Support input one box

Signed-off-by: shiyu22 <shiyu.chen@zilliz.com>

image_crop_cv2.py

@@ -31,20 +31,28 @@ log = logging.getLogger()
 class ImageCropCV2(PyOperator):
     def __init__(self, clamp = False):
         self.clamp = clamp
+        self.h = None
+        self.w = None
 
     @staticmethod
     def _clamp(x, minimum, maximum):
         return max(minimum, min(x, maximum))
     
+    def get_box(self, img, box):
+        x1, y1, x2, y2 = box
+        x1 = ImageCropCV2._clamp(x1, 0, self.w)
+        x2 = ImageCropCV2._clamp(x2, 0, self.w)
+        y1 = ImageCropCV2._clamp(y1, 0, self.h)
+        y2 = ImageCropCV2._clamp(y2, 0, self.h)
+        return img[y1:y2,x1:x2,:]
+
     def __call__(self, img: np.ndarray, bboxes: List[Tuple]):
-        h, w, _ = img.shape
+        self.h, self.w, _ = img.shape
         res = []
+        try:
+            res.append(self.get_box(img, bboxes))
+        except:
             for box in bboxes:
-            x1, y1, x2, y2 = box
-            x1 = ImageCropCV2._clamp(x1, 0, w)
-            x2 = ImageCropCV2._clamp(x2, 0, w)
-            y1 = ImageCropCV2._clamp(y1, 0, h)
-            y2 = ImageCropCV2._clamp(y2, 0, h)
-            res.append(img[y1:y2,x1:x2,:])
+                res.append(self.get_box(img, box))
         return res