def read_from_mets(metsfile,
filegrp,
page_ids,
outputfile,
pagelabel='pageId',
overwrite=False):
overwrite = overwrite == 'true'
mets = OcrdMets(filename=metsfile)
inputfiles = []
pagelabels = []
metadata = get_metadata(mets)
for f in mets.find_files(mimetype='application/pdf',
fileGrp=filegrp,
pageId=(page_ids or None)):
# ignore multipaged pdfs
if f.pageId:
inputfiles.append(f.local_filename)
if pagelabel != "pagenumber":
pagelabels.append(getattr(f, pagelabel, ""))
log = getLogger('processor.pagetopdf')
if not inputfiles:
log.warning("No PDF input files for merging %s", outputfile)
return None
if pdfmerge(inputfiles,
outputfile,
pagelabels=pagelabels,
metadata=metadata):
mets.add_file(filegrp,
mimetype='application/pdf',
ID=outputfile,
url=str(Path(filegrp).joinpath(outputfile + '.pdf')),
force=overwrite)
with atomic_write(metsfile, overwrite=True) as f:
f.write(mets.to_xml(xmllint=True).decode('utf-8'))
def test_encoding_entities(self):
mets = OcrdMets(content="""
<mets>
<metsHdr>
<agent>
<name>Őh śéé Áŕ</name>
<note>OCR-D</note>
</agent>
</metsHdr>
</mets>
""")
self.assertIn('Őh śéé Áŕ', mets.to_xml().decode('utf-8'))
def read_from_mets(metsfile, filegrp, outputfile, pagelabel='pageId'):
mets = OcrdMets(filename=metsfile)
inputfiles = []
pagelabels = []
metadata = get_metadata(mets)
for f in mets.find_files(mimetype='application/pdf', fileGrp=filegrp):
# ingore mulitpaged pdfs
if f.pageId:
inputfiles.append(f.local_filename)
if pagelabel != "pagenumber":
pagelabels.append(getattr(f, pagelabel, ""))
if inputfiles:
if not pdfmerge(
inputfiles, outputfile, pagelabels=pagelabels,
metadata=metadata):
mets.add_file(filegrp,
mimetype='application/pdf',
ID=outputfile,
url=str(Path(filegrp).joinpath(outputfile + '.pdf')))
with atomic_write(metsfile, overwrite=True) as f:
f.write(mets.to_xml(xmllint=True).decode('utf-8'))
return None
class Workspace():
"""
A workspace is a temporary directory set up for a processor. It's the
interface to the METS/PAGE XML and delegates download and upload to the
Resolver.
Args:
directory (string) : Folder to work in
mets (:class:`OcrdMets`) : OcrdMets representing this workspace. Loaded from 'mets.xml' if ``None``.
mets_basename (string) : Basename of the METS XML file. Default: Last URL segment of the mets_url.
overwrite_mode (boolean) : Whether to force add operations on this workspace globally
baseurl (string) : Base URL to prefix to relative URL.
"""
def __init__(self,
resolver,
directory,
mets=None,
mets_basename='mets.xml',
automatic_backup=False,
baseurl=None):
self.resolver = resolver
self.directory = directory
self.mets_target = str(Path(directory, mets_basename))
self.overwrite_mode = False
if mets is None:
mets = OcrdMets(filename=self.mets_target)
self.mets = mets
self.automatic_backup = automatic_backup
self.baseurl = baseurl
# print(mets.to_xml(xmllint=True).decode('utf-8'))
def __str__(self):
return 'Workspace[directory=%s, baseurl=%s, file_groups=%s, files=%s]' % (
self.directory,
self.baseurl,
self.mets.file_groups,
[str(f) for f in self.mets.find_files()],
)
def reload_mets(self):
"""
Reload METS from disk.
"""
self.mets = OcrdMets(filename=self.mets_target)
@deprecated(version='1.0.0', reason="Use workspace.download_file")
def download_url(self, url, **kwargs):
"""
Download a URL to the workspace.
Args:
url (string): URL to download to directory
**kwargs : See :py:mod:`ocrd_models.ocrd_file.OcrdFile`
Returns:
The local filename of the downloaded file
"""
f = OcrdFile(None, url=url, **kwargs)
f = self.download_file(f)
return f.local_filename
def download_file(self, f, _recursion_count=0):
"""
Download a :py:mod:`ocrd.model.ocrd_file.OcrdFile` to the workspace.
"""
log = getLogger('ocrd.workspace.download_file')
log.debug('download_file %s [_recursion_count=%s]' %
(f, _recursion_count))
with pushd_popd(self.directory):
try:
# If the f.url is already a file path, and is within self.directory, do nothing
url_path = Path(f.url).resolve()
if not (url_path.exists() and url_path.relative_to(
str(Path(self.directory).resolve()))):
raise Exception("Not already downloaded, moving on")
except Exception as e:
basename = '%s%s' % (f.ID, MIME_TO_EXT.get(
f.mimetype, '')) if f.ID else f.basename
try:
f.url = self.resolver.download_to_directory(
self.directory,
f.url,
subdir=f.fileGrp,
basename=basename)
except FileNotFoundError as e:
if not self.baseurl:
raise Exception(
"No baseurl defined by workspace. Cannot retrieve '%s'"
% f.url)
if _recursion_count >= 1:
raise Exception(
"Already tried prepending baseurl '%s'. Cannot retrieve '%s'"
% (self.baseurl, f.url))
log.debug(
"First run of resolver.download_to_directory(%s) failed, try prepending baseurl '%s': %s",
f.url, self.baseurl, e)
f.url = '%s/%s' % (self.baseurl, f.url)
f.url = self.download_file(f, _recursion_count +
1).local_filename
f.local_filename = f.url
return f
def remove_file(self,
ID,
force=False,
keep_file=False,
page_recursive=False,
page_same_group=False):
"""
Remove a file from the workspace.
