diff -up hplip-3.14.6/scan.py.lineart hplip-3.14.6/scan.py
--- hplip-3.14.6/scan.py.lineart	2014-07-23 12:30:52.361517852 +0100
+++ hplip-3.14.6/scan.py	2014-07-23 12:32:17.052940000 +0100
@@ -977,8 +977,8 @@ try:
                         try:
                             pixels_per_line = bytes_per_line * 8          # Calculation of pixels_per_line for Lineart must be 8 time of bytes_per_line
                                                                           # Otherwise, scanned image will be corrupted (slanted)
-                            im = Image.frombuffer('RGBA', (pixels_per_line, lines), buffer.read(),
-                                'raw', 'RGBA', 0, 1).convert('L')
+                            im = Image.frombuffer('1', (pixels_per_line, lines), buffer.read(),
+                                'raw', '1', 0, 1).convert('L')
                         except ValueError:
                             log.error("Did not read enough data from scanner (I/O Error?)")
                             sys.exit(1)