/usr/lib/python3/dist-packages/sane.py is in python3-sane 2.8.3-1.
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#
# Python wrapper on top of the _sane module, which is in turn a very
# thin wrapper on top of the SANE library. For a complete understanding
# of SANE, consult the documentation at the SANE home page:
# http://www.sane-project.org/docs.html
__version__ = '2.8.3'
__author__ = ['Andrew Kuchling', 'Ralph Heinkel', 'Sandro Mani']
import _sane
TYPE_STR = {_sane.TYPE_BOOL: "TYPE_BOOL", _sane.TYPE_INT: "TYPE_INT",
_sane.TYPE_FIXED: "TYPE_FIXED", _sane.TYPE_STRING: "TYPE_STRING",
_sane.TYPE_BUTTON: "TYPE_BUTTON", _sane.TYPE_GROUP: "TYPE_GROUP"}
UNIT_STR = {_sane.UNIT_NONE: "UNIT_NONE",
_sane.UNIT_PIXEL: "UNIT_PIXEL",
_sane.UNIT_BIT: "UNIT_BIT",
_sane.UNIT_MM: "UNIT_MM",
_sane.UNIT_DPI: "UNIT_DPI",
_sane.UNIT_PERCENT: "UNIT_PERCENT",
_sane.UNIT_MICROSECOND: "UNIT_MICROSECOND"}
class Option:
"""
Class representing a SANE option. These are returned by a
:func:`SaneDev.__getitem__` lookup of an option on the device, i.e.::
option = scanner["mode"]
The :class:`Option` class has the following attributes:
* `index` -- Number from ``0`` to ``n``, giving the option number.
* `name` -- A string uniquely identifying the option.
* `title` -- Single-line string containing a title for the option.
* `desc` -- A long string describing the option, useful as a help
message.
* `type` -- Type of this option: ``TYPE_BOOL``, ``TYPE_INT``,
``TYPE_STRING``, etc.
* `unit` -- Units of this option. ``UNIT_NONE``, ``UNIT_PIXEL``, etc.
* `size` -- Size of the value in bytes.
* `cap` -- Capabilities available: ``CAP_EMULATED``, ``CAP_SOFT_SELECT``,
etc.
* `constraint` -- Constraint on values. Possible values:
- None : No constraint
- ``(min,max,step)`` : Range
- list of integers or strings: listed of permitted values
"""
def __init__(self, args, scanDev):
self.scanDev = scanDev # needed to get current value of this option
self.index, self.name = args[0], args[1]
self.title, self.desc = args[2], args[3]
self.type, self.unit = args[4], args[5]
self.size, self.cap = args[6], args[7]
self.constraint = args[8]
if not isinstance(self.name, str):
self.py_name = str(self.name)
else:
self.py_name = self.name.replace("-", "_")
def is_active(self):
"""
:returns: Whether the option is active.
"""
return _sane.OPTION_IS_ACTIVE(self.cap)
def is_settable(self):
"""
:returns: Whether the option is settable.
"""
return _sane.OPTION_IS_SETTABLE(self.cap)
def __repr__(self):
if self.is_settable():
settable = 'yes'
else:
settable = 'no'
if self.is_active():
active = 'yes'
curValue = repr(getattr(self.scanDev, self.py_name))
else:
active = 'no'
curValue = '<not available, inactive option>'
s = ("\n"
"Name: %s\n"
"Cur value: %s\n"
"Index: %d\n"
"Title: %s\n"
"Desc: %s\n"
"Type: %s\n"
"Unit: %s\n"
"Constr: %s\n"
"active: %s\n"
"settable: %s\n" % (self.py_name, curValue, self.index,
self.title, self.desc, TYPE_STR[self.type],
UNIT_STR[self.unit], repr(self.constraint),
active, settable))
return s
class _SaneIterator:
"""
Iterator for ADF scans.
"""
def __init__(self, device):
self.device = device
def __iter__(self):
return self
def __del__(self):
self.device.cancel()
def next(self):
try:
self.device.start()
except Exception as e:
if str(e) == 'Document feeder out of documents':
raise StopIteration
else:
raise
return self.device.snap(True)
class SaneDev:
"""
Class representing a SANE device. Besides the functions documented below,
the class has some special attributes which can be read:
* `devname` -- The scanner device name (as passed to
:func:`sane.open`).
* `sane_signature` -- The tuple ``(devname, brand, name, type)``.
* `scanner_model` -- The tuple ``(brand, name)``.
* `opt` -- Dictionary of options.
* `optlist` -- List of option names.
* `area` -- Scan area.
Furthermore, the scanner options are also exposed as attributes, which
can be read and set::
print scanner.mode
scanner.mode = 'Color'
An :class:`Option` object for a scanner option can be retrieved via
:func:`__getitem__`, i.e.::
option = scanner['mode']
"""
def __init__(self, devname):
d = self.__dict__
d['devname'] = devname
d['dev'] = _sane._open(devname)
self.__load_option_dict()
def __get_sane_signature(self):
d = self.__dict__
if 'sane_signature' not in d:
devices = _sane.get_devices()
if devices:
for dev in devices:
if d['devname'] == dev[0]:
d['sane_signature'] = dev
break
if 'sane_signature' not in d:
raise RuntimeError("No such scan device '%s'" % d['devname'])
return d['sane_signature']
def __load_option_dict(self):
d = self.__dict__
d['opt'] = {}
for t in d['dev'].get_options():
o = Option(t, self)
if o.type != _sane.TYPE_GROUP:
d['opt'][o.py_name] = o
def __setattr__(self, key, value):
d = self.__dict__
if key in ('dev', 'optlist', 'area', 'sane_signature',
'scanner_model'):
raise AttributeError("Read-only attribute: " + key)
if key not in self.opt:
d[key] = value
return
opt = d['opt'][key]
if opt.type == _sane.TYPE_BUTTON:
raise AttributeError("Buttons don't have values: " + key)
if opt.type == _sane.TYPE_GROUP:
raise AttributeError("Groups don't have values: " + key)
if not _sane.OPTION_IS_ACTIVE(opt.cap):
raise AttributeError("Inactive option: " + key)
if not _sane.OPTION_IS_SETTABLE(opt.cap):
raise AttributeError("Option can't be set by software: " + key)
if isinstance(value, int) and opt.type == _sane.TYPE_FIXED:
# avoid annoying errors of backend if int is given instead float:
value = float(value)
result = d['dev'].set_option(opt.index, value)
# do binary AND to find if we have to reload options:
if result & _sane.INFO_RELOAD_OPTIONS:
self.__load_option_dict()
def __getattr__(self, key):
d = self.__dict__
if key == 'optlist':
return list(self.opt.keys())
if key == 'area':
return (self.tl_x, self.tl_y), (self.br_x, self.br_y)
if key == 'sane_signature':
return self.__get_sane_signature()
if key == 'scanner_model':
return self.__get_sane_signature()[1:3]
if key in d:
return d[key]
if key not in d['opt']:
raise AttributeError("No such attribute: " + key)
opt = d['opt'][key]
if opt.type == _sane.TYPE_BUTTON:
raise AttributeError("Buttons don't have values: " + key)
if opt.type == _sane.TYPE_GROUP:
raise AttributeError("Groups don't have values: " + key)
if not _sane.OPTION_IS_ACTIVE(opt.cap):
raise AttributeError("Inactive option: " + key)
return d['dev'].get_option(opt.index)
def __getitem__(self, key):
return self.opt[key]
def get_parameters(self):
"""
Returns a 5-tuple holding all the current device settings:
``(format, last_frame, (pixels_per_line, lines), depth,
bytes_per_line)``
* `format` -- One of ``"grey"``, ``"color"``, ``"red"``,
``"green"``, ``"blue"`` or ``"unknown format"``.
* `last_frame` -- Whether this is the last frame of a multi frame
image.
* `pixels_per_line` -- Width of the scanned image.
* `lines` -- Height of the scanned image.
* `depth` -- The number of bits per sample.
