 1, the output PDF cannot be opened with the
PDF tool.
The command line is as follows
scanimage --mode color --format=pdf --batch-count=1
When mode is set to gray or lineart, the output PDF is abnormal. (there were
three images in one sheet of PDF)