Fix MPR geometry

Author: nroduit

weasis-dicom/weasis-dicom-viewer2d/src/main/java/org/weasis/dicom/viewer2d/mpr/OriginalStack.java

@@ -11,7 +11,6 @@
 
 import static org.weasis.dicom.viewer2d.mpr.MprView.Plane.AXIAL;
 import static org.weasis.dicom.viewer2d.mpr.VolumeBounds.EPSILON;
-import static org.weasis.dicom.viewer2d.mpr.VolumeBounds.needsRectification;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -68,7 +67,11 @@ protected DicomImageElement getStartingImage() {
     return plane == AXIAL ? getLastImage() : getFirstImage();
   }
 
-  public GeometryOfSlice getFistSliceGeometry() {
+  protected DicomImageElement getEndingImage() {
+    return plane == AXIAL ? getFirstImage() : getLastImage();
+  }
+
+  public GeometryOfSlice getFirstSliceGeometry() {
     return fistSliceGeometry;
   }
 
@@ -163,68 +166,6 @@ private void checkSliceParallelism() {
     }
   }
 
-  /**
-   * Computes the spacing correction factor from the image orientation geometry. This generalizes
-   * the gantry tilt correction to handle both column and row shear.
-   *
-   * @return correction factor to apply to measured slice spacing
-   */
-  double computeSpacingCorrectionFromGeometry() {
-    GeometryOfSlice geometry = fistSliceGeometry;
-    if (geometry == null) {
-      return 1.0;
-    }
-
-    // Get shear components based on plane orientation
-    double colShear = getColumnShearComponent(geometry.getColumn());
-    double rowShear = getRowShearComponent(geometry.getRow());
-
-    // If no significant shear, no correction needed
-    if (!needsRectification(colShear) && !needsRectification(rowShear)) {
-      return 1.0;
-    }
-
-    // Combined shear magnitude
-    double combinedShear = Math.sqrt(colShear * colShear + rowShear * rowShear);
-
-    // The correction factor compensates for the apparent shortening of spacing
-    // when slices are acquired at an angle
-    double shearAngle = Math.atan(combinedShear);
-    return 1.0 / Math.cos(shearAngle);
-  }
-
-  /**
-   * Gets the column shear component based on the acquisition plane. Column shear represents
-   * deviation in the slice normal direction.
-   */
-  private double getColumnShearComponent(Vector3d col) {
-    return switch (plane) {
-      case AXIAL -> col.z;
-      case CORONAL -> col.y;
-      case SAGITTAL -> col.x;
-    };
-  }
-
-  /**
-   * Gets the row shear component based on the acquisition plane. Row shear represents deviation
-   * perpendicular to column shear.
-   */
-  private double getRowShearComponent(Vector3d row) {
-    return switch (plane) {
-      case AXIAL -> row.z;
-      case CORONAL -> row.y;
-      case SAGITTAL -> row.x;
-    };
-  }
-
-  private double getPlanRotationComponent(Vector3d row) {
-    return switch (plane) {
-      case AXIAL -> row.y();
-      case CORONAL -> row.z();
-      case SAGITTAL -> -row.z();
-    };
-  }
-
   public double getSliceSpace() {
     return sliceSpace;
   }
@@ -247,13 +188,13 @@ public boolean equals(Object o) {
     return Double.compare(getSliceSpace(), that.getSliceSpace()) == 0
         && isVariableSliceSpacing() == that.isVariableSliceSpacing()
         && Objects.equals(getSourceStack(), that.getSourceStack())
-        && Objects.equals(getFistSliceGeometry(), that.getFistSliceGeometry());
+        && Objects.equals(getFirstSliceGeometry(), that.getFirstSliceGeometry());
   }
 
   @Override
   public int hashCode() {
     return Objects.hash(
-        getSourceStack(), getFistSliceGeometry(), getSliceSpace(), isVariableSliceSpacing());
+        getSourceStack(), getFirstSliceGeometry(), getSliceSpace(), isVariableSliceSpacing());
   }
 
   /**
@@ -279,11 +220,6 @@ public VolumeBounds computeVolumeBounds() {
     normalizeToPositiveDirection(row);
     normalizeToPositiveDirection(col);
 
-    // Compute shear factors for potential rectification
-    double columnShear = getColumnShearComponent(firstGeom.getColumn());
-    double rowShear = getRowShearComponent(firstGeom.getRow());
-    double planRotation = getPlanRotationComponent(firstGeom.getRow());
-
     // Get pixel spacing from first image
     double pixelSpacing = firstImg.getPixelSize();
     double sliceSpacing = getSliceSpace();
@@ -300,32 +236,23 @@ public VolumeBounds computeVolumeBounds() {
               origin,
               row,
               col,
-              normal,
-              columnShear,
-              rowShear,
-              planRotation);
+              normal);
       case CORONAL ->
           new VolumeBounds(
               new Vector3i(getWidth(), numSlices, getHeight()),
               new Vector3d(pixelSpacing, sliceSpacing, pixelSpacing),
               origin,
               row,
               col,
-              normal,
-              columnShear,
-              rowShear,
-              planRotation);
+              normal);
       case SAGITTAL ->
           new VolumeBounds(
               new Vector3i(numSlices, getWidth(), getHeight()),
               new Vector3d(sliceSpacing, pixelSpacing, pixelSpacing),
               origin,
               row,
               col,
-              normal,
-              columnShear,
-              rowShear,
-              planRotation);
+              normal);
     };
   }
 

weasis-dicom/weasis-dicom-viewer2d/src/main/java/org/weasis/dicom/viewer2d/mpr/VolImageIO.java

@@ -242,7 +242,7 @@ public PlanarImage getSlice(Vector3d volumeCenter) {
     int instanceNumber = mprAxis.getSliceIndex();
     rawIO.setTag(TagD.get(Tag.InstanceNumber), instanceNumber + 1);
 
-    GeometryOfSlice geometry = volume.stack.getFistSliceGeometry();
+    GeometryOfSlice geometry = volume.stack.getFirstSliceGeometry();
     Vector3d thlc = transformPosition(geometry, volumeCenter);
     rawIO.setTag(TagD.get(Tag.ImagePositionPatient), new double[] {thlc.x, thlc.y, thlc.z});