fix(overlay): read overlay planes that dcmjs names by keyword

platform/core/src/classes/MetadataProvider.test.ts

@@ -107,4 +107,54 @@ describe('MetadataProvider', () => {
       });
     });
   });
+
+  describe('the overlay plane module', () => {
+    it('reads an overlay that dcmjs named by keyword', () => {
+      // What dcmjs >= 0.50 makes of group 6000 in DICOMweb metadata.
+      const instance = {
+        OverlayRows: 512,
+        OverlayColumns: 256,
+        OverlayType: 'G',
+        OverlayOrigin: [1, 1],
+        OverlayBitsAllocated: 1,
+        OverlayBitPosition: 0,
+        OverlayData: { BulkDataURI: 'http://localhost/bulk/overlay-6000' },
+      };
+
+      const { overlays } = metadataProvider.getTagFromInstance('overlayPlaneModule', instance);
+
+      expect(overlays).toHaveLength(1);
+      expect(overlays[0]).toMatchObject({
+        rows: 512,
+        columns: 256,
+        type: 'G',
+        x: 1,
+        y: 1,
+        pixelData: { BulkDataURI: 'http://localhost/bulk/overlay-6000' },
+      });
+    });
+
+    it('reads overlays that dcmjs kept under their tag', () => {
+      // dcmjs < 0.50 keeps the hex tag as the key.
+      const instance = {
+        '60000010': 512,
+        '60000011': 256,
+        '60000040': 'G',
+        '60000050': [1, 1],
+        '60003000': { BulkDataURI: 'http://localhost/bulk/overlay-6000' },
+        '60020010': 64,
+        '60020011': 32,
+        '60020040': 'R',
+        '60020050': [5, 7],
+        '60023000': { BulkDataURI: 'http://localhost/bulk/overlay-6002' },
+      };
+
+      const { overlays } = metadataProvider.getTagFromInstance('overlayPlaneModule', instance);
+
+      expect(overlays).toMatchObject([
+        { rows: 512, columns: 256, type: 'G', x: 1, y: 1 },
+        { rows: 64, columns: 32, type: 'R', x: 5, y: 7 },
+      ]);
+    });
+  });
 });

platform/core/src/classes/MetadataProvider.ts

@@ -279,8 +279,14 @@ class MetadataProvider {
             groupStr = `600${overlayGroup.toString(16)}`;
           }
 
+          // dcmjs >= 0.50 names 60xx tags by keyword (OverlayData, OverlayRows, ...) instead of
+          // by tag. All overlay groups share these keywords, so dcmjs keeps at most one overlay
+          // under them; it is read as group 6000.
+          const getValue = (tag: string, keyword: string) =>
+            instance[tag] ?? (overlayGroup === 0x00 ? instance[keyword] : undefined);
+
           const OverlayDataTag = `${groupStr}3000`;
-          const OverlayData = instance[OverlayDataTag];
+          const OverlayData = getValue(OverlayDataTag, 'OverlayData');
 
           if (!OverlayData) {
             continue;
@@ -295,24 +301,26 @@ class MetadataProvider {
           const ROIAreaTag = `${groupStr}1301`;
           const ROIMeanTag = `${groupStr}1302`;
           const ROIStandardDeviationTag = `${groupStr}1303`;
-          const OverlayOrigin = instance[OverlayOriginTag];
+          const OverlayOrigin = getValue(OverlayOriginTag, 'OverlayOrigin');
+          const OverlayRows = getValue(OverlayRowsTag, 'OverlayRows');
+          const OverlayColumns = getValue(OverlayColumnsTag, 'OverlayColumns');
 
           let rows = 0;
-          if (instance[OverlayRowsTag] instanceof Array) {
+          if (OverlayRows instanceof Array) {
             // The DICOM VR for overlay rows is US (unsigned short).
-            const rowsInt16Array = new Uint16Array(instance[OverlayRowsTag][0]);
+            const rowsInt16Array = new Uint16Array(OverlayRows[0]);
             rows = rowsInt16Array[0];
           } else {
-            rows = instance[OverlayRowsTag];
+            rows = OverlayRows;
           }
 
           let columns = 0;
-          if (instance[OverlayColumnsTag] instanceof Array) {
+          if (OverlayColumns instanceof Array) {
             // The DICOM VR for overlay columns is US (unsigned short).
-            const columnsInt16Array = new Uint16Array(instance[OverlayColumnsTag][0]);
+            const columnsInt16Array = new Uint16Array(OverlayColumns[0]);
             columns = columnsInt16Array[0];
           } else {
-            columns = instance[OverlayColumnsTag];
+            columns = OverlayColumns;
           }
 
           let x = 0;
@@ -330,15 +338,15 @@ class MetadataProvider {
           const overlay = {
             rows: rows,
             columns: columns,
-            type: instance[OverlayType],
+            type: getValue(OverlayType, 'OverlayType'),
             x,
             y,
             pixelData: OverlayData,
-            description: instance[OverlayDescriptionTag],
-            label: instance[OverlayLabelTag],
-            roiArea: instance[ROIAreaTag],
-            roiMean: instance[ROIMeanTag],
-            roiStandardDeviation: instance[ROIStandardDeviationTag],
+            description: getValue(OverlayDescriptionTag, 'OverlayDescription'),
+            label: getValue(OverlayLabelTag, 'OverlayLabel'),
+            roiArea: getValue(ROIAreaTag, 'ROIArea'),
+            roiMean: getValue(ROIMeanTag, 'ROIMean'),
+            roiStandardDeviation: getValue(ROIStandardDeviationTag, 'ROIStandardDeviation'),
           };
 
           overlays.push(overlay);