diff --git a/ereg/registration.py b/ereg/registration.py
index 360d2f7..7ab2bed 100644
--- a/ereg/registration.py
+++ b/ereg/registration.py
@@ -65,6 +65,7 @@ def __init__(
         ]
         self.total_attempts = 5
         self.log_file = None
+        self.transform = None
         if config_file is not None:
             self.update_parameters(config_file)
 
@@ -275,23 +276,23 @@ def register(
         if transform_file is not None:
             if os.path.isfile(transform_file):
                 try:
-                    transform = sitk.ReadTransform(transform_file)
+                    self.transform = sitk.ReadTransform(transform_file)
                     compute_transform = False
                 except:
                     self.logger.info(
-                        "Could not read transform file. Computing transform transform."
+                        "Could not read transform file. Computing transform."
                     )
                     pass
         if compute_transform:
             self.logger.info(
                 f"Starting registration with parameters:: {self.parameters}"
             )
-            transform = self._register_image_and_get_transform(
+            self.transform = self._register_image_and_get_transform(
                 target_image=target_image,
                 moving_image=moving_image,
             )
         if transform_file is not None:
-            sitk.WriteTransform(transform, transform_file)
+            sitk.WriteTransform(self.transform, transform_file)
 
         # apply composite transform if provided
         if self.parameters["composite_transform"] is not None:
@@ -299,7 +300,9 @@ def register(
             transform_composite = sitk.ReadTransform(
                 self.parameters["composite_transform"]
             )
-            transform = sitk.CompositeTransform(transform_composite, transform)
+            self.transform = sitk.CompositeTransform(
+                transform_composite, self.transform
+            )
 
         if self.parameters["composite_transform"]:
             self.logger.info("Applying previous transforms.")
@@ -307,28 +310,79 @@ def register(
             for previous_transform in self.parameters["previous_transforms"]:
                 previous_transform = sitk.ReadTransform(previous_transform)
                 current_transform = (
-                    sitk.CompositeTransform(previous_transform, transform)
+                    sitk.CompositeTransform(previous_transform, self.transform)
                     if current_transform is None
                     else sitk.CompositeTransform(previous_transform, current_transform)
                 )
 
-            transform = current_transform
-
-        self.logger.info("Resampling image.")
-        resampler = sitk.ResampleImageFilter()
-        resampler.SetReferenceImage(target_image)
-        interpolator_type = self.interpolator_type.get(self.parameters["interpolator"])
-        resampler.SetInterpolator(interpolator_type)
-        resampler.SetDefaultPixelValue(0)
-        resampler.SetTransform(transform)
-        output_image_struct = resampler.Execute(moving_image)
-        sitk.WriteImage(output_image_struct, output_image)
-        self.ssim_score = get_ssim(target_image, output_image_struct)
-        self.logger.info(
-            f"SSIM score of moving against target image: {self.ssim_score}"
-        )
+            self.transform = current_transform
+
+        # no need for logging since resample_image will log by itself
         logging.shutdown()
 
+        # resample the moving image to the target image
+        self.resample_image(
+            target_image=target_image,
+            moving_image=moving_image,
+            output_image=output_image,
+            transform_file=transform_file,
+        )
+
+    def resample_image(
+        self,
+        target_image: Union[str, sitk.Image],
+        moving_image: Union[str, sitk.Image],
+        output_image: str,
+        transform_file: str = None,
+        **kwargs,
+    ) -> None:
+        """
+        Resample the moving image to the target image.
+
+        Args:
+            logger (logging.Logger): The logger to use.
+            target_image (Union[str, sitk.Image]): The target image.
+            moving_image (Union[str, sitk.Image]): The moving image.
+            output_image (str): The output image.
+            transform_file (str, optional): The transform file. Defaults to None.
+        """
+
+        # check if output image exists
+        if not os.path.exists(output_image):
+            if self.transform is not None:
+                if self.log_file is None:
+                    self.log_file = output_image.replace(".nii.gz", ".log")
+                logging.basicConfig(
+                    filename=self.log_file,
+                    format="%(asctime)s,%(name)s,%(levelname)s,%(message)s",
+                    datefmt="%H:%M:%S",
+                    level=logging.DEBUG,
+                )
+                self.logger = logging.getLogger("registration")
+
+                self.logger.info(
+                    f"Target image: {target_image}, Moving image: {moving_image}, Transform file: {transform_file}"
+                )
+                target_image = read_image_and_cast_to_32bit_float(target_image)
+                moving_image = read_image_and_cast_to_32bit_float(moving_image)
+
+                self.logger.info("Resampling image.")
+                resampler = sitk.ResampleImageFilter()
+                resampler.SetReferenceImage(target_image)
+                interpolator_type = self.interpolator_type.get(
+                    self.parameters["interpolator"]
+                )
+                resampler.SetInterpolator(interpolator_type)
+                resampler.SetDefaultPixelValue(0)
+                resampler.SetTransform(self.transform)
+                output_image_struct = resampler.Execute(moving_image)
+                sitk.WriteImage(output_image_struct, output_image)
+                self.ssim_score = get_ssim(target_image, output_image_struct)
+                self.logger.info(
+                    f"SSIM score of moving against target image: {self.ssim_score}"
+                )
+                logging.shutdown()
+
     def _get_transform_wrapper(self, transform: str, dim: int) -> sitk.Transform:
         """
         Get the transform class.