RED-6019: Remove hidden text when processing OCR

*code refactor
*upgrade to java 17

ocr-service-v1/ocr-service-server-v1/pom.xml

@@ -86,16 +86,6 @@
     </dependencies>
     <build>
         <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <annotationProcessors>
-                        <annotationProcessor>lombok.launch.AnnotationProcessorHider$AnnotationProcessor</annotationProcessor>
-                        <annotationProcessor>com.dslplatform.json.processor.CompiledJsonAnnotationProcessor</annotationProcessor>
-                    </annotationProcessors>
-                </configuration>
-            </plugin>
             <plugin>
                 <!-- generate git.properties for exposure in /info -->
                 <groupId>pl.project13.maven</groupId>

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/model/ClippingPathStack.java

@@ -1,53 +1,67 @@
 package com.iqser.red.service.ocr.v1.server.model;
 
-import com.pdftron.pdf.Rect;
+import static com.iqser.red.service.ocr.v1.server.service.InvisibleElementRemovalService.TOLERANCE;
-import lombok.Data;
-import lombok.SneakyThrows;
 
 import java.awt.geom.Area;
 import java.awt.geom.GeneralPath;
 import java.awt.geom.Rectangle2D;
-import java.util.ArrayDeque;
 import java.util.Deque;
+import java.util.LinkedList;
+
+import com.pdftron.pdf.Rect;
+
+import lombok.Data;
+import lombok.SneakyThrows;
 
 @Data
 public class ClippingPathStack {
 
-    private Deque<Area> stack = new ArrayDeque<>();
+    private Deque<Area> stack = new LinkedList<>();
+
 
     @SneakyThrows
     public ClippingPathStack(Rect rectangle) {
+
         stack.push(new Area(new Rectangle2D.Double(rectangle.getX1(), rectangle.getY1(), rectangle.getWidth(), rectangle.getHeight()).getBounds2D()));
     }
 
 
     @SneakyThrows
     public void intersectClippingPath(GeneralPath path) {
+
         getCurrentClippingPath().intersect(new Area(path));
     }
 
+
     public boolean almostIntersects(double x, double y, double width, double height) {
+        // To address inconsistencies in the calculation of the bounding box we slightly increase the rectangle
         // Height or width are zero for straight lines, even though they are being rendered. Therefore, height or width must be at minimum >0.
-        double tolerance = 1e-3;
+
-        double x_with_tolerance = x > 0 ? x - tolerance : x + tolerance;
+        double x_with_tolerance = x > 0 ? x - TOLERANCE : x + TOLERANCE;
-        double y_with_tolerance = y > 0 ? y - tolerance : y + tolerance;
+        double y_with_tolerance = y > 0 ? y - TOLERANCE : y + TOLERANCE;
-        double width_with_tolerance = width + 2 * tolerance;
+        double width_with_tolerance = width + (2 * TOLERANCE);
-        double height_with_tolerance = height + 2 * tolerance;
+        double height_with_tolerance = height + (2 * TOLERANCE);
         return getCurrentClippingPath().intersects(x_with_tolerance, y_with_tolerance, width_with_tolerance, height_with_tolerance);
     }
 
+
     public Area getCurrentClippingPath() {
+
         return stack.peek();
     }
 
+
     public void enterNewGState() {
+
         Area current = stack.peek();
         Area cloned = new Area();
         cloned.add(current);
         stack.push(cloned);
     }
 
+
     public void leaveGState() {
+
         stack.pop();
     }
 

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/model/ElementFeatures.java

@@ -1,148 +1,170 @@
 package com.iqser.red.service.ocr.v1.server.model;
 
+import static com.iqser.red.service.ocr.v1.server.service.InvisibleElementRemovalService.TOLERANCE;
+
+import java.awt.geom.Rectangle2D;
+
 import com.pdftron.common.PDFNetException;
 import com.pdftron.pdf.Element;
 import com.pdftron.pdf.Rect;
-import lombok.*;
+
+import lombok.AccessLevel;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.SneakyThrows;
+import lombok.experimental.FieldDefaults;
 import lombok.experimental.SuperBuilder;
 
-import java.awt.geom.Rectangle2D;
+@Getter
-
-@Data
 @SuperBuilder
-@NoArgsConstructor
+@FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
-@AllArgsConstructor
+public class ElementFeatures {
-public abstract class ElementFeatures {
+
-    private int elementType;
+    int elementType;
-    private Rectangle2D boundingBox;
+    Rectangle2D boundingBox;
+
 
     public boolean almostMatches(Element element) throws PDFNetException {
-        if (element.getType() != elementType) return false;
+
-        if (element.getBBox() == null) return false;
+        return element.getType() == elementType && //
-        return rectsAlmostMatch(element.getBBox());
+                element.getBBox() != null && //
+                rectsAlmostMatch(element.getBBox());
     }
 
+
     protected boolean almostEqual(double a, double b) {
-        double tolerance = 1e-3;
+
-        return Math.abs(a - b) < tolerance;
+        return Math.abs(a - b) < TOLERANCE;
     }
 
+
     @SneakyThrows
     private boolean rectsAlmostMatch(Rect bBox) {
-        if (!almostEqual(bBox.getX1(), boundingBox.getX())) return false;
+        // To address the inconsistencies in the calculation of the bounding box we check equality with a tolerance
-        if (!almostEqual(bBox.getY1(), boundingBox.getY())) return false;
+
-        if (!almostEqual(bBox.getWidth(), boundingBox.getWidth())) return false;
+        return almostEqual(bBox.getX1(), boundingBox.getX()) && //
-        return almostEqual(bBox.getHeight(), boundingBox.getHeight());
+                almostEqual(bBox.getY1(), boundingBox.getY()) && //
+                almostEqual(bBox.getWidth(), boundingBox.getWidth()) && //
+                almostEqual(bBox.getHeight(), boundingBox.getHeight());
     }
 
+
     @EqualsAndHashCode(callSuper = true)
-    @Data
+    @Getter
     @SuperBuilder
-    @NoArgsConstructor
+    @FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
-    @AllArgsConstructor
+    private static class Text extends ElementFeatures {
-    public static class Text extends ElementFeatures {
+
-        private String text;
+        String text;
-        private int font;
+        int font;
-        private double fontsize;
+        double fontsize;
+
 
         @Override
         public boolean almostMatches(Element element) throws PDFNetException {
-            if (!super.almostMatches(element)) return false;
+
-            if (!text.equals(element.getTextString())) return false;
+            return super.almostMatches(element) && //
-            if (font != element.getGState().getFont().getType()) return false;
+                    text.equals(element.getTextString()) && //
-            return almostEqual(fontsize, element.getGState().getFontSize());
+                    font == element.getGState().getFont().getType() && //
+                    almostEqual(fontsize, element.getGState().getFontSize());
         }
 
