Source code for large_image_source_tiff

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#  Copyright Kitware Inc.
#
#  Licensed under the Apache License, Version 2.0 ( the "License" );
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
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import base64
import io
import itertools
import json
import math
import os

import cachetools
import numpy
import PIL.Image
import tifftools

from large_image import config
from large_image.cache_util import LruCacheMetaclass, methodcache
from large_image.constants import TILE_FORMAT_NUMPY, TILE_FORMAT_PIL, SourcePriority
from large_image.exceptions import TileSourceError, TileSourceFileNotFoundError
from large_image.tilesource import FileTileSource, nearPowerOfTwo

from .tiff_reader import (InvalidOperationTiffException, IOTiffException,
                          IOTiffOpenException, TiffException,
                          TiledTiffDirectory, ValidationTiffException)

try:
    from importlib.metadata import PackageNotFoundError
    from importlib.metadata import version as _importlib_version
except ImportError:
    from importlib_metadata import PackageNotFoundError
    from importlib_metadata import version as _importlib_version
try:
    __version__ = _importlib_version(__name__)
except PackageNotFoundError:
    # package is not installed
    pass


@cachetools.cached(cache=cachetools.LRUCache(maxsize=10))
def _cached_read_tiff(path):
    return tifftools.read_tiff(path)


[docs]class TiffFileTileSource(FileTileSource, metaclass=LruCacheMetaclass): """ Provides tile access to TIFF files. """ cacheName = 'tilesource' name = 'tiff' extensions = { None: SourcePriority.MEDIUM, 'tif': SourcePriority.HIGH, 'tiff': SourcePriority.HIGH, 'ptif': SourcePriority.PREFERRED, 'ptiff': SourcePriority.PREFERRED, 'qptiff': SourcePriority.PREFERRED, } mimeTypes = { None: SourcePriority.FALLBACK, 'image/tiff': SourcePriority.HIGH, 'image/x-tiff': SourcePriority.HIGH, 'image/x-ptif': SourcePriority.PREFERRED, } # When getting tiles for otherwise empty directories (missing powers of # two), we composite the tile from higher resolution levels. This can use # excessive memory if there are too many missing levels. For instance, if # there are six missing levels and the tile size is 1024 square RGBA, then # 16 Gb are needed for the composited tile at a minimum. By setting # _maxSkippedLevels, such large gaps are composited in stages. _maxSkippedLevels = 3 _maxAssociatedImageSize = 8192 def __init__(self, path, **kwargs): # noqa """ Initialize the tile class. See the base class for other available parameters. :param path: a filesystem path for the tile source. """ super().__init__(path, **kwargs) self._largeImagePath = str(self._getLargeImagePath()) try: self._initWithTiffTools() return except Exception as exc: config.getConfig('logger').debug('Cannot read with tifftools route; %r', exc) try: alldir = self._scanDirectories() except IOTiffOpenException: raise TileSourceError('File cannot be opened via tiff source.') except (ValidationTiffException, TiffException) as exc: alldir = [] lastException = exc # If there are no tiled images, raise an exception. if not len(alldir): if not os.path.isfile(self._largeImagePath): raise TileSourceFileNotFoundError(self._largeImagePath) from None msg = "File %s didn't meet requirements for tile source: %s" % ( self._largeImagePath, lastException) config.getConfig('logger').debug(msg) raise TileSourceError(msg) # Sort the known directories by image area (width * height). Given # equal area, sort by the level. alldir.sort() # The highest resolution image is our preferred image highest = alldir[-1][-1] directories = {} # Discard any images that use a different tiling scheme than our # preferred image for tdir in alldir: td = tdir[-1] level = tdir[2] if (td.tileWidth != highest.tileWidth or td.tileHeight != highest.tileHeight): if not len(self._associatedImages): self._addAssociatedImage(self._largeImagePath, tdir[-2], True, highest) continue # If a layer's image is not a multiple of the tile size, it should # be near a power of two of the highest resolution image. if (((td.imageWidth % td.tileWidth) and not nearPowerOfTwo(td.imageWidth, highest.imageWidth)) or ((td.imageHeight % td.tileHeight) and not nearPowerOfTwo(td.imageHeight, highest.imageHeight))): continue # If a layer is a multiple of the tile size, the number of tiles # should be a power of two rounded up from the primary. if (not (td.imageWidth % td.tileWidth) and not (td.imageHeight % td.tileHeight)): htw = highest.imageWidth // td.tileWidth hth = highest.imageHeight // td.tileHeight ttw = td.imageWidth // td.tileWidth tth = td.imageHeight // td.tileHeight while (htw > ttw and htw > 1) or (hth > tth and hth > 1): htw = (htw + 1) // 2 hth = (hth + 1) // 2 if htw != ttw or hth != tth: continue directories[level] = td if not len(directories) or (len(directories) < 2 and max(directories.keys()) + 1 > 4): raise TileSourceError( 'Tiff image must have at least two levels.') # Sort the directories so that the highest resolution is the last one; # if a level is missing, put a None value in its place. self._tiffDirectories = [directories.get(key) for key in range(max(directories.keys()) + 1)] self.tileWidth = highest.tileWidth self.tileHeight = highest.tileHeight self.levels = len(self._tiffDirectories) self.sizeX = highest.imageWidth self.sizeY = highest.imageHeight self._checkForInefficientDirectories() def _scanDirectories(self): lastException = None # Associated images are smallish TIFF images that have an image # description and are not tiled. They have their own TIFF directory. # Individual TIFF images can also have images embedded into their # directory as tags (this is a vendor-specific method of adding more # images into a file) -- those are stored in the individual # directories' _embeddedImages field. self._associatedImages = {} dir = None # Query all know directories in the tif file. Only keep track of # directories that contain tiled images. alldir = [] associatedDirs = [] for directoryNum in itertools.count(): # pragma: no branch try: if dir is None: dir = TiledTiffDirectory(self._largeImagePath, directoryNum, validate=False) else: dir._setDirectory(directoryNum) dir._loadMetadata() dir._validate() except ValidationTiffException as exc: lastException = exc associatedDirs.append(directoryNum) continue except TiffException as exc: if not lastException: lastException = exc break if not dir.tileWidth or not dir.tileHeight: continue # Calculate the tile level, where 0 is a single tile, 1 is up to a # set of 2x2 tiles, 2 is 4x4, etc. level = int(math.ceil(math.log(max( float(dir.imageWidth) / dir.tileWidth, float(dir.imageHeight) / dir.tileHeight)) / math.log(2))) if level < 0: continue td, dir = dir, None # Store information for sorting with the directory. alldir.append((level > 0, td.tileWidth * td.tileHeight, level, td.imageWidth * td.imageHeight, directoryNum, td)) if not alldir and lastException: raise lastException for directoryNum in associatedDirs: self._addAssociatedImage(self._largeImagePath, directoryNum) return alldir def _levelFromIfd(self, ifd, baseifd): """ Get the level based on information in an ifd and on the full-resolution 0-frame ifd. An exception is raised if the ifd does not seem to represent a possible level. :param ifd: an ifd record returned from tifftools. :param baseifd: the ifd record of the full-resolution frame 0. :returns: the level, where self.levels - 1 is full resolution and 0 is the lowest resolution. """ sizeX = ifd['tags'][tifftools.Tag.ImageWidth.value]['data'][0] sizeY = ifd['tags'][tifftools.Tag.ImageLength.value]['data'][0] tileWidth = baseifd['tags'][tifftools.Tag.TileWidth.value]['data'][0] tileHeight = baseifd['tags'][tifftools.Tag.TileLength.value]['data'][0] for tag in { tifftools.Tag.SamplesPerPixel.value, tifftools.Tag.BitsPerSample.value, tifftools.Tag.PlanarConfig.value, tifftools.Tag.Photometric.value, tifftools.Tag.Orientation.value, tifftools.Tag.Compression.value, tifftools.Tag.TileWidth.value, tifftools.Tag.TileLength.value, }: if ((tag in ifd['tags'] and tag not in baseifd['tags']) or (tag not in ifd['tags'] and tag in baseifd['tags']) or (tag in ifd['tags'] and ifd['tags'][tag]['data'] != baseifd['tags'][tag]['data'])): raise TileSourceError('IFD does not match first IFD.') sizes = [(self.sizeX, self.sizeY)] for level in range(self.levels - 1, -1, -1): if (sizeX, sizeY) in sizes: return level altsizes = [] for w, h in sizes: w2f = int(math.floor(w / 2)) h2f = int(math.floor(h / 2)) w2c = int(math.ceil(w / 2)) h2c = int(math.ceil(h / 2)) w2t = int(math.floor((w / 2 + tileWidth - 1) / tileWidth)) * tileWidth h2t = int(math.floor((h / 2 + tileHeight - 1) / tileHeight)) * tileHeight for w2, h2 in [(w2f, h2f), (w2f, h2c), (w2c, h2f), (w2c, h2c), (w2t, h2t)]: if (w2, h2) not in altsizes: altsizes.append((w2, h2)) sizes = altsizes raise TileSourceError('IFD size is not a power of two smaller than first IFD.') def _initWithTiffTools(self): # noqa """ Use tifftools to read all of the tiff directory information. Check if the zeroth directory can be validated as a tiled directory. If so, then check if the remaining directories are either tiled in descending size or have subifds with tiles in descending sizes. All primary tiled directories are the same size and format; all non-tiled directories are treated as associated images. """ dir0 = TiledTiffDirectory(self._largeImagePath, 0) self.tileWidth = dir0.tileWidth self.tileHeight = dir0.tileHeight self.sizeX = dir0.imageWidth self.sizeY = dir0.imageHeight self.levels = max(1, int(math.ceil(math.log(max( dir0.imageWidth / dir0.tileWidth, dir0.imageHeight / dir0.tileHeight)) / math.log(2))) + 1) info = _cached_read_tiff(self._largeImagePath) frames = [] associated = [] # for now, a list of directories curframe = -1 for idx, ifd in enumerate(info['ifds']): # if not tiles, add to associated images if tifftools.Tag.tileWidth.value not in ifd['tags']: associated.append(idx) continue level = self._levelFromIfd(ifd, info['ifds'][0]) # if the same resolution as the main image, add a frame if level == self.levels - 1: curframe += 1 frames.append({'dirs': [None] * self.levels}) frames[-1]['dirs'][-1] = (idx, 0) try: frameMetadata = json.loads( ifd['tags'][tifftools.Tag.ImageDescription.value]['data']) for key in {'channels', 'frame'}: if key in frameMetadata: frames[-1][key] = frameMetadata[key] except Exception: pass # otherwise, add to the first frame missing that level elif level < self.levels - 1 and any( frame for frame in frames if frame['dirs'][level] is None): frames[next( idx for idx, frame in enumerate(frames) if frame['dirs'][level] is None )]['dirs'][level] = (idx, 0) else: raise TileSourceError('Tile layers are in a surprising order') # if there are sub ifds, add them if tifftools.Tag.SubIfd.value in ifd['tags']: for subidx, subifds in enumerate(ifd['tags'][tifftools.Tag.SubIfd.value]['ifds']): if len(subifds) != 1: raise TileSourceError( 'When stored in subifds, each subifd should be a single ifd.') level = self._levelFromIfd(subifds[0], info['ifds'][0]) if level < self.levels - 1 and frames[-1]['dirs'][level] is None: frames[-1]['dirs'][level] = (idx, subidx + 1) else: raise TileSourceError('Tile layers are in a surprising order') self._associatedImages = {} for dirNum in associated: self._addAssociatedImage(self._largeImagePath, dirNum) self._frames = frames self._tiffDirectories = [ TiledTiffDirectory( self._largeImagePath, frames[0]['dirs'][idx][0], subDirectoryNum=frames[0]['dirs'][idx][1]) if frames[0]['dirs'][idx] is not None else None for idx in range(self.levels - 1)] self._tiffDirectories.append(dir0) self._checkForInefficientDirectories() return True def _checkForInefficientDirectories(self, warn=True): """ Raise a warning for inefficient files. :param warn: if True and inefficient, emit a warning. """ missing = [v is None for v in self._tiffDirectories] maxMissing = max(0 if not v else missing.index(False, idx) - idx for idx, v in enumerate(missing)) self._skippedLevels = maxMissing if maxMissing >= self._maxSkippedLevels: if warn: config.getConfig('logger').warning( 'Tiff image is missing many lower resolution levels (%d). ' 'It will be inefficient to read lower resolution tiles.', maxMissing) self._inefficientWarning = True def _reorient_numpy_image(self, image, orientation): """ Reorient a numpy image array based on a tiff orientation. :param image: the numpy array to reorient. :param orientation: one of the tiff orientation