BaseProcessor.input_files: Implement logic for PAGEXML/image in same …

…folder

OCR-D/spec#164
#505
cisocrgroup/ocrd_cis#57 (comment)

ocrd/ocrd/processor/base.py

@@ -3,7 +3,7 @@
 from click import wrap_text
 from time import time
 import subprocess
-from ocrd_utils import getLogger, VERSION as OCRD_VERSION
+from ocrd_utils import getLogger, VERSION as OCRD_VERSION, MIMETYPE_PAGE
 from ocrd_validators import ParameterValidator
 
 log = getLogger('ocrd.processor')
@@ -239,6 +239,26 @@ def process(self):
  @property
  def input_files(self):
  """
- List the input files
+ List the input files.
+
+ - If there's a PAGE-XML for the page, take it (and forget about all
+ other files for that page)
+ - Else if there's only one image, take it (and forget about all other
+ files for that page)
+ - Otherwise raise an error (complaining that only PAGE-XML warrants
+
+ having multiple images for a single page)
+ (https:/cisocrgroup/ocrd_cis/pull/57#issuecomment-656336593)
  """
- return self.workspace.mets.find_files(fileGrp=self.input_file_grp, pageId=self.page_id)
+ ret = self.workspace.mets.find_files(
+ fileGrp=self.input_file_grp, pageId=self.page_id, mimetype=MIMETYPE_PAGE)
+ if ret:
+ return ret
+ ret = self.workspace.mets.find_files(
+ fileGrp=self.input_file_grp, pageId=self.page_id, mimetype="//image/.*")
+ if self.page_id and len(ret) > 1:
+ raise ValueError("No PAGE-XML %s in fileGrp '%s' but multiple images." % (
+ "for page '%s'" % self.page_id if self.page_id else '',
+ self.input_file_grp
+ ))
+ return ret