     }
 
     @EqualsAndHashCode(callSuper = true)
-    @Data
+    @Getter
     @SuperBuilder
-    @NoArgsConstructor
+    @FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
-    @AllArgsConstructor
+    private static class Path extends ElementFeatures {
-    public static class Path extends ElementFeatures {
+
-        private boolean isClippingPath;
+        boolean isClippingPath;
-        private boolean isClipWindingFill;
+        boolean isClipWindingFill;
-        private boolean isStroked;
+        boolean isStroked;
-        private boolean isFilled;
+        boolean isFilled;
-        private boolean isWindingFill;
+        boolean isWindingFill;
+
 
         @Override
         public boolean almostMatches(Element element) throws PDFNetException {
-            if (!super.almostMatches(element)) return false;
-            if (isClippingPath != element.isClippingPath()) return false;
-            if (isClipWindingFill != element.isClipWindingFill()) return false;
-            if (isStroked != element.isStroked()) return false;
-            if (isFilled != element.isFilled()) return false;
-            if (isWindingFill != element.isWindingFill()) return false;
 
-            return true;
+            return super.almostMatches(element) && //
+                    isClippingPath == element.isClippingPath() && //
+                    isClipWindingFill == element.isClipWindingFill() && //
+                    isStroked == element.isStroked() && //
+                    isFilled == element.isFilled() && //
+                    isWindingFill == element.isWindingFill();
+
         }
+
     }
 
     @EqualsAndHashCode(callSuper = true)
-    @Data
+    @Getter
     @SuperBuilder
-    @NoArgsConstructor
+    @FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
-    public static class Image extends ElementFeatures {
+    private static class Image extends ElementFeatures {
-        private int dataSize;
+
-        private int height;
+        int dataSize;
-        private int width;
+        int height;
-        private int renderingIntent;
+        int width;
-        private int componentNum;
+        int renderingIntent;
-        private int bitsPerComponent;
+        int componentNum;
+        int bitsPerComponent;
+
 
         @Override
         public boolean almostMatches(Element element) throws PDFNetException {
-            if (!super.almostMatches(element)) return false;
+
-            if (dataSize != element.getImageDataSize()) return false;
+            return super.almostMatches(element) && //
-            if (height != element.getImageHeight()) return false;
+                    dataSize == element.getImageDataSize() && //
-            if (width != element.getImageWidth()) return false;
+                    height == element.getImageHeight() && //
-            if (renderingIntent != element.getImageRenderingIntent()) return false;
+                    width == element.getImageWidth() && //
-            if (componentNum != element.getComponentNum()) return false;
+                    renderingIntent == element.getImageRenderingIntent() && //
-            if (bitsPerComponent != element.getBitsPerComponent()) return false;
+                    componentNum == element.getComponentNum() && //
-            return true;
+                    bitsPerComponent == element.getBitsPerComponent();
         }
+
     }
 
+
     public static ElementFeatures extractFeatures(Element element) throws PDFNetException {
-        switch (element.getType()) {
+
-            case Element.e_path:
+        return switch (element.getType()) {
-                return ElementFeatures.Path.builder()
+            case Element.e_path -> Path.builder()
-                        .elementType(element.getType())
+                    .elementType(element.getType())
-                        .boundingBox(toRectangle2D(element.getBBox()))
+                    .boundingBox(toRectangle2D(element.getBBox()))
-                        .isClippingPath(element.isClippingPath())
+                    .isClippingPath(element.isClippingPath())
-                        .isClipWindingFill(element.isClipWindingFill())
+                    .isClipWindingFill(element.isClipWindingFill())
-                        .isStroked(element.isStroked())
+                    .isStroked(element.isStroked())
-                        .isFilled(element.isFilled())
+                    .isFilled(element.isFilled())
-                        .isWindingFill(element.isWindingFill())
+                    .isWindingFill(element.isWindingFill())
-                        .build();
+                    .build();
-            case Element.e_text:
+            case Element.e_text -> Text.builder()
-                return ElementFeatures.Text.builder()
+                    .elementType(element.getType())
-                        .elementType(element.getType())
+                    .boundingBox(toRectangle2D(element.getBBox()))
-                        .boundingBox(toRectangle2D(element.getBBox()))
+                    .text(element.getTextString())
-                        .text(element.getTextString())
+                    .font(element.getGState().getFont().getType())
-                        .font(element.getGState().getFont().getType())
+                    .fontsize(element.getGState().getFontSize())
-                        .fontsize(element.getGState().getFontSize())
+                    .build();
-                        .build();
+            case Element.e_image, Element.e_inline_image -> Image.builder()
-            case Element.e_image:
+                    .elementType(element.getType())
-            case Element.e_inline_image:
+                    .boundingBox(toRectangle2D(element.getBBox()))
-                return Image.builder()
+                    .dataSize(element.getImageDataSize())
-                        .elementType(element.getType())
+                    .height(element.getImageHeight())
-                        .boundingBox(toRectangle2D(element.getBBox()))
+                    .width(element.getImageWidth())
-                        .dataSize(element.getImageDataSize())
+                    .renderingIntent(element.getImageRenderingIntent())
-                        .height(element.getImageHeight())
+                    .componentNum(element.getComponentNum())
-                        .width(element.getImageWidth())
+                    .bitsPerComponent(element.getBitsPerComponent())
-                        .renderingIntent(element.getImageRenderingIntent())
+                    .build();
-                        .componentNum(element.getComponentNum())
+            // This technically should never happen, it's a safetynet
-                        .bitsPerComponent(element.getBitsPerComponent())
+            default -> throw new RuntimeException("Feature Extraction is not supported for PDFTron.Element with type: " + element.getType());
-                        .build();
+        };
-            default:
-                throw new UnsupportedOperationException("Feature Extraction is not supported for PDFTron.Element with type: " + element.getType());
-        }
     }
 
+
     private static Rectangle2D toRectangle2D(Rect rect) throws PDFNetException {
+
         return new Rectangle2D.Double(rect.getX1(), rect.getY1(), rect.getWidth(), rect.getHeight());
     }
+
 }

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/model/InvisibleElementRemovalDto.java

@@ -0,0 +1,25 @@
+package com.iqser.red.service.ocr.v1.server.model;
+
+import java.util.List;
+import java.util.Set;
+
+import com.pdftron.pdf.ElementReader;
+
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Data;
+import lombok.experimental.FieldDefaults;
+
+@Data
+@Builder
+@FieldDefaults(level = AccessLevel.PRIVATE, makeFinal = true)
+public class InvisibleElementRemovalDto {
+
+    boolean delta;
+    ElementReader reader;
+    ClippingPathStack clippingPathStack;
+    List<ElementFeatures> overlappedElements;
+    List<ElementFeatures> visibleElements;
+    Set<Long> visitedXObjIds;
+
+}

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/service/InvisibleElementRemovalService.java

@@ -0,0 +1,419 @@
+package com.iqser.red.service.ocr.v1.server.service;
+
+import java.awt.Shape;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.GeneralPath;
+import java.awt.geom.Rectangle2D;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.springframework.stereotype.Service;
+
+import com.google.common.primitives.Bytes;
+import com.google.common.primitives.Doubles;
+import com.iqser.red.service.ocr.v1.server.model.ClippingPathStack;
+import com.iqser.red.service.ocr.v1.server.model.ElementFeatures;
+import com.iqser.red.service.ocr.v1.server.model.InvisibleElementRemovalDto;
+import com.pdftron.common.Matrix2D;
+import com.pdftron.common.PDFNetException;
+import com.pdftron.pdf.ColorPt;
+import com.pdftron.pdf.ColorSpace;
+import com.pdftron.pdf.Element;
+import com.pdftron.pdf.ElementBuilder;
+import com.pdftron.pdf.ElementReader;
+import com.pdftron.pdf.ElementWriter;
+import com.pdftron.pdf.GState;
+import com.pdftron.pdf.PDFDoc;
+import com.pdftron.pdf.Page;
+import com.pdftron.pdf.PageIterator;
+import com.pdftron.pdf.PathData;
+import com.pdftron.pdf.Rect;
+import com.pdftron.sdf.Obj;
+import com.pdftron.sdf.SDFDoc;
+
+import lombok.SneakyThrows;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Service
+public class InvisibleElementRemovalService {
+
+    static public final double TOLERANCE = 1e-3;
+
+
+    /**
+     * Removes all hidden Text, Path and Image Elements from a PDF Document.
+     * handled cases:
+     * -Text which is transparent or is set to not render
+     * -Elements outside of clipping path
+     * -Elements that have been painted over by visible and filled Paths
+     * unhandled cases:
+     * -Elements covered by widely stroked path
+     * -Elements with the same color as background
+     * -Any Text set to clipping with its many interactions with other elements
+     *
+     * @param pdfFile The PDF file to process
+     * @param delta   If this flag is set only the removed Elements will be written to the output file.
+     *                The Elements are red if they are removed by clipping path, blue for transparency, and a green bounding box for overlap.
+     * @return The resulting PDF File as bytes.
+     **/
+    @SneakyThrows
+    public byte[] removeInvisibleElements(InputStream pdfFile, boolean delta) {
+
+        PDFDoc pdfDoc = new PDFDoc(pdfFile);
+
+        ElementWriter writer = new ElementWriter();
+        ElementReader reader = new ElementReader();
+        Set<Long> visitedXObjIds = new TreeSet<>();
+
+        for (PageIterator iterator = pdfDoc.getPageIterator(); iterator.hasNext(); ) {
+
+            Page page = iterator.next();
+
+            visitedXObjIds.add(page.getSDFObj().getObjNum());
+            InvisibleElementRemovalDto dto = InvisibleElementRemovalDto.builder()
+                    .reader(reader)
+                    .clippingPathStack(new ClippingPathStack(page.getMediaBox()))
+                    .delta(delta)
+                    .overlappedElements(new ArrayList<>())
+                    .visibleElements(new ArrayList<>())
+                    .visitedXObjIds(visitedXObjIds)
+                    .build();
+
+            removeClippedElementsAndInvisibleTextAndRememberOverlappedElements(page, writer, dto);
+
+            dto.getVisitedXObjIds().clear();
+
+            removeOverlappedElements(page, writer, dto);
+        }
+        return pdfDoc.save(SDFDoc.SaveMode.REMOVE_UNUSED, null);
+    }
+
+
+    private void removeClippedElementsAndInvisibleTextAndRememberOverlappedElements(Page page, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        dto.getReader().begin(page);
+        writer.begin(page, ElementWriter.e_replacement, false, true, page.getResourceDict());
+        processElements(writer, dto);
+        writer.end();
+        dto.getReader().end();
+    }
+
+
+    private void processElements(ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        for (Element element = dto.getReader().next(); element != null; element = dto.getReader().next())
+            switch (element.getType()) {
+                case Element.e_image, Element.e_inline_image -> processImages(element, writer, dto);
+                case Element.e_text -> processText(element, writer, dto);
+                case Element.e_path -> processPath(element, writer, dto);
+                case Element.e_form -> processForm(element, writer, dto);
+                case Element.e_group_begin -> {
+                    dto.getClippingPathStack().enterNewGState();
+                    writer.writeElement(element);
+                }
+                case Element.e_group_end -> {
+                    dto.getClippingPathStack().leaveGState();
+                    writer.writeElement(element);
+                }
+                default -> writer.writeElement(element);
+            }
+    }
+
+
+    private void processImages(Element imageElement, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        Rect rect = imageElement.getBBox();
+
+        if (rect == null) {
+            return;
+        }
+
+        boolean inClippingPath = dto.getClippingPathStack().almostIntersects(rect.getX1(), rect.getY1(), rect.getWidth(), rect.getHeight());
+
+        if (!dto.isDelta() && inClippingPath) {
+            dto.getVisibleElements().add(ElementFeatures.extractFeatures(imageElement));
+        }
+
+        if (dto.isDelta() ^ inClippingPath) {
+            writer.writeElement(imageElement);
+        }
+    }
+
+
+    private void processText(Element textElement, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        Rect rect = textElement.getBBox();
+
+        if (rect == null) {
+            writer.writeElement(textElement);
+            return;
+        }
+
+        GState gState = textElement.getGState();
+
+        boolean inClippingPath = dto.getClippingPathStack().almostIntersects(rect.getX1(), rect.getY1(), rect.getWidth(), rect.getHeight());
+
+        boolean isTextVisible = isTextRenderedVisibly(gState);
+
+        if (inClippingPath && isTextVisible) {
+            dto.getVisibleElements().add(ElementFeatures.extractFeatures(textElement));
+        }
+        if (!dto.isDelta()) {
+            if (inClippingPath && isTextVisible) {
+                writer.writeElement(textElement);
+            } else if (textElement.hasTextMatrix()) {
+                /*
+                PDFTron Element with type "text" refers to a Tj command. If a Tm command is just above it in the pdf file, PDFTron will join the two commands and treat them as one Element.
+                hasTextMatrix() checks for this case specifically. Also, Tm changes the position for a whole BT/ET segment, possibly containing multiple Tj commands.
+                Therefore, the position of a following Tj is affected by not writing the first Element.
+                This is why, we write only the Tm command:
+                */
+                writer.writeGStateChanges(textElement);
+            }
+        } else {
+            if (!inClippingPath) {
+                gState.setFillColorSpace(ColorSpace.createDeviceRGB());
+                gState.setFillColor(new ColorPt(1, 0, 0));
+                writer.writeElement(textElement);
+            }
+            if (!isTextVisible) {
+                gState.setFillColorSpace(ColorSpace.createDeviceRGB());
+                gState.setFillColor(new ColorPt(0, 0, 1));
+                gState.setTextRenderMode(GState.e_fill_text);
+                gState.setFillOpacity(1);
+                writer.writeElement(textElement);
+            }
+        }
+    }
+
+
+    private void processForm(Element formElement, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        writer.writeElement(formElement);
+        Obj formObj = formElement.getXObject();
+
+        if (!dto.getVisitedXObjIds().contains(formObj.getObjNum())) {
+            dto.getVisitedXObjIds().add(formObj.getObjNum());
+            // writer needs to be newly initialized when entering a new content stream
+            // see ElementEditTest in PDFTron (https://www.pdftron.com/documentation/samples/android/java/ElementEditTest)
+            ElementWriter formWriter = new ElementWriter();
+            dto.getReader().formBegin();
+            formWriter.begin(formObj);
+
+            dto.getReader().clearChangeList();
+            formWriter.setDefaultGState(dto.getReader());
+
+            processElements(formWriter, dto);
+            formWriter.end();
+            dto.getReader().end();
+        }
+    }
+
+
+    private void processPath(Element pathElement, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        GeneralPath linePath = convertToGeneralPath(pathElement.getPathData());
+
+        //transform path to initial user space
+        var ctm = pathElement.getCTM();
+        var affineTransform = getAffineTransform(ctm);
+        linePath.transform(affineTransform);
+
+        var rect = linePath.getBounds2D();
+
+        boolean inClippingPath = dto.getClippingPathStack().almostIntersects(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
+
+        if (pathElement.isClippingPath()) {
