Update app.py

app.py

@@ -61,32 +61,6 @@ def _text_size(draw, text, font):
 
 # ─── Visual polygon helpers ───────────────────────────────────────────────────
 
-def _smooth_polygon(pts_xy, window=11):
-    """
-    Hanning-weighted circular sliding-window average on polygon vertices.
-    pts_xy  : numpy (N, 2) float — already in original image coordinates
-              from results.masks.xy (no resize, no drift).
-    Returns : int32 array (N, 1, 2) for cv2.polylines / fillPoly.
-    VISUAL ONLY — backend mask uses raw polygon via _polygon_to_mask().
-    """
-    pts = pts_xy.astype(np.float32)
-    n   = len(pts)
-    if n < 6:
-        return pts.astype(np.int32).reshape(-1, 1, 2)
-
-    window  = min(window | 1, (n - 1) | 1)
-    half    = window // 2
-    padded  = np.vstack([pts[-half:], pts, pts[:half]])
-    weights = np.hanning(window).astype(np.float32)
-    weights /= weights.sum()
-
-    smoothed = np.zeros_like(pts)
-    for i in range(n):
-        smoothed[i] = (padded[i : i + window] * weights[:, None]).sum(axis=0)
-
-    return smoothed.astype(np.int32).reshape(-1, 1, 2)
-
-
 def _polygon_to_mask(pts_xy, h, w):
     """Rasterise raw polygon → binary uint8 mask. BACKEND / measurements only."""
     mask = np.zeros((h, w), dtype=np.uint8)
@@ -95,6 +69,21 @@ def _polygon_to_mask(pts_xy, h, w):
     return mask
 
 
+def _rotated_box_from_mask(mask_np):
+    """
+    Compute tight rotated bounding box from backend mask.
+    Returns the 4 corner points as int32 array (4, 1, 2) — ready for
+    cv2.polylines / fillPoly.
+    """
+    pts_y, pts_x = np.where(mask_np == 1)
+    if len(pts_x) < 5:
+        return None, None
+    pts = np.column_stack([pts_x.astype(np.float32), pts_y.astype(np.float32)])
+    rect = cv2.minAreaRect(pts)
+    box  = cv2.boxPoints(rect)          # 4 corners (float)
+    return box.astype(np.int32).reshape(-1, 1, 2), rect
+
+
 # ─────────────────────────────────────────────────────────────────────────────
 # STEP 1 — Segmentation + visual output
 #
@@ -126,10 +115,10 @@ def run_segmentation(img_np):
             counts[cls_name] += 1
 
             # Backend mask: raw polygon fill (measurements only)
-            mask_np  = _polygon_to_mask(poly_xy, h, w)
+            mask_np = _polygon_to_mask(poly_xy, h, w)
 
-            # Visual polygon: Hanning-smoothed (display only)
-            vis_poly = _smooth_polygon(poly_xy, window=11)
+            # Visual: tight rotated bounding box from the backend mask
+            vis_box, rect = _rotated_box_from_mask(mask_np)
 
             # Bounding box from backend mask for zoom crop
             ys, xs = np.where(mask_np == 1)
@@ -139,25 +128,27 @@ def run_segmentation(img_np):
                 all_x2 = max(all_x2, int(xs.max()))
                 all_y2 = max(all_y2, int(ys.max()))
 
-            cv2.fillPoly(overlay, [vis_poly], color)
+            if vis_box is not None:
+                cv2.fillPoly(overlay, [vis_box], color)
 
             grain_boxes.append({
                 "cls_id":   cls_id,
                 "cls_name": cls_name,
-                "mask_np":  mask_np,     # backend only
-                "vis_poly": vis_poly,    # visual only
+                "mask_np":  mask_np,    # backend only
+                "vis_box":  vis_box,    # visual rotated bbox
             })
 
     # Blend fill
     annotated = cv2.addWeighted(annotated, 0.72, overlay, 0.28, 0)
 
-    # Anti-aliased contour lines
+    # Draw crisp rotated bbox outlines (no fill — just the border)
     for g in grain_boxes:
-        cv2.polylines(
-            annotated, [g["vis_poly"]],
-            isClosed=True, color=CLASS_COLORS[g["cls_id"]], thickness=2,
-            lineType=cv2.LINE_AA,
-        )
+        if g["vis_box"] is not None:
+            cv2.polylines(
+                annotated, [g["vis_box"]],
+                isClosed=True, color=CLASS_COLORS[g["cls_id"]], thickness=2,
+                lineType=cv2.LINE_AA,
+            )
 
     # Zoom
     if all_x2 > all_x1 and all_y2 > all_y1: