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# coding: utf-8
#
# Project: X-ray image reader
# https://github.com/silx-kit/fabio
#
#
# Copyright (C) European Synchrotron Radiation Facility, Grenoble, France
#
# Principal author: Jérôme Kieffer (Jerome.Kieffer@ESRF.eu)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE
"""
Authors: Henning O. Sorensen & Erik Knudsen
Center for Fundamental Research: Metal Structures in Four Dimensions
Risoe National Laboratory
Frederiksborgvej 399
DK-4000 Roskilde
email:henning.sorensen@risoe.dk
* Jérôme Kieffer:
European Synchrotron Radiation Facility;
Grenoble (France)
License: MIT
"""
__authors__ = ["Jérôme Kieffer", "Henning O. Sorensen", "Erik Knudsen"]
__date__ = "18/12/2020"
__license__ = "MIT"
__copyright__ = "ESRF, Grenoble & Risoe National Laboratory"
__status__ = "stable"
import io
import logging
import numpy
logger = logging.getLogger(__name__)
from .fabioimage import FabioImage
SUBFORMATS = (b'P1', b'P2', b'P3', b'P4', b'P5', b'P6', b'P7')
HEADERITEMS = (b'SUBFORMAT', b'WIDTH', b'HEIGHT', b'MAXVAL')
P7HEADERITEMS = (b'WIDTH', b'HEIGHT', b'DEPTH', b'MAXVAL', b'TUPLTYPE', b'ENDHDR')
class PnmImage(FabioImage):
DESCRIPTION = "PNM file format"
DEFAULT_EXTENSIONS = ["pnm", "pgm", "pbm"]
def __init__(self, *arg, **kwargs):
FabioImage.__init__(self, *arg, **kwargs)
self.header['Subformat'] = 'P5'
def _readheader(self, f):
# pnm images have a 3-line header but ignore lines starting with '#'
# 1st line contains the pnm image sub format
# 2nd line contains the image pixel dimension
# 3rd line contains the maximum pixel value (at least for grayscale - check this)
line = f.readline().strip()
if line not in SUBFORMATS:
raise IOError('unknown subformat of pnm: %s' % line)
else:
self.header[b'SUBFORMAT'] = line
if self.header[b'SUBFORMAT'] == 'P7':
# this one has a special header
while b'ENDHDR' not in line:
line = f.readline()
while(line[0] == '#'):
line = f.readline()
s = line.lsplit(' ', 1)
if s[0] not in P7HEADERITEMS:
raise IOError('Illegal pam (netpnm p7) headeritem %s' % s[0])
self.header[s[0]] = s[1]
else:
values = list(line.split())
while len(values) < len(HEADERITEMS):
line = f.readline()
while line[0] == '#':
line = f.readline()
values += line.split()
for k, v in zip(HEADERITEMS, values):
self.header[k] = v.strip()
# set the dimensions
dim1 = int(self.header[b"WIDTH"])
dim2 = int(self.header[b"HEIGHT"])
self._shape = dim2, dim1
# figure out how many bytes are used to store the data
# case construct here!
m = int(self.header[b'MAXVAL'])
if m < 256:
self._dtype = numpy.dtype(numpy.uint8)
elif m < 65536:
self._dtype = numpy.dtype(numpy.uint16)
elif m < 2147483648:
self._dtype = numpy.dtype(numpy.uint32)
logger.warning('32-bit pixels are not really supported by the netpgm standard')
else:
raise IOError('could not figure out what kind of pixels you have')
def read(self, fname, frame=None):
"""
try to read PNM images
:param fname: name of the file
:param frame: not relevant here! PNM is always single framed
"""
self.header = self.check_header()
self.resetvals()
infile = self._open(fname)
self._readheader(infile)
# read the image data
fmt = str(self.header[b'SUBFORMAT'], encoding="latin-1")
decoder_name = "%sdec" % fmt
if decoder_name in dir(PnmImage):
decoder = getattr(PnmImage, decoder_name)
self.data = decoder(self, infile, self._dtype)
else:
raise IOError("No decoder named %s for file %s" % (decoder_name, fname))
self.resetvals()
return self
def write(self, fname):
"""
try to write image. For now, limited to
:param fname: name of the file
"""
self.header[b"SUBFORMAT"] = "P5"
self.header[b"WIDTH"] = self.shape[-1]
self.header[b"HEIGHT"] = self.shape[-2]
self.header[b"MAXVAL"] = self.data.max()
header = (" ".join([str(self.header[key]) for key in HEADERITEMS[1:]])).encode("latin-1")
with self._open(fname, "wb") as fobj:
fobj.write(b"P5 \n")
fobj.write(header)
fobj.write(b" \n")
if isinstance(fobj, io.BufferedWriter):
if numpy.little_endian:
self.data.byteswap().tofile(fobj)
else:
self.data.tofile(fobj)
else:
if numpy.little_endian:
fobj.write(self.data.byteswap().tobytes())
else:
fobj.write(self.data.tobytes())
def P1dec(self, buf, bytecode):
data = numpy.zeros(self.shape)
i = 0
for l in buf:
try:
data[i,:] = numpy.array(l.split()).astype(bytecode)
except ValueError:
raise IOError('Size spec in pnm-header does not match size of image data field')
return data
def P4dec(self, buf, bytecode):
err = 'single bit (pbm) images are not supported - yet'
logger.error(err)
raise NotImplementedError(err)
def P2dec(self, buf, bytecode):
data = numpy.zeros(self.shape)
i = 0
for l in buf:
try:
data[i,:] = numpy.array(l.split()).astype(bytecode)
except ValueError:
raise IOError('Size spec in pnm-header does not match size of image data field')
return data
def P5dec(self, buf, bytecode):
data = buf.read()
try:
data = numpy.frombuffer(data, bytecode).copy()
except ValueError:
raise IOError('Size spec in pnm-header does not match size of image data field')
data.shape = self.shape
if numpy.little_endian:
data.byteswap(True)
return data
def P3dec(self, buf, bytecode):
err = '(plain-ppm) RGB images are not supported - yet'
logger.error(err)
raise NotImplementedError(err)
def P6dec(self, buf, bytecode):
err = '(ppm) RGB images are not supported - yet'
logger.error(err)
raise NotImplementedError(err)
def P7dec(self, buf, bytecode):
err = '(pam) images are not supported - yet'
logger.error(err)
raise NotImplementedError(err)
@staticmethod
def check_data(data=None):
if data is None:
return None
else:
data = data.clip(0, 65535)
if data.max() < 256:
return data.astype(numpy.uint8)
else:
return data.astype(numpy.uint16)
pnmimage = PnmImage
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