+            if (pathElement.isClipWindingFill()) {
+                linePath.setWindingRule(GeneralPath.WIND_NON_ZERO);
+            } else {
+                linePath.setWindingRule(GeneralPath.WIND_EVEN_ODD);
+            }
+
+            dto.getClippingPathStack().intersectClippingPath(linePath);
+            pathElement.setPathClip(!dto.isDelta());
+            writer.writeElement(pathElement);
+
+        } else {
+            if (inClippingPath) {
+                // TODO: WINDING RULE
+                if (isFilledAndNonTransparent(pathElement)) {
+                    List<ElementFeatures> currentOverlappedElements = dto.getVisibleElements()
+                            .stream()
+                            .filter(features -> almostContains(linePath, features.getBoundingBox()))
+                            .toList();
+                    dto.getOverlappedElements().addAll(currentOverlappedElements);
+                    dto.getVisibleElements().removeAll(currentOverlappedElements);
+                }
+                dto.getVisibleElements().add(ElementFeatures.extractFeatures(pathElement));
+                if (!dto.isDelta()) {
+                    writer.writeElement(pathElement);
+                }
+            }
+            if (dto.isDelta() && !inClippingPath) {
+                pathElement.getGState().setFillColorSpace(ColorSpace.createDeviceRGB());
+                pathElement.getGState().setFillColor(new ColorPt(1, 0, 0));
+                pathElement.getGState().setStrokeColorSpace(ColorSpace.createDeviceRGB());
+                pathElement.getGState().setStrokeColor(new ColorPt(1, 0, 0));
+                writer.writeElement(pathElement);
+            }
+        }
+    }
+
+
+    private static AffineTransform getAffineTransform(Matrix2D ctm) throws PDFNetException {
+
+        return new AffineTransform(ctm.getA(), ctm.getB(), ctm.getC(), ctm.getD(), ctm.getH(), ctm.getV());
+    }
+
+
+    private void removeOverlappedElements(Page page, ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        dto.getReader().begin(page);
+        writer.begin(page, ElementWriter.e_replacement, false, true, page.getResourceDict());
+        if (dto.isDelta()) {
+            dto.getOverlappedElements().forEach(feature -> drawBBox(writer, feature.getBoundingBox(), "#00FF00"));
+            dto.getOverlappedElements().clear();
+        }
+        processOverlappedElements(writer, dto);
+        writer.end();
+        dto.getReader().end();
+
+        if (dto.getOverlappedElements().size() > 0) {
+            log.warn(dto.getOverlappedElements().size() + " overlapped elements have not been found or removed");
+        }
+    }
+
+
+    private void processOverlappedElements(ElementWriter writer, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        for (Element element = dto.getReader().next(); element != null; element = dto.getReader().next()) {
+            switch (element.getType()) {
+                case Element.e_form -> processFormOverlappedElements(writer, element, dto);
+                case Element.e_path, Element.e_image, Element.e_inline_image, Element.e_text -> {
+                    boolean anyMatch = false;
+                    for (ElementFeatures elementToRemove : dto.getOverlappedElements()) {
+                        if (elementToRemove.almostMatches(element)) {
+                            dto.getOverlappedElements().remove(elementToRemove);
+                            anyMatch = true;
+                            break;
+                        }
+                    }
+                    if (!anyMatch) {
+                        writer.writeElement(element);
+                    } else if (element.getType() == 3 && element.hasTextMatrix()) {
+                        /*
+                        PDFTron Element with type "text" refers to a Tj command. If a Tm command is just above it in the pdf file, PDFTron will join the two commands and treat them as one Element.
+                        hasTextMatrix() checks for this case specifically. Also, Tm changes the position for a whole BT/ET segment, possibly containing multiple Tj commands.
+                        Therefore, the position of a following Tj is affected by not writing the first Element.
+                        This is why, we write only the Tm command:
+                        */
+                        writer.writeGStateChanges(element);
+                    }
+                }
+                default -> writer.writeElement(element);
+            }
+        }
+    }
+
+
+    private void processFormOverlappedElements(ElementWriter writer, Element formElement, InvisibleElementRemovalDto dto) throws PDFNetException {
+
+        writer.writeElement(formElement);
+        Obj formObj = formElement.getXObject();
+
+        if (!dto.getVisitedXObjIds().contains(formObj.getObjNum())) {
+            dto.getVisitedXObjIds().add(formObj.getObjNum());
+            // writer needs to be newly initialized when entering a new content stream
+            // see ElementEditTest in PDFTron (https://www.pdftron.com/documentation/samples/android/java/ElementEditTest)
+            ElementWriter formWriter = new ElementWriter();
+            dto.getReader().formBegin();
+            formWriter.begin(formObj);
+
+            dto.getReader().clearChangeList();
+            formWriter.setDefaultGState(dto.getReader());
+
+            processOverlappedElements(formWriter, dto);
+            formWriter.end();
+            dto.getReader().end();
+        }
+    }
+
+
+    private boolean isTextRenderedVisibly(GState gState) throws PDFNetException {
+
+        return gState.getTextRenderMode() != GState.e_invisible_text && //
+                !(gState.getTextRenderMode() == GState.e_fill_text && gState.getFillOpacity() == 0) && //
+                !(gState.getTextRenderMode() == GState.e_stroke_text && gState.getStrokeOpacity() == 0) && //
+                !(gState.getTextRenderMode() == GState.e_fill_stroke_text && gState.getFillOpacity() == 0 && gState.getStrokeOpacity() == 0);
+    }
+
+
+    private GeneralPath convertToGeneralPath(PathData pathData) throws PDFNetException {
+
+        GeneralPath linePath = new GeneralPath();
+        Iterator<Double> points = Doubles.asList(pathData.getPoints()).iterator();
+        Iterable<Byte> operators = Bytes.asList(pathData.getOperators());
+        for (var operator : operators) {
+            switch (operator) {
+                case PathData.e_moveto -> linePath.moveTo(points.next(), points.next());
+                case PathData.e_lineto -> linePath.lineTo(points.next(), points.next());
+                case PathData.e_cubicto -> linePath.curveTo(points.next(), points.next(), points.next(), points.next(), points.next(), points.next());
+                case PathData.e_closepath -> linePath.closePath();
+                case PathData.e_rect -> {
+                    double x = points.next();
+                    double y = points.next();
+                    double w = points.next();
+                    double h = points.next();
+                    linePath.moveTo(x, y);
+                    linePath.lineTo(x + w, y);
+                    linePath.lineTo(x + w, y + h);
+                    linePath.lineTo(x, y + h);
+                    linePath.closePath();
+                }
+                default -> throw new PDFNetException("Invalid Element Type", 0, "", "", "");
+            }
+        }
+        return linePath;
+    }
+
+
+    private boolean almostContains(Shape outer, Rectangle2D inner) {
+        //To address inconsistencies in the calculation of the bounding box we slightly shrink the inner rectangle
+
+        double x_with_tolerance = inner.getX() >= 0 ? inner.getX() + TOLERANCE : inner.getX() - TOLERANCE;
+        double y_with_tolerance = inner.getY() >= 0 ? inner.getY() + TOLERANCE : inner.getY() - TOLERANCE;
+        double height_with_tolerance = inner.getHeight() - (2 * TOLERANCE);
+        double width_with_tolerance = inner.getWidth() - (2 * TOLERANCE);
+        Rectangle2D innerRect = new Rectangle2D.Double(x_with_tolerance, y_with_tolerance, width_with_tolerance, height_with_tolerance);
+
+        return outer.contains(innerRect);
+    }
+
+
+    private boolean isFilledAndNonTransparent(Element element) throws PDFNetException {
+
+        return element.isFilled() && element.getGState().getFillOpacity() == 1;
+    }
+
+
+    @SneakyThrows
+    private void drawBBox(ElementWriter writer, Rectangle2D r, String hexcolor) {
+
+        ColorPt colorPt = new ColorPt(Integer.valueOf(hexcolor.substring(1, 3), 16) / 255d,
+                Integer.valueOf(hexcolor.substring(3, 5), 16) / 255d,
+                Integer.valueOf(hexcolor.substring(5, 7), 16) / 255d);
+        ElementBuilder eb = new ElementBuilder();
+        Element rect = eb.createRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
+        rect.setPathStroke(true);
+        rect.getGState().setStrokeColorSpace(ColorSpace.createDeviceRGB());
+        rect.getGState().setStrokeColor(colorPt);
+        writer.writePlacedElement(rect);
+    }
+
+}

