fix: 修复 NMSBoxes 索引错误

internal/nsfw/server.py

@@ -189,11 +189,20 @@ def _raw_detect(det, data):
             scores.append(float(max_score))
             class_ids.append(class_id)
 
-    indices = cv2.dnn.NMSBoxes(boxes, scores, 0.1, 0.45)
+    # 没有检测到任何类别，直接返回空
+    if not boxes:
+        return []
+
+    # 转成 numpy array，OpenCV 的 NMSBoxes 需要
+    boxes_arr = np.array(boxes, dtype=np.float32)
+    scores_arr = np.array(scores, dtype=np.float32)
+
+    indices = cv2.dnn.NMSBoxes(boxes_arr.tolist(), scores_arr.tolist(), 0.1, 0.45)
 
     detections = []
-    for i in indices:
-        idx = i if isinstance(i, int) else i[0]
+    if indices is not None and len(indices) > 0:
+        for i in np.array(indices).flatten():
+            idx = int(i)
             detections.append({
                 "class": __labels[class_ids[idx]],
                 "score": scores[idx],
@@ -201,7 +210,6 @@ def _raw_detect(det, data):
             })
     return detections
 
-
 # NudeNet 的标签表（和 nudenet.nudenet.__labels 一致）
 __labels = [
     "FEMALE_GENITALIA_COVERED", "FACE_FEMALE", "BUTTOCKS_EXPOSED",