Source code for pyexttiff

#!/usr/bin/env python
# -*- coding: utf-8 -*
# Copyright (c) Météo France (2014-)
# This software is governed by the CeCILL-C license under French law.
# http://www.cecill.info
"""
This module aims at reading tiff with private IFDs.
It uses PIL for image reading.

This module uses code from pylibtiff (https://pypi.python.org/pypi/libtiff, https://code.google.com/p/pylibtiff or https://github.com/hmeine/pylibtiff)
"""

from __future__ import print_function, absolute_import, division  # , unicode_literals

import os
import StringIO
import numpy
import mmap
import PIL.Image
import six


[docs]class PyexttiffError(Exception): """Error handling for pyexttiff.""" pass
[docs]class TiffFile(object): """ This class allows the access to the entire tiff file (tags and images). """ _rational = numpy.dtype([('numer', numpy.uint32), ('denom', numpy.uint32)]) _srational = numpy.dtype([('numer', numpy.int32), ('denom', numpy.int32)]) _type2name = {1:'BYTE', 2:'ASCII', 3:'SHORT', 4:'LONG', 5:'RATIONAL', # two longs, lsm uses it for float64 6:'SBYTE', 7:'UNDEFINED', 8:'SSHORT', 9:'SLONG', 10:'SRATIONAL', 11:'FLOAT', 12:'DOUBLE', } _name2type = dict((v, k) for k, v in _type2name.items()) _name2type['SHORT|LONG'] = _name2type['LONG'] _name2type['LONG|SHORT'] = _name2type['LONG'] _type2bytes = {1:1, 2:1, 3:2, 4:4, 5:8, 6:1, 7:1, 8:2, 9:4, 10:8, 11:4, 12:8} _type2dtype = {1:numpy.uint8, 2:numpy.uint8, 3:numpy.uint16, 4:numpy.uint32, 5:_rational, 6:numpy.int8, 7:numpy.uint8, 8:numpy.int16, 9:numpy.int32, 10:_srational, 11:numpy.float32, 12:numpy.float64} class _LittleEndianNumpyDTypes(object): uint8 = numpy.dtype('<u1') uint16 = numpy.dtype('<u2') uint32 = numpy.dtype('<u4') uint64 = numpy.dtype('<u8') int8 = numpy.dtype('<i1') int16 = numpy.dtype('<i2') int32 = numpy.dtype('<i4') int64 = numpy.dtype('<i8') float32 = numpy.dtype('<f4') float64 = numpy.dtype('<f8') complex64 = numpy.dtype('<c8') complex128 = numpy.dtype('<c16') @property def type2dt(self): return dict((k, numpy.dtype(v).newbyteorder('<')) for k, v in TiffFile._type2dtype.items()) class _BigEndianNumpyDTypes(object): uint8 = numpy.dtype('>u1') uint16 = numpy.dtype('>u2') uint32 = numpy.dtype('>u4') uint64 = numpy.dtype('>u8') int8 = numpy.dtype('>i1') int16 = numpy.dtype('>i2') int32 = numpy.dtype('>i4') int64 = numpy.dtype('>i8') float32 = numpy.dtype('>f4') float64 = numpy.dtype('>f8') complex64 = numpy.dtype('>c8') complex128 = numpy.dtype('>c16') @property def type2dt(self): return dict((k, numpy.dtype(v).newbyteorder('>')) for k, v in TiffFile._type2dtype.items()) def __init__(self, filename, subIFDpaths=[], method=1): """ Opens a tiff file, reads header and IFDs. *filename* is the filename containing the tiff *subIFDpaths* is the list of tag path whose values are offset to private IFDs a tag path is a tuple representing the path to a given tag which must represent an IFD (34665) means that tag 34665 of any given public IFD is an offset to a private IFD (32001, 521) means that tag 32001 of any given public IFD is an offset to a private IFD and that tag 521 of any private tag referenced by a 32001 public tag is also an offset to a private IFD *method* is the method used to read data: 1: f=open(..., 'rb') ; numpy.frombuffer(f.read(), dtype=numpy.ubyte) 2: f=open(..., 'rb') ; numpy.ndarray(buffer=mmap(f), dtype=numpy.ubyte) 3: same as 2 but with modifications allowed - DANGEROUS """ self._filename = filename self._subIFDpaths = subIFDpaths self._fileHandle = None if not os.path.exists(filename): raise IOError(filename + " must exists.") # Reading file if method == 1: with open(filename, 'rb') as f: self._data = numpy.frombuffer(f.read(), dtype=numpy.ubyte) elif method == 2: self._fileHandle = open(filename, 'rb') mm = mmap.mmap(self._fileHandle.fileno(), 0, prot=mmap.PROT_READ) self._data = numpy.ndarray(shape=(mm.size(),), buffer=mm, dtype=numpy.ubyte) elif method == 3: self._fileHandle = open(filename, 'r+b') mm = mmap.mmap(self._fileHandle.fileno(), 0) self._data = numpy.ndarray(shape=(mm.size(),), buffer=mm, dtype=numpy.ubyte) else: raise PyexttiffError("This method is unknown.") # Decoding header - byte order byteorder = self._data[0:2].view(dtype=numpy.uint16)[0] if byteorder == 0x4949: self.endian = 'little' self.dtypes = TiffFile._LittleEndianNumpyDTypes() elif byteorder == 0x4d4d: self.endian = 'big' self.dtypes = TiffFile._BigEndianNumpyDTypes() else: raise IOError('unrecognized byteorder: %s' % (hex(byteorder))) # Decoding header - magic number magic = self._get_uint16(2) if magic != 42: raise IOError('wrong magic number for TIFF file: %s' % (magic)) # Decoding header - first IFD offset IFD0offset = self._get_uint32(4) # IFD reading self.IFDs = [] offset = IFD0offset num = 0 while offset: ifd, offset = self._readIFD(offset, (), subIFDpaths, num) if ifd.has_image(): num += 1 else: raise PyexttiffError("Not sure about IFD that does not contain image.") self.IFDs.append(ifd) def _readIFD(self, offset, path, subIFDpaths, num): """ Reads recursively IFDs """ ifd = IFD() n = self._get_uint16(offset) for i in range(n): entryOffset = offset + 2 + i * 12 entrytag = self._get_uint16(entryOffset) entrytype = self._get_uint16(entryOffset + 2) entrycount = self._get_uint32(entryOffset + 4) entrybytes = TiffFile._type2bytes.get(entrytype, 0) if entrycount == 1 and 1 <= entrybytes <= 4: entryvalue = self._get_values(entryOffset + 8, entrytype, entrycount) else: valueOffset = self._get_int32(entryOffset + 8) entryvalue = self._get_values(valueOffset, entrytype, entrycount) entrypath = tuple(list(path) + [entrytag]) if entrypath in [mypath[:len(entrypath)] for mypath in subIFDpaths]: subifd, _ = self._readIFD(entryvalue, entrypath, subIFDpaths, None) ifd.append(IFDEntry(entrytag, entrytype, subifd)) else: ifd.append(IFDEntry(entrytag, entrytype, entryvalue)) if path == () and ifd.has_tag(273): # Raw data nbRows = ifd.get_value(257) offsetValues = ifd.get_value(273) nbRowsPerStrip = ifd.get_value(278) nbBytesPerStrip = ifd.get_value(279) if not isinstance(offsetValues, numpy.ndarray): offsetValues = numpy.array([offsetValues]) nbBytesPerStrip = numpy.array([nbBytesPerStrip]) if nbRows / nbRowsPerStrip + (1 if nbRows % nbRowsPerStrip != 0 else 0) != len(offsetValues): raise PyexttiffError("Total number of rows, strip numbers and number of rows per strips are not consistent.") data = [] for i in range(len(offsetValues)): data.append(self._get_values(offsetValues[i], 1, nbBytesPerStrip[i])) ifd.get_entry(273).set_value(data) # Image data im = self.get_PILImage() im.seek(num) data = numpy.array(im) if data.shape == (): data = numpy.array(im) # Sometimes must be called twice to return values... ifd._image = data nextIFD = self._get_uint32(offset + 2 + n * 12) return (ifd, nextIFD)
[docs] def get_data(self): """ Returns the ndarray containing the data. """ return self._data
[docs] def get_buffer(self): """ Returns the buffer """ return numpy.getbuffer(self.get_data())
[docs] def get_stringio(self): """ Returns the stringio representeing the buffer. """ return StringIO.StringIO(self.get_buffer())
[docs] def get_PILImage(self): """ Returns the PIL image object of the file. """ return PIL.Image.open(self.get_stringio())
def _get_uint16(self, offset): return self.get_data()[offset:offset + 2].view(dtype=self.dtypes.uint16)[0] def _get_uint32(self, offset): return self.get_data()[offset:offset + 4].view(dtype=self.dtypes.uint32)[0] def _get_int32(self, offset): return self.get_data()[offset:offset + 4].view(dtype=self.dtypes.int32)[0] def _get_values(self, offset, typ, count): if isinstance(typ, numpy.dtype): dtype = typ size = typ.itemsize elif isinstance(typ, type) and issubclass(typ, numpy.generic): dtype = typ size = typ().itemsize else: if isinstance(typ, six.string_types): ntyp = typ typ = TiffFile._name2type.get(typ) else: ntyp = str(typ) dtype = self.dtypes.type2dt.get(typ) size = TiffFile._type2bytes.get(typ) if dtype is None or size is None: raise PyexttiffError('_get_values: incomplete info for type=%r [%r]: dtype=%s, bytes=%s\n' % (typ, ntyp, dtype, size)) result = self.get_data()[offset:offset + size * count].view(dtype=dtype) return result
[docs] def close(self): """ Closes the file. """ if self._fileHandle is not None: self._fileHandle.close()
def __del__(self): """ __del__ method """ self.close()
[docs]class IFD(list): """This class represent an IFD.""" def __init__(self): """Initialisation method of IFD class.""" self._image = None
[docs] def has_tag(self, tag): """Returns True if an entry fits the tag given""" result = False for entry in self: if entry.get_tag() == tag: result = True return result
[docs] def get_entry(self, tag): """Returns the entry for a tag""" if not self.has_tag(tag): raise PyexttiffError("This tag doesn't exist in this IFD.") for entry in self: if entry.get_tag() == tag: result = entry return result
[docs] def get_value(self, tag, human=True): """ Returns the value for a tag if human=True, value is modified: - value[0] is retruned instead of value if array contains only one element - conversion in string is achieved for arrays representing strings """ if not self.has_tag(tag): raise PyexttiffError("This tag doesn't exist in this IFD.") return self.get_entry(tag).get_value(human)
[docs] def has_image(self): """Returns True if one tag is an image""" return self._image is not None
[docs] def get_image(self): """Returns the image""" if not self.has_image(): raise PyexttiffError("This IFD doesn't contain an image.") return self._image
[docs] def get_tags(self): """Returns the list of the tags""" return [entry.get_tag() for entry in self]
[docs] def as_dict(self): """Returns a dictionary containing all entries.""" return dict([(entry.get_tag(), entry.get_value()) for entry in self])
[docs]class IFDEntry(object): """This class represent an IFD entry""" # <TagName> <Hex> <Type> <Number of values> _tag_info = ''' # standard tags: NewSubfileType FE LONG 1 SubfileType FF SHORT 1 ImageWidth 100 SHORT|LONG 1 ImageLength 101 SHORT|LONG 1 BitsPerSample 102 SHORT SamplesPerPixel Compression 103 SHORT 1 Uncompressed 1 CCITT1D 2 Group3Fax 3 Group4Fax 4 LZW 5 JPEG 6 PackBits 32773 PhotometricInterpretation 106 SHORT 1 WhiteIsZero 0 BlackIsZero 1 RGB 2 RGBPalette 3 TransparencyMask 4 CMYK 5 YCbCr 6 CIELab 8 Threshholding 107 SHORT 1 CellWidth 108 SHORT 1 CellLength 109 SHORT 1 FillOrder 10A SHORT 1 DocumentName 10D ASCII ImageDescription 10E ASCII Make 10F ASCII Model 110 ASCII StripOffsets 111 SHORT|LONG StripsPerImage Orientation 112 SHORT 1 TopLeft 1 TopRight 2 BottomRight 3 BottomLeft 4 LeftTop 5 RightTop 6 RightBottom 7 LeftBottom 8 SamplesPerPixel 115 SHORT 1 RowsPerStrip 116 SHORT|LONG 1 StripByteCounts 117 LONG|SHORT StripsPerImage MinSampleValue 118 SHORT SamplesPerPixel MaxSampleValue 119 SHORT SamplesPerPixel XResolution 11A RATIONAL 1 YResolution 11B RATIONAL 1 PlanarConfiguration 11C SHORT 1 Chunky 1 Planar 2 PageName 11D ASCII XPosition 11E DOUBLE YPosition 11F DOUBLE FreeOffsets 120 LONG FreeByteCounts 121 LONG GrayResponseUnit 122 SHORT 1 GrayResponseCurve 123 SHORT 2**BitsPerSample T4Options 124 LONG 1 T6Options 125 LONG 1 ResolutionUnit 128 SHORT 1 PageNumber 129 SHORT 2 TransferFunction 12D SHORT (1|SamplesPerPixel)*2**BitsPerSample Software 131 ASCII DateTime 132 ASCII 20 Artist 13B ASCII HostComputer 13C ASCII Predictor 13D SHORT 1 WhitePoint 13E RATIONAL 2 PrimaryChromaticities 13F RATIONAL 6 ColorMap 140 SHORT 3*(2**BitsPerSample) HalftoneHints 141 SHORT 2 TileWidth 142 SHORT|LONG 1 TileLength 143 SHORT|LONG 1 TileOffsets 144 LONG TilesPerImage TileByteCounts 145 SHORT|LONG TilesPerImage InkSet 14C SHORT 1 InkNames 14D ASCII <total number of chars in all ink name strings, including zeros> NumberOfInks 14E SHORT 1 DotRange 150 BYTE|SHORT 2|2*NumberOfInks TargetPrinter 151 ASCII any ExtraSamples 152 BYTE <number of extra components per pixel> SampleFormat 153 SHORT SamplesPerPixel SMinSampleValue 154 Any SamplesPerPixel SMaxSampleValue 155 Any SamplesPerPixel TransferRange 156 SHORT 6 JPEGProc 200 SHORT 1 JPEGInterchangeFormat 201 LONG 1 JPEGInterchangeFormatLength 202 LONG 1 JPEGRestartInterval 203 SHORT 1 JPEGLosslessPredictos 205 SHORT SamplesPerPixel JPEGPointTransforms 206 SHORT SamplesPerPixel JPEGQTables 207 LONG SamplesPerPixel JPEGDCTables 208 LONG SamplesPerPixel JPEGACTables 209 LONG SamplesPerPixel YCbCrCoefficients 211 RATIONAL 3 YCbCrSubSampling 212 SHORT 2 YCbCrPositioning 213 SHORT 1 ReferenceBlackWhite 214 LONG 2*SamplesPerPixel Copyright 8298 ASCII Any # non-standard tags: CZ_LSMInfo 866C CZ_LSM # EXIF tags, see http://www.awaresystems.be/imaging/tiff/tifftags/privateifd/exif.html EXIF_IFDOffset 8769 SHORT 1 EXIF_ExposureTime 829a RATIONAL 1 EXIF_FNumber 829d RATIONAL 1 EXIF_ExposureProgram 8822 SHORT 1 EXIF_SpectralSensitivity 8824 ASCII EXIF_ISOSpeedRatings 8827 SHORT 1 EXIF_OECF 8828 UNDEFINED EXIF_ExifVersion 9000 UNDEFINED 4 EXIF_DateTimeOriginal 9003 ASCII EXIF_DateTimeDigitized 9004 ASCII EXIF_ComponentsConfiguration 9101 UNDEFINED 4 EXIF_CompressedBitsPerPixel 9102 RATIONAL 1 EXIF_ShutterSpeedValue 9201 SRATIONAL 1 EXIF_ApertureValue 9202 RATIONAL 1 EXIF_BrightnessValue 9203 SRATIONAL 1 EXIF_ExposureBiasValue 9204 SRATIONAL 1 EXIF_MaxApertureValue 9205 RATIONAL 1 EXIF_SubjectDistance 9206 RATIONAL 1 EXIF_MeteringMode 9207 SHORT 1 EXIF_LightSource 9208 SHORT 1 EXIF_Flash 9209 SHORT 1 EXIF_FocalLength 920a RATIONAL 1 EXIF_SubjectArea 9214 SHORT 2|3|4 EXIF_MakerNote 927c UNDEFINED EXIF_UserComment 9286 UNDEFINED EXIF_SubsecTime 9290 ASCII EXIF_SubsecTimeOriginal 9291 ASCII EXIF_SubsecTimeDigitized 9292 ASCII EXIF_FlashpixVersion a000 UNDEFINED 4 EXIF_ColorSpace a001 SHORT 1 EXIF_PixelXDimension a002 SHORT!LONG 1 EXIF_PixelYDimension a003 SHORT!LONG 1 EXIF_RelatedSoundFile a004 ASCII 13 EXIF_FlashEnergy a20b RATIONAL 1 EXIF_SpatialFrequencyResponse a20c UNDEFINED EXIF_FocalPlaneXResolution a20e RATIONAL 1 EXIF_FocalPlaneYResolution a20f RATIONAL 1 EXIF_FocalPlaneResolutionUnit a210 SHORT 1 EXIF_SubjectLocation a214 SHORT 2 EXIF_ExposureIndex a215 RATIONAL 1 EXIF_SensingMethod a217 SHORT 1 EXIF_FileSource a300 UNDEFINED 1 EXIF_SceneType a301 UNDEFINED 1 EXIF_CFAPattern a302 UNDEFINED EXIF_CustomRendered a401 SHORT 1 EXIF_ExposureMode a402 SHORT 1 EXIF_WhiteBalance a403 SHORT 1 EXIF_DigitalZoomRatio a404 RATIONAL 1 EXIF_FocalLengthIn35mmFilm a405 SHORT 1 EXIF_SceneCaptureType a406 SHORT 1 EXIF_GainControl a407 SHORT 1 EXIF_Contrast a408 SHORT 1 EXIF_Saturation a409 SHORT 1 EXIF_Sharpness a40a SHORT 1 EXIF_DeviceSettingDescription a40b UNDEFINED EXIF_SubjectDistanceRange a40c SHORT 1 EXIF_ImageUniqueID a420 ASCII 33 ''' _tag_value2name = {} _tag_name2value = {} _tag_value2type = {} for line in _tag_info.split('\n'): if not line or line.startswith('#'): continue if line[0] == ' ': pass else: n, h, t = line.split()[:3] h = eval('0x' + h) _tag_value2name[h] = n _tag_value2type[h] = t _tag_name2value[n] = h def __init__(self, tag, entrytype, value=None): """ *tag* is the tag number of the entry *entrytype* is the type of the entry *value* is the value associated to the tag """ self._tag = tag self._type = entrytype self._value = value
[docs] def is_image(self): """Returns True if content in an image""" return self.get_tag() == 273
[docs] def is_IFD(self): """Returns True if content is an IFD.""" return isinstance(self.get_value(), IFD)
[docs] def get_tag(self): """Returns the tag""" return self._tag
[docs] def get_value(self, human=True): """ Returns the value if human=True, value is modified: - value[0] is retruned instead of value if array contains only one element - conversion in string is achieved for arrays representing strings """ value = self._value if human: if len(value) == 1: value = value[0] if self.get_type() == 2: value = ''.join(value.view('|S%s' % (value.nbytes // value.size))) return value
[docs] def get_tagName(self): """Returns the tag name""" return self._tag_value2name.get(self.get_tag, 'TAG%s' % (hex(self._tag),))
[docs] def get_type(self): """Returns the type of entry.""" return self._type
[docs] def set_value(self, value): """Sets the value of the entry.""" self._value = value