diff --git a/python/ouroboros/pipeline/pipeline_input.py b/python/ouroboros/pipeline/pipeline_input.py
index 188712d..3fd472e 100644
--- a/python/ouroboros/pipeline/pipeline_input.py
+++ b/python/ouroboros/pipeline/pipeline_input.py
@@ -30,6 +30,7 @@ class PipelineInput(BasePipelineInput):
     backproject_options: BackprojectOptions | None = None
     source_url: str | None = None
     sample_points: np.ndarray | None = None
+    annotation_points: np.ndarray | None = None
     slice_rects: np.ndarray | None = None
     volume_cache: VolumeCache | None = None
     output_file_path: str | None = None
@@ -37,11 +38,11 @@ class PipelineInput(BasePipelineInput):
     config_file_path: str | None = None
     backprojection_offset: str | None = None
 
-    @field_serializer("sample_points", "slice_rects")
+    @field_serializer("sample_points", "annotation_points", "slice_rects")
     def to_list(self, value) -> list | None:
         return value.tolist() if value is not None else None
 
-    @field_validator("sample_points", "slice_rects", mode="before")
+    @field_validator("sample_points", "annotation_points", "slice_rects", mode="before")
     @classmethod
     def validate_list(cls, value: any) -> np.ndarray | None:
         if isinstance(value, list):
diff --git a/python/ouroboros/pipeline/slices_geom_pipeline.py b/python/ouroboros/pipeline/slices_geom_pipeline.py
index 481d8d4..35cf205 100644
--- a/python/ouroboros/pipeline/slices_geom_pipeline.py
+++ b/python/ouroboros/pipeline/slices_geom_pipeline.py
@@ -65,6 +65,28 @@ def _process(self, input_data: tuple[any]) -> None | str:
 
         equidistant_points = spline(equidistant_params)
 
+        # Convert annotation points to straightened-volume coordinates.
+        # `spline.u` are the fit parameters corresponding to these input points.
+        annotation_projection_points = spline(spline.u).T
+
+        _, normal_vectors, binormal_vectors = spline.calculate_rotation_minimizing_vectors(spline.u)
+
+        annotation_offsets = sample_points - annotation_projection_points
+        lateral_offsets_x = np.einsum("ij,ij->i", annotation_offsets, normal_vectors.T)
+        lateral_offsets_y = np.einsum("ij,ij->i", annotation_offsets, binormal_vectors.T)
+
+        straightened_depth = np.interp(spline.u, equidistant_params,
+                                       np.arange(len(equidistant_params), dtype=np.float32))
+
+        straightened_annotation_points = np.column_stack(
+            (
+                (config.slice_width - 1) / 2.0 + lateral_offsets_x,
+                (config.slice_height - 1) / 2.0 - lateral_offsets_y,
+                straightened_depth,
+            )
+        )
+        pipeline_input.annotation_points = straightened_annotation_points
+
         self.update_progress(0.5)
 
         # Calculate the slice rects for each t value