Testcase and fix for get_image_paths returning non images sometimes

Fixes #51 False warning about number of images per grp/page

ocrd_browser/model/document.py

@@ -246,7 +246,7 @@ def get_file_index(self) -> Dict[str, OcrdFile]:
 
         return file_index
 
-    def get_image_paths(self, file_group: str) -> Dict[str, Path]:
+    def get_image_paths(self, file_group: FileGroupHandle) -> Dict[str, Path]:
         """
         Builds a Dict ID->Path for all page_ids fast
 
@@ -256,12 +256,11 @@ def get_image_paths(self, file_group: str) -> Dict[str, Path]:
         image_paths = {}
         file_index = self.get_file_index()
         for page_id in self.page_ids:
-            images = [image for image in file_index.values() if
-                      image.static_page_id == page_id and image.fileGrp == file_group]
-            if len(images) == 1:
+            images = [image for image in file_index.values() if image.static_page_id == page_id and file_group.match(image)]
+            if len(images) > 0:
                 image_paths[page_id] = self.directory.joinpath(images[0].local_filename)
             else:
-                log.warning('Found %d images for PAGE %s and fileGrp %s, expected 1', len(images), page_id, file_group)
+                log.warning('Found no images for PAGE %s and fileGrp %s', page_id, file_group)
                 image_paths[page_id] = None
         return image_paths
 

tests/example/workspaces/kant_aufklaerung_1784_bin/OCR-D-IMG-BIN/OCR-D-IMG-BIN_0001.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<pc:PcGts xmlns:pc="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15/pagecontent.xsd" pcGtsId="OCR-D-IMG-BIN_0001">
+    <pc:Metadata>
+        <pc:Creator>OCR-D/core 2.38.0</pc:Creator>
+        <pc:Created>2022-10-23T22:26:03.882709</pc:Created>
+        <pc:LastChange>2022-10-23T22:26:03.882709</pc:LastChange>
+        <pc:MetadataItem type="processingStep" name="preprocessing/optimization/binarization" value="ocrd-doxa-binarize">
+            <pc:Labels externalModel="ocrd-tool" externalId="parameters">
+                <pc:Label value="0" type="dpi"/>
+                <pc:Label value="page" type="level-of-operation"/>
+                <pc:Label value="ISauvola" type="algorithm"/>
+                <pc:Label value="{}" type="parameters"/>
+            </pc:Labels>
+        </pc:MetadataItem>
+    </pc:Metadata>
+    <pc:Page imageFilename="OCR-D-IMG/INPUT_0017.tif" imageWidth="1457" imageHeight="2083">
+        <pc:AlternativeImage filename="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0001.IMG-BIN.png" comments=",binarized"/>
+    </pc:Page>
+</pc:PcGts>

tests/example/workspaces/kant_aufklaerung_1784_bin/OCR-D-IMG-BIN/OCR-D-IMG-BIN_0002.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<pc:PcGts xmlns:pc="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15 http://schema.primaresearch.org/PAGE/gts/pagecontent/2019-07-15/pagecontent.xsd" pcGtsId="OCR-D-IMG-BIN_0002">
+    <pc:Metadata>
+        <pc:Creator>OCR-D/core 2.38.0</pc:Creator>
+        <pc:Created>2022-10-23T22:26:04.307376</pc:Created>
+        <pc:LastChange>2022-10-23T22:26:04.307376</pc:LastChange>
+        <pc:MetadataItem type="processingStep" name="preprocessing/optimization/binarization" value="ocrd-doxa-binarize">
+            <pc:Labels externalModel="ocrd-tool" externalId="parameters">
+                <pc:Label value="0" type="dpi"/>
+                <pc:Label value="page" type="level-of-operation"/>
+                <pc:Label value="ISauvola" type="algorithm"/>
+                <pc:Label value="{}" type="parameters"/>
+            </pc:Labels>
+        </pc:MetadataItem>
+    </pc:Metadata>
+    <pc:Page imageFilename="OCR-D-IMG/INPUT_0020.tif" imageWidth="1457" imageHeight="2084">
+        <pc:AlternativeImage filename="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0002.IMG-BIN.png" comments=",binarized"/>
+    </pc:Page>
+</pc:PcGts>

tests/example/workspaces/kant_aufklaerung_1784_bin/mets.xml

@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<mets:mets xmlns:mets="http://www.loc.gov/METS/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="info:lc/xmlns/premis-v2 http://www.loc.gov/standards/premis/v2/premis-v2-0.xsd http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-6.xsd http://www.loc.gov/METS/ http://www.loc.gov/standards/mets/version17/mets.v1-7.xsd http://www.loc.gov/mix/v10 http://www.loc.gov/standards/mix/mix10/mix10.xsd">
+  <mets:metsHdr CREATEDATE="2017-11-30T16:18:26">
+    <mets:agent OTHERTYPE="SOFTWARE" ROLE="CREATOR" TYPE="OTHER">
+      <mets:name>DFG-Koordinierungsprojekt zur Weiterentwicklung von Verfahren der Optical Character Recognition (OCR-D)</mets:name>
+      <mets:note>OCR-D</mets:note>
+    </mets:agent>
+    <mets:agent TYPE="OTHER" OTHERTYPE="SOFTWARE" ROLE="OTHER" OTHERROLE="preprocessing/optimization/binarization">
+      <mets:name>ocrd-doxa-binarize v0.0.2</mets:name>
+      <mets:note xmlns:ocrd="https://ocr-d.de" ocrd:option="input-file-grp">OCR-D-IMG</mets:note>
+      <mets:note xmlns:ocrd="https://ocr-d.de" ocrd:option="output-file-grp">OCR-D-IMG-BIN</mets:note>
+      <mets:note xmlns:ocrd="https://ocr-d.de" ocrd:option="parameter">{"dpi": 0, "level-of-operation": "page", "algorithm": "ISauvola", "parameters": {}}</mets:note>
+      <mets:note xmlns:ocrd="https://ocr-d.de" ocrd:option="page-id"/>
+    </mets:agent>
+  </mets:metsHdr>
+  <mets:dmdSec ID="DMDLOG_0001">
+    <mets:mdWrap MDTYPE="MODS">
+      <mets:xmlData>
+        <mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
+          <mods:identifier type="purl">http://kant_aufklaerung_1784</mods:identifier>
+        </mods:mods>
+      </mets:xmlData>
+    </mets:mdWrap>
+  </mets:dmdSec>
+  <mets:fileSec>
+    <mets:fileGrp USE="OCR-D-IMG">
+      <mets:file ID="INPUT_0017" MIMETYPE="image/tiff">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-IMG/INPUT_0017.tif" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+      <mets:file ID="INPUT_0020" MIMETYPE="image/tiff">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-IMG/INPUT_0020.tif" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+    </mets:fileGrp>
+    <mets:fileGrp USE="OCR-D-GT-PAGE">
+      <mets:file ID="PAGE_0017_PAGE" MIMETYPE="application/vnd.prima.page+xml">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-GT-PAGE/PAGE_0017_PAGE.xml" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+      <mets:file ID="PAGE_0020_PAGE" MIMETYPE="application/vnd.prima.page+xml">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-GT-PAGE/PAGE_0020_PAGE.xml" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+    </mets:fileGrp>
+    <mets:fileGrp USE="OCR-D-GT-ALTO">
+      <mets:file ID="PAGE_0017_ALTO" MIMETYPE="application/alto+xml">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-GT-ALTO/PAGE_0017_ALTO.xml" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+      <mets:file ID="PAGE_0020_ALTO" MIMETYPE="application/alto+xml">
+        <mets:FLocat LOCTYPE="OTHER" xlink:href="OCR-D-GT-ALTO/PAGE_0020_ALTO.xml" OTHERLOCTYPE="FILE"/>
+      </mets:file>
+    </mets:fileGrp>
+    <mets:fileGrp USE="OCR-D-IMG-BIN">
+      <mets:file ID="OCR-D-IMG-BIN_0001.IMG-BIN" MIMETYPE="image/png">
+        <mets:FLocat LOCTYPE="OTHER" OTHERLOCTYPE="FILE" xlink:href="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0001.IMG-BIN.png"/>
+      </mets:file>
+      <mets:file ID="OCR-D-IMG-BIN_0001" MIMETYPE="application/vnd.prima.page+xml">
+        <mets:FLocat LOCTYPE="OTHER" OTHERLOCTYPE="FILE" xlink:href="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0001.xml"/>
+      </mets:file>
+      <mets:file ID="OCR-D-IMG-BIN_0002.IMG-BIN" MIMETYPE="image/png">
+        <mets:FLocat LOCTYPE="OTHER" OTHERLOCTYPE="FILE" xlink:href="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0002.IMG-BIN.png"/>
+      </mets:file>
+      <mets:file ID="OCR-D-IMG-BIN_0002" MIMETYPE="application/vnd.prima.page+xml">
+        <mets:FLocat LOCTYPE="OTHER" OTHERLOCTYPE="FILE" xlink:href="OCR-D-IMG-BIN/OCR-D-IMG-BIN_0002.xml"/>
+      </mets:file>
+    </mets:fileGrp>
+  </mets:fileSec>
+  <mets:structMap TYPE="PHYSICAL">
+    <mets:div TYPE="physSequence">
+      <mets:div TYPE="page" ID="PHYS_0017">
+        <mets:fptr FILEID="INPUT_0017"/>
+        <mets:fptr FILEID="PAGE_0017_PAGE"/>
+        <mets:fptr FILEID="PAGE_0017_ALTO"/>
+        <mets:fptr FILEID="OCR-D-IMG-BIN_0001.IMG-BIN"/>
+        <mets:fptr FILEID="OCR-D-IMG-BIN_0001"/>
+      </mets:div>
+      <mets:div TYPE="page" ID="PHYS_0020">
+        <mets:fptr FILEID="INPUT_0020"/>
+        <mets:fptr FILEID="PAGE_0020_PAGE"/>
+        <mets:fptr FILEID="PAGE_0020_ALTO"/>
+        <mets:fptr FILEID="OCR-D-IMG-BIN_0002.IMG-BIN"/>
+        <mets:fptr FILEID="OCR-D-IMG-BIN_0002"/>
+      </mets:div>
+    </mets:div>
+  </mets:structMap>
+</mets:mets>

tests/model/test_document.py

@@ -43,6 +43,16 @@ def test_get_image_paths(self):
         self.assertEqual('INPUT_0017.tif', image_paths['PHYS_0017'].name)
         self.assertEqual('INPUT_0020.tif', image_paths['PHYS_0020'].name)
 
+    def test_get_image_paths_only_returns_matching_groups(self):
+        """
+        Testcase for https://github.com/hnesk/browse-ocrd/issues/51
+        """
+        doc = Document.load(ASSETS_PATH / '../example/workspaces/kant_aufklaerung_1784_bin/mets.xml')
+        image_paths = doc.get_image_paths(FileGroupHandle('OCR-D-IMG-BIN', 'image/png'))
+        self.assertEqual(2, len(image_paths))
+        self.assertEqual('OCR-D-IMG-BIN_0001.IMG-BIN.png', image_paths['PHYS_0017'].name)
+        self.assertEqual('OCR-D-IMG-BIN_0002.IMG-BIN.png', image_paths['PHYS_0020'].name)
+
     def test_get_default_image_group(self):
         doc = Document.load(ASSETS_PATH / 'kant_aufklaerung_1784-complex/data/mets.xml')
         file_group = doc.get_default_image_group(['OCR-D-IMG-BIN', 'OCR-D-IMG.*'])