Arguments:
ID (string|OcrdFile): ID of the file to delete or the file itself
force (boolean): Continue removing even if file not found in METS
keep_file (boolean): Whether to keep files on disk
page_recursive (boolean): Whether to remove all images referenced in the file if the file is a PAGE-XML document.
page_same_group (boolean): Remove only images in the same file group as the PAGE-XML. Has no effect unless ``page_recursive`` is ``True``.
"""
log = getLogger('ocrd.workspace.remove_file')
log.debug('Deleting mets:file %s', ID)
if not force and self.overwrite_mode:
force = True
if isinstance(ID, OcrdFile):
ID = ID.ID
try:
ocrd_file_ = self.mets.remove_file(ID)
ocrd_files = [ocrd_file_] if isinstance(ocrd_file_,
OcrdFile) else ocrd_file_
if page_recursive:
with pushd_popd(self.directory):
for ocrd_file in ocrd_files:
if ocrd_file.mimetype != MIMETYPE_PAGE:
continue
ocrd_page = parse(
self.download_file(ocrd_file).local_filename,
silence=True)
for img_url in ocrd_page.get_AllAlternativeImagePaths(
):
img_kwargs = {'url': img_url}
if page_same_group:
img_kwargs['fileGrp'] = ocrd_file.fileGrp
for img_file in self.mets.find_files(**img_kwargs):
self.remove_file(img_file,
keep_file=keep_file,
force=force)
if not keep_file:
with pushd_popd(self.directory):
for ocrd_file in ocrd_files:
if not ocrd_file.local_filename:
log.warning("File not locally available %s",
ocrd_file)
if not force:
raise Exception(
"File not locally available %s" %
ocrd_file)
else:
log.info("rm %s [cwd=%s]",
ocrd_file.local_filename, self.directory)
unlink(ocrd_file.local_filename)
return ocrd_file_
except FileNotFoundError as e:
if not force:
raise e
def remove_file_group(self,
USE,
recursive=False,
force=False,
keep_files=False,
page_recursive=False,
page_same_group=False):
"""
Remove a fileGrp.
Arguments:
USE (string): USE attribute of the fileGrp to delete
recursive (boolean): Whether to recursively delete all files in the group
force (boolean): Continue removing even if group or containing files not found in METS
keep_files (boolean): When deleting recursively whether to keep files on disk
page_recursive (boolean): Whether to remove all images referenced in the file if the file is a PAGE-XML document.
page_same_group (boolean): Remove only images in the same file group as the PAGE-XML. Has no effect unless ``page_recursive`` is ``True``.
"""
if not force and self.overwrite_mode:
force = True
if (not USE.startswith(REGEX_PREFIX)) and (
USE not in self.mets.file_groups) and (not force):
raise Exception("No such fileGrp: %s" % USE)
file_dirs = []
if recursive:
for f in self.mets.find_files(fileGrp=USE):
self.remove_file(f,
force=force,
keep_file=keep_files,
page_recursive=page_recursive,
page_same_group=page_same_group)
if f.local_filename:
file_dirs.append(path.dirname(f.local_filename))
self.mets.remove_file_group(USE, force=force)
# PLEASE NOTE: this only removes directories in the workspace if they are empty
# and named after the fileGrp which is a convention in OCR-D.
with pushd_popd(self.directory):
if Path(USE).is_dir() and not listdir(USE):
Path(USE).rmdir()
if file_dirs:
for file_dir in set(file_dirs):
if Path(file_dir).is_dir() and not listdir(file_dir):
Path(file_dir).rmdir()
def add_file(self, file_grp, content=None, **kwargs):
"""
Add an output file. Creates an :class:`OcrdFile` to pass around and adds that to the
OcrdMets OUTPUT section.
"""
log = getLogger('ocrd.workspace.add_file')
log.debug('outputfile file_grp=%s local_filename=%s content=%s',
file_grp, kwargs.get('local_filename'), content is not None)
if 'pageId' not in kwargs:
raise ValueError(
"workspace.add_file must be passed a 'pageId' kwarg, even if it is None."
)
if content is not None and 'local_filename' not in kwargs:
raise Exception("'content' was set but no 'local_filename'")
if self.overwrite_mode:
kwargs['force'] = True
with pushd_popd(self.directory):
if 'local_filename' in kwargs:
# If the local filename has folder components, create those folders
local_filename_dir = kwargs['local_filename'].rsplit('/', 1)[0]
if local_filename_dir != kwargs['local_filename'] and not Path(
local_filename_dir).is_dir():
makedirs(local_filename_dir)
if 'url' not in kwargs:
kwargs['url'] = kwargs['local_filename']
# print(kwargs)
ret = self.mets.add_file(file_grp, **kwargs)
if content is not None:
with open(kwargs['local_filename'], 'wb') as f:
if isinstance(content, str):
content = bytes(content, 'utf-8')
f.write(content)
return ret
def save_mets(self):
"""
Write out the current state of the METS file.
"""
log = getLogger('ocrd.workspace.save_mets')
log.info("Saving mets '%s'", self.mets_target)
if self.automatic_backup:
WorkspaceBackupManager(self).add()
with atomic_write(self.mets_target, overwrite=True) as f:
f.write(self.mets.to_xml(xmllint=True).decode('utf-8'))
def resolve_image_exif(self, image_url):
"""
Get the EXIF metadata about an image URL as :class:`OcrdExif`
Args:
image_url (string) : URL of image
Return
:class:`OcrdExif`
"""
files = self.mets.find_files(url=image_url)
f = files[0] if files else OcrdFile(None, url=image_url)
image_filename = self.download_file(f).local_filename
with Image.open(image_filename) as pil_img:
ocrd_exif = OcrdExif(pil_img)
return ocrd_exif
@deprecated(
version='1.0.0',
reason="Use workspace.image_from_page and workspace.image_from_segment"
)
def resolve_image_as_pil(self, image_url, coords=None):
return self._resolve_image_as_pil(image_url, coords)
def _resolve_image_as_pil(self, image_url, coords=None):
"""
Resolve an image URL to a PIL image.
Args:
- coords (list) : Coordinates of the bounding box to cut from the image
Returns:
Image or region in image as PIL.Image
"""
log = getLogger('ocrd.workspace._resolve_image_as_pil')
files = self.mets.find_files(url=image_url)
f = files[0] if files else OcrdFile(None, url=image_url)
image_filename = self.download_file(f).local_filename
with pushd_popd(self.directory):
pil_image = Image.open(image_filename)
pil_image.load() # alloc and give up the FD
if coords is None:
return pil_image
log.debug("Converting PIL to OpenCV: %s", image_url)
color_conversion = cv2.COLOR_GRAY2BGR if pil_image.mode in (
'1', 'L') else cv2.COLOR_RGB2BGR
pil_as_np_array = np.array(pil_image).astype(
'uint8') if pil_image.mode == '1' else np.array(pil_image)
cv2_image = cv2.cvtColor(pil_as_np_array, color_conversion)
poly = np.array(coords, np.int32)
log.debug("Cutting region %s from %s", coords, image_url)
region_cut = cv2_image[np.min(poly[:, 1]):np.max(poly[:, 1]),
np.min(poly[:, 0]):np.max(poly[:, 0])]
return Image.fromarray(region_cut)
def image_from_page(self,
page,
page_id,
fill='background',
transparency=False,
feature_selector='',
feature_filter=''):
"""Extract an image for a PAGE-XML page from the workspace.
Given ``page``, a PAGE PageType object, extract its PIL.Image,
either from its AlternativeImage (if it exists), or from its
@imageFilename (otherwise). Also crop it, if a Border exists,
and rotate it, if any @orientation angle is annotated.
If ``feature_selector`` and/or ``feature_filter`` is given, then
select/filter among the @imageFilename image and the available
AlternativeImages the last one which contains all of the selected,
but none of the filtered features (i.e. @comments classes), or
raise an error.
(Required and produced features need not be in the same order, so
``feature_selector`` is merely a mask specifying Boolean AND, and
``feature_filter`` is merely a mask specifying Boolean OR.)
If the chosen image does not have the feature "cropped" yet, but
a Border exists, and unless "cropped" is being filtered, then crop it.
Likewise, if the chosen image does not have the feature "deskewed" yet,
but an @orientation angle is annotated, and unless "deskewed" is being
filtered, then rotate it. (However, if @orientation is above the
[-45°,45°] interval, then apply as much transposition as possible first,
unless "rotated-90" / "rotated-180" / "rotated-270" is being filtered.)
Cropping uses a polygon mask (not just the bounding box rectangle).
Areas outside the polygon will be filled according to ``fill``:
- if ``background`` (the default),
then fill with the median color of the image;
- otherwise, use the given color, e.g. ``white`` or (255,255,255).
Moreover, if ``transparency`` is true, and unless the image already
has an alpha channel, then add an alpha channel which is fully opaque
before cropping and rotating. (Thus, only the exposed areas will be
transparent afterwards, for those that can interpret alpha channels).
Return a tuple:
* the extracted image,
* a dictionary with information about the extracted image:
- ``transform``: a Numpy array with an affine transform which
converts from absolute coordinates to those relative to the image,
i.e. after cropping to the page's border / bounding box (if any)
and deskewing with the page's orientation angle (if any)
- ``angle``: the rotation/reflection angle applied to the image so far,
- ``features``: the AlternativeImage @comments for the image, i.e.
names of all operations that lead up to this result,
* an OcrdExif instance associated with the original image.
(The first two can be used to annotate a new AlternativeImage,
or be passed down with ``image_from_segment``.)
Example:
* get a raw (colored) but already deskewed and cropped image:
``
page_image, page_coords, page_image_info = workspace.image_from_page(
page, page_id,
feature_selector='deskewed,cropped',
feature_filter='binarized,grayscale_normalized')
``
"""
log = getLogger('ocrd.workspace.image_from_page')
page_image = self._resolve_image_as_pil(page.imageFilename)
page_image_info = OcrdExif(page_image)
page_coords = dict()
# use identity as initial affine coordinate transform:
page_coords['transform'] = np.eye(3)
# interim bbox (updated with each change to the transform):
page_bbox = [0, 0, page_image.width, page_image.height]
page_xywh = {
'x': 0,
'y': 0,
'w': page_image.width,
'h': page_image.height
}
border = page.get_Border()
# page angle: PAGE @orientation is defined clockwise,
# whereas PIL/ndimage rotation is in mathematical direction:
page_coords['angle'] = -(page.get_orientation() or 0)
# map angle from (-180,180] to [0,360], and partition into multiples of 90;
# but avoid unnecessary large remainders, i.e. split symmetrically:
orientation = (page_coords['angle'] + 45) % 360
orientation = orientation - (orientation % 90)
skew = (page_coords['angle'] % 360) - orientation
skew = 180 - (180 - skew) % 360 # map to [-45,45]
page_coords['angle'] = 0 # nothing applied yet (depends on filters)
log.debug("page '%s' has %s orientation=%d skew=%.2f", page_id,
"border," if border else "", orientation, skew)
# initialize AlternativeImage@comments classes as empty:
page_coords['features'] = ''
alternative_image = None
alternative_images = page.get_AlternativeImage()
if alternative_images:
# (e.g. from page-level cropping, binarization, deskewing or despeckling)
if feature_selector or feature_filter:
alternative_image = None
# search from the end, because by convention we always append,
# and among multiple satisfactory images we want the most recent:
for alternative_image in reversed(alternative_images):
features = alternative_image.get_comments()
if (all(feature in features
for feature in feature_selector.split(',')
if feature) and
not any(feature in features
for feature in feature_filter.split(',')
if feature)):
break
else:
alternative_image = None
else:
alternative_image = alternative_images[-1]
features = alternative_image.get_comments()
if alternative_image:
log.debug("Using AlternativeImage %d (%s) for page '%s'",
alternative_images.index(alternative_image) + 1,
features, page_id)
page_image = self._resolve_image_as_pil(
alternative_image.get_filename())
page_coords['features'] = features
# adjust the coord transformation to the steps applied on the image,
# and apply steps on the existing image in case it is missing there,
# but traverse all steps (crop/reflect/rotate) in a particular order:
# - existing image features take priority (in the order annotated),
# - next is cropping (if necessary but not already applied),
# - next is reflection (if necessary but not already applied),
# - next is rotation (if necessary but not already applied).
# This helps deal with arbitrary workflows (e.g. crop then deskew,
# or deskew then crop), regardless of where images are generated.
alternative_image_features = page_coords['features'].split(',')
for i, feature in enumerate(
alternative_image_features + (['cropped'] if (
border and not 'cropped' in page_coords['features']
and not 'cropped' in feature_filter.split(',')) else []) +
(['rotated-%d' % orientation] if
(orientation and not 'rotated-%d' %
orientation in page_coords['features'] and not 'rotated-%d' %
orientation in feature_filter.split(',')) else []) +
(['deskewed'] if
(skew and not 'deskewed' in page_coords['features']
and not 'deskewed' in feature_filter.split(',')) else []) +
# not a feature to be added, but merely as a fallback position
# to always enter loop at i == len(alternative_image_features)
['_check']):
# image geometry vs feature consistency can only be checked
# after all features on the existing AlternativeImage have
# been adjusted for in the transform, and when there is a mismatch,
# additional steps applied here would only repeat the respective
# error message; so we only check once at the boundary between
# existing and new features
# FIXME we should check/enforce consistency when _adding_ AlternativeImage
if (i == len(alternative_image_features)
and not (page_xywh['w'] - 2 < page_image.width <
page_xywh['w'] + 2 and page_xywh['h'] - 2 <
page_image.height < page_xywh['h'] + 2)):
log.error(
'page "%s" image (%s; %dx%d) has not been cropped properly (%dx%d)',
page_id, page_coords['features'], page_image.width,
page_image.height, page_xywh['w'], page_xywh['h'])
# adjust transform to feature, possibly apply feature to image
if feature == 'cropped':
page_points = border.get_Coords().points
log.debug(
"Using explicitly set page border '%s' for page '%s'",
page_points, page_id)
# get polygon outline of page border:
page_polygon = np.array(polygon_from_points(page_points),
dtype=np.int32)
page_polygon = transform_coordinates(page_polygon,
page_coords['transform'])
page_polygon = np.round(page_polygon).astype(np.int32)
page_bbox = bbox_from_polygon(page_polygon)
# get size of the page after cropping but before rotation:
page_xywh = xywh_from_bbox(*page_bbox)
# subtract offset in affine coordinate transform:
# (consistent with image cropping or AlternativeImage below)
page_coords['transform'] = shift_coordinates(
page_coords['transform'],
np.array([-page_xywh['x'], -page_xywh['y']]))
# crop, if (still) necessary:
if not 'cropped' in page_coords['features']:
log.debug(
"Cropping %s for page '%s' to border",
"AlternativeImage" if alternative_image else "image",
page_id)
# create a mask from the page polygon:
page_image = image_from_polygon(page_image,
page_polygon,
fill=fill,
transparency=transparency)
# recrop into page rectangle:
page_image = crop_image(page_image, box=page_bbox)
page_coords['features'] += ',cropped'
elif feature == 'rotated-%d' % orientation:
# Transpose in affine coordinate transform:
# (consistent with image transposition or AlternativeImage below)
transposition = {
90: Image.ROTATE_90,
180: Image.ROTATE_180,
270: Image.ROTATE_270
}.get(orientation) # no default
page_coords['transform'] = transpose_coordinates(
page_coords['transform'], transposition,
np.array([0.5 * page_xywh['w'], 0.5 * page_xywh['h']]))
(page_xywh['w'],
page_xywh['h']) = adjust_canvas_to_transposition(
[page_xywh['w'], page_xywh['h']], transposition)
page_coords['angle'] = orientation
# transpose, if (still) necessary:
if not 'rotated-%d' % orientation in page_coords['features']:
log.info(
"Transposing %s for page '%s' by %d°",
"AlternativeImage" if alternative_image else "image",
page_id, orientation)
page_image = transpose_image(
page_image, {
90: Image.ROTATE_90,
180: Image.ROTATE_180,
270: Image.ROTATE_270
}.get(orientation)) # no default
page_coords['features'] += ',rotated-%d' % orientation
elif feature == 'deskewed':
# Rotate around center in affine coordinate transform:
# (consistent with image rotation or AlternativeImage below)
page_coords['transform'] = rotate_coordinates(
page_coords['transform'], skew,
np.array([0.5 * page_xywh['w'], 0.5 * page_xywh['h']]))
page_coords['angle'] += skew
# deskew, if (still) necessary:
if not 'deskewed' in page_coords['features']:
log.info(
"Rotating %s for page '%s' by %.2f°",
"AlternativeImage" if alternative_image else "image",
page_id, skew)
page_image = rotate_image(page_image,
skew,
fill=fill,
transparency=transparency)
page_coords['features'] += ',deskewed'
(page_xywh['w'], page_xywh['h']) = adjust_canvas_to_rotation(
[page_xywh['w'], page_xywh['h']], skew)
# verify constraints again:
if not all(feature in page_coords['features']
for feature in feature_selector.split(',') if feature):
raise Exception(
'Found no AlternativeImage that satisfies all requirements ' +
'selector="%s" in page "%s"' % (feature_selector, page_id))
if any(feature in page_coords['features']
for feature in feature_filter.split(',') if feature):
raise Exception(
'Found no AlternativeImage that satisfies all requirements ' +
'filter="%s" in page "%s"' % (feature_filter, page_id))
page_image.format = 'PNG' # workaround for tesserocr#194
return page_image, page_coords, page_image_info
def image_from_segment(self,
segment,
parent_image,
parent_coords,
fill='background',
transparency=False,
feature_selector='',
feature_filter=''):
"""Extract an image for a PAGE-XML hierarchy segment from its parent's image.
Given...
* ``parent_image``, a PIL.Image of the parent, with
* ``parent_coords``, a dict with information about ``parent_image``:
- ``transform``: a Numpy array with an affine transform which
converts from absolute coordinates to those relative to the image,
i.e. after applying all operations (starting with the original image)
- ``angle``: the rotation/reflection angle applied to the image so far,
- ``features``: the AlternativeImage @comments for the image, i.e.
names of all operations that lead up to this result, and
* ``segment``, a PAGE segment object logically contained in it
(i.e. TextRegionType / TextLineType / WordType / GlyphType),
...extract the segment's corresponding PIL.Image, either from
AlternativeImage (if it exists), or producing a new image via
cropping from ``parent_image`` (otherwise).
If ``feature_selector`` and/or ``feature_filter`` is given, then
select/filter among the cropped ``parent_image`` and the available
AlternativeImages the last one which contains all of the selected,
but none of the filtered features (i.e. @comments classes), or
raise an error.
(Required and produced features need not be in the same order, so
``feature_selector`` is merely a mask specifying Boolean AND, and
``feature_filter`` is merely a mask specifying Boolean OR.)
Cropping uses a polygon mask (not just the bounding box rectangle).
Areas outside the polygon will be filled according to ``fill``:
- if ``background`` (the default),
then fill with the median color of the image;
- otherwise, use the given color, e.g. ``white`` or (255,255,255).
Moreover, if ``transparency`` is true, and unless the image already
has an alpha channel, then add an alpha channel which is fully opaque
before cropping and rotating. (Thus, only the exposed areas will be
transparent afterwards, for those that can interpret alpha channels).
When cropping, compensate any @orientation angle annotated for the
parent (from parent-level deskewing) by rotating the segment coordinates
in an inverse transformation (i.e. translation to center, then passive
rotation, and translation back).
Regardless, if any @orientation angle is annotated for the segment
(from segment-level deskewing), and the chosen image does not have
the feature "deskewed" yet, and unless "deskewed" is being filtered,
then rotate it - compensating for any previous ``angle``. (However,
if @orientation is above the [-45°,45°] interval, then apply as much
transposition as possible first, unless "rotated-90" / "rotated-180" /
"rotated-270" is being filtered.)
Return a tuple:
* the extracted image,
* a dictionary with information about the extracted image:
- ``transform``: a Numpy array with an affine transform which
converts from absolute coordinates to those relative to the image,
i.e. after applying all parent operations, and then cropping to
the segment's bounding box, and deskewing with the segment's
orientation angle (if any)
- ``angle``: the rotation/reflection angle applied to the image so far,
- ``features``: the AlternativeImage @comments for the image, i.e.
names of all operations that lead up to this result.
(These can be used to create a new AlternativeImage, or passed down
for calls on lower hierarchy levels.)
Example:
* get a raw (colored) but already deskewed and cropped image:
``image, xywh = workspace.image_from_segment(region,
page_image, page_xywh,
feature_selector='deskewed,cropped',
feature_filter='binarized,grayscale_normalized')``
"""
log = getLogger('ocrd.workspace.image_from_segment')
# note: We should mask overlapping neighbouring segments here,
# but finding the right clipping rules can be difficult if operating
# on the raw (non-binary) image data alone: for each intersection, it
# must be decided which one of either segment or neighbour to assign,
# e.g. an ImageRegion which properly contains our TextRegion should be
# completely ignored, but an ImageRegion which is properly contained
# in our TextRegion should be completely masked, while partial overlap
# may be more difficult to decide. On the other hand, on the binary image,
# we can use connected component analysis to mask foreground areas which
# originate in the neighbouring regions. But that would introduce either
# the assumption that the input has already been binarized, or a dependency
# on some ad-hoc binarization method. Thus, it is preferable to use
# a dedicated processor for this (which produces clipped AlternativeImage
# or reduced polygon coordinates).
# get polygon outline of segment relative to parent image:
segment_polygon = coordinates_of_segment(segment, parent_image,
parent_coords)
# get relative bounding box:
segment_bbox = bbox_from_polygon(segment_polygon)
# get size of the segment in the parent image after cropping
# (i.e. possibly different from size before rotation at the parent, but
# also possibly different from size after rotation below/AlternativeImage):
segment_xywh = xywh_from_bbox(*segment_bbox)
# create a mask from the segment polygon:
segment_image = image_from_polygon(parent_image,
segment_polygon,
fill=fill,
transparency=transparency)
# recrop into segment rectangle:
segment_image = crop_image(segment_image, box=segment_bbox)
# subtract offset from parent in affine coordinate transform:
# (consistent with image cropping)
segment_coords = {
'transform':
shift_coordinates(parent_coords['transform'],
np.array([-segment_bbox[0], -segment_bbox[1]]))
}
if 'orientation' in segment.__dict__:
# region angle: PAGE @orientation is defined clockwise,
# whereas PIL/ndimage rotation is in mathematical direction:
segment_coords['angle'] = -(segment.get_orientation() or 0)
else:
segment_coords['angle'] = 0
if segment_coords['angle']:
# @orientation is always absolute; if higher levels
# have already rotated, then we must compensate:
angle = segment_coords['angle'] - parent_coords['angle']
# map angle from (-180,180] to [0,360], and partition into multiples of 90;
# but avoid unnecessary large remainders, i.e. split symmetrically:
orientation = (angle + 45) % 360
orientation = orientation - (orientation % 90)
skew = (angle % 360) - orientation
skew = 180 - (180 - skew) % 360 # map to [-45,45]
log.debug("segment '%s' has orientation=%d skew=%.2f", segment.id,
orientation, skew)
else:
orientation = 0
skew = 0
segment_coords['angle'] = parent_coords[
'angle'] # nothing applied yet (depends on filters)
if (orientation and
not 'rotated-%d' % orientation in feature_filter.split(',')):
# Transpose in affine coordinate transform:
# (consistent with image transposition or AlternativeImage below)
transposition = {
90: Image.ROTATE_90,
180: Image.ROTATE_180,
270: Image.ROTATE_270
}.get(orientation) # no default
segment_coords['transform'] = transpose_coordinates(
segment_coords['transform'], transposition,
np.array([0.5 * segment_xywh['w'], 0.5 * segment_xywh['h']]))
segment_xywh['w'], segment_xywh[
'h'] = adjust_canvas_to_transposition(
[segment_xywh['w'], segment_xywh['h']], transposition)
segment_coords['angle'] += orientation
if (skew and not 'deskewed' in feature_filter.split(',')):
# Rotate around center in affine coordinate transform:
# (consistent with image rotation or AlternativeImage below)
segment_coords['transform'] = rotate_coordinates(
segment_coords['transform'], skew,
np.array([0.5 * segment_xywh['w'], 0.5 * segment_xywh['h']]))
segment_coords['angle'] += skew
# initialize AlternativeImage@comments classes from parent, except
# for those operations that can apply on multiple hierarchy levels:
segment_coords['features'] = ','.join([
feature for feature in parent_coords['features'].split(',')
if feature in
['binarized', 'grayscale_normalized', 'despeckled', 'dewarped']
])
alternative_image = None
alternative_images = segment.get_AlternativeImage()
if alternative_images:
# (e.g. from segment-level cropping, binarization, deskewing or despeckling)
if feature_selector or feature_filter:
alternative_image = None
# search from the end, because by convention we always append,
# and among multiple satisfactory images we want the most recent:
for alternative_image in reversed(alternative_images):
features = alternative_image.get_comments()
if (all(feature in features
for feature in feature_selector.split(',')
if feature) and
not any(feature in features
for feature in feature_filter.split(',')
if feature)):
break
else:
alternative_image = None
else:
alternative_image = alternative_images[-1]
features = alternative_image.get_comments()
if alternative_image:
log.debug("Using AlternativeImage %d (%s) for segment '%s'",
alternative_images.index(alternative_image) + 1,
features, segment.id)
segment_image = self._resolve_image_as_pil(
alternative_image.get_filename())
segment_coords['features'] = features
# transpose, if (still) necessary:
if (orientation and
not 'rotated-%d' % orientation in segment_coords['features']
and
not 'rotated-%d' % orientation in feature_filter.split(',')):
log.info("Transposing %s for segment '%s' by %d°",
"AlternativeImage" if alternative_image else "image",
segment.id, orientation)
segment_image = transpose_image(segment_image, {
90: Image.ROTATE_90,
180: Image.ROTATE_180,
270: Image.ROTATE_270
}.get(orientation)) # no default
segment_coords['features'] += ',rotated-%d' % orientation
if (orientation and
not 'rotated-%d' % orientation in feature_filter.split(',')):
# FIXME we should enforce consistency here (i.e. split into transposition
# and minimal rotation)
if not (segment_image.width == segment_xywh['w']
and segment_image.height == segment_xywh['h']):
log.error(
'segment "%s" image (%s; %dx%d) has not been transposed properly (%dx%d) during rotation',
segment.id, segment_coords['features'],
segment_image.width, segment_image.height,
segment_xywh['w'], segment_xywh['h'])
# deskew, if (still) necessary:
if (skew and not 'deskewed' in segment_coords['features']
and not 'deskewed' in feature_filter.split(',')):
log.info("Rotating %s for segment '%s' by %.2f°",
"AlternativeImage" if alternative_image else "image",
segment.id, skew)
segment_image = rotate_image(segment_image,
skew,
fill=fill,
transparency=transparency)
segment_coords['features'] += ',deskewed'
if (skew and not 'deskewed' in feature_filter.split(',')):
# FIXME we should enforce consistency here (i.e. rotation always reshapes,
# and rescaling never happens)
w_new, h_new = adjust_canvas_to_rotation(
[segment_xywh['w'], segment_xywh['h']], skew)
if not (w_new - 2 < segment_image.width < w_new + 2
and h_new - 2 < segment_image.height < h_new + 2):
log.error(
'segment "%s" image (%s; %dx%d) has not been reshaped properly (%dx%d) during rotation',
segment.id, segment_coords['features'],
segment_image.width, segment_image.height, w_new, h_new)
else:
# FIXME: currently unavoidable with line-level dewarping (which increases height)
if not (segment_xywh['w'] - 2 < segment_image.width <
segment_xywh['w'] + 2 and segment_xywh['h'] - 2 <
segment_image.height < segment_xywh['h'] + 2):
log.error(
'segment "%s" image (%s; %dx%d) has not been cropped properly (%dx%d)',
segment.id, segment_coords['features'],
segment_image.width, segment_image.height,
segment_xywh['w'], segment_xywh['h'])
# verify constraints again:
if not all(feature in segment_coords['features']
for feature in feature_selector.split(',') if feature):
raise Exception(
'Found no AlternativeImage that satisfies all requirements' +
'selector="%s" in segment "%s"' %
(feature_selector, segment.id))
if any(feature in segment_coords['features']
for feature in feature_filter.split(',') if feature):
raise Exception(
'Found no AlternativeImage that satisfies all requirements ' +
'filter="%s" in segment "%s"' % (feature_filter, segment.id))
segment_image.format = 'PNG' # workaround for tesserocr#194
return segment_image, segment_coords
# pylint: disable=redefined-builtin
def save_image_file(self,
image,
file_id,
file_grp,
page_id=None,
mimetype='image/png',
force=False):
"""Store and reference an image as file into the workspace.
Given a PIL.Image `image`, and an ID `file_id` to use in METS,
store the image under the fileGrp `file_grp` and physical page
`page_id` into the workspace (in a file name based on
the `file_grp`, `file_id` and `format` extension).
Return the (absolute) path of the created file.
"""
log = getLogger('ocrd.workspace.save_image_file')
if not force and self.overwrite_mode:
force = True
image_bytes = io.BytesIO()
image.save(image_bytes, format=MIME_TO_PIL[mimetype])
file_path = str(
Path(file_grp, '%s%s' % (file_id, MIME_TO_EXT[mimetype])))
out = self.add_file(ID=file_id,
file_grp=file_grp,
pageId=page_id,
local_filename=file_path,
mimetype=mimetype,
content=image_bytes.getvalue(),
force=force)
log.info('created file ID: %s, file_grp: %s, path: %s', file_id,
file_grp, out.local_filename)
return file_path
class Workspace():
"""
A workspace is a temporary directory set up for a processor. It's the
interface to the METS/PAGE XML and delegates download and upload to the
Resolver.
Args:
directory (string) : Folder to work in
mets (:class:`OcrdMets`) : OcrdMets representing this workspace. Loaded from 'mets.xml' if ``None``.
mets_basename (string) : Basename of the METS XML file. Default: Last URL segment of the mets_url.
baseurl (string) : Base URL to prefix to relative URL.
"""
def __init__(self,
resolver,
directory,
mets=None,
mets_basename='mets.xml',
automatic_backup=False,
baseurl=None):
self.resolver = resolver
self.directory = directory
self.mets_target = os.path.join(directory, mets_basename)
if mets is None:
mets = OcrdMets(filename=self.mets_target)
self.mets = mets
self.automatic_backup = automatic_backup
self.baseurl = baseurl
# print(mets.to_xml(xmllint=True).decode('utf-8'))
self.image_cache = {
'pil': {},
'cv2': {},
'exif': {},
}
def __str__(self):
return 'Workspace[directory=%s, file_groups=%s, files=%s]' % (
self.directory,
self.mets.file_groups,
[str(f) for f in self.mets.find_files()],
)
def reload_mets(self):
"""
Reload METS from disk.
"""
self.mets = OcrdMets(filename=self.mets_target)
def download_url(self, url, **kwargs):
"""
Download a URL to the workspace.
Args:
url (string): URL to download to directory
**kwargs : See :py:mod:`ocrd.resolver.Resolver`
Returns:
The local filename of the downloaded file
"""
if self.baseurl and '://' not in url:
url = join(self.baseurl, url)
return self.resolver.download_to_directory(self.directory, url,
**kwargs)
def download_file(self, f):
"""
Download a :py:mod:`ocrd.model.ocrd_file.OcrdFile` to the workspace.
"""
# os.chdir(self.directory)
# log.info('f=%s' % f)
oldpwd = os.getcwd()
try:
os.chdir(self.directory)
if is_local_filename(f.url):
f.local_filename = abspath(f.url)
else:
if f.local_filename:
log.debug("Already downloaded: %s", f.local_filename)
else:
f.local_filename = self.download_url(f.url,
basename='%s/%s' %
(f.fileGrp, f.ID))
finally:
os.chdir(oldpwd)
# print(f)
return f
def add_file(self, file_grp, content=None, **kwargs):
"""
Add an output file. Creates an :class:`OcrdFile` to pass around and adds that to the
OcrdMets OUTPUT section.
"""
log.debug('outputfile file_grp=%s local_filename=%s content=%s',
file_grp, kwargs.get('local_filename'), content is not None)
if content is not None and 'local_filename' not in kwargs:
raise Exception("'content' was set but no 'local_filename'")
oldpwd = os.getcwd()
try:
os.chdir(self.directory)
if 'local_filename' in kwargs:
local_filename_dir = kwargs['local_filename'].rsplit('/', 1)[0]
if not os.path.isdir(local_filename_dir):
os.makedirs(local_filename_dir)
if 'url' not in kwargs:
kwargs['url'] = kwargs['local_filename']
# print(kwargs)
ret = self.mets.add_file(file_grp, **kwargs)
if content is not None:
with open(kwargs['local_filename'], 'wb') as f:
if isinstance(content, str):
content = bytes(content, 'utf-8')
f.write(content)
finally:
os.chdir(oldpwd)
return ret
def save_mets(self):
"""
Write out the current state of the METS file.
"""
log.info("Saving mets '%s'" % self.mets_target)
if self.automatic_backup:
WorkspaceBackupManager(self).add()
with open(self.mets_target, 'wb') as f:
f.write(self.mets.to_xml(xmllint=True))
def resolve_image_exif(self, image_url):
"""
Get the EXIF metadata about an image URL as :class:`OcrdExif`
Args:
image_url (string) : URL of image
Return
:class:`OcrdExif`
"""
files = self.mets.find_files(url=image_url)
if files:
image_filename = self.download_file(files[0]).local_filename
else:
image_filename = self.download_url(image_url)
if image_url not in self.image_cache['exif']:
self.image_cache['exif'][image_url] = OcrdExif(
Image.open(image_filename))
return self.image_cache['exif'][image_url]
def resolve_image_as_pil(self, image_url, coords=None):
"""
Resolve an image URL to a PIL image.
Args:
coords (list) : Coordinates of the bounding box to cut from the image
Returns:
Image or region in image as PIL.Image
"""
files = self.mets.find_files(url=image_url)
if files:
image_filename = self.download_file(files[0]).local_filename
else:
image_filename = self.download_url(image_url)
if image_url not in self.image_cache['pil']:
self.image_cache['pil'][image_url] = Image.open(image_filename)
pil_image = self.image_cache['pil'][image_url]
if coords is None:
return pil_image
if image_url not in self.image_cache['cv2']:
log.debug("Converting PIL to OpenCV: %s", image_url)
color_conversion = cv2.COLOR_GRAY2BGR if pil_image.mode in (
'1', 'L') else cv2.COLOR_RGB2BGR
pil_as_np_array = np.array(pil_image).astype(
'uint8') if pil_image.mode == '1' else np.array(pil_image)
self.image_cache['cv2'][image_url] = cv2.cvtColor(
pil_as_np_array, color_conversion)
cv2_image = self.image_cache['cv2'][image_url]
poly = np.array(coords, np.int32)
log.debug("Cutting region %s from %s", coords, image_url)
region_cut = cv2_image[np.min(poly[:, 1]):np.max(poly[:, 1]),
np.min(poly[:, 0]):np.max(poly[:, 0])]
return Image.fromarray(region_cut)