constants. :returns: an image with top-left orientation. """ if len(image.shape) == 2: image = numpy.resize(image, (image.shape[0], image.shape[1], 1)) if orientation in { tifftools.constants.Orientation.LeftTop.value, tifftools.constants.Orientation.RightTop.value, tifftools.constants.Orientation.LeftBottom.value, tifftools.constants.Orientation.RightBottom.value}: image = image.transpose(1, 0, 2) if orientation in { tifftools.constants.Orientation.BottomLeft.value, tifftools.constants.Orientation.BottomRight.value, tifftools.constants.Orientation.LeftBottom.value, tifftools.constants.Orientation.RightBottom.value}: image = image[::-1, ::, ::] if orientation in { tifftools.constants.Orientation.TopRight.value, tifftools.constants.Orientation.BottomRight.value, tifftools.constants.Orientation.RightTop.value, tifftools.constants.Orientation.RightBottom.value}: image = image[::, ::-1, ::] return image def _addAssociatedImage(self, largeImagePath, directoryNum, mustBeTiled=False, topImage=None): """ Check if the specified TIFF directory contains an image with a sensible image description that can be used as an ID. If so, and if the image isn't too large, add this image as an associated image. :param largeImagePath: path to the TIFF file. :param directoryNum: libtiff directory number of the image. :param mustBeTiles: if true, use tiled images. If false, require untiled images. :param topImage: if specified, add image-embedded metadata to this image. """ try: associated = TiledTiffDirectory(largeImagePath, directoryNum, mustBeTiled) id = '' desc = associated._tiffInfo.get('imagedescription') if desc: id = desc.strip().split(None, 1)[0].lower() if b'\n' in desc: id = desc.split(b'\n', 1)[1].strip().split(None, 1)[0].lower() or id elif mustBeTiled: id = 'dir%d' % directoryNum if not len(self._associatedImages): id = 'macro' if not isinstance(id, str): id = id.decode() # Only use this as an associated image if the parsed id is # a reasonable length, alphanumeric characters, and the # image isn't too large. if (id.isalnum() and len(id) > 3 and len(id) <= 20 and associated._pixelInfo['width'] <= self._maxAssociatedImageSize and associated._pixelInfo['height'] <= self._maxAssociatedImageSize): image = associated._tiffFile.read_image() # Optrascan scanners store xml image descriptions in a "tiled # image". Check if this is the case, and, if so, parse such # data if image.tobytes()[:6] == b'<?xml ': self._parseImageXml(image.tobytes().rsplit(b'>', 1)[0] + b'>', topImage) return image = self._reorient_numpy_image(image, associated._tiffInfo.get('orientation')) self._associatedImages[id] = image except (TiffException, AttributeError): # If we can't validate or read an associated image or it has no # useful imagedescription, fail quietly without adding an # associated image. pass except Exception: # If we fail for other reasons, don't raise an exception, but log # what happened. config.getConfig('logger').exception( 'Could not use non-tiled TIFF image as an associated image.') def _parseImageXml(self, xml, topImage): """ Parse metadata stored in arbitrary xml and associate it with a specific image. :param xml: the xml as a string or bytes object. :param topImage: the image to add metadata to. """ if not topImage or topImage.pixelInfo.get('magnificaiton'): return topImage.parse_image_description(xml) if not topImage._description_record: return try: xml = topImage._description_record # Optrascan metadata scanDetails = xml.get('ScanInfo', xml.get('EncodeInfo'))['ScanDetails'] mag = float(scanDetails['Magnification']) # In microns; convert to mm scale = float(scanDetails['PixelResolution']) * 1e-3 topImage._pixelInfo = { 'magnification': mag, 'mm_x': scale, 'mm_y': scale, } except Exception: pass
[docs] def getNativeMagnification(self): """ Get the magnification at a particular level. :return: magnification, width of a pixel in mm, height of a pixel in mm. """ pixelInfo = self._tiffDirectories[-1].pixelInfo mm_x = pixelInfo.get('mm_x') mm_y = pixelInfo.get('mm_y') # Estimate the magnification if we don't have a direct value mag = pixelInfo.get('magnification') or 0.01 / mm_x if mm_x else None return { 'magnification': mag, 'mm_x': mm_x, 'mm_y': mm_y, }
def _xmlToMetadata(self, xml): if not isinstance(xml, dict) or set(xml.keys()) != {'DataObject'}: return xml values = {} try: objlist = xml['DataObject'] if not isinstance(objlist, list): objlist = [objlist] for obj in objlist: attrList = obj['Attribute'] if not isinstance(attrList, list): attrList = [attrList] for attr in attrList: if 'Array' not in attr: values[attr['Name']] = attr.get('text', '') else: if 'DataObject' in attr['Array']: subvalues = self._xmlToMetadata(attr['Array']) for key, subvalue in subvalues.items(): if key not in {'PIM_DP_IMAGE_DATA', }: values[attr['Name'] + '|' + key] = subvalue except Exception: return xml return values
[docs] def getMetadata(self): """ Return a dictionary of metadata containing levels, sizeX, sizeY, tileWidth, tileHeight, magnification, mm_x, mm_y, and frames. :returns: metadata dictionary. """ result = super().getMetadata() if hasattr(self, '_frames') and len(self._frames) > 1: result['frames'] = [frame.get('frame', {}) for frame in self._frames] self._addMetadataFrameInformation(result, self._frames[0].get('channels', None)) return result
[docs] def getInternalMetadata(self, **kwargs): """ Return additional known metadata about the tile source. Data returned from this method is not guaranteed to be in any particular format or have specific values. :returns: a dictionary of data or None. """ results = {} for idx, dir in enumerate(self._tiffDirectories[::-1]): if dir: if hasattr(dir, '_description_record'): results['xml' + ( '' if not results.get('xml') else '_' + str(idx))] = self._xmlToMetadata( dir._description_record) for k, v in dir._tiffInfo.items(): if k == 'imagedescription' and hasattr(dir, '_description_record'): continue if isinstance(v, (str, bytes)) and k: if isinstance(v, bytes): try: v = v.decode() except UnicodeDecodeError: continue results.setdefault('tiff', {}) if not idx and k not in results['tiff']: results['tiff'][k] = v elif k not in results['tiff'] or v != results['tiff'][k]: results['tiff'][k + ':%d' % idx] = v return results
[docs] @methodcache() def getTile(self, x, y, z, pilImageAllowed=False, numpyAllowed=False, sparseFallback=False, **kwargs): frame = self._getFrame(**kwargs) self._xyzInRange(x, y, z, frame, len(self._frames) if hasattr(self, '_frames') else None) if frame > 0: if hasattr(self, '_frames') and self._frames[frame]['dirs'][z] is not None: dir = self._getDirFromCache(*self._frames[frame]['dirs'][z]) else: dir = None else: dir = self._tiffDirectories[z] try: allowStyle = True if dir is None: try: if not kwargs.get('inSparseFallback'): tile = self.getTileFromEmptyDirectory(x, y, z, **kwargs) else: raise IOTiffException('Missing z level %d' % z) except Exception: if sparseFallback: raise IOTiffException('Missing z level %d' % z) else: raise allowStyle = False format = TILE_FORMAT_PIL else: tile = dir.getTile(x, y) format = 'JPEG' if isinstance(tile, PIL.Image.Image): format = TILE_FORMAT_PIL if isinstance(tile, numpy.ndarray): format = TILE_FORMAT_NUMPY return self._outputTile(tile, format, x, y, z, pilImageAllowed, numpyAllowed, applyStyle=allowStyle, **kwargs) except InvalidOperationTiffException as e: raise TileSourceError(e.args[0]) except IOTiffException as e: return self.getTileIOTiffError( x, y, z, pilImageAllowed=pilImageAllowed, numpyAllowed=numpyAllowed, sparseFallback=sparseFallback, exception=e, **kwargs)
def _getDirFromCache(self, dirnum, subdir=None): if not hasattr(self, '_directoryCache'): self._directoryCache = {} self._directoryCacheMaxSize = max(20, self.levels * 3) key = (dirnum, subdir) result = self._directoryCache.get(key) if result is None: if len(self._directoryCache) >= self._directoryCacheMaxSize: self._directoryCache = {} try: result = TiledTiffDirectory( self._largeImagePath, dirnum, mustBeTiled=None, subDirectoryNum=subdir) except IOTiffException: result = None self._directoryCache[key] = result return result
[docs] def getTileIOTiffError(self, x, y, z, pilImageAllowed=False, numpyAllowed=False, sparseFallback=False, exception=None, **kwargs): if sparseFallback: if z: noedge = kwargs.copy() noedge.pop('edge', None) noedge['inSparseFallback'] = True image = self.getTile( x // 2, y // 2, z - 1, pilImageAllowed=True, numpyAllowed=False, sparseFallback=sparseFallback, edge=False, **noedge) if not isinstance(image, PIL.Image.Image): image = PIL.Image.open(io.BytesIO(image)) image = image.crop(( self.tileWidth / 2 if x % 2 else 0, self.tileHeight / 2 if y % 2 else 0, self.tileWidth if x % 2 else self.tileWidth / 2, self.tileHeight if y % 2 else self.tileHeight / 2)) image = image.resize((self.tileWidth, self.tileHeight)) else: image = PIL.Image.new('RGBA', (self.tileWidth, self.tileHeight)) return self._outputTile(image, TILE_FORMAT_PIL, x, y, z, pilImageAllowed, numpyAllowed, applyStyle=False, **kwargs) raise TileSourceError('Internal I/O failure: %s' % exception.args[0])
[docs] def getTileFromEmptyDirectory(self, x, y, z, **kwargs): """ Given the x, y, z tile location in an unpopulated level, get tiles from higher resolution levels to make the lower-res tile. :param x: location of tile within original level. :param y: location of tile within original level. :param z: original level. :returns: tile in PIL format. """ basez = z scale = 1 dirlist = self._tiffDirectories frame = self._getFrame(**kwargs) if frame > 0 and hasattr(self, '_frames'): dirlist = self._frames[frame]['dirs'] while dirlist[z] is None: scale *= 2 z += 1 while z - basez > self._maxSkippedLevels: z -= self._maxSkippedLevels scale = int(scale / 2 ** self._maxSkippedLevels) tile = PIL.Image.new('RGBA', ( min(self.sizeX, self.tileWidth * scale), min(self.sizeY, self.tileHeight * scale))) maxX = 2.0 ** (z + 1 - self.levels) * self.sizeX / self.tileWidth maxY = 2.0 ** (z + 1 - self.levels) * self.sizeY / self.tileHeight for newX in range(scale): for newY in range(scale): if ((newX or newY) and ((x * scale + newX) >= maxX or (y * scale + newY) >= maxY)): continue subtile = self.getTile( x * scale + newX, y * scale + newY, z, pilImageAllowed=True, numpyAllowed=False, sparseFallback=True, edge=False, frame=frame) if not isinstance(subtile, PIL.Image.Image): subtile = PIL.Image.open(io.BytesIO(subtile)) tile.paste(subtile, (newX * self.tileWidth, newY * self.tileHeight)) return tile.resize((self.tileWidth, self.tileHeight), getattr(PIL.Image, 'Resampling', PIL.Image).LANCZOS)
[docs] def getPreferredLevel(self, level): """ Given a desired level (0 is minimum resolution, self.levels - 1 is max resolution), return the level that contains actual data that is no lower resolution. :param level: desired level :returns level: a level with actual data that is no lower resolution. """ level = max(0, min(level, self.levels - 1)) baselevel = level while self._tiffDirectories[level] is None and level < self.levels - 1: level += 1 while level - baselevel >= self._maxSkippedLevels: level -= self._maxSkippedLevels return level
[docs] def getAssociatedImagesList(self): """ Get a list of all associated images. :return: the list of image keys. """ imageList = set(self._associatedImages) for td in self._tiffDirectories: if td is not None: imageList |= set(td._embeddedImages) return sorted(imageList)
def _getAssociatedImage(self, imageKey): """ Get an associated image in PIL format. :param imageKey: the key of the associated image. :return: the image in PIL format or None. """ # The values in _embeddedImages are sometimes duplicated with the # _associatedImages. There are some sample files where libtiff's # read_image fails to read the _associatedImage properly because of # separated jpeg information. For the samples we currently have, # preferring the _embeddedImages is sufficient, but if find other files # with seemingly bad associated images, we may need to read them with a # more complex process than read_image. for td in self._tiffDirectories: if td is not None and imageKey in td._embeddedImages: return PIL.Image.open(io.BytesIO(base64.b64decode(td._embeddedImages[imageKey]))) if imageKey in self._associatedImages: return PIL.Image.fromarray(self._associatedImages[imageKey])
[docs]def open(*args, **kwargs): """ Create an instance of the module class. """ return TiffFileTileSource(*args, **kwargs)
[docs]def canRead(*args, **kwargs): """ Check if an input can be read by the module class. """ return TiffFileTileSource.canRead(*args, **kwargs)