add random interpolation for UnifiedResize

ppcls/data/preprocess/ops/operators.py

@@ -38,7 +38,8 @@ class UnifiedResize(object):
             'bilinear': cv2.INTER_LINEAR,
             'area': cv2.INTER_AREA,
             'bicubic': cv2.INTER_CUBIC,
-            'lanczos': cv2.INTER_LANCZOS4
+            'lanczos': cv2.INTER_LANCZOS4,
+            'random': (cv2.INTER_LINEAR, cv2.INTER_CUBIC)
         }
         _pil_interp_from_str = {
             'nearest': Image.NEAREST,
@@ -46,10 +47,18 @@ class UnifiedResize(object):
             'bicubic': Image.BICUBIC,
             'box': Image.BOX,
             'lanczos': Image.LANCZOS,
-            'hamming': Image.HAMMING
+            'hamming': Image.HAMMING,
+            'random': (Image.BILINEAR, Image.BICUBIC)
         }
 
+        def _cv2_resize(src, size, resample):
+            if isinstance(resample, tuple):
+                resample = random.choice(resample)
+            return cv2.resize(src, size, interpolation=resample)
+
         def _pil_resize(src, size, resample):
+            if isinstance(resample, tuple):
+                resample = random.choice(resample)
             pil_img = Image.fromarray(src)
             pil_img = pil_img.resize(size, resample)
             return np.asarray(pil_img)
@@ -60,7 +69,7 @@ class UnifiedResize(object):
             # compatible with opencv < version 4.4.0
             elif interpolation is None:
                 interpolation = cv2.INTER_LINEAR
-            self.resize_func = partial(cv2.resize, interpolation=interpolation)
+            self.resize_func = partial(_cv2_resize, resample=interpolation)
         elif backend.lower() == "pil":
             if isinstance(interpolation, str):
                 interpolation = _pil_interp_from_str[interpolation.lower()]