Add interpolation mode handling to transforms. Removes InterpolationM…

…ode warning. Works for torchvision versions w/ and w/o InterpolationMode enum. Fix #738.

timm/data/transforms.py

@@ -1,5 +1,10 @@
 import torch
 import torchvision.transforms.functional as F
+try:
+    from torchvision.transforms.functional import InterpolationMode
+    has_interpolation_mode = True
+except ImportError:
+    has_interpolation_mode = False
 from PIL import Image
 import warnings
 import math
@@ -31,28 +36,50 @@ def __call__(self, pil_img):
 
 
 _pil_interpolation_to_str = {
-    Image.NEAREST: 'PIL.Image.NEAREST',
-    Image.BILINEAR: 'PIL.Image.BILINEAR',
-    Image.BICUBIC: 'PIL.Image.BICUBIC',
-    Image.LANCZOS: 'PIL.Image.LANCZOS',
-    Image.HAMMING: 'PIL.Image.HAMMING',
-    Image.BOX: 'PIL.Image.BOX',
+    Image.NEAREST: 'nearest',
+    Image.BILINEAR: 'bilinear',
+    Image.BICUBIC: 'bicubic',
+    Image.BOX: 'box',
+    Image.HAMMING: 'hamming',
+    Image.LANCZOS: 'lanczos',
 }
+_str_to_pil_interpolation = {b: a for a, b in _pil_interpolation_to_str.items()}
 
 
-def _pil_interp(method):
-    if method == 'bicubic':
-        return Image.BICUBIC
-    elif method == 'lanczos':
-        return Image.LANCZOS
-    elif method == 'hamming':
-        return Image.HAMMING
+if has_interpolation_mode:
+    _torch_interpolation_to_str = {
+        InterpolationMode.NEAREST: 'nearest',
+        InterpolationMode.BILINEAR: 'bilinear',
+        InterpolationMode.BICUBIC: 'bicubic',
+        InterpolationMode.BOX: 'box',
+        InterpolationMode.HAMMING: 'hamming',
+        InterpolationMode.LANCZOS: 'lanczos',
+    }
+    _str_to_torch_interpolation = {b: a for a, b in _torch_interpolation_to_str.items()}
+else:
+    _pil_interpolation_to_torch = {}
+    _torch_interpolation_to_str = {}
+
+
+def str_to_pil_interp(mode_str):
+    return _str_to_pil_interpolation[mode_str]
+
+
+def str_to_interp_mode(mode_str):
+    if has_interpolation_mode:
+        return _str_to_torch_interpolation[mode_str]
+    else:
+        return _str_to_pil_interpolation[mode_str]
+
+
+def interp_mode_to_str(mode):
+    if has_interpolation_mode:
+        return _torch_interpolation_to_str[mode]
     else:
-        # default bilinear, do we want to allow nearest?
-        return Image.BILINEAR
+        return _pil_interpolation_to_str[mode]
 
 
-_RANDOM_INTERPOLATION = (Image.BILINEAR, Image.BICUBIC)
+_RANDOM_INTERPOLATION = (str_to_interp_mode('bilinear'), str_to_interp_mode('bicubic'))
 
 
 class RandomResizedCropAndInterpolation:
@@ -82,7 +109,7 @@ def __init__(self, size, scale=(0.08, 1.0), ratio=(3. / 4., 4. / 3.),
         if interpolation == 'random':
             self.interpolation = _RANDOM_INTERPOLATION
         else:
-            self.interpolation = _pil_interp(interpolation)
+            self.interpolation = str_to_interp_mode(interpolation)
         self.scale = scale
         self.ratio = ratio
 
@@ -146,9 +173,9 @@ def __call__(self, img):
 
     def __repr__(self):
         if isinstance(self.interpolation, (tuple, list)):
-            interpolate_str = ' '.join([_pil_interpolation_to_str[x] for x in self.interpolation])
+            interpolate_str = ' '.join([interp_mode_to_str(x) for x in self.interpolation])
         else:
-            interpolate_str = _pil_interpolation_to_str[self.interpolation]
+            interpolate_str = interp_mode_to_str(self.interpolation)
         format_string = self.__class__.__name__ + '(size={0}'.format(self.size)
         format_string += ', scale={0}'.format(tuple(round(s, 4) for s in self.scale))
         format_string += ', ratio={0}'.format(tuple(round(r, 4) for r in self.ratio))

timm/data/transforms_factory.py

@@ -10,7 +10,7 @@
 
 from timm.data.constants import IMAGENET_DEFAULT_MEAN, IMAGENET_DEFAULT_STD, DEFAULT_CROP_PCT
 from timm.data.auto_augment import rand_augment_transform, augment_and_mix_transform, auto_augment_transform
-from timm.data.transforms import _pil_interp, RandomResizedCropAndInterpolation, ToNumpy, ToTensor
+from timm.data.transforms import str_to_interp_mode, str_to_pil_interp, RandomResizedCropAndInterpolation, ToNumpy
 from timm.data.random_erasing import RandomErasing
 
 
@@ -25,7 +25,7 @@ def transforms_noaug_train(
         # random interpolation not supported with no-aug
         interpolation = 'bilinear'
     tfl = [
-        transforms.Resize(img_size, _pil_interp(interpolation)),
+        transforms.Resize(img_size, interpolation=str_to_interp_mode(interpolation)),
         transforms.CenterCrop(img_size)
     ]
     if use_prefetcher:
@@ -87,7 +87,7 @@ def transforms_imagenet_train(
             img_mean=tuple([min(255, round(255 * x)) for x in mean]),
         )
         if interpolation and interpolation != 'random':
-            aa_params['interpolation'] = _pil_interp(interpolation)
+            aa_params['interpolation'] = str_to_pil_interp(interpolation)
         if auto_augment.startswith('rand'):
             secondary_tfl += [rand_augment_transform(auto_augment, aa_params)]
         elif auto_augment.startswith('augmix'):
@@ -147,7 +147,7 @@ def transforms_imagenet_eval(
         scale_size = int(math.floor(img_size / crop_pct))
 
     tfl = [
-        transforms.Resize(scale_size, _pil_interp(interpolation)),
+        transforms.Resize(scale_size, interpolation=str_to_interp_mode(interpolation)),
         transforms.CenterCrop(img_size),
     ]
     if use_prefetcher: