preserve cutoff line color in rotated preview

WebSite/src/App.tsx

@@ -86,9 +86,11 @@ type LibraryInfo = {
 type StoredDeformationJob = {
   job: BackendJob;
   progress: number;
+  renderVersion?: string;
 };
 
 const DEFORMATION_JOB_STORAGE_KEY = 'head_ct_morph_deformation_job';
+const DEFORMATION_RESULT_RENDER_VERSION = 'quick-preview-cutoff-only-v1';
 
 const API_BASE = typeof window === 'undefined'
   ? 'http://127.0.0.1:8787'
@@ -109,6 +111,10 @@ function readStoredDeformationJob(): StoredDeformationJob | null {
     if (!rawValue) return null;
     const parsed = JSON.parse(rawValue) as StoredDeformationJob;
     if (!parsed?.job?.id) return null;
+    if (parsed.renderVersion !== DEFORMATION_RESULT_RENDER_VERSION) {
+      window.localStorage.removeItem(DEFORMATION_JOB_STORAGE_KEY);
+      return null;
+    }
     return {
       job: parsed.job,
       progress: Math.max(0, Math.min(100, parsed.progress || 0)),
@@ -417,6 +423,7 @@ export default function App() {
       JSON.stringify({
         job: deformationJob,
         progress: deformationJob.status === 'completed' ? 100 : progress,
+        renderVersion: DEFORMATION_RESULT_RENDER_VERSION,
       })
     );
   }, [deformationJob, progress]);

head_extension_app.py

@@ -159,8 +159,8 @@ def preview_deform_2d(image, angle_degrees):
     except Exception:
         return image
 
-    arr = np.asarray(image.convert("L")).astype(np.float32)
-    h, w = arr.shape
+    arr = np.asarray(image.convert("RGB")).astype(np.float32)
+    h, w, _ = arr.shape
     yy, xx = np.mgrid[0:h, 0:w]
 
     pivot_x = int(w * 0.55)
@@ -183,7 +183,11 @@ def preview_deform_2d(image, angle_degrees):
     src_x = pivot_x + cos_t * dx + sin_t * dy
     src_y = pivot_y - sin_t * dx + cos_t * dy
 
-    warped = map_coordinates(arr, [src_y, src_x], order=1, mode="constant", cval=0)
+    warped_channels = [
+        map_coordinates(arr[..., channel], [src_y, src_x], order=1, mode="constant", cval=0)
+        for channel in range(arr.shape[2])
+    ]
+    warped = np.stack(warped_channels, axis=2)
     return Image.fromarray(np.clip(warped, 0, 255).astype(np.uint8)).convert("RGB")