RED-8666 - implement reading order resolver

- added double column detection logic
- removing non y-intersecting left/right zones and adding them to middle for manual sorting

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/LayoutParsingPipeline.java

@@ -256,15 +256,14 @@ public class LayoutParsingPipeline {
             PDRectangle cropbox = pdPage.getCropBox();
             CleanRulings cleanRulings = rulingCleaningService.getCleanRulings(pdfTableCells.get(pageNumber), stripper.getRulings());
 
-            List<Cell> emptyTableCells = tableExtractionService.findCells(cleanRulings.getHorizontal(), cleanRulings.getVertical());
+            List<Cell> emptyTableCells = TableExtractionService.findCells(cleanRulings.getHorizontal(), cleanRulings.getVertical());
 
             ClassificationPage classificationPage = switch (layoutParsingType) {
                 case REDACT_MANAGER_OLD ->
                         redactManagerBlockificationService.blockify(stripper.getTextPositionSequences(), cleanRulings.getHorizontal(), cleanRulings.getVertical());
                 case TAAS -> taasBlockificationService.blockify(stripper.getTextPositionSequences(), cleanRulings.getHorizontal(), cleanRulings.getVertical());
                 case DOCUMINE -> docuMineBlockificationService.blockify(stripper.getTextPositionSequences(), cleanRulings.getHorizontal(), cleanRulings.getVertical());
-                case DOCSTRUM -> docstrumBlockificationService.blockify(stripper.getTextPositionSequences(), emptyTableCells, false);
+                case DOCSTRUM, REDACT_MANAGER -> docstrumBlockificationService.blockify(stripper.getTextPositionSequences(), emptyTableCells);
-                case REDACT_MANAGER -> docstrumBlockificationService.blockify(stripper.getTextPositionSequences(), emptyTableCells, true);
             };
             classificationPage.setCleanRulings(cleanRulings);
             classificationPage.setRotation(rotation);

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/blockification/DocstrumBlockificationService.java

@@ -38,7 +38,7 @@ public class DocstrumBlockificationService {
     static final float THRESHOLD = 1f;
 
 
-    public ClassificationPage blockify(List<TextPositionSequence> textPositions, List<Cell> cells, boolean xyOder) {
+    public ClassificationPage blockify(List<TextPositionSequence> textPositions, List<Cell> cells) {
 
         // Underlined or strikethrough are also in rulings but we dont want to split blocks with them so we use cells.
         List<Ruling> usedHorizonalRulings = new ArrayList<>();
@@ -52,7 +52,7 @@ public class DocstrumBlockificationService {
         });
 
         List<AbstractPageBlock> abstractPageBlocks = new ArrayList<>();
-        var zones = docstrumSegmentationService.segmentPage(textPositions, xyOder);
+        var zones = docstrumSegmentationService.segmentPage(textPositions);
         zones.forEach(zone -> {
 
             List<TextPositionSequence> textPositionSequences = new ArrayList<>();

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/DocstrumSegmentationService.java

@@ -29,7 +29,7 @@ public class DocstrumSegmentationService {
     private final ReadingOrderService readingOrderService;
 
 
-    public List<Zone> segmentPage(List<TextPositionSequence> textPositions, boolean xyOder) {
+    public List<Zone> segmentPage(List<TextPositionSequence> textPositions) {
 
         List<Zone> zones = new ArrayList<>();
         zones.addAll(computeZones(textPositions, TextDirection.ZERO));
@@ -37,7 +37,7 @@ public class DocstrumSegmentationService {
         zones.addAll(computeZones(textPositions, TextDirection.HALF_CIRCLE));
         zones.addAll(computeZones(textPositions, TextDirection.THREE_QUARTER_CIRCLE));
 
-        return readingOrderService.resolve(zones, xyOder);
+        return readingOrderService.resolve(zones);
     }
 
 

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/model/BoundingBox.java

@@ -42,7 +42,16 @@ public abstract class BoundingBox {
 
     public boolean contains(Rectangle2D contained, double tolerance) {
 
-        return bBox.getX() <= contained.getX() + tolerance && bBox.getY() <= contained.getY() + tolerance && bBox.getX() + bBox.getWidth() >= contained.getX() + contained.getWidth() - tolerance && bBox.getY() + bBox.getHeight() >= contained.getY() + contained.getHeight() - tolerance;
+        return bBox.getX() <= contained.getX() + tolerance
+               && bBox.getY() <= contained.getY() + tolerance
+               && bBox.getX() + bBox.getWidth() >= contained.getX() + contained.getWidth() - tolerance
+               && bBox.getY() + bBox.getHeight() >= contained.getY() + contained.getHeight() - tolerance;
+    }
+
+
+    public boolean intersectsY(BoundingBox other) {
+
+        return this.getBBox().getMinY() <= other.getBBox().getMaxY() && this.getBBox().getMaxY() >= other.getBBox().getMinY();
     }
 
 }

layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/docstrum/service/ReadingOrderService.java

@@ -2,8 +2,10 @@ package com.knecon.fforesight.service.layoutparser.processor.services.docstrum.s
 
 import java.util.ArrayList;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
 import java.util.ListIterator;
+import java.util.Map;
 
 import org.springframework.stereotype.Service;
 
@@ -15,22 +17,42 @@ import com.knecon.fforesight.service.layoutparser.processor.services.docstrum.ut
 public class ReadingOrderService {
 
     private static final double THRESHOLD = 5;
+    public static final double MULTI_COLUMN_DETECTION_THRESHOLD = 1.5;
 
 
-    public List<Zone> resolve(List<Zone> zones, boolean xyOrder) {
+    public List<Zone> resolve(List<Zone> zones) {
 
         if (zones.isEmpty() || zones.size() == 1) {
             return zones;
         }
 
-        if (xyOrder) {
+        Map<Long, Integer> histogram = new HashMap<>();
-//            QuickSort.sort(zones, new ZoneComparator());
+        for (Zone zone : zones) {
-            zones.sort(Comparator.comparing(BoundingBox::getY, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD))
+            long minY = Math.round(zone.getBBox().getMinY());
-                    .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, 0)));
+            long maxY = Math.round(zone.getBBox().getMaxY());
-            return zones;
+            for (long i = minY; i <= maxY; i++) {
+                histogram.put(i, histogram.getOrDefault(i, 0) + 1);
+            }
         }
 
-        return resolveMultiColumnReadingOder(zones);
+        if (histogram.values()
+                    .stream()
+                    .mapToInt(Integer::intValue).average()
+                    .orElse(1) < MULTI_COLUMN_DETECTION_THRESHOLD) {
+            return resolveSingleColumnReadingOrder(zones);
+        } else {
+
+            return resolveMultiColumnReadingOder(zones);
+        }
+
+    }
+
+
+    private static List<Zone> resolveSingleColumnReadingOrder(List<Zone> zones) {
+
+        zones.sort(Comparator.comparing(BoundingBox::getY, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD))
+                           .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
+        return zones;
     }
 
 
@@ -67,13 +89,55 @@ public class ReadingOrderService {
         }
 
         leftOf.sort(Comparator.comparing(BoundingBox::getY, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD))
-                .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
+                            .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
 
         rightOf.sort(Comparator.comparing(BoundingBox::getY, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD))
-                .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
+                             .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
 
         middle.sort(Comparator.comparing(BoundingBox::getY, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD))
-                .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
+                            .thenComparing(BoundingBox::getX, (o1, o2) -> DoubleUtils.compareDouble(o1, o2, THRESHOLD)));
+
+        List<Zone> leftNotIntersecting = new ArrayList<>();
+        for (Zone leftZone : leftOf) {
+            boolean intersects = false;
+            for (Zone rightZone : rightOf) {
+                if (leftZone.intersectsY(rightZone)) {
+                    intersects = true;
+                    break;
+                }
+                // early stopping
+                if (rightZone.getBBox().getMinY() > leftZone.getBBox().getMaxY()) {
+                    break;
+                }
+            }
+            if (!intersects) {
+                leftNotIntersecting.add(leftZone);
+            }
+        }
+
+        List<Zone> rightNotIntersecting = new ArrayList<>();
+        for (Zone rightZone : rightOf) {
+            boolean intersects = false;
+            for (Zone leftZone : leftOf) {
+                if (rightZone.intersectsY(leftZone)) {
+                    intersects = true;
+                    break;
+                }
+                // early stopping
+                if (leftZone.getBBox().getMinY() > rightZone.getBBox().getMaxY()) {
+                    break;
+                }
+            }
+            if (!intersects) {
+                rightNotIntersecting.add(rightZone);
+            }
+        }
+
+        leftOf.removeAll(leftNotIntersecting);
+        rightOf.removeAll(rightNotIntersecting);
+
+        middle.addAll(leftNotIntersecting);
+        middle.addAll(rightNotIntersecting);
 
         List<Zone> sortedZones = new ArrayList<>();
         sortedZones.addAll(leftOf);

layoutparser-service/layoutparser-service-server/src/test/java/com/knecon/fforesight/service/layoutparser/server/graph/ViewerDocumentTest.java

@@ -26,7 +26,7 @@ public class ViewerDocumentTest extends BuildDocumentTest {
     @SneakyThrows
     public void testViewerDocument() {
 
-        String fileName = "files/new/270 rotated text on non rotated pages.pdf";
+        String fileName = "files/Plenarprotokoll 1 (keine Druchsache!) (1).pdf";
         String tmpFileName = "/tmp/" + Path.of(fileName).getFileName() + "_VIEWER.pdf";
 
         var documentFile = new ClassPathResource(fileName).getFile();