"""
Validating a workspace.
"""
import re
from traceback import format_exc
from pathlib import Path
from ocrd_utils import getLogger, MIMETYPE_PAGE, pushd_popd, is_local_filename
from ocrd_models import ValidationReport
from ocrd_modelfactory import page_from_file
from .constants import FILE_GROUP_CATEGORIES, FILE_GROUP_PREFIX
from .page_validator import PageValidator
from .xsd_page_validator import XsdPageValidator
from .xsd_mets_validator import XsdMetsValidator
#
# -------------------------------------------------
#
[docs]class WorkspaceValidator():
"""
Validator for `OcrdMets <../ocrd_models/ocrd_models.ocrd_mets.html>`.
"""
[docs] @staticmethod
def check_file_grp(workspace, input_file_grp=None, output_file_grp=None, page_id=None, report=None):
"""
Return a report on whether input_file_grp is/are in workspace.mets and output_file_grp is/are not.
To be run before processing
Arguments:
workspacec (Workspace) the workspace to validate
input_file_grp (list|string) list or comma-separated list of input file groups
output_file_grp (list|string) list or comma-separated list of output file groups
page_id (list|string) list or comma-separated list of page_ids to write to
"""
if not report:
report = ValidationReport()
if isinstance(input_file_grp, str):
input_file_grp = input_file_grp.split(',') if input_file_grp else []
if isinstance(output_file_grp, str):
output_file_grp = output_file_grp.split(',') if output_file_grp else []
if page_id and isinstance(page_id, str):
page_id = page_id.split(',')
log = getLogger('ocrd.workspace_validator')
log.debug("input_file_grp=%s output_file_grp=%s" % (input_file_grp, output_file_grp))
if input_file_grp:
for grp in input_file_grp:
if grp not in workspace.mets.file_groups:
report.add_error("Input fileGrp[@USE='%s'] not in METS!" % grp)
if output_file_grp:
for grp in output_file_grp:
if grp in workspace.mets.file_groups:
if page_id:
for one_page_id in page_id:
if next(workspace.mets.find_files(fileGrp=grp, pageId=one_page_id), None):
report.add_error("Output fileGrp[@USE='%s'] already contains output for page %s" % (grp, one_page_id))
else:
report.add_error("Output fileGrp[@USE='%s'] already in METS!" % grp)
return report
def __init__(self, resolver, mets_url, src_dir=None, skip=None, download=False,
page_strictness='strict', page_coordinate_consistency='poly'):
"""
Construct a new WorkspaceValidator.
Args:
resolver (Resolver):
mets_url (string):
src_dir (string):
skip (list):
download (boolean):
page_strictness ("strict"|"lax"|"fix"|"off"): how strict to check
multi-level TextEquiv consistency of PAGE XML files
page_coordinate_consistency ("poly"|"baseline"|"both"|"off"): check whether each
segment's coords are fully contained within its parent's:
* `"poly"`: *Region/TextLine/Word/Glyph in Border/*Region/TextLine/Word
* `"baseline"`: Baseline in TextLine
* `"both"`: both `poly` and `baseline` checks
* `"off"`: no coordinate checks
"""
self.report = ValidationReport()
self.skip = skip if skip else []
self.log = getLogger('ocrd.workspace_validator')
self.log.debug('resolver=%s mets_url=%s src_dir=%s', resolver, mets_url, src_dir)
self.resolver = resolver
if mets_url is None and src_dir is not None:
mets_url = '%s/mets.xml' % src_dir
self.mets_url = mets_url
self.download = download
self.page_strictness = page_strictness
self.page_coordinate_consistency = page_coordinate_consistency
self.page_checks = []
# there will be more options to come
if 'mets_fileid_page_pcgtsid' not in self.skip:
self.page_checks.append('pcgtsid')
self.src_dir = src_dir
self.workspace = None
self.mets = None
[docs] @staticmethod
def validate(*args, **kwargs):
"""
Validates the workspace of a METS URL against the specs
Arguments:
resolver (:class:`ocrd.Resolver`): Resolver
mets_url (string): URL of the METS file
src_dir (string, None): Directory containing mets file
skip (list): Validation checks to omit. One or more of
'mets_unique_identifier', 'mets_file_group_names',
'mets_files', 'pixel_density', 'dimension', 'url',
'multipage', 'page', 'page_xsd', 'mets_xsd',
'mets_fileid_page_pcgtsid'
download (boolean): Whether to download remote file references
temporarily during validation (like a processor would)
Returns:
report (:class:`ValidationReport`) Report on the validity
"""
validator = WorkspaceValidator(*args, **kwargs)
return validator._validate() # pylint: disable=protected-access
def _validate(self):
"""
Actual validation.
"""
try:
self._resolve_workspace()
except Exception as e: # pylint: disable=broad-except
self.log.warning("Failed to instantiate workspace: %s", e)
self.report.add_error("Failed to instantiate workspace: %s" % e)
return self.report
with pushd_popd(self.workspace.directory):
try:
if 'mets_unique_identifier' not in self.skip:
self._validate_mets_unique_identifier()
if 'mets_file_group_names' not in self.skip:
self._validate_mets_file_group_names()
if 'mets_files' not in self.skip:
self._validate_mets_files()
if 'pixel_density' not in self.skip:
self._validate_pixel_density()
if 'multipage' not in self.skip:
self._validate_multipage()
if 'dimension' not in self.skip:
self._validate_dimension()
if 'imagefilename' not in self.skip:
self._validate_imagefilename()
if 'page' not in self.skip:
self._validate_page()
if 'page_xsd' not in self.skip:
self._validate_page_xsd()
if 'mets_xsd' not in self.skip:
self._validate_mets_xsd()
except Exception: # pylint: disable=broad-except
self.report.add_error("Validation aborted with exception: %s" % format_exc())
return self.report
def _resolve_workspace(self):
"""
Clone workspace from mets_url unless workspace was provided.
"""
self.log.debug('_resolve_workspace')
if self.workspace is None:
self.workspace = self.resolver.workspace_from_url(self.mets_url, src_baseurl=self.src_dir)
self.mets = self.workspace.mets
def _validate_mets_unique_identifier(self):
"""
Validate METS unique identifier exists.
See `spec <https://ocr-d.github.io/mets#unique-id-for-the-document-processed>`_.
"""
self.log.debug('_validate_mets_unique_identifier')
if self.mets.unique_identifier is None:
self.report.add_error("METS has no unique identifier")
def _validate_imagefilename(self):
"""
Validate that the imageFilename is correctly set to a filename relative to the workspace
"""
self.log.debug('_validate_imagefilename')
for f in self.mets.find_files(mimetype=MIMETYPE_PAGE):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
page = page_from_file(f).get_Page()
imageFilename = page.imageFilename
if not self.mets.find_files(url=imageFilename):
self.report.add_error("PAGE-XML %s : imageFilename '%s' not found in METS" % (f.local_filename, imageFilename))
if is_local_filename(imageFilename) and not Path(imageFilename).exists():
self.report.add_warning("PAGE-XML %s : imageFilename '%s' points to non-existent local file" % (f.local_filename, imageFilename))
def _validate_dimension(self):
"""
Validate image height and PAGE imageHeight match
"""
self.log.info('_validate_dimension')
for f in self.mets.find_files(mimetype=MIMETYPE_PAGE):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
page = page_from_file(f).get_Page()
_, _, exif = self.workspace.image_from_page(page, f.pageId)
if page.imageHeight != exif.height:
self.report.add_error("PAGE '%s': @imageHeight != image's actual height (%s != %s)" % (f.ID, page.imageHeight, exif.height))
if page.imageWidth != exif.width:
self.report.add_error("PAGE '%s': @imageWidth != image's actual width (%s != %s)" % (f.ID, page.imageWidth, exif.width))
def _validate_multipage(self):
"""
Validate the number of images per file is 1 (TIFF allows multi-page images)
See `spec <https://ocr-d.github.io/mets#no-multi-page-images>`_.
"""
self.log.debug('_validate_multipage')
for f in self.mets.find_files(mimetype='//image/.*'):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
try:
exif = self.workspace.resolve_image_exif(f.local_filename)
if exif.n_frames > 1:
self.report.add_error("Image %s: More than 1 frame: %s" % (f.ID, exif.n_frames))
except FileNotFoundError:
self.report.add_error("Image %s: Could not retrieve %s (local_filename=%s, url=%s)" % (f.ID, f.local_filename, f.url))
return
def _validate_pixel_density(self):
"""
Validate image pixel density
See `spec <https://ocr-d.github.io/mets#pixel-density-of-images-must-be-explicit-and-high-enough>`_.
"""
self.log.debug('_validate_pixel_density')
for f in self.mets.find_files(mimetype='//image/.*'):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
exif = self.workspace.resolve_image_exif(f.local_filename)
for k in ['xResolution', 'yResolution']:
v = exif.__dict__.get(k)
if v is None or v <= 72:
self.report.add_notice("Image %s: %s (%s pixels per %s) is suspiciously low" % (f.ID, k, v, exif.resolutionUnit))
def _validate_mets_file_group_names(self):
"""
Ensure ``USE`` attributes of ``mets:fileGrp`` conform to OCR-D naming schema..
See `spec <https://ocr-d.github.io/mets#file-group-use-syntax>`_.
"""
self.log.debug('_validate_mets_file_group_names')
for fileGrp in self.mets.file_groups:
if not fileGrp.startswith(FILE_GROUP_PREFIX):
self.report.add_notice("fileGrp USE does not begin with '%s': %s" % (FILE_GROUP_PREFIX, fileGrp))
else:
# OCR-D-FOO-BAR -> ('FOO', 'BAR')
# \____/\_/ \_/
# | | |
# Prefix | Name
# Category
category = fileGrp[len(FILE_GROUP_PREFIX):]
name = None
if '-' in category:
category, name = category.split('-', 1)
if category not in FILE_GROUP_CATEGORIES:
self.report.add_notice("Unspecified USE category '%s' in fileGrp '%s'" % (category, fileGrp))
if name is not None and not re.match(r'^[A-Z0-9-]{3,}$', name):
self.report.add_notice("Invalid USE name '%s' in fileGrp '%s'" % (name, fileGrp))
def _validate_mets_files(self):
"""
Validate ``mets:file`` URLs are sane.
"""
self.log.debug('_validate_mets_files')
try:
next(self.mets.find_files())
except StopIteration:
self.report.add_error("No files")
for f in self.mets.find_files():
if f._el.get('GROUPID'): # pylint: disable=protected-access
self.report.add_notice("File '%s' has GROUPID attribute - document might need an update" % f.ID)
if not (f.url or f.local_filename):
self.report.add_error("File '%s' has neither mets:Flocat[@LOCTYPE='URL']/@xlink:href nor mets:FLocat[@LOCTYPE='OTHER'][@OTHERLOCTYPE='FILE']/xlink:href" % f.ID)
continue
if f.url and 'url' not in self.skip:
if re.match(r'^file:/[^/]', f.url):
self.report.add_error("File '%s' has an invalid (Java-specific) file URL '%s'" % (f.ID, f.url))
scheme = f.url[0:f.url.index(':')]
if scheme not in ('http', 'https', 'file'):
self.report.add_warning("File '%s' has non-HTTP, non-file URL '%s'" % (f.ID, f.url))
def _validate_page(self):
"""
Run PageValidator on the PAGE-XML documents referenced in the METS.
"""
self.log.debug('_validate_page')
for f in self.mets.find_files(mimetype=MIMETYPE_PAGE):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
page_report = PageValidator.validate(ocrd_file=f,
page_textequiv_consistency=self.page_strictness,
check_coords=self.page_coordinate_consistency in ['poly', 'both'],
check_baseline=self.page_coordinate_consistency in ['baseline', 'both'])
pg = page_from_file(f)
if 'pcgtsid' in self.page_checks and pg.pcGtsId != f.ID:
page_report.add_warning('pc:PcGts/@pcGtsId differs from mets:file/@ID: "%s" !== "%s"' % (pg.pcGtsId or '', f.ID or ''))
self.report.merge_report(page_report)
def _validate_page_xsd(self):
"""
Validate all PAGE-XML files against PAGE XSD schema
"""
self.log.debug('_validate_page_xsd')
for f in self.mets.find_files(mimetype=MIMETYPE_PAGE):
if not f.local_filename and not self.download:
self.log.warning("Not available locally and 'download' is not set: %s", f)
continue
self.workspace.download_file(f)
for err in XsdPageValidator.validate(Path(f.local_filename)).errors:
self.report.add_error("%s: %s" % (f.ID, err))
self.log.debug("Finished validating all PAGE-XML files against XSD")
def _validate_mets_xsd(self):
"""
Validate METS against METS XSD schema
"""
self.log.debug('_validate_mets_xsd')
self.log.debug("Validating METS %s against XSD" % self.workspace.mets_target)
for err in XsdMetsValidator.validate(Path(self.workspace.mets_target)).errors:
self.report.add_error("%s: %s" % (self.workspace.mets_target, err))
self.log.debug("Finished Validating METS against XSD")
