fix(segmentGroups): workaround direction matrix bug in writeImage

src/store/segmentGroups.ts

@@ -47,6 +47,18 @@ const writeImage = async (format: string, image: vtkImageData) => {
   }
   // copyImage so writeImage does not detach live data when passing to worker
   const itkImage = copyImage(vtkITKHelper.convertVtkToItkImage(image));
+
+  // Transpose the direction matrix to fix bug in @itk-wasm/image-io.writeImage
+  // Remove when @itk-wasm/image-io version is above 0.5.0 https://github.com/InsightSoftwareConsortium/itk-wasm/commit/ad9ca85eedc47c9d3444cf36859569c529886bde
+  const oldDirection = [...itkImage.direction];
+  const { dimension } = itkImage.imageType;
+  for (let idx = 0; idx < dimension; ++idx) {
+    for (let idy = 0; idy < dimension; ++idy) {
+      itkImage.direction[idx + idy * dimension] =
+        oldDirection[idy + idx * dimension];
+    }
+  }
+
   const result = await writeImageItk(null, itkImage, `image.${format}`);
   return result.serializedImage.data;
 };