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/service/InvisibleElementService.java

@@ -1,448 +0,0 @@
-package com.iqser.red.service.ocr.v1.server.service;
-
-import com.iqser.red.service.ocr.v1.server.model.ClippingPathStack;
-import com.iqser.red.service.ocr.v1.server.model.ElementFeatures;
-import com.pdftron.common.Matrix2D;
-import com.pdftron.common.PDFNetException;
-import com.pdftron.pdf.*;
-import com.pdftron.sdf.Obj;
-import com.pdftron.sdf.SDFDoc;
-import lombok.SneakyThrows;
-import lombok.extern.slf4j.Slf4j;
-import org.springframework.stereotype.Service;
-
-import java.awt.*;
-import java.awt.geom.AffineTransform;
-import java.awt.geom.GeneralPath;
-import java.awt.geom.Rectangle2D;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Set;
-import java.util.TreeSet;
-import java.util.stream.Collectors;
-
-@Slf4j
-@Service
-public class InvisibleElementService {
-    
-    /*
-        handled cases:
-            Text which is transparent or is set to not render
-            Text or Path or Images outside of clipping path
-            Text or Path or Images that have been painted over by visible and filled Paths
-        unhandled cases:
-            Text covered by widely stroked path
-            Text same color as background
-            Any Text set to clipping with its many interactions with other elements
-         */
-    @SneakyThrows
-    public byte[] removeInvisibleElements(byte[] pdfFile, boolean delta) {
-        PDFDoc pdfDoc = new PDFDoc(pdfFile);
-
-        ElementWriter writer = new ElementWriter();
-        ElementReader reader = new ElementReader();
-        Set<Integer> visited = new TreeSet<>();
-
-        for (PageIterator iterator = pdfDoc.getPageIterator(); iterator.hasNext(); ) {
-            Page page = iterator.next();
-            List<ElementFeatures> overlappedElements = removeClippedElementsAndInvisibleTextAndRememberOverlappedElements(page, reader, writer, visited, delta);
-            visited.clear();
-            removeOverlappedElements(page, reader, writer, visited, overlappedElements, delta);
-        }
-
-        return pdfDoc.save(SDFDoc.SaveMode.REMOVE_UNUSED, null);
-    }
-
-
-    private List<ElementFeatures> removeClippedElementsAndInvisibleTextAndRememberOverlappedElements(Page page, ElementReader reader, ElementWriter writer, Set<Integer> visited, boolean delta)
-            throws PDFNetException {
-        var overlappedElements = new ArrayList<ElementFeatures>();
-        var visibleElements = new ArrayList<ElementFeatures>();
-        ClippingPathStack clippingPathStack = new ClippingPathStack(page.getMediaBox());
-        visited.add((int) page.getSDFObj().getObjNum());
-        reader.begin(page);
-        writer.begin(page, ElementWriter.e_replacement, false, true, page.getResourceDict());
-        processElements(reader, writer, visited, clippingPathStack, delta, overlappedElements, visibleElements);
-        writer.end();
-        reader.end();
-        return overlappedElements;
-    }
-
-    private void processElements(ElementReader reader, ElementWriter writer, Set<Integer> visited, ClippingPathStack clippingPathStack, Boolean delta,
-                                 List<ElementFeatures> coveredElements, List<ElementFeatures> visibleElements)
-            throws PDFNetException {
-
-        for (Element element = reader.next(); element != null; element = reader.next())
-            switch (element.getType()) {
-
-                case Element.e_image:
-                case Element.e_inline_image:
-                    processImages(element, writer, clippingPathStack, delta, visibleElements);
-                    break;
-
-                case Element.e_text:
-                    processText(element, writer, clippingPathStack, delta, visibleElements);
-                    break;
-
-                case Element.e_path:
-                    processPath(element, writer, clippingPathStack, delta, coveredElements, visibleElements);
-                    break;
-
-                case Element.e_form:
-                    processForm(reader, writer, element, visited, clippingPathStack, delta, coveredElements, visibleElements);
-                    break;
-
-                case Element.e_group_begin:
-                    clippingPathStack.enterNewGState();
-                    writer.writeElement(element);
-                    break;
-
-                case Element.e_group_end:
-                    clippingPathStack.leaveGState();
-                    writer.writeElement(element);
-                    break;
-
-                default:
-                    writer.writeElement(element);
-            }
-    }
-
-    private void processImages(Element imageElement, ElementWriter writer, ClippingPathStack clippingPathStack, Boolean delta, List<ElementFeatures> visibleElements)
-            throws PDFNetException {
-
-        Rect rect = imageElement.getBBox();
-
-        if (rect == null) {
-            return;
-        }
-
-        boolean inClippingPath = clippingPathStack.almostIntersects(rect.getX1(), rect.getY1(), rect.getWidth(), rect.getHeight());
-
-        if (!delta && inClippingPath) {
-            visibleElements.add(ElementFeatures.extractFeatures(imageElement));
-            writer.writeElement(imageElement);
-        }
-
-        if (delta && !inClippingPath) {
-            writer.writeElement(imageElement);
-        }
-    }
-
-    private void processText(Element textElement, ElementWriter writer, ClippingPathStack clippingPathStack,
-                             Boolean delta, List<ElementFeatures> visibleElements)
-            throws PDFNetException {
-
-        Rect rect = textElement.getBBox();
-
-        if (rect == null) {
-            writer.writeElement(textElement);
-            return;
-        }
-
-        GState gState = textElement.getGState();
-
-        boolean inClippingPath = clippingPathStack.almostIntersects(rect.getX1(), rect.getY1(), rect.getWidth(), rect.getHeight());
-
-        boolean isTextVisible = isTextRenderedVisibly(gState);
-
-        if (inClippingPath && isTextVisible) {
-            visibleElements.add(ElementFeatures.extractFeatures(textElement));
-        }
-        if (!delta) {
-            if (inClippingPath && isTextVisible) {
-                writer.writeElement(textElement);
-            } else if (textElement.hasTextMatrix()) {
-                /*
-                PDFTron Element with type "text" refers to a Tj command. If a Tm command is just above it in the pdf file, PDFTron will join the two commands and treat them as one Element.
-                hasTextMatrix() checks for this case specifically. Also, Tm changes the position for a whole BT/ET segment, possibly containing multiple Tj commands.
-                Therefore, the position of a following Tj is affected by not writing the first Element.
-                This is why, we write only the Tm command:
-                */
-                writer.writeGStateChanges(textElement);
-            }
-        } else {
-            if (!inClippingPath) {
-                gState.setFillColorSpace(ColorSpace.createDeviceRGB());
-                gState.setFillColor(new ColorPt(1, 0, 0));
-                writer.writeElement(textElement);
-            }
-            if (!isTextVisible) {
-                gState.setFillColorSpace(ColorSpace.createDeviceRGB());
-                gState.setFillColor(new ColorPt(0, 0, 1));
-                gState.setTextRenderMode(GState.e_fill_text);
-                gState.setFillOpacity(1);
-                writer.writeElement(textElement);
-            }
-        }
-    }
-
-    private void processForm(ElementReader reader, ElementWriter writer, Element element, Set<Integer> visited, ClippingPathStack clippingPathStack, Boolean delta,
-                             List<ElementFeatures> coveredElements, List<ElementFeatures> allElements)
-            throws PDFNetException {
-
-        writer.writeElement(element);
-        Obj formObj = element.getXObject();
-
-        if (!visited.contains((int) formObj.getObjNum())) {
-            visited.add((int) formObj.getObjNum());
-            ElementWriter new_writer = new ElementWriter();
-            reader.formBegin();
-            new_writer.begin(formObj);
-
-            reader.clearChangeList();
-            new_writer.setDefaultGState(reader);
-
-            processElements(reader, new_writer, visited, clippingPathStack, delta, coveredElements, allElements);
-            new_writer.end();
-            reader.end();
-        }
-    }
-
-    private void processPath(Element pathElement, ElementWriter writer, ClippingPathStack clippingPathStack, Boolean delta,
-                             List<ElementFeatures> overlappedElements, List<ElementFeatures> visibleElements)
-            throws PDFNetException {
-
-        GeneralPath linePath = convertToGeneralPath(pathElement.getPathData());
-
-        //transform path to initial user space
-        var ctm = pathElement.getCTM();
-        var affineTransform = getAffineTransform(ctm);
-        linePath.transform(affineTransform);
-
-        var rect = linePath.getBounds2D();
-
-        boolean inClippingPath = clippingPathStack.almostIntersects(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
-
-        if (pathElement.isClippingPath()) {
-            if (pathElement.isClipWindingFill()) {
-                linePath.setWindingRule(GeneralPath.WIND_NON_ZERO);
-            } else {
-                linePath.setWindingRule(GeneralPath.WIND_EVEN_ODD);
-            }
-
-            clippingPathStack.intersectClippingPath(linePath);
-            pathElement.setPathClip(!delta);
-            writer.writeElement(pathElement);
-
-        } else {
-            if (inClippingPath) {
-                if (isFilledAndNonTransparent(pathElement)) {
-                    List<ElementFeatures> currentOverlappedElements = visibleElements.stream()