* `bytes_per_line` -- The number of bytes per line.
:returns: A tuple containing the device settings.
:raises _sane.error: If an error occurs.
Note: Some backends may return different parameters depending on
whether :func:`SaneDev.start` was called or not.
"""
return self.__dict__['dev'].get_parameters()
def get_options(self):
"""
:returns: A list of tuples describing all the available options.
"""
return self.dev.get_options()
def start(self):
"""
Initiate a scanning operation.
:throws _sane.error: If an error occurs, for instance if an option is
set to an invalid value.
"""
self.dev.start()
def cancel(self):
"""
Cancel an in-progress scanning operation.
"""
self.dev.cancel()
def snap(self, no_cancel=False):
"""
Read image data and return a ``PIL.Image`` object. An RGB image is
returned for multi-band images, an L image for single-band images.
``no_cancel`` is used for ADF scans by :class:`_SaneIterator`.
:returns: A ``PIL.Image`` object.
:raises _sane.error: If an error occurs.
:raises RuntimeError: If `PIL.Image` cannot be imported.
"""
try:
from PIL import Image
except:
raise RuntimeError("Cannot import PIL.Image")
(data, width, height, samples, sampleSize) = self.dev.snap(no_cancel)
if not data:
raise RuntimeError("Scanner returned no data")
mode = 'RGB' if samples == 3 else 'L'
return Image.frombuffer(mode, (width, height), bytes(data), "raw",
mode, 0, 1)
def scan(self):
"""
Convenience method which calls :func:`SaneDev.start` followed by
:func:`SaneDev.snap`.
"""
self.start()
return self.snap()
def arr_snap(self):
"""
Read image data and return a 3d numpy array of the shape
``(width, height, nbands)``.
:returns: A ``numpy.array`` object.
:raises _sane.error: If an error occurs.
:raises RuntimeError: If `numpy` cannot be imported.
"""
try:
import numpy
except:
raise RuntimeError("Cannot import numpy")
(data, width, height, samples, sampleSize) = self.dev.snap(False, True)
if not data:
raise RuntimeError("Scanner returned no data")
if sampleSize == 1:
np = numpy.frombuffer(data, numpy.uint8)
elif sampleSize == 2:
np = numpy.frombuffer(data, numpy.uint16)
else:
raise RuntimeError("Unexpected sample size: %d" % sampleSize)
return numpy.reshape(np, (height, width, samples))
def arr_scan(self):
"""
Convenience method which calls :func:`SaneDev.start` followed by
:func:`SaneDev.arr_snap`.
"""
self.start()
return self.arr_snap()
def multi_scan(self):
"""
:returns: A :class:`_SaneIterator` for ADF scans.
"""
return _SaneIterator(self)
def fileno(self):
"""
:returns: The file descriptor for the scanning device, if any.
:raises _sane.error: If an error occurs.
"""
return self.dev.fileno()
def close(self):
"""
Close the scanning device.
"""
self.dev.close()
def init():
"""
Initialize sane.
:returns: A tuple ``(sane_ver, ver_maj, ver_min, ver_patch)``.
:raises _sane.error: If an error occurs.
"""
return _sane.init()
def get_devices(localOnly=False):
"""
Return a list of 4-tuples containing the available scanning devices.
If `localOnly` is `True`, only local devices will be returned.
Each tuple is of the format ``(device_name, vendor, model, type)``, with:
* `device_name` -- The device name, suitable for passing to
:func:`sane.open`.
* `vendor` -- The device vendor.
* `model` -- The device model vendor.
* `type` -- the device type, such as
``"virtual device"`` or ``"video camera"``.
:returns: A list of scanning devices.
:raises _sane.error: If an error occurs.
"""
return _sane.get_devices(localOnly)
def open(devname):
"""
Open a device for scanning. Suitable values for devname are returned in the
first item of the tuples returned by :func:`sane.get_devices`.
:returns: A :class:`SaneDev` object on success.
:raises _sane.error: If an error occurs.
"""
return SaneDev(devname)
def exit():
"""
Exit sane.
"""
_sane.exit()
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