-                            .filter(features -> almostContains(linePath, features.getBoundingBox()))
-                            .collect(Collectors.toList());
-                    overlappedElements.addAll(currentOverlappedElements);
-                    visibleElements.removeAll(currentOverlappedElements);
-                }
-                visibleElements.add(ElementFeatures.extractFeatures(pathElement));
-                if (!delta) {
-                    writer.writeElement(pathElement);
-                }
-            }
-            if (delta && !inClippingPath) {
-                pathElement.getGState().setFillColorSpace(ColorSpace.createDeviceRGB());
-                pathElement.getGState().setFillColor(new ColorPt(1, 0, 0));
-                pathElement.getGState().setStrokeColorSpace(ColorSpace.createDeviceRGB());
-                pathElement.getGState().setStrokeColor(new ColorPt(1, 0, 0));
-                writer.writeElement(pathElement);
-            }
-        }
-    }
-
-    private static AffineTransform getAffineTransform(Matrix2D ctm) throws PDFNetException {
-        return new AffineTransform(ctm.getA(), ctm.getB(), ctm.getC(), ctm.getD(), ctm.getH(), ctm.getV());
-    }
-
-    private void removeOverlappedElements(Page page, ElementReader reader, ElementWriter writer, Set<Integer> visited, List<ElementFeatures> overlappedElements, boolean delta)
-            throws PDFNetException {
-        reader.begin(page);
-        writer.begin(page, ElementWriter.e_replacement, false, true, page.getResourceDict());
-        if (delta) {
-            overlappedElements.forEach(feature -> drawBBox(writer, feature.getBoundingBox(), "#00FF00"));
-            overlappedElements.clear();
-        }
-        processOverlappedElements(reader, writer, visited, overlappedElements, delta);
-        writer.end();
-        reader.end();
-
-        if (overlappedElements.size() > 0) {
-            log.warn(overlappedElements.size() + " overlapped elements have not been found and removed");
-        }
-    }
-
-    private void processOverlappedElements(ElementReader reader, ElementWriter writer, Set<Integer> visited, List<ElementFeatures> coveredElements, boolean delta)
-            throws PDFNetException {
-        for (Element element = reader.next(); element != null; element = reader.next()) {
-            switch (element.getType()) {
-                case Element.e_form:
-                    processFormOverlappedElements(reader, writer, element, visited, coveredElements, delta);
-                    break;
-                case Element.e_path:
-                case Element.e_image:
-                case Element.e_inline_image:
-                case Element.e_text:
-                    boolean anyMatch = false;
-                    for (ElementFeatures elementToRemove : coveredElements) {
-                        if (elementToRemove.almostMatches(element)) {
-                            coveredElements.remove(elementToRemove);
-                            anyMatch = true;
-                            break;
-                        }
-                    }
-                    if (!anyMatch) {
-                        writer.writeElement(element);
-                    } else if (element.getType() == 3 && element.hasTextMatrix()) {
-                        /*
-                        PDFTron Element with type "text" refers to a Tj command. If a Tm command is just above it in the pdf file, PDFTron will join the two commands and treat them as one Element.
-                        hasTextMatrix() checks for this case specifically. Also, Tm changes the position for a whole BT/ET segment, possibly containing multiple Tj commands.
-                        Therefore, the position of a following Tj is affected by not writing the first Element.
-                        This is why, we write only the Tm command:
-                        */
-                        writer.writeGStateChanges(element);
-                    }
-                    break;
-
-                default:
-                    writer.writeElement(element);
-
-            }
-        }
-    }
-
-    private void processFormOverlappedElements(ElementReader reader, ElementWriter writer, Element element, Set<Integer> visited, List<ElementFeatures> elementsToRemove, boolean delta)
-            throws PDFNetException {
-
-        writer.writeElement(element);
-        Obj formObj = element.getXObject();
-
-        if (!visited.contains((int) formObj.getObjNum())) {
-            visited.add((int) formObj.getObjNum());
-            ElementWriter new_writer = new ElementWriter();
-            reader.formBegin();
-            new_writer.begin(formObj);
-
-            reader.clearChangeList();
-            new_writer.setDefaultGState(reader);
-
-            processOverlappedElements(reader, new_writer, visited, elementsToRemove, delta);
-            new_writer.end();
-            reader.end();
-        }
-    }
-
-    private boolean isTextRenderedVisibly(GState gState) throws PDFNetException {
-        if (gState.getTextRenderMode() == GState.e_invisible_text) return false;
-        if (gState.getTextRenderMode() == GState.e_fill_text && gState.getFillOpacity() == 0) return false;
-        if (gState.getTextRenderMode() == GState.e_stroke_text && gState.getStrokeOpacity() == 0) return false;
-        if (gState.getTextRenderMode() == GState.e_fill_stroke_text && gState.getFillOpacity() == 0 && gState.getStrokeOpacity() == 0) return false;
-        return true;
-    }
-
-    private GeneralPath convertToGeneralPath(PathData pathData) throws PDFNetException {
-        GeneralPath linePath = new GeneralPath();
-
-        double[] dataPoints = pathData.getPoints();
-        byte[] opr = pathData.getOperators();
-
-        double x1;
-        double y1;
-        double x2;
-        double y2;
-        double x3;
-        double y3;
-
-        int data_index = 0;
-        for (int opr_index = 0; opr_index < opr.length; ++opr_index) {
-            switch (opr[opr_index]) {
-                case PathData.e_moveto:
-                    x1 = dataPoints[data_index];
-                    ++data_index;
-                    y1 = dataPoints[data_index];
-                    ++data_index;
-
-                    linePath.moveTo(x1, y1);
-                    break;
-                case PathData.e_lineto:
-                    x1 = dataPoints[data_index];
-                    ++data_index;
-                    y1 = dataPoints[data_index];
-                    ++data_index;
-
-                    linePath.lineTo(x1, y1);
-                    break;
-                case PathData.e_cubicto:
-                    x1 = dataPoints[data_index];
-                    ++data_index;
-                    y1 = dataPoints[data_index];
-                    ++data_index;
-                    x2 = dataPoints[data_index];
-                    ++data_index;
-                    y2 = dataPoints[data_index];
-                    ++data_index;
-                    x3 = dataPoints[data_index];
-                    ++data_index;
-                    y3 = dataPoints[data_index];
-                    ++data_index;
-
-                    linePath.curveTo(x1, y1, x2, y2, x3, y3);
-                    break;
-                case PathData.e_rect:
-                    x1 = dataPoints[data_index];
-                    ++data_index;
-                    y1 = dataPoints[data_index];
-                    ++data_index;
-                    double w = dataPoints[data_index];
-                    ++data_index;
-                    double h = dataPoints[data_index];
-                    ++data_index;
-                    x2 = x1 + w;
-                    y2 = y1;
-                    x3 = x2;
-                    y3 = y1 + h;
-                    double x4 = x1;
-                    double y4 = y3;
-
-                    linePath.moveTo(x1, y1);
-                    linePath.lineTo(x2, y2);
-                    linePath.lineTo(x3, y3);
-                    linePath.lineTo(x4, y4);
-                    break;
-                case PathData.e_closepath:
-                    linePath.closePath();
-                    break;
-                default:
-                    throw new PDFNetException("Invalid Element Type", 0, "", "", "");
-            }
-        }
-        return linePath;
-    }
-
-    private boolean almostContains(Shape outer, Rectangle2D inner) {
-        double tolerance = 1e-3;
-
-        double x_with_tolerance = inner.getX() >= 0 ? inner.getX() + tolerance : inner.getX() - tolerance;
-        double y_with_tolerance = inner.getY() >= 0 ? inner.getY() + tolerance : inner.getY() - tolerance;
-        double height_with_tolerance = inner.getHeight() - (2 * tolerance);
-        double width_with_tolerance = inner.getWidth() - (2 * tolerance);
-        Rectangle2D innerRect = new Rectangle2D.Double(x_with_tolerance, y_with_tolerance, width_with_tolerance, height_with_tolerance);
-
-        return outer.contains(innerRect);
-    }
-
-    private boolean isFilledAndNonTransparent(Element element) throws PDFNetException {
-        return element.isFilled() && element.getGState().getFillOpacity() == 1;
-    }
-
-
-    @SneakyThrows
-    private void drawBBox(ElementWriter writer, Rectangle2D r, String hexcolor) {
-        ColorPt colorPt = new ColorPt(Integer.valueOf(hexcolor.substring(1, 3), 16) / 255d,
-                Integer.valueOf(hexcolor.substring(3, 5), 16) / 255d,
-                Integer.valueOf(hexcolor.substring(5, 7), 16) / 255d);
-        ElementBuilder eb = new ElementBuilder();
-        Element rect = eb.createRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
-        rect.setPathStroke(true);
-        rect.getGState().setStrokeColorSpace(ColorSpace.createDeviceRGB());
-        rect.getGState().setStrokeColor(colorPt);
-        writer.writePlacedElement(rect);
-    }
-}

ocr-service-v1/ocr-service-server-v1/src/main/java/com/iqser/red/service/ocr/v1/server/service/OCRService.java

@@ -1,5 +1,17 @@
 package com.iqser.red.service.ocr.v1.server.service;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.stereotype.Service;
+
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.iqser.red.service.ocr.v1.api.model.OCRStatusUpdateResponse;
 import com.iqser.red.service.ocr.v1.server.configuration.MessagingConfiguration;
@@ -8,19 +20,17 @@ import com.iqser.red.service.ocr.v1.server.model.image.ImageServiceResponse;
 import com.iqser.red.service.ocr.v1.server.settings.OcrServiceSettings;
 import com.iqser.red.service.redaction.v1.model.Point;
 import com.iqser.red.service.redaction.v1.model.Rectangle;
-import com.pdftron.pdf.*;
+import com.pdftron.pdf.OCRModule;
+import com.pdftron.pdf.OCROptions;
+import com.pdftron.pdf.Optimizer;
+import com.pdftron.pdf.PDFDoc;
+import com.pdftron.pdf.Page;
+import com.pdftron.pdf.RectCollection;
 import com.pdftron.sdf.SDFDoc;
+
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.commons.io.IOUtils;
-import org.springframework.amqp.rabbit.core.RabbitTemplate;
-import org.springframework.stereotype.Service;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.InputStream;
-import java.util.*;
 
 @Slf4j
 @Service
@@ -36,20 +46,18 @@ public class OCRService {
 
     private final ObjectMapper objectMapper;
 
-    private final InvisibleElementService invisibleElementService;
+    private final InvisibleElementRemovalService invisibleElementRemovalService;
 
 
     @SneakyThrows
     public InputStream ocrDocument(String dossierId, String fileId) {
 
-        var fileStream = fileStorageService.getOriginalFileAsStream(dossierId, fileId);
+        InputStream fileStream = fileStorageService.getOriginalFileAsStream(dossierId, fileId);
-        var imageServiceResponse = fileStorageService.getImageServiceResponse(dossierId, fileId);
+        ImageServiceResponse imageServiceResponse = fileStorageService.getImageServiceResponse(dossierId, fileId);
 
-        var fileBytes = IOUtils.toByteArray(fileStream);
+        byte[] fileWithoutInvisibleTextStream = invisibleElementRemovalService.removeInvisibleElements(fileStream, false);
 
-        byte[] fileWithoutInvisibleTextBytes = invisibleElementService.removeInvisibleElements(fileBytes, false);
+        byte[] ocrBytes = ocr(fileWithoutInvisibleTextStream, fileId, imageServiceResponse);
-
-        var ocrBytes = ocr(fileWithoutInvisibleTextBytes, fileId, imageServiceResponse);
 
         return new ByteArrayInputStream(ocrBytes);
 

ocr-service-v1/ocr-service-server-v1/src/test/java/com/iqser/red/service/ocr/v1/server/InvisibleElementRemovalServiceTest.java

@@ -1,12 +1,12 @@
 package com.iqser.red.service.ocr.v1.server;
 
-import com.iqser.red.service.ocr.v1.server.service.InvisibleElementService;
+import static com.iqser.red.service.ocr.v1.server.utils.OsUtils.getTemporaryDirectory;
-import com.pdftron.pdf.PDFDoc;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
-import com.pdftron.pdf.Page;
+
-import com.pdftron.pdf.PageIterator;
+import java.io.FileOutputStream;
-import com.pdftron.pdf.TextExtractor;
+import java.io.IOException;
-import lombok.SneakyThrows;
+import java.nio.file.Files;
-import org.apache.commons.io.FileUtils;
+
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
@@ -17,62 +17,69 @@ import org.springframework.context.annotation.Import;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.test.context.junit.jupiter.SpringExtension;
 
-import java.io.File;
+import com.iqser.red.service.ocr.v1.server.service.InvisibleElementRemovalService;
-import java.io.IOException;
+import com.pdftron.pdf.PDFDoc;
-import java.nio.file.Files;
+import com.pdftron.pdf.Page;
+import com.pdftron.pdf.PageIterator;
+import com.pdftron.pdf.TextExtractor;
 
-import static com.iqser.red.service.ocr.v1.server.utils.OsUtils.getTemporaryDirectory;
+import lombok.SneakyThrows;
-import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
 
 @ExtendWith(SpringExtension.class)
 @SpringBootTest(classes = Application.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT //
         , properties = {"pdftron.ocrmodule.path=/YourOCRModulePath"})
 @Import(OcrServiceIntegrationTest.TestConfiguration.class)
-public class InvisibleElementServiceTest {
+public class InvisibleElementRemovalServiceTest {
 
     @Autowired
-    private InvisibleElementService invisibleElementService;
+    private InvisibleElementRemovalService invisibleElementRemovalService;
 
     @MockBean
     protected RabbitTemplate rabbitTemplate;
 
+
     @Test
     @SneakyThrows
     public void testRemoveInvisibleText() {
+
         String fileName = "InvisibleText";
 
         ClassPathResource pdfFileResource = new ClassPathResource("files/" + fileName + ".pdf");
 
-        var initialFileBytes = Files.readAllBytes(pdfFileResource.getFile().toPath());
+        var initialFileStream = Files.newInputStream(pdfFileResource.getFile().toPath());
+        var fileWithoutInvisibleElements = invisibleElementRemovalService.removeInvisibleElements(initialFileStream, false);
 
-        var fileWithoutInvisibleText = invisibleElementService.removeInvisibleElements(initialFileBytes, false);
+        initialFileStream = Files.newInputStream(pdfFileResource.getFile().toPath());
-        var deltaFile = invisibleElementService.removeInvisibleElements(initialFileBytes, true);
+        var deltaFile = invisibleElementRemovalService.removeInvisibleElements(initialFileStream, true);
 
         String fileWithoutInvisibleTextLocation = getTemporaryDirectory() + "/" + fileName + ".pdf";
         String deltaFileLocation = getTemporaryDirectory() + "/" + fileName + "_delta.pdf";
 
-        saveToFile(fileWithoutInvisibleTextLocation, fileWithoutInvisibleText);
+        saveToFile(fileWithoutInvisibleTextLocation, fileWithoutInvisibleElements);
         saveToFile(deltaFileLocation, deltaFile);
 
         System.out.println("Output File without invisible elements: " + fileWithoutInvisibleTextLocation);
         System.out.println("Output Delta File: " + deltaFileLocation);
         TextExtractor extractor = new TextExtractor();
-        PDFDoc pdfDoc = new PDFDoc(fileWithoutInvisibleText);
+        PDFDoc pdfDoc = new PDFDoc(fileWithoutInvisibleElements);
         PageIterator iterator = pdfDoc.getPageIterator();
         while (iterator.hasNext()) {
             Page page = iterator.next();
             extractor.begin(page);
             String[] text = extractor.getAsText().split("\n");
-            assertThat(text).containsAnyOf("APPENDIX 16 Pathology Report", "Amendment 1", "Page 255 of 260");
+            assertThat(text).contains("APPENDIX 16 Pathology Report", "Amendment 1", "Page 255 of 260");
         }
     }
 
+
     private void saveToFile(String location, byte[] fileBytes) {
-        try (var f_out = FileUtils.openOutputStream(new File(location))) {
+
+        try (var f_out = new FileOutputStream(location)) {
             f_out.write(fileBytes);
         } catch (IOException e) {
             throw new RuntimeException("File location: " + location + "could not be openend, no file will be saved");
         }
 
     }
+
 }

ocr-service-v1/pom.xml

@@ -7,7 +7,7 @@
     <parent>
         <groupId>com.iqser.red</groupId>
         <artifactId>platform-dependency</artifactId>
-        <version>1.14.0</version>
+        <version>RED-6114-1</version>
         <relativePath/>
